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Microbial communities play a crucial role in the processes of material cycling, energy conversion, and information transfer in river water. Analyzing the distribution characteristics of microbial community structure is crucial for preserving the long-term stability of river water ecosystems. In order to investigate the structure characteristics of the microbial communities and the relationships between microbial communities and hydrochemical compositions in agricultural region and urban region of Qingshui River, a total of 20 river water samples, including 13 samples from the agricultural region and 7 samples from the urban region, were collected from the River. The hydrogeochemical methods, high-throughput sequencing technology, and bioinformatics analysis were used to determine the relationships between microbial communities and hydrochemical compositions in the different functional regions of the River. The results showed that river water is generally weakly alkaline water (8.35≤pH≤9.44). The chemical type of river water is mainly HCO3-Ca•Mg water (80%), followed by Cl-Ca•Mg water (20%). Hydrochemical compositions in agricultural region were mainly controlled by the carbonate dissolution and agricultural fertilization inputs, while these in the unban region were primarily affected by the upstream hydrochemical characteristics and unban discharges. The hardening of river bottoms and its banks resulted in lower level of microbial diversity in the urban region than that in the agricultural region, and further caused the differences in microbial community structure. Limnohabitans, Rhodobacter and Flavobacterium were identified as the main genus in the agricultural region, and Cyanobium_PCC-6307, Limnohabitans and norank_f_norank_o_Chloroplast were the primary genus in the urban region. The order of the influence of hydrochemical factors on microbial community structure was NO3- (P=0.001)>SO42- (P=0.003)>DO(P=0.071)>pH(P=0.222), and among these NO3- emitted from agricultural fertilization has the most significant impact on the microbial community structure in the River. NO3- concentrition in river water was increased by the microbial nitrification process in the agricultural region, whereas it was decreased by microbial denitrification process between the agricultural region and the urban region. [ABSTRACT FROM AUTHOR]

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Soil pollution from antibiotics has become increasingly severe, posing significant environmental and human health threats. Many soil organisms can survive and sustain their roles in maintaining soil ecosystems, even in polluted conditions. Exploring the life-sustaining mechanisms of these organisms in contaminated environments is scientifically significant. This study used Eisenia fetida as the test organism and antibiotics (oxytetracycline hydrochloride) as exogenous stress substances. Oxidative stress response experiments were conducted using the artificial soil method to examine the response of earthworms to oxidative stress. Additionally, 16S rRNA technology was employed to analyze the succession of microbial community structures inside and outside the earthworms. A screening canonical correlation analysis (SCCA) model was developed to investigate the relationship between microbial communities and earthworm oxidative stress system under oxytetracycline stress, revealing survival strategies in antibiotic-contaminated soil. The results showed that Proteobacteria and Bacteriodetes were the dominant phyla of microbial communities in earthworms under oxytetracycline stress, while Proteobacteria and Firmicutes were dominant bacterial phyla in soil. Bacteriodetes and Firmicutes in earthworms worked synergistically with catalase (CAT) and glutathione peroxidase (GPX) in oxidative stress responses. In soil, Actinobacteria, Verrucomicrobia, and Spirochaeta synergistically resisted oxytetracycline stress alongside peroxidase (POD) and glutathione S-transferase (GST). Earthworm mucus played a crucial role in this synergistic resistance. These findings provide a scientific and experimental basis for assessing the ecological safety risks of antibiotic-contaminated soil.

Diverse microbial community structures (MCS) in wastewater treatment plants (WWTPs) are vital for effectively removing nutrients and chemicals from wastewater. However, the regular monitoring of MCS in WWTP bioreactors remains unattractive owing to the skill and cost required for deploying modern microbial molecular techniques in the routine assessment of engineered systems. In contrast, low-resolution methods for assessing broad changes in the MCS, such as phospholipid fatty acid (PLFA) analysis, have been used effectively in soil studies for decades. Despite using PLFA analysis in soil remediation studies to capture the long-term effects of environmental changes on MCS, its application in WWTPs, where the microbial mass is dynamic and operational conditions are more fluid, remains limited. In this study, microbial communities in a controlled pilot plant and 12 full-scale activated sludge plants (ASPs) were surveyed over a two-year period using PLFA analysis. This study revealed that changes in the MCS in wastewater bioreactors could be detected using PLFA analysis. The MCS comprised 59 % Gram-negative and 9 % Gram-positive bacteria, 31 % fungi, and 1 % actinomycetes. The abundances of Gram-negative bacteria and fungi were strongly inversely correlated, with an R2 = 0.93, while the fatty acids cy17:0 and 16:1ω7c positively correlated (R2 = 0.869). Variations in temperature, solid retention time, and WWTP configuration significantly influenced the MCS in activated sludge reactors. This study showed that WWTP bioreactors can be routinely monitored using PLFA analysis, and changes in the bioreactor profile that may indicate imminent bioreactor failure can be identified.

The fresh carbon (C) induced priming effect (PE) on soil organic C (SOC) decomposition is critical for global C cycling. Climate warming could raise absorptive roots production and turnover, and then increase the input of absorptive roots litter (ABRL). Therefore, it is urgent to understand the PE induced by ABRL under warming. We conducted a 210-day experiment by adding ABRL of Cunninghamia lanceolata into a C4 soil and incubating them at 19 °C and 23 °C. We found that adding ABRL caused positive PE throughout the incubation. At the early stage (ES: first 30 days), labile C compounds dominated the decomposition of ABRL, significantly higher dissolved organic C (DOC), microbial biomass C (MBC), and absolute hydrolase activities were found in the ABRL treatment than in the control. These results supports that labile C inputs stimulating microbial growth, enzyme activities and cause positive PE via co-metabolic. At the later stage (LS: after 180 days), the release of structural C compounds dominated the decomposition of ABRL, a significantly lower available nitrogen (N) and a significantly higher specific potential N-acquisition (Nacq) enzymes were found in the ABRL treatment than in the control. These results suggests that microbes utilizing the C as energy to increase Nacq enzymes to decompose SOC for N mining under N limitation induced positive PE. Warming significantly increased the PEs at both stages. At the ES, warming increased the MBC at the cost of DOC, suggesting that warming intensifies the microbial co-metabolism. At the LS, warming significantly decreased the available N and increases the absolute potential oxidases activities, suggesting an increased N limitation and oxidation for N-rich recalcitrant SOC, i.e., a promoted microbial N mining. Nevertheless, we did not observe a significant effect of ABRL addition on the temperature sensitivity of SOC decomposition compared to the control. This study provides a valuable insight that warming could consistently increase the ABRL induced PE but through different microbial mechanisms along with the decomposition processing.

The appropriate volume of filtered water samples is crucial for accurately reflecting microbial community characteristics. Previous research has shown that changes in water sample volumes significantly affect bacterial diversity and the relative abundance of dominant taxa in marine environments. However, the specific impact on freshwater microbial diversity and community structure, particularly for eukaryotic microorganisms, remains unclear. To address this gap, we collected water samples from eutrophic Lake Taihu and mesotrophic Lake Bosten. We filtered the samples through 0.2 μm filters using volumes ranging from 0.1 to 2 L for Lake Taihu and 0.1 to 3.2 L for Lake Bosten. Analysis of 18S rRNA gene amplicons revealed that variations in filtered water sample volume significantly affected the diversity, community structure, and composition of eukaryotic microorganisms. In light of these findings, we recommend using a filtered water sample volume of approximately 0.2 L for eutrophic aquatic ecosystems and 0.8 L for mesotrophic aquatic ecosystems in microbial analyses. These recommendations underscore the importance of selecting the appropriate filtered water sample volume to ensure representative and reliable results in the study of eukaryotic microorganisms in freshwater ecosystems.

ContextIntercropping in agriculture is crucial for addressing challenges in intensive tea farming. Forage legumes reduce fertilizer dependence and significantly boost productivity. Currently, intercropping with legumes enhances the environmental conditions of tea plantations and improves tea quality.ObjectiveHowever, the comprehension of the rhizosphere’s impact on the associated microbes and the community structure of tea plants is still somewhat constrained.MethodsHence, four distinct planting methodologies were examined: Monoculture cultivation of Tieguanyin tea plants (MT), Laredo forage soybean (Glycine max Linn.) without partitioning in conjunction with tea (IT), intercropping with tea using plastic partitions (PPIT), and intercropping with tea facilitated by net partitions (NPIT). An absolute quantitative analysis of soil phospholipid fatty acids, labeled with the rhizosphere microbial characteristics of tea plants, was conducted through multi-ion reaction monitoring (MRM). The bacterial and fungal communities were anticipated utilizing the FAPROTAX and FUNG databases, respectively. Gas chromatography was employed to ascertain greenhouse gas emissions across diverse root interaction cultivation systems.Results and conclusionThe rhizospheric influence culminated in a 44.6% increase in total phospholipid fatty acids (PLFAs) and a remarkable 100.9% escalation in the ratio of unsaturated to saturated fatty acids. This rhizospheric enhancement has significantly potentiated the ecological functionalities within the bacterial community, including xylanolysis, ureolysis, nitrogen respiration, nitrogen fixation, nitrite respiration, nitrite ammonification, and nitrate reduction. Mycorrhizomonas, encompassing both ectomycorrhizal and arbuscular forms, has notably colonized the rhizosphere. The interspecific mutualistic interactions within the rhizosphere have resulted in a significant enhancement of plant growth-promoting bacteria, including allorhizobium, bradyrhizobium, rhizobium, burkholderia, gluconacetobacter, and gluconobacter, while concurrently reducing the prevalence of pathogenic microorganisms such as xanthomonas, ralstonia, fusarium, and opportunistic fungi responsible for white and soft rot. The intercropping system showed lower total greenhouse gas emissions than monocultured tea plants, particularly reducing soil CO2 emissions due to complex interspecific rhizosphere interactions. This tea/legume intercropping approach promotes a sustainable ecosystem, enhancing microbial biomass and vitality, which helps suppress rhizospheric pathogens.SignificanceThese findings are instrumental in enhancing our comprehension of the pivotal practical implications of rhizosphere intercropping, thereby optimizing the structure of rhizosphere communities and alleviating the impact of greenhouse gases within croplands.

Adding corn straw to the anaerobic fermentation system of coal can significantly increase the gas production of coal-to-biomethane. However, the changes in substrate and microbial metabolism accompanying this combined fermentation are rarely studied. The Scanning Electron Microscope (SEM) test was utilized to analyze the microbial adhesion characteristics of coal and corn straw, while the X-ray Photoelectron Spectroscopy (XPS) test examined the changes in surface elements of coal. The results indicated that the optimal ratios of lean coal, weakly caking coal, and coking coal to corn straw were 2∶1, 2∶1, and 3∶1, respectively, and the corresponding methane yields were 17.28 mL/g, 12.51 mL/g, and 14.88 mL/g. The promotional effect of co-fermentation of different rank coal and straw was observed in the order of lean coal > coking coal > weakly caking coal. Microbial identification revealed that Sphaerochaeta and Proteiniphilum were the dominant bacterial genera in the mixed fermentation system, comprising 35.95% and 24.36% of the population, respectively. Additionally, Methanosarcina, Methanobacterium, and Methanoculleus emerged as the dominant archaea, constituting 49.71%, 31.83%, and 9.87%, respectively. In comparison with coking coal and weakly caking coal, the bacterial and archaeal genera, along with their associated gene functions responsible for carbohydrate metabolism in the combined fermentation broth of lean coal, coking coal, and weakly caking coal, were found to be dominant. This observation aligns with the principles governing methane production. Notably, in mixed substrate fermentation, as coal rank increased, bacterial presence on the coal surface gradually declined, while a substantial bacterial population consistently adhered to the surface of corn straw, indicating the latter's sustained advantage in degradation. After co-fermentation, the relative content of C element on the surface of coking coal and weakly caking coal decreased more significantly than that of lean coal, while the total relative content of oxygen-containing organic carbon ( C—O, C=O and O—C=O ) increased significantly, indicating that co-fermentation can promote the growth and metabolism of bacteria, so that more organic carbon can be converted into biological methane. The research results identified the effect of co-fermentation of different rank coal and corn straw at the micro level, which has reference significance for revealing the internal mechanism of co-fermentation of coal and corn straw.

In order to explore the effect of co-fermentation with Monascus and Aspergillus oryzae on the quality of soybean paste, the volatile flavor components in soybean pastes produced using pure and mixed cultures of A. oryzae (Piniang M003) and Monascus (PM001) were determined by headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and comparatively analyzed by principal component analysis (PCA), and Illumina MiSeq sequencing technology was used to analyze the changes in the microbial community structure during the mixed culture fermentation process. Meanwhile, the correlation between the major microorganisms and the major flavor substances was analyzed. The results showed that the composition and content of flavor substances and the composition and relative abundance of microbial communities in the soybean paste produced by co-fermentation were significantly better than those in the soybean paste fermented with A. oryzae monoculture. The major flavor substances in soybean paste were significantly positively correlated with dominant genera such as Aspergillus, Bacillus, Monascus and Leuconostoc. The flavor quality of the soybean paste produced with a mixed culture of A. oryzae and Monascus in a ratio of 3:1 (m/m) was best. The results of the study showed that the mixed culture fermentation with Monascus and A. oryzae could significantly improve the flavor quality of soybean paste, which will be informative for the improvement of the flavor quality of soybean paste.

The denitrification efficiencies of two continuous flow mixed-culture denitrification reactors with Fe0 alone and carbon fiber reinforced Fe0 were compared by treating the synthetic wastewater containing NO3--N. The results showed that the average removal efficiencies of total nitrogen(TN) and NO3--N were as high as 89.04% and 97.13% for the experimental group R1 with carbon fiber and Fe0 injection at COD/NO3--N of 2.9-3.1 and hydraulic retention time(HRT) of 24 h, which were significantly higher than the control group R0 with Fe0 injection alone. The extracellular polymeric substances(EPS) and electron transfer activity(ETSA) variation patterns indicated that the input of carbon fiber further promoted the synthesis of EPS and enhanced the utilization of electrons by microorganisms. Scanning electron microscopy-energy dispersive spectrometry(SEM-EDS) and X-ray diffractometer(XRD) analyses revealed that there was obvious microbial corrosion on the surface of Fe0 in R1 reactor, and FeO(OH) and bioorganic-Fe complexes were the main corrosion products. Microbiological analysis showed that the increase of organic carbon source and the injection of carbon fiber effectively increased the abundance of iron autotrophic denitrifying bacteria genus and promoted the enrichment of denitrifying functional genes.

Anaerobic fermentation has attracted wide attention to effectively reduce carbon footprint and alleviate potential energy shortages, which is being regarded as a sustainable and promising technology to obtain high biohydrogen production from widespread organic wastes. However, biohydrogen commercial uptake is now dominantly inhibited by the low hydrogen yield and process instability. In this work, Al 2 O 3 /BaFe 2 O 4 nanoparticles (NPs) are successfully applied to anaerobic fermentation for investigating their effects on hydrogen yield, activity of bacteria and microbial community structure. The benefits of Al 2 O 3 /BaFe 2 O 4 NPs with respect to microbial metabolism, reactivity of enzymes and process optimization are systematically researched through batch experiments. In addition, various characterizations are used to verify the physical and chemical properties of Al 2 O 3 /BaFe 2 O 4 NPs. The results show that the activity of hydrogenases and microbe metabolism can be significantly inhibited by excess addition of Al 2 O 3 /BaFe 2 O 4 NPs (150 mg/L and 200 mg/L) while the optimum addition 100 mg/L of Al 2 O 3 /BaFe 2 O 4 NPs can boost the biohydrogen yield by 49% via facilitating microorganism growth and enhancing key enzymatic activities, which indicate that the Al 2 O 3 /BaFe 2 O 4 NPs display a beneficial influence on electron transfer efficiency and process stability. The existence of Fe3+, Al3+and Ba2+ derived from the corrosion of Al 2 O 3 /BaFe 2 O 4 NPs by organic acids synergistically improve the microbial transmembrane transportation and substrate utilization, which contribute to higher conversion rate of glucose into acetate, butyrate and H 2. Meanwhile, the complementary functions of Fe3+ and Al3+ can powerfully shorten the lag phase and promote the glycolysis, which finally accelerate the dark fermentation process. Compared with the control group, Clostridium _ sensu _ stricto _1 is selectively enriched by the addition of Al 2 O 3 /BaFe 2 O 4 NPs, which keep heavily involved in the synthesis of H 2. On balance, this study provides an effective strategy to enhance hydrogen productivity and maintain process stability, which offer the valuable information for the sustainable utilization of sewage sludge. [Display omitted] • Al 2 O 3 /BaFe 2 O 4 NPs are synthesized to enhance H 2 production. • Al 2 O 3 /BaFe 2 O 4 NPs show positive effects on activity of H 2 -producing bacteria. • The addition of Al 2 O 3 /BaFe 2 O 4 NPs can facilitate H 2 -producing bacteria growth. • Humic acids are reduced by addition of Al 2 O 3 /BaFe 2 O 4 NPs. • Firmicutes and Clostridium_sensu_stricto_ 1 are selectively enriched by Al 2 O 3 /BaFe 2 O 4 NPs. [ABSTRACT FROM AUTHOR]

Simple Summary: The utilization of reclaimed land and enhancement of its productivity are crucial for alleviating China's food production shortage. Previous research has indicated that co-cultivating rice with frogs can enhance soil fertility. However, there is limited research on the use of integrated rice–frog farming techniques to improve soil fertility on reclaimed barren land for enhanced food production efficiency. Therefore, this study evaluated the impact of rice–frog co-cultivation on soil fertility and microbial diversity of reclaimed land. Experimental plots were established for rice monoculture, low-density rice–frog co-cultivation, and high-density rice–frog co-cultivation. The study found that during the rice maturity period, the soil fertility in the plots with high-density rice–frog co-cultivation was significantly higher compared to the rice monoculture plots. Additionally, rice–frog co-cultivation increased the soil microbial diversity and altered the structure of the microbial community compared to the rice monoculture. This research indicates that compared with rice monoculture, rice–frog co-cultivation can enhance the soil fertility and microbial diversity of reclaimed land. This study provides a theoretical basis for the construction of integrated farming models on reclaimed land, offering new perspectives and opportunities for the efficient utilization of such land. Utilizing and improving the productivity of reclaimed land are highly significant for alleviating the problem of food production shortage in China, and the integrated rice–frog farming model can improve soil fertility. However, there are few studies on the use of integrated rice–frog farming technology to improve the fertility of reclaimed land and increase its efficiency in food production. Therefore, this study was conducted to evaluate the effects of the rice–frog co-cropping mode on the soil fertility and microbial diversity of reclaimed land. A rice monoculture group (SF), low-density rice–frog co-cropping group (SD, 5000 frogs/mu, corresponds to 8 frogs/m2), and high-density rice–frog co-cropping group (SG, 10,000 frogs/mu, corresponds to 15 frogs/m2) were established and tested. The contents of total nitrogen, soil organic matter, available potassium, and available phosphorus of the soil in the SG group were significantly higher than those in the SF group (p < 0.05) in the mature stage of rice. Compared with the SF group, the SD and SG groups improved the soil microbial diversity and changed the structure of the microbial community. This study indicates that compared with the rice monoculture mode, the rice–frog co-cropping pattern can improve the soil fertility, as well as microbial diversity, of reclaimed land. [ABSTRACT FROM AUTHOR]

Intercropping, a well-established agroecological technique designed to bolster ecological stability, has been shown to have a significant impact on soil health. However, the specific effects of tea/Trachelospermum jasminoides intercropping on the physicochemical properties and functional microbial community structure in practical cultivation have not been thoroughly investigated. In this study, we utilized high-throughput sequencing technology on the 16S/ITS rDNA genes to assess the impact of tea intercropping with T. jasminoides on the composition, diversity, and potential functions of the soil microbial community in tea gardens. The results indicated that the tea/T. jasminoides intercropping system significantly increased pH levels, soil organic matter, available nitrogen, phosphorus, potassium, and enzyme activity, ultimately augmenting soil nutrient levels. Furthermore, an in-depth analysis of the bacterial co-occurrence network and topological structure portrayed a more intricate and interconnected soil bacterial community in tea gardens. Remarkably, the abundance of beneficial genera, including Burkholderia, Mesorhizobium, Penicillium, and Trichoderma, underwent a substantial increase, whereas the relative abundance of pathogenic fungi such as Aspergillus, Fusarium, and Curvularia experienced a marked decline. Functional predictions also indicated a notable enhancement in the abundance of microorganisms associated with nitrogen and carbon cycling processes. In summary, the intercropping of tea and T. jasminoides holds the potential to enrich soil nutrient content, reshape the microbial community structure, bolster the abundance of functional microorganisms, and mitigate the prevalence of pathogenic fungi. Consequently, this intercropping system offers a promising solution for sustainable tea garden management, overcoming the limitations of traditional cultivation methods and providing valuable insights for sustainable agriculture practices. [ABSTRACT FROM AUTHOR]

During wastewater treatment by integrated algal pond systems (IAPS), microalgal-bacterial flocs (MaB-flocs) form naturally but periodically disaggregate, resulting in poor settling, low biomass recovery, and reduced effluent quality. This study investigates biotic/abiotic-induced changes in microbial community structure in high-rate algal oxidation ponds (HRAOP) of an IAPS on MaB-floc formation and stability during sewage treatment. Results show that dominance by Pseudopediastrum, Desmodesmus and Micractinium species in spring and summer and the chytrids, Paraphysoderma sp. in spring and Sanchytrium sp. in summer, occurred coincident with enhanced MaB-floc formation and biomass recovery (≥90%). In winter, poor floc formation and low biomass recovery were associated with dominance by Desmodesmus, Chlorella, and the Chlorella-like genus Micractinium. A principal components analysis (PCA) confirmed that combinations of colonial microalgae and associated parasitic chytrids underpin MaB-floc formation and stability in spring and summer and that unicells dominated in winter. Dominance by Thiothrix sp. coincided with floc disaggregation. Thus, changes in season, composition and abundance of colonial microalgae and associated parasitic fungi appeared to impact MaB-floc formation, whereas species composition of the bacterial population and emergence of Thiothrix coincided with floc instability and disaggregation. [ABSTRACT FROM AUTHOR]

Introduction: Microplastics (MPs), identified as emerging contaminants, have been detected across diverse environmental media. Their enduring presence and small size facilitate the adsorption of organic pollutants and heavy metals, leading to combined pollution effects. MPs also accumulate in the food chain thus pose risks to animals, plants, and human health, garnering significant scholarly attention in recent years. Aerobic granular sludge (AGS) technology emerges as an innovative approach to wastewater treatment. However, the impacts of MPs on the operational efficiency and microbial characteristics of AGS systems has been insufficiently explored. Methods: This study investigated the effects of varying concentration (10, 50, and 100 mg/L) of biodegradable MPs (Polylactic Acid, PLA) and nonbiodegradable MPs (Polyethylene Terephthalate, PET) on the properties of AGS and explored the underlying mechanisms. Results and discussions: It was discovered that low and medium concentration of MPs (10 and 50 mg/L) showed no significant effects on COD removal by AGS, but high concentration (100 mg/L) of MPs markedly diminished the ability to remove COD of AGS, by blocking most of the nutrient transport channels of AGS. However, both PLA and PE promoted the nitrogen and phosphorus removal ability of AGS, and significantly increased the removal efficiency of total inorganic nitrogen (TIN) and total phosphorus (TP) at stages II and III (P < 0.05). High concentration of MPs inhibited the growth of sludge. PET noticeably deteriorate the sedimentation performance of AGS, while 50 mg/L PLA proved to be beneficial to sludge sedimentation at stage II. The addition of MPs promoted the abundance of Candidatus_Competibacter and Acinetobacter in AGS, thereby promoting the phosphorus removal capacity of AGS. Both 50 mg/L PET and 100 mg/L PLA caused large amount of white Thiothrix filamentous bacteria forming on the surface of AGS, leading to deterioration of the sludge settling performance and affecting the normal operation of the reactor. Comparing with PET, AGS proved to be more resistant to PLA, so more attention should be paid to the effect of non-biodegradable MPs on AGS in the future. [ABSTRACT FROM AUTHOR]

Background: Conventional biofilters, which rely on bacterial activity, face challenges in eliminating hydrophobic compounds, such as aromatic compounds. This is due to the low solubility of these compounds in water, which makes them difficult to absorb by bacterial biofilms. Furthermore, biofilter operational stability is often hampered by acidification and drying out of the filter bed. Methods: Two bioreactors, a bacterial biofilter (B-BF) and a fungal–bacterial coupled biofilter (F&B-BF) were inoculated with activated sludge from the secondary sedimentation tank of the Sinopec Yangzi Petrochemical Company wastewater treatment plant located in Nanjing, China. For approximately 6 months of operation, a F&B-BF was more effective than a B-BF in eliminating a gas-phase mixture containing benzene, toluene, ethylbenzene, and para-xylene (BTEp-X). Results: After operating for four months, the F&B-BF showed higher removal efficiencies for toluene (T), ethylbenzene (E), benzene (B), and para-X (p-Xylene), at 96.9%, 92.6%, 83.9%, and 83.8%, respectively, compared to those of the B-BF (90.1%, 78.7%, 64.8%, and 59.3%). The degradation activity order for B-BF and F&B-BF was T > E > B > p-X. Similarly, the rates of mineralization for BTEp-X in the F&B-BF were 74.9%, 66.5%, 55.3%, and 45.1%, respectively, which were higher than those in the B-BF (56.5%, 50.8%, 43.8%, and 30.5%). Additionally, the F&B-BF (2 days) exhibited faster recovery rates than the B-BF (5 days). Conclusions: It was found that a starvation protocol was beneficial for the stable operation of both the B-BF and F&B-BF. Community structure analysis showed that the bacterial genus Pseudomonas and the fungal genus Phialophora were both important in the degradation of BTEp-X. The fungal-bacterial consortia can enhance the biofiltration removal of BTEp-X vapors. [ABSTRACT FROM AUTHOR]

Clean tillage frequently causes the loss of soil nutrients and weakens microbial ecosystem service functions. In order to improve orchard soil nutrient cycling, enhance enzyme activities and microbial community structure in a "Jiro" sweet persimmon orchard, sod culture management was carried out to clarify the relationship among soil nutrient, microbial communities, and fruit yield and quality in persimmon orchard. The results showed that sod culture management increased the content of organic matter, total organic carbon, nitrogen, phosphorus, and potassium in the soil, thus improving soil fertility. Compared with clean tillage orchards, sod culture methods significantly increased soil enzyme activities and microbial biomass carbon (MBC) content. The abundance-based coverage estimator (ACE) and the simplest richness estimators (Chao l) indices of the bacterial community and all diversity and richness indices of the fungal community significantly increased in the sod culture orchard, which indicated that sod culture could increase the richness and diversity of the soil microbial community. The dominant bacterial phyla were Proteobacteria (32.21~41.13%) and Acidobacteria (18.76~23.86%), and the dominant fungal phyla were Mortierellomycota (31.11~83.40%) and Ascomycota (3.45~60.14%). Sod culture drove the composition of the microbial community to increase the beneficial microbiome. Correlation analyses and partial least squares path modeling (PLS-PM) comparative analyses showed that the soil chemical properties (mainly including soil organic matter content, total organic carbon content, total potassium content, and total nitrogen content), soil enzyme activities and soil microorganisms were strongly correlated with fruit yield and quality. Meanwhile, soil nutrient, soil enzyme, and soil microbes had also influenced each other. Our results showed that long-term ryegrass planting could improve soil fertility, enzyme activities, and microbial community compositions. Such changes might lead to a cascading effect on the fruit yield and quality of "Jiro" sweet persimmons. [ABSTRACT FROM AUTHOR]

Aerobic composting of food waste (FW) from rural China using a composting device results in a substantial financial burden on the government. This study aimed to assess the feasibility of mitigating this cost using vermicomposting of composted FW. The specific aims were to elucidate the effects of composted FW on earthworm growth and reproduction, reveal the changes in the physical and chemical properties of earthworm casts during vermicomposting, identify the microbial community structure associated with vermicomposting, and perform a financial analysis based on the yield of earthworms and earthworm casts. Mixing composted FW and mature cow dung in an equal ratio achieved the highest earthworm reproduction rate, where 100 adult earthworms produced 567 juvenile earthworms and 252 cocoons in 40 d. Earthworms reduce salt content of vermicomposting substrates by assimilating Na+ and promoting humification by transforming humin into humic and fulvic acid, thus producing earthworm casts with a high generation index > 80%. When composted FW was added to a vermicomposting substrate, a distinctive microbial community structure with alkaliphilic, halophilic, and lignocellulolytic microorganisms dominated the microflora. The dominant bacterial species was Saccharopolyspora rectivirgula, and the dominant fungal species changed from Kernia nitida to Coprinopsis scobicola. Furthermore, microbial genes for refractory organic matter and fat degradation were observed in Vibrio cholerae, Kernia nitida, and Coprinopsis scobicola. Financial analysis showed that vermicomposting has the potential to reduce the cost associated with FW disposal from $ 57 to $ 18/t. [ABSTRACT FROM AUTHOR]

In order to solve the problems of difficult selection of carbon sources and high cost of dosage in advanced treatment of wastewater treatment plant, denitrification biological filter was used to explore the denitrification performance of different carbon sources. In this study, the denitrification performance of three carbon sources (sodium acetate, ethanol and methanol) at different hydraulic retention time (HRT), nitrogen ratio (C/N) and influent NH4+-N concentration and the microbial community structure at different heights of the reactor were investigated. The results showed that under the condition of low carbon nitrogen ratio, as the HRT increased, the removal efficiency of NH4+-N and NO3--N in the effluent of three systems with sodium acetate ethanol and methanol as carbon sources gradually increased, and the accumulation of NO2--N in methanol system was the lowest in the three systems. With the gradual increase of carbon to C/N, the concentration of NH4+-N and NO3--N in the three systems gradually decreased. The effluent TN concentration of sodium acetate and methanol system was less than 1.5 mg/L when C/N was 6 and 5, which met the Class W of Environmental Quality Standard for Surface Water. With the increase of influent NH4+-N concentration, it led to the increase of NO2--N accumulation degree, resulting in the increase of effluent TN concentration. Carbon sources led to significant differences in the abundance of the three systems at the phylum level. The differences at the genus level were more obvious, and the total relative abundance of denitrifying bacteria was in the order of sodium acetate system > ethanol system > methanol system. The results of this study can provide a theoretical reference for the selection of carbon source and the use of dosage in waste-water treatment plants. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFASs) have attracted significant attention as a emerging environmental contaminant. The biological toxicities and ecological health risks associated with PFASs have emerged as a popular subject for ecotoxicology related research. PFASs have a detrimental impact on individual microbes in the environment. Furthermore, prolonged exposure to PFASs can disrupt the composition, structure and enzyme activity of the microbial community in the environment, disrupting the normal cycling of materials and energy in the ecosystem. This paper reviewed the impact of PFASs on microbial community structure and diversity across various environmental media, namely freshwater, marine and soil. Additionally, it summarizes the effects of enzyme activity and function in response to PFASs. Based on these findings, an assessment of the future direction of ecological risk assessment of PFASs was conducted to provide a theoretical basis and support for unbiased environmental and ecological risk assessment of PFASs. [ABSTRACT FROM AUTHOR]

This study analyzed the effects of benzoic acid (BA) on the physicochemical properties and microbial community structure of perilla rhizosphere soil. The analysis was based on high-throughput sequencing technology and physiological and biochemical detection. The results showed that with the increase in BA concentration, soil pH significantly decreased, while the contents of total nitrogen (TN), alkaline nitrogen (AN), available phosphorus (AP), and available potassium (AK) significantly increased. The activities of soil conversion enzymes urease and phosphatase significantly increased, but the activities of catalase and peroxidase significantly decreased. This indicates that BA can increase soil enzyme activity and improve nutrient conversion; the addition of BA significantly altered the composition and diversity of soil bacterial and fungal communities. The relative abundance of beneficial bacteria such as Gemmatimonas, Pseudolabrys, and Bradyrhizobium decreased significantly, while the relative abundance of harmful fungi such as Pseudogymnoascus, Pseudoeurotium, and Talaromyces increased significantly. Correlation analysis shows that AP, AN, and TN are the main physicochemical factors affecting the structure of soil microbial communities. This study elucidates the effects of BA on the physicochemical properties and microbial community structure of perilla soil, and preliminarily reveals the mechanism of its allelopathic effect on the growth of perilla. [ABSTRACT FROM AUTHOR]

Salt-tolerant aerobic granular sludge(AGS) was successfully cultivated under the dual stress of tetracycline and 2.5% salinity, resulting in an average particle size of 435.0 ± 0.5 and exhibiting a chemical oxygen demand(COD) removal rate exceeding 80%, as well as excellent sedimentation performance. The analysis of metagenomics technology revealed a significant pattern of succession in the development of AGS. The proportion of Oleiagrimonas, a type of salt-tolerant bacteria, exhibited a gradual increase and reached 38.07% after 42 days, which indicated that an AGS system based on moderate halophilic bacteria was successfully constructed. The expression levels of targeted genes were found to be reduced across the entire AGS process and formation, as evidenced by qPCR analysis. The presence of int1 (7.67 log10 gene copies g−1 in 0 d sludge sample) enabled microbes to horizontally transfer ARGs genes along the AGS formation under the double pressure of TC and 2.5% salinity. These findings will enhance our understanding of ARG profiles and the development in AGS under tetracycline pressure, providing a foundation for guiding the use of AGS to treat hypersaline pharmaceutical wastewater. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hemorrhoids are a common ailment that can cause significant disruptions to one's daily life. While some researchers have speculated about a potential link between hemorrhoid development and gut microbes, there is currently insufficient evidence to support this claim. In this study, we collected samples from 60 hemorrhoid patients and analyzed the composition and characteristics of microbiomes in hemorrhoids. PCoA results revealed distinct differences between the microbiomes of hemorrhoids, skin-originated microbiomes, and gut microbes, highlighting the complex nature of hemorrhoidal microbiomes. The distribution characteristics of Staphylococcus suggest that the skin microbiome influences the microbiome of hemorrhoids. Additionally, we observed higher levels of Prevotella in two cases of thrombosed hemorrhoids compared to non-thrombosed hemorrhoids. This finding suggests that Prevotella may play a crucial role in the development of thrombosed hemorrhoids. [ABSTRACT FROM AUTHOR]

Hydrochar as a carbon-based fertiliser is hypothesised to permanently improve soils by modifying soil carbon quality through the regulation of soil organic carbon dynamics, aggregation properties and microbial diversity. However, the interactions between soil organic carbon (SOC) molecular structure, soil aggregates and soil microbial communities as a result of hydrochar application have not been fully elucidated. In this study, the use of hydrochar derived from duck farm biomass waste for a maize cultivation experiment verified that hydrochar had a promoting effect on maize growth, effectively increasing the nutrient supply to the soil. The application of hydrochar increased the soil organic carbon content by 78 to 253 per cent, which was dominated by CHON-type lignin, carbohydrates and condensed aromatic structural compounds. Meanwhile, hydrochar had a significant effect on both soil aromatic structures and oxygenated functional groups, forming more soil macroaggregates. In addition, hydrochar had a positive effect on soil bacterial abundance. This study suggests that the key mechanism by which hydrochar regulates soil carbon dynamics is mainly through the stabilising effect of hydrochar on macroaggregates while increasing the abundance of carbon-related microscopic bacteria. These results will help to elucidate the potential effects of aqueous carbon on the biogeochemical cycling of carbon in soils. [ABSTRACT FROM AUTHOR]

Anaerobic digestion is an important means to turn agricultural waste into resources and an important way to address the challenges in treating vegetable residues in China. In this study, the co-digestion of dairy manure with tomato residue was investigated to clarify the effect of the total solids (TS) of the digestion substrate on methane's production and mechanism using the self-made anaerobic digestion device. The results showed that all treatments could rapidly ferment methane and that the daily methane production showed a trend of increasing first and then decreasing. The optimal concentrations of the digestion substrate for liquid anaerobic digestion (L-AD), hemi-solid-state anaerobic digestion (HSS-AD), and solid-state anaerobic digestion (SS-AD) were 10%, 18%, and 25%, respectively. Compared with SS-AD and HSS-AD, L-AD gas production peaked 3–6 days earlier. Treatment TS25 had the best cumulative methane production, reaching 117.4 mL/g VS. However, treatment TS6 had acid accumulation and a very unstable system. The cumulative methane production of SS-AD was higher than that of HSS-AD and L-AD. Firmicutes and Bacteroidetes were the dominant flora, and Methanoculleus, Methanosarcina, and Methanobrevibacter were the main archaeal groups. The TS significantly changed the microbial community composition of the digestion system, especially the low TS treatment. The results presented herein indicated that TS significantly changed the bacterial and archaeal community composition of the digestion system, and thus with the increase in TS from 6% to 25%, the methane yield increased. [ABSTRACT FROM AUTHOR]

Background and aims: Conservation tillage enhances soil aggregate function, —a key factor for promoting soil nutrient cycling and plant growth. However, there is a limited understanding of how tillage practices impact soil nutrients, enzymes and microbes distribution among different-sized aggregates, and their potential subsequent effects on other soil functions and processes. Methods: We conducted a long-term experiment involving maize (Zea mays L.) cultivation in a semiarid farming region in Northwest China. Four tillages were implemented: no-tillage, minimal tillage, fold-tillage, and sub-tillage. Soil aggregates were categorized based on size: <0.25 mm ('micro'), 0.25–2 mm ('small'), and > 2 mm ('macro'). We measured the nutrient contents, enzyme activity, enzymatic stoichiometry, and soil microbial community structure with each fraction, and assessed crop productivity. Results: The no-tillage treatment increased soil C content, microbial biomass, and P and N availability within micro-aggregates and bulk soil. It also enhanced enzymatic activity related to C and P acquisition and the C: N enzymatic ratio but decreased the N: P enzymatic ratio in micro-aggregates. Notably, no-tillage promoted straw and root biomass and crop yield compared to conventional tillage. Microbial community structure differed under the different tillage regimes and among aggregate size fractions, particularly under conventional tillage, but the tillage system did not affect alpha diversity. Conclusions: Our results highlight that long-term conservation tillage positively influenced soil aggregates by increasing carbon content and enzyme activity, thereby, reshaping the soil microbial community composition within aggregate size fractions in semiarid agroecosystems. [ABSTRACT FROM AUTHOR]

Background and aims: There is still limited knowledge regarding the dynamics of soil microbial community structures and functional groups during forest secondary succession after rubber monocultures (RP) abandonment. Methods: Bacterial and fungal communities and functions were investigated for the soil from six forest stands with three replicate plots. Selected stands included an RP, four spontaneous secondary forest stands that formed after RP abandonment at 1 (SF_1), 10 (SF_10), 20 (SF_20), and 40 (SF_40) years, as well as a primary forest (PF, approximately 100 years). Results: After RP abandonment, the alpha-diversity metrics of soil microbial communities increased during the first 40 years of succession but decreased in PF. The biomarkers Proteobacteria and Mortierellomycota increased significantly (P < 0.05) by 84% and 633% in PF, respectively, while Firmicutes showed a significant decrease of 89% in comparison with SF_1. Secondary succession increased the relative abundance of bacterial functional groups related to carbon cycling and fungal functional groups (especially ericoid mycorrhizal). Soil pH was the main edaphic factor in shaping microbial communities and functions. In addition, soil moisture and seasonal variations had direct impacts on fungal communities and bacterial functions. Conclusions: Collectively, these findings suggest that different successional trajectories occur in bacteria and fungi, owing to their divergent responses to the changes in season, soil moisture, and nutrients. Specifically, the frequent shifts in bacterial dominant phyla during succession, as well as the increased susceptibility of diversity and functional groups to season, indicate that bacteria respond more quickly to disturbances compared to fungi. [ABSTRACT FROM AUTHOR]

To address the issue of insufficient carbon sources in urban sewage, which leads to poor nitrogen removal performance in sewage treatment systems, an anaerobic/anoxic/aerobic (AAO) pilotscale reactor was established. The reactor aimed to treat low C/N (chemical oxygen demand; COD/total nitrogen; TN) municipal wastewater (C/N<5). To enhance nitrogen removal and investigate the mechanism in the AAO process, a Pall ring modified biological suspended filler was introduced to the aerobic zone after achieving partial nitrification and denitrification (PND). The results revealed that the activated sludge-biofilm composite system can be successfully formed within 40 days, with a stable loaded biomass on the membrane at 40.06 mg/g (measured by volatile suspended solids (VSS)/filler). The aerobic zone of the activated sludge-biofilm composite system demonstrated an increase in nitrite accumulation rate (NAR) and simultaneous nitrification and denitrification efficiency (SND), from 60.46% and 19.42% in the initial stage (stage 1) to 69.62% and 46.47% in the stable forming stage (stage 3), respectively. By promoting both PND and SND pathways for nitrogen removal, the effluent from the system exhibited decreased concentrations of ammonia nitrogen (NH4+-N) at 0.11 mg/L and total nitrogen (TN) at 4.55 mg/L, indicating the significant synergistic effect of the biofilm on nitrogen removal. 16S rRNA amplification and sequencing analysis revealed that Proteobacteria was the dominant microorganism in the 60-day biofilm, accounting for 76.12% of the relative abundance. The main ammonia oxidizing bacteria (AOB) were Nitrosomanas (1.77%) and Nitrosococcus (1.69%). Meanwhile, denitrification microbial species were found to have a substantial proportion (29.11%), along with a small amount of Anammox bacteria (Anammoxoglobus, 0.35%) within the biofilm. These sequencing results were consistent with the macroscopic performance of the reactor. Overall, these findings establish a theoretical foundation for enhancing nitrogen removal in the AAO system. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cow dung is a kind of high quality and renewable biological resource. Biochar made from cow dung can be used as a soil amendment to improve soil nutrient status. The relationship between soil water and phosphorus is very close, and the water status determines the form, content, and availability of phosphorus. In order to investigate the effects of biochar on soil inorganic phosphorus components, available phosphorus, enzyme activities related to the phosphorus cycle, microbial functional genes, and seedling growth under different soil water conditions were investigated. Field experiments were carried out by setting different water conditions (30%, 60%, and 100%) and biochar addition (0 t hm−2, 2.63 t hm−2, 5.26 t hm−2, and 7.89 t hm−2). The results showed that applying biochar significantly increased the soil's accessible phosphorus content and the phosphorus content in both the aboveground and subsurface parts of P. euphratica seedlings. This is mainly attributable to biochar's direct and indirect effects on soil properties. Because biochar is naturally alkaline, it raises soil pH and reduces acid phosphatase activity in the soil around P. euphratica seedlings in the rhizosphere. Perhaps the alkaline phosphatase level first showed an upward trend due to the combined impacts of water and biochar, and then it started to decline when the biochar addition was increased. Soil phosphorus functional genes phoC, phoD, gcd, and pqqc had an increase in copy number with biochar addition but not without treatment. Indirectly, the biochar treatment increased the soil's phosphorus availability by increasing the population of the phosphate-solubilizing bacteria Fusarium and Sphingomonas. Soil phosphorus availability is positively affected by biochar under various water conditions. This impact is due to chemical and microbiological mechanisms. [ABSTRACT FROM AUTHOR]

Modern coal chemical industry is an important means to realize the clean utilization of coal resources, the coal chemical sludge generated during the process of coal conversion process is a typical refractory solid waste restricting the development of coal chemical industry since its extremely high water content and the poor dewaterability. It has been documented that the dewaterability of coal chemical sludge is affected by the microbial community structure and water distribution characteristics; and thus, it is necessary to investigate the microbial community information and water distribution in coal chemical sludge to provide theoretical guidance for the high-efficiency sludge dewatering technology. In this study, coal-to-olefins sludge and coal-to-oil sludge were selected and the microbial community structure of the two sludge was obtained through analyzing 16s rRNA gene sequencing, and the water distribution was obtained by DSC and LF-NMR method. The results show that the different sewage treatment processes chosen by two coal chemical industries lead to certain differences in the microbial community structures of coal chemical sludge, Proteobacteria, Bacteroidetes and Chloroflexi are the dominant phylum in the two sludge. The LF-NMR method can more accurately measure the water distribution, and the water in the sludge can be classified into bound water, mechanical bound water and free water according. [ABSTRACT FROM AUTHOR]

The biological degradation of plant residues in the soil or on the soil surface is an integral part of the natural life cycle of annual plants and does not have adverse effects on the environment. Crop straw is characterized by a complex structure and exhibits stability and resistance to rapid microbial decomposition. In this study, we conducted a microcosm experiment to investigate the dynamic succession of the soil microbial community and the functional characteristics associated with lignocellulose-degrading pathways. Additionally, we aimed to identify lignocellulose-degrading microorganisms from the straw of three crop species prevalent in Northeast China: soybean (Glycine max Merr.), rice (Oryza sativa L.), and maize (Zea mays L.). Our findings revealed that both the type of straw and the degradation time influenced the bacterial and fungal community structure and composition. Metagenome sequencing results demonstrated that during degradation, different straw types assembled carbohydrate-active enzymes (CAZymes) and KEGG pathways in distinct manners, contributing to lignocellulose and hemicellulose degradation. Furthermore, isolation of lignocellulose-degrading microbes yielded 59 bacterial and 14 fungal strains contributing to straw degradation, with fungi generally exhibiting superior lignocellulose-degrading enzyme production compared to bacteria. Experiments were conducted to assess the potential synergistic effects of synthetic microbial communities (SynComs) comprising both fungi and bacteria. These SynComs resulted in a straw weight loss of 42% at 15 days post-inoculation, representing a 22% increase compared to conditions without any SynComs. In summary, our study provides novel ecological insights into crop straw degradation by microbes. [ABSTRACT FROM AUTHOR]

To avoid the unreasonable use of chemical fertilizer, an environmentally friendly means of improving soil fertility is required. This study explored the role of the plant growth-promoting rhizosphere bacteria (PGPR) strain Bacillus velezensis SAAS-63 in improving nutrient stress in lettuce. Compared with no inoculation, B. velezensis SAAS-63 inoculants exhibited significantly increased fresh weight, root length, and shoot height under nutrient deficiency, as well as improved antioxidant activities and proline contents. The exogenous addition of B. velezensis SAAS-63 also significantly increased the accumulation of macroelements and micronutrients in lettuce. To elucidate the resistance mechanisms induced by B. velezensis SAAS-63 under nutrient stress, high-throughput sequencing and multi-omics analysis were performed. Inoculation with B. velezensis SAAS-63 altered the microbial community of the rhizosphere and increased the relative abundances of Streptomyces, Actinoallomurus, Verrucomicrobia, and Chloroflexi. It is worth noting that the inoculant SAAS-63 can affect plant rhizosphere metabolism. The inoculant changed the metabolic flow of phenylpropanoid metabolic pathway under nutrient deficiency and promoted phenylalanine to participate more in the synthesis of lignin precursors and coumarin substances by inhibiting the synthesis of flavone and isoflavone, thus improving plant resistance. This study showed that the addition of inoculant SAAS-63 could help plants recruit microorganisms to decompose and utilize trehalose and re-established the carbon metabolism of the plant rhizosphere. Additionally, microbes were found to be closely related to the accumulation of metabolites based on correlation analysis. The results indicated that the addition of PGPRs has an important role in regulating soil rhizosphere microbes and metabolism, providing valuable information for understanding how PGPRs affect complex biological processes and enhance plant adaptation to nutrient deficiency. Key points: • Inoculation with SAAS-63 significantly promoted plant growth under nutrient-deficient conditions • Inoculation with SAAS-63 affected rhizosphere microbial diversity and community structure • Inoculation with SAAS-63 affected plant rhizosphere metabolism and induced plants to synthesize substances that resist stress [ABSTRACT FROM AUTHOR]

Long‐term continuous cropping of strawberry induces soil degradation, which reduces strawberry growth and yield. Agricultural waste and microorganisms have great potential in improving soil health. The aim of this study was to identify the potential mechanisms of Bacillus velezensis containing agricultural waste to improve soil health. Soil that had been cropped continuously for more than 10 years was flooded with water for approximately 28 days. After flooding, agricultural waste fermented with microorganisms was applied to improve soil health. Microbial biofilm formation and rhizosphere colonization were also determined. Different agricultural waste coupled with pre‐flooding resulted in a significant increase of strawberry biomass by 33.0%–98.4% compared with control and changes in soil properties. The application of agricultural waste also significantly increased soil bacterial diversity, with the Shannon index increased by 2.37%–6.11% compared with control, and changed the bacterial community composition. The promotion of plant growth was linked with detectable shifts in the soil bacterial taxa after pre‐flooding and B. velezensis containing agricultural waste usage. Most importantly, random forest and correlated analyses showed that taxa affiliated with Pseudomonas may be important in strawberry growth after treatment. Subsequent bacterial isolation and pot inoculation experiments validated that co‐inoculation of Pseudomonas fluorescens and B. velezensis significantly promoted strawberry growth by 21.7% and 31.4%, respectively, compared with inoculation of only P. fluorescens or only B. velezensis, thus confirming the beneficial effect on strawberry plant growth in continuous cropped soils. Our results also indicate that co‐culture of P. fluorescens and B. velezensis could enhance biofilm formation and rhizosphere colonization, which may be essential in promoting plant growth. B. velezensis containing agricultural waste could stimulate indigenous Pseudomonas and promote plant growth by enhancing biofilm formation and rhizosphere colonization. [ABSTRACT FROM AUTHOR]

In order to effectively repair and beautify the polluted soil and reduce the pollution of heavy metals, the cultivation of biological agents and two enrichment plants were combined to repair the lead soil. After 30 and 60 days of combined remediation with 400 mg / kg, the concentration of heavy metals in soil was decreased 19. 61% and 19. 48%, respectively. So the adsorption rate were increased by 16. 82% and 17. 83%, respectively. The activity of catalase was increased from 5. 6 mg / kg to 11. 4 mg / kg and 15. 9 mg / kg. The activity of alkaline phosphatase was increased from 45. 6 mg / kg to 88. 4 mg / kg and 93. 4 mg / kg, respectively. The activity of sucrase was increased from 4. 2 mg / kg to 9. 6 mg / kg and 9. 9 mg / kg, respectively. So the activity of urease was increased from 32. 6 mg / kg to 66. 3 mg / kg and 71. 2 mg / kg, respectively. The content of chlorophyll was increased 9. 16% and 9. 18%, respectively. The number of heavy metal resistant bacteria was decreased 21. 31% and 20. 27%, respectively. The number of bacteria, fungi and actinomycetes were increased by 97. 68%, 67. 63% and 210. 09%, respectively. The diversity and abundance of microbial community were increased 2. 7% and 2. 9%, respectively. The results showed that the photosynthesis of plants were enhanced. The adsorption and transport of heavy metals were accelerated. So were the enzyme activity, and the tolerance of plants to heavy metals were enhanced gradually. Meantime, the number of heavy metal-resistant bacteria were decreased apparently. And so on, the number of bacteria, fungi and actinomycetes were increased significantly. It was concluded that the plants and microbial agents could effectively promote the adsorption of plants to heavy metals and strengthen the repair effect, and which could provided scientific basis for the study of heavy metal pollution remediation. [ABSTRACT FROM AUTHOR]

• CTS-Fe effectively promoted the methane production during AD of WAS. • CTS-Fe addition enriched the abundance of IRB during AD process. • CTS-Fe had great promotion for hydrolysis process via dissimilatory iron reduction. • CTS-Fe inhibited acetoclastic and hydrogenotrophic methanogenesis process. Anaerobic digestion (AD) of waste activated sludge (WAS) is usually limited by the low generation efficiency of methane. Fe(III)-loaded chitosan composite (CTS-Fe) have been reported to effectively enhanced the digestion of WAS, but its role in promoting anaerobic sludge digestion remains unclear. In present study, the effects of CTS-Fe on the hydrolysis and methanogenesis stages of WAS anaerobic digestion were investigated. The addition of CTS-Fe increased methane production potential by 8%–23% under the tested conditions with the addition of 5–20 g/L CTS-Fe. Besides, the results demonstrate that the addition of CTS-Fe could effectively promote the hydrolysis of WAS, evidenced by lower protein or polysaccharides concentration, higher soluble organic carbon in rector adding CTS-Fe, as well as the increased activity of extracellular hydrolase with higher CTS-Fe concentration. Meanwhile, the enrichment of Clostridia abundance (iron-reducing bacteria (IRBs)) was observed in CTS-Fe adding reactor (8.9%–13.8%), which was higher than that in the control reactor (7.9%). The observation further suggesting the acceleration of hydrolysis through dissimilatory iron reduction (DIR) process, thus providing abundant substrates for methanogenesis. However, the presence of CTS-Fe was inhibited the acetoclastic and hydrogenotrophic methanogenesis process, which could be ascribed to the Fe(III) act as electron acceptor coupled to methane for anaerobic oxidation. Furthermore, coenzyme F420 activity in the CTS-Fe added reactor was 34.9% lower than in the blank, also abundance of microorganisms involved in hydrogenotrophic methanogenesis was decreased. Results from this study could provide theoretical support for the practical applications of CTS-Fe. [Display omitted] [ABSTRACT FROM AUTHOR]

The use of traditional Chinese medicine (TCM) residue as a crop culture substrate has unique advantages in alleviating the obstacles associated with continuous monocropping, such as increasing production, improving quality and alleviating pests and diseases. However, the effect of TCM residue application on substrates in continuous monocropping practices has not been determined. In this study, the cucumber variety "Jinyou No. 10" was used as the material, and fermented TCM residue, vermiculite and perlite were used as organic substrates (3:1:1). The cucumbers were cultivated on substrates for different durations of continuous monocropping, which were the first cropping cycle (A1), second cropping cycle (A2), third cropping cycle (A3) and fourth cropping cycle (A4). The control (A0) was the substrate sample without any crop planted in it. After the cucumbers were harvested, substrate samples (areas around the cucumber roots) were collected. The physiochemical properties of the cultivated substrates were determined, and the microbial community structures were analyzed through 16S rRNA and ITS sequencing. The physiochemical indices of the substrates with different durations of continuous monocropping (A1–A4) were significantly different than those of the control (A0) substrate. Moreover, the continuous cropping of cucumber had greater effects on fungal communities than on bacterial communities. Bacterial community structure analysis revealed a greater proportion of important bacterial taxa (Proteobacteria, Chloroflexi, and Nitrospirae) in the continuous monocropping substrates than in the A0 substrate. For the fungal community, Ascomycota accounted for the largest percentage of the fungal community in all the samples. The diversity of the microbial community was found to be influenced primarily by electrical conductivity, organic matter content, pH and total potassium content according to the correlation analysis of physicochemical properties and relative abundance of the microbial community. Our study would provide a basis for addressing persistent challenges in continuous cropping and for obtaining the utmost benefit from using TCM organic residue waste. [ABSTRACT FROM AUTHOR]

【Objective】This study aims to investigate the changes in the bacterial community structure of sorghum roots under salt stress, as well as the characteristics of the rhizosphere bacterial co-occurrence network structure.【Method】Two sorghum varieties, HN16（saltsensitive）and GLZ（salt-tolerant）, with varying levels of salt tolerance were cultivated in pots and subjected to salt stress. The root microbiome of these plants was then analyzed using 16S amplicon sequencing technology.【Result】With the aggravation of salt stress, the contents of total phenols and flavonoids in the sorghum roots gradually increased, and the appropriate salt stress induced the synthesis of phenolic acids to improve the salt tolerance of sorghum. The results of the microbial community structure analysis showed that Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes and Chloroflexi were the dominant phyla in sorghum rhizosphere soils. Comparative analysis of samples showed that the bacterial composition of sorghum rhizosphere under salt stress was less affected by growth stage, and the bacterial community structure of sorghum rhizosphere changed with the aggravation of salt stress. Through WGCNA analysis of all filters OTUs, a total of 12 gene co-expression module were identified, pink module had significantly positive correlation with salinity and greenyellow module had significantly positive correlation with period and the contents of total phenols and flavonoids after salt treatment. The bacterial co-occurrence network was more complex in low salt stress soils than in higher salt stress soils, reflected by more nodes and more edges. The 13 network key OTUs were identified, OTU8480, OTU6866, OTU3247 and OTU3499 was the keyOTUs in S0 network; OTU6895, OTU4206, OTU6470, OTU1810 and OTU4916 in S3 network; OTU4217, OTU8426, OTU4847, and OTU6066 were the key OTUs in S7 network.【Conclusion】The composition of rhizosphere bacteria in both varieties of sorghum has been modified in response to salt stress. After salt stress, with more complex co-occurrence network and tighter connections between OTUs of rhizosphere soil bacterial communities. [ABSTRACT FROM AUTHOR]

The amendment of salt-affected soils with elemental sulfur (S0) has been recognized for its potential to effectively reduce soil salinity and pH, thereby enhancing soil physicochemical properties, promoting crop growth, and improving yields. Despite these known benefits, the widespread adoption of S0 for managing saline soils, particularly in arid calcareous regions, remains limited. Consequently, this study aimed to evaluate the impact of S0 on salt leaching, soil pH, nutrient uptake, plant growth, microbial diversity, and community structure under alkaline saline soil conditions. The study includes three main experiments: a preliminary column experiment without plants, a field trial with Rhodes grass (Chloris gayana), and a greenhouse pot experiment with wheat (Triticum spp.). Our findings demonstrated that S0 incorporation into the soil exerted a positive influence, resulting in increased salt removal, reduced soil pH, and improved plant growth. Specifically, soil amendment with 750 kg S0 ha−1 led to a substantial salt removal, exceeding double in the column experiment, approximately 91.3 % in the field trial, and about 34.1 % in the greenhouse pot experiment compared to the control. S0 amendment also significantly lowered soil and leachate pH in both field and greenhouse trials, with reductions of 3.3 % and 6.3 %, and 8.1 % and 4.4 %, respectively, relative to the control. Calcium and phosphorus uptake by Rhodes grass increased significantly by 75 % and 14 %, respectively, compared with the control. Soil organic matter content significantly increased from 0.6 % to 1.5 % compared to that of the control. This overall enhancement in soil conditions resulted in a considerable increase in Rhodes grass and wheat yields by 13 % and 59 %, respectively. While the prokaryotic diversity (16S V4 rRNA sequencing) in the Rhodes grass field trial was not significantly affected by S0 amendments after two months, the microbial community composition showed remarkable differences between the S0-amended and control samples. Eighty-three unique taxa were exclusively found in the S0-amended samples. In conclusion, our findings suggest that the amendment of soil with S0 is a promising strategy for the sustainable management of calcareous salt-affected soils in arid regions. [ABSTRACT FROM AUTHOR]

Background: Previous research on whole-soil measurements has failed to explain the spatial distribution of soil carbon transformations, which is essential for a precise understanding of the microorganisms responsible for carbon transformations. The microorganisms involved in the transformation of soil carbon were investigated at the microscopic scale by combining 16S rDNA sequencing technology with particle-level soil classification. Methods: In this experiment,16S rDNA sequencing analysis was used to evaluate the variations in the microbial community structure of different aggregates in no-tillage black soil. The prokaryotic microorganisms involved in carbon transformation were measured before and after the freezing and thawing of various aggregates in no-tillage black soil. Each sample was divided into six categories based on aggregate grain size: >5, 2-5, 1-2, 0.5-1, 0.25-0.5, <0.25 mm, and bulk soil. Results: The relative abundance of Actinobacteria phylum in <0.25 mm aggregates was significantly higher compared to that in other aggregates. The Chao1 index, Shannon index, and phylogenetic diversity (PD) whole tree index of <0.25 mm aggregates were significantly smaller than those of in bulk soil and >5 mm aggregates. Orthogonal partial least-squares discrimination analysis showed that the microbial community composition of black soil aggregates was significantly different between <1 and >1 mm. The redundancy analysis (RDA) showed that the organic carbon conversion rate of 0.25--0.5 mm agglomerates had a significantly greater effect on their bacterial community structure. Moreover, humic acid conversion rates on aggregates <0.5 mm had a greater impact on community structure. The linear discriminant analysis effect size (LEfSe) analysis and RDA analysis were combined. Bradyrhizobium, Actinoplane, Streptomyces, Dactylosporangium, Yonghaparkia, Fleivirga, and Xiangella in <0.25 mm aggregates were positively correlated with soil organic carbon conversion rates. Blastococcus and Pseudarthrobacter were positively correlated with soil organic carbon conversion rates in 0.25--0.5 mm aggregates. In aggregates smaller than 1 mm, the higher the abundance of functional bacteria that contributed to the soil's ability to fix carbon and nitrogen. Discussion: There were large differences in prokaryotic microbial community composition between <1 and >1 mm aggregates. The <1 mm aggregates play an important role in soil carbon transformation and carbon fixation. The 0.25-0.5 mm aggregates had the fastest organic carbon conversion rate and increased significantly more than the other aggregates. Some genus or species of Actinobacteria and Proteobacteria play a positive role in the carbon transformation of <1 mmaggregates. Such analyses may help to identify microbial partners that play an important role in carbon transformation at the micro scale of no-till black soils. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Biochar (BC) and artificial humic acid (A-HA), both classified as artificial carbon materials, play crucial roles in enhancing soil fertility and promoting carbon sequestration. Despite their significance, limited research has explored the combined effects of these two components when applied to soil. This study aims to investigate the synergistic impacts of BC and A-HA under alternating wet and dry soil conditions. Materials and methods: We synthesized A-HA and BC as exogenous additives derived from corn stover. These additives were subsequently introduced into the soil in varying proportions during a 60-day alternating wetting and drying soil column experiment. The experiment encompassed six treatment groups, each consisting of three replicates. Results and discussion: The results of our study suggest that the simultaneous application of A-HA and BC addresses limitations observed with individual applications. A-HA proves more effective than BC in enhancing soil physical properties such as total nitrogen, total organic carbon, microbial biomass carbon, dissolved organic carbon, and cation exchange. Conversely, BC excels in improving effective phosphorus, effective potassium, and soil organic matter. Both A-HA and BC contributed to the reduction of net soil greenhouse gas (GHG) emissions, with A-HA notably effective in reducing net nitrous oxide emissions and BC excelling in reducing net carbon dioxide emissions. The findings also revealed an augmentation in the diversity and abundance of soil microorganisms, particularly those associated with carbon sequestration functions (e.g., Chloroflexi). Hence, the coapplication of BC and A-HA demonstrates a harmonious balance across these indicators, showcasing remarkable synergistic effects. Conclusion: Analyzing these factors provides valuable insights into the synergistic effects of BC and A-HA on soil dynamics, particularly in realistic irrigation scenarios. This contributes to a comprehensive understanding of their applications in sustainable agriculture and climate change mitigation. Our study advances knowledge on the potential of BC and A-HA for soil carbon sequestration and quality improvement, providing practical guidance for field application. [ABSTRACT FROM AUTHOR]

Purpose: Co-composting of chicken manure and edible mushroom residue inoculated with oxytetracycline-degrading strain T4 was conducted to reduce the risk of residual oxytetracycline and tetracycline resistance genes (TRGs) to the ecological environment. Materials and methods: Three treatments (CK: without bacteria agent T4 inoculated; AM: 1% bacteria agent T4 inoculated in mesophilic phase; AC: 1% bacteria agent T4 inoculated in cooling phase) were set to investigate dynamics of physicochemical properties, microbial composition, and antibiotic and antibiotic resistance genes. Results and discussion: The bacteria agent T4 inoculated in the mesophilic phase was conductive to the reservation of nutrients and maturity of chicken manure and improved oxytetracycline degradation (t1/2 was 2.77 days, and the total degradation rate was 80.78%). Bacterial community dynamic analysis showed that strain T4 reduced microbial richness and diversity in composting. In addition, the bacteria agent T4 could reduce the relative abundance of encoding efflux pump (EFP) TRGs significantly, and inoculated in the mesophilic phase was better than the cooling phase while having little effect on ribosomal protection protein (RPP) TRGs and enzymatic inactivation (EI) TRG. Conclusions: Inoculation of strain T4 in the initial stage of composting could be a promising technology to solve the problem of oxytetracycline residue and its resistance genes in chicken manure. It was also found that the abundance of TRGs was affected by bacterial composition and dynamic, which was affected by the physicochemical properties of composting and fates of oxytetracycline, and vice versa. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The soaking and fermentation of the stems and leaves is an important intermediate step in the processing of Indigo Naturalis. However, the relationship between microbiota and Indigo Naturalis yields is still poorly understood. This study aimed to compare microbial communities and metabolite profiles at various stages of soaking fermentation, followed by validation of the results using HPLC. A total of 731 compounds were identified through metabolite analysis, with the levels of indigo and indirubin peaking after 36 h of fermentation. Metagenomes revealed Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were identified as the most abundant microbial phyla in soaking fermentation. Correlation analysis indicated that the yields of indigo and indirubin may be affected by Lactococcus, Clostridium, and Enterobacter through the regulation of related synthetic enzymes. The findings offered novel perspectives on the relationship of microorganisms and Indigo Naturalis yields.

Acid rain and invasive plants have quintessential adverse impacts on terrestrial ecosystems. As an environmentally safe method for disposal of invasive plants, we tested the effect of biochar produced from these plants in altering soil deterioration under acid rain as compared with lime. Given the impacts of the feedstock type and soil properties on the response of soil to the added biochar, we hypothesized that the microbial community and functions would respond differently to the charred invasive plants under acid rain. A pot experiment was conducted to examine the response of soil microbiomes and functions to the biochar produced from Blackjack (Biden Pilosa), Wedelia (Wedelia trilobata), and Bitter vine (Mikania micrantha Kunth), or quicklime (CaO) at a rate of 1 % (w/w) under acid rain. Like soil pH, the nutrient contents (nitrogen, phosphorus, and potassium), calcium, and cation exchange capacity (CEC) were important as dominant edaphic factors affecting soil microbial community and functionality. In this respect, lime decreased nutrients availability, driven by 11-fold, 44 %, and 2-fold increments in calcium content, pH, and C/N ratio. Meanwhile, biochar improved nutrients availability under acid rain owing to maintaining a neutral pH (∼6.5), increasing calcium (by only 2-fold), and improving CEC, water repellency, and aggregation while decreasing the C/N ratio and aluminum content. Unlike biochar, lime decreased the relative abundance of Nitrosomonadaceae (the dominant ammonia-oxidizing bacteria) while augmenting the relative abundance of some fungal pathogens such as Spizellomycetaceae and Sporormiaceae. Given the highest nitrogen and dissolved organic carbon content than other biochar types, Wedelia-biochar resulted in the greatest relative abundance of Nitrosomonadaceae; thus, the microbial carbon and nitrogen biomasses were maximized. This study outlined the responses of the soil biogeochemical properties and the related microbial community structure and functionality to the biochar produced from invasive plants under acid rain. This study suggests that biochar can replace lime to ameliorate the effects of acid rain on soil physical, chemical and biological properties.

With the rapid expansion of artificial light in the global nocturnal environment, the ecological impacts of artificial light at night (ALAN) on plant communities have garnered increasing research interest. However, the role of phyllosphere microorganisms as mediators in the regulation between ALAN and plants remains unclear. In this study, we conducted a field experiment in natural grassland plots, employing two treatments: one with no artificial light at night (control) and another with artificial light at night (ALAN). We then investigated the response of phyllosphere microorganisms in three grassland plant species (Leymus chinensis, Vicia sepium, and Aster altaicus) to ALAN exposure. The results revealed that the constructive species L. chinensis demonstrated a markedly higher diversity of phyllosphere bacteria and fungi compared to V. sepium and A. altaicus and thus had the most abundant microbial community. However, ALAN exposure reduced the diversity of phyllosphere bacteria and fungi in all three plant species to varying degrees. ALAN induced certain changes to the phyllosphere bacterial community composition, particularly manifesting in a reduction in the abundance of beneficial bacteria, including Sphingomonas, Hymenobacter, Methylobacterium-Methylorubrum, and Bacillus. Compared with phyllosphere bacterial communities, the alterations in phyllosphere fungal communities were more sensitive, characterized by a significant decrease in the abundance of certain fungi, including Zymoseptoria, Mycosphaerella, Cladosporium, and Epicoccum. The functional predictions of phyllosphere bacteria and fungi further corroborate these conclusions. In summary, ALAN exposure may suppress the functional capacity of phyllosphere microorganisms in grassland plants while decreasing the probability of fungal pathogen occurrence.