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Ni foam was introduced as an interlayer to improve the performance of the brazed C/C composite-TC4 titanium alloy joint, and high-quality brazed connections of c/c composites and TC4 were realized. Compared to a brazing joint without foam, the introduction of a foam Ni interlayer can achieve a more uniform bonding interface. The effects of the thickness and pore size of the foam Ni interlayer on the microstructure, mechanical properties and residual stresses of the joints were investigated. With increasing thickness and pore diameter, Ag-based solid solutions and Ti–Cu intermetallic compounds first become more dispersed and smaller at the center of the brazed joints, and then aggregate to become larger. The brazed interface microstructure with a 0.4 mm thick foam Ni interlayer with a pore size of 0.5 mm was more uniform, and the shear strength of the joint reached 21.23 MPa, representing an 85.96 % increase compared to the joint without the foam Ni interlayer. The residual stress and its distribution calculated by finite element method (FEM), and the residual stress of the brazed joint decreased from 467 MPa/-289.53 MPa to 457.96 MPa/-234.98 MPa. These results indicated that the Ni foam could act as a buffer layer to reduce the residual thermal stress, and improve the mechanical properties of C/C composite-TC4 titanium alloy joint.

In this study, a phase-field scheme that rigorously obeys conservation laws and irreversible thermodynamics is developed for modeling stress-corrosion coupled damage (SCCD). The coupling constitutive relationships of the deformation, phase-field damage, mass transfer, and electrostatic field are derived from the entropy inequality. The SCCD localization induced by secondary phases in Mg is numerically simulated using the implicit iterative algorithm of the self-defined finite elements. The quantitative evaluation of the SCCD of a C-ring is in good agreement with the experimental results. To capture the damage localization, a micro-galvanic corrosion domain is defined, and the buffering effect on charge migration is explored. Three cases are investigated to reveal the effect of localization on corrosion acceleration and provide guidance for the design for resistance to SCCD at the crystal scale.

Volcanic ash alteration supports chemolithotrophic activity at the seabed and contributes to the production of microbial biomass during diagenesis, suggest analyses of isoprenoid and branched glycerol dialkyl glycerol tetraethers distributions in Mariana Trough tuffs and adjacent sediments.

The gut microbiota of fish is crucial for their growth, development, nutrient uptake, physiological balance, and disease resistance. Yet our knowledge of these microbial communities in wild fish populations in their natural ecosystems is insufficient. This study systematically examined the gut microbial communities of seven wild fish species in Chaohu Lake, a fishing-restricted area with minimal water turnover, across four seasons. We found significant variations in gut microbial community structures among species. Additionally, we observed significant seasonal and regional variations in the gut microbial communities. The Chaohu Lake fish gut microbial communities were predominantly composed of the phyla Firmicutes, Proteobacteria(Gamma), Proteobacteria(Alpha), Actinobacteriota, and Cyanobacteria. At the genus level, Aeromonas, Cetobacterium, Clostridium sensu stricto 1, Romboutsia, and Pseudomonas emerged as the most prevalent. A co-occurrence network analysis revealed that C. auratus, C. carpio, and C. brachygnathus possessed more complex and robust gut microbial networks than H. molitrix, C. alburnus, C. ectenes taihuensis, and A. nobilis. Certain microbial groups, such as Clostridium sensu stricto 1, Romboutsia, and Pseudomonas, were both dominant and keystone in the fish gut microbial network. Our study offers a new approach for studying the wild fish gut microbiota in natural, controlled environments. It offers an in-depth understanding of gut microbial communities in wild fish living in stable, limited water exchange natural environments.

IntroductionPapillomaviruses (PVs) can cause hyperplasia in the skin and mucous membranes of humans, mammals, and non-mammalian animals, and are a significant risk factor for cervical and genital cancers.MethodsUsing next-generation sequencing (NGS), we identified two novel strains of papillomavirus, PV-HMU-1 and PV-HMU-2, in swabs taken from belugas (Delphinapterus leucas) at Polar Ocean Parks in Qingdao and Dalian.ResultsWe amplified the complete genomes of both strains and screened ten belugas and one false killer whale (Pseudorca crassidens) for the late gene (L1) to determine the infection rate. In Qingdao, 50% of the two sampled belugas were infected with PV-HMU-1, while the false killer whale was negative. In Dalian, 71% of the eight sampled belugas were infected with PV-HMU-2. In their L1 genes, PV-HMU-1 and PV-HMU-2 showed 64.99 and 68.12% amino acid identity, respectively, with other members of Papillomaviridae. Phylogenetic analysis of combinatorial amino acid sequences revealed that PV-HMU-1 and PV-HMU-2 clustered with other known dolphin PVs but formed distinct branches. PVs carried by belugas were proposed as novel species under Firstpapillomavirinae.ConclusionThe discovery of these two novel PVs enhances our understanding of the genetic diversity of papillomaviruses and their impact on the beluga population.

Abstract The discovery of new viruses is important for predicting their potential threats to the health of humans and other animals. A novel picornavirus was identified from oral, throat, and anal swab samples collected from belugas (Delphinapterus leucas), from Dalian Sun Asia Tourism Holding Co., China, between January and December 2018, using a metagenomics approach. The genome of this novel PicoV-HMU-1 strain was 8197 nucleotides (nt) in length, with a open reading frame (from 1091 to 8074 nt) that encoded a polyprotein precursor of 2328 amino acids. Moreover, the genomic length and GC content of PicoV-HMU-1 were within the ranges found in other picornaviruses, and the genome organization was also similar. Nevertheless, PicoV-HMU-1 had a lower amino acid identity and distinct host species compared with other members of the Picornaviridae family. Phylogenetic trees were constructed based on the P1 and 3D amino acid sequences of PicoV-HMU-1 along with representative members of the Picornaviridae family, which showed that PicoV-HMU-1 was related to unclassified bat picornaviruses groups. These findings suggest that the PicoV-HMU-1 strain represents a potentially novel genus of picornavirus. These data can enhance our understanding of the picornavirus genetic diversity and evolution.

Seawater intrusion is a major concern commonly found in coastal aquifers worldwide. Because of the intense aquifer exploitation and land-based marine aquaculture in the coastal area of Beihai City, Guangxi Zhuang Autonomous Region, China, numerous underground aquifers in this area have been affected by seawater intrusion. However, the microbial communities in freshwater aquifers and their response to seawater intrusion are still unclear. In this study, groundwater from three aquifers was collected from three monitoring sites at different distances from the coastline in the coastal area of Beihai City, and the hydrochemical characteristics of these groundwater samples and the structure of the associated microbial communities were analyzed. The Cl− concentration of the samples indicated that seawater intrusion had occurred in the research area up to 1.5 km away from the coastline, but the monitoring site 2 km away from the coastline had yet to be affected. Statistical analysis showed that the bacterial communities in different groundwater aquifers were significantly correlated with the Cl− concentration, thereby suggesting that the extent of seawater intrusion might be one of the primary factors shaping bacterial composition in groundwater of this area, but the composition and distribution of archaea did not show a significant response to seawater intrusion and presented no apparent correlation with the Cl− concentration. α-, γ-Proteobacteria and Bacteroidota were the dominant bacterial lineages, accounting for about 58–95% of the bacterial communities. Meanwhile, the predominant archaeal taxa were mainly composed of Crenarchaeota, Nanoarchaeota, and Thermoplasmatota, as accounting for 83–100%. Moreover, there was significant spatial heterogeneity of microbial communities in the aquifers affected by varying degrees of seawater intrusion. The microbial communities inhabiting the unconfined aquifer were influenced by the geochemical fluctuation caused by seawater infiltration from land-based marine aquaculture ponds and the diffusion of eutrophic surface water. In contrast, changes in microbial community structure in the confined aquifers were closely related to the environmental gradient caused by different degrees of seawater intrusion. In addition, we also found that the tidal cycle did not significantly affect the structure of microbial communities inhabiting confined aquifers that had been long affected by seawater intrusion.

Astroviruses infect human and animals and cause diarrhea, fever, and vomiting. In severe cases, these infections may be fatal in infants and juvenile animals. Previous evidence showed that humans in contact with infected animals can develop serological responses to astroviruses. Mamastrovirus 11 is a species of Mamastrovirus and was first reported in 2018. It was detected in the fecal samples of a California sea lion. The genome sequence of its capsid protein (CP) was submitted to GenBank. However, the genome sequence of its non-structural protein region was not elucidated. In the present study, we characterized the genome sequences of the novel astroviruses AstroV-HMU-1 and AstroV-like-HMU-2. These were obtained from California sea lions (Zalophus californianus) and walruses (Odobenus rosmarus) presenting with loose stools. A phylogenetic analysis revealed that the CP of AstroV-HMU-1 closely clustered with Mamastrovirus 11 while its RNA-dependent RNA polymerase (RdRp) and serine protease (SP) were closely related to the mink astrovirus in the genus Mamastrovirus. The genome of AstroV-HMU-1 provided basic information regarding the NS protein regions of Mamastrovirus 11. Recombination analyses showed that the genomes of Z. californianus AstroV-HMU-1, VA2/human and the mink astrovirus may have recombined long ago. The NS of AstroV-like-HMU-2 segregated from the Astroviridae in the deep root of the phylogenetic tree and exhibited 36% amino acid identity with other mamastroviruses. Thus, AstroV-like-HMU-2 was proposed as a member of a new genus in the unclassified Astroviridae. The present study suggested that that the loose stools of pinnipeds may be the result of occasional infection by this novel astrovirus. This discovery provides a scientific basis for future investigations into other animal-borne infectious diseases.

Solid-state hydrogen storage is the best choice for balancing economy and safety among various hydrogen storage technologies, and hydrogen storage in the secondary phase might be a promising solid-state hydrogen storage scheme. In the current study, to unmask its physical mechanisms and details, a thermodynamically consistent phase-field framework is built for the first time to model hydrogen trapping, enrichment, and storage in the secondary phases of alloys. The hydrogen trapping processes, together with hydrogen charging, are numerically simulated using the implicit iterative algorithm of the self-defined finite elements. Some important results are attained: 1. Hydrogen can overcome the energy barrier under the assistance of the local elastic driving force and then spontaneously enter the trap site from the lattice site. The high binding energy makes it difficult for the trapped hydrogens to escape. 2. The secondary phase geometry stress concentration significantly induces the hydrogen to overcome the energy barrier. 3. The manipulation of the geometry, volume fraction, dimension, and type of the secondary phases is capable of dictating the tradeoff between the hydrogen storage capacity and the hydrogen charging rate. The new hydrogen storage scheme, together with the material design ideology, promises a viable path toward the optimization of critical hydrogen storage and transport for the hydrogen economy.

The transition areas of riverine, estuarine, and marine environments are particularly valuable for the research of microbial ecology, biogeochemical processes, and other physical–chemical studies. Although a large number of microbial-related studies have been conducted within such systems, the vast majority of sampling have been conducted over a large span of time and distance, which may lead to separate batches of samples receiving interference from different factors, thus increasing or decreasing the variability between samples to some extent. In this study, a new in situ filtration system was used to collect membrane samples from six different sampling sites along the Sanya River, from upstream freshwater to the sea, over a nine-hour period. We used high-throughput sequencing of 16S and 18S rRNA genes to analyze the diversity and composition of prokaryotic and eukaryotic communities. The results showed that the structures of these communities varied according to the different sampling sites. The α-diversity of the prokaryotic and eukaryotic communities both decreased gradually along the downstream course. The structural composition of prokaryotic and eukaryotic communities changed continuously with the direction of river flow; for example, the relative abundances of Rhodobacteraceae and Flavobacteriaceae increased with distance downstream, while Sporichthyaceae and Comamonadaceae decreased. Some prokaryotic taxa, such as Phycisphaeraceae and Chromobacteriaceae, were present nearly exclusively in pure freshwater environments, while some additional prokaryotic taxa, including the SAR86 clade, Clade I, AEGEAN-169 marine group, and Actinomarinaceae, were barely present in pure freshwater environments. The eukaryotic communities were mainly composed of the Chlorellales X, Chlamydomonadales X, Sphaeropleales X, Trebouxiophyceae XX, Annelida XX, and Heteroconchia. The prokaryotic and eukaryotic communities were split into abundant, common, and rare communities for NCM analysis, respectively, and the results showed that assembly of the rare community assembly was more impacted by stochastic processes and less restricted by species dispersal than that of abundant and common microbial communities for both prokaryotes and eukaryotes. Overall, this study provides a valuable reference and new perspectives on microbial ecology during the transition from freshwater rivers to estuaries and the sea.

The primary objective of the present study was to investigate the impact of wall film on the combustion characteristics of premixed flames in internal combustion engines through the joint experimental and numerical techniques. The interaction between the premixed methane-air flame and n-dodecane film attached to the wall of a constant volume combustion bomb was experimentally examined. The flame propagation processes, as well as pressure evolution were quantitatively characterized. Then, computational fluid dynamic (CFD) simulation was performed incorporating the combustion chemistry model. To enable efficient simulation of the chemically reacting flow in engine chambers, a simplified modeling approach based on a two-step reaction scheme was developed. A compact reaction model for the selected model fuel n-dodecane was constructed and reduced to include 35 chemical species and 180 reactions. The flame propagation process of the premixed flame and its interaction with dry and wet walls was studied. The results showed that the propagation of the premixed flame could be divided into four stages, and the existence of the slit structure increased the instability of the flame structure in the near-wall region. The wall film tended to promote emissions, producing more unburned hydrocarbons, soot precursors and aldehydes.

The microbial communities of the hydrothermal Scaly-foot Snails (SFSs) from independent hydrothermal vent fields have not been investigated in depth. In this study, we collected SFSs from two different hydrothermal environments located on the Central Indian Ridge (CIR) and the Southwest Indian Ridge (SWIR), the Kairei and Longqi vent fields, respectively. Additionally, one SFS collected from the Kairei vent field was reared for 16 days with in situ deep-sea seawater. The epibiotic and internal samples of SFSs, including ctenidium, esophageal gland, visceral mass, shells, and scales, were examined for microbial community compositions based on the 16S rRNA gene. Our results revealed significant differences in microbial community composition between SFSs samples collected from Kairei and Longqi vent fields. Moreover, the microbial communities of epibiotic and internal SFS samples also exhibited significant differences. Epibiotic SFS samples were dominated by the bacterial lineages of Sulfurovaceae, Desulfobulbaceae, Flavobacteriaceae, and Campylobacteraceae. While in the internal SFS samples, the genus Candidatus Thiobios, affiliated with the Chromatiaceae, was the most dominant bacterial lineage. Furthermore, the core microbial communities of all samples, which accounted for 78 ∼ 92% of sequences, were dominated by Chromatiaceae (27 ∼ 49%), Sulfurovaceae (10 ∼ 35%), Desulfobulbaceae (2 ∼ 7%), and Flavobacteriaceae (3 ∼ 7%) at the family level. Based on the results of random forest analysis, we also found the genera Desulfobulbus and Sulfurovum were the primary bacterial lineages responsible for the dissimilarity of microbial communities between the SFS samples collected from the Kairei and Longqi vent fields. Our results indicated that the microbial lineages involved in the sulfur cycle were the key microorganisms, playing a crucial role in the hydrothermal vent ecosystems. Our findings expand current knowledge on microbial diversity and composition in the epibiotic and internal microbial communities of SFS collected from different hydrothermal vent fields.

Despite an increasing appreciation in the importance of host–microbe interactions in ecological and evolutionary processes, information on the gut microbial communities of some marine mammals is still lacking. Moreover, whether diet, environment, or host phylogeny has the greatest impact on microbial community structure is still unknown. To fill part of this knowledge gap, we exploited a natural experiment provided by an aquarium with belugas (Delphinapterus leucas) affiliated with family Monodontidae, Pacific white-sided dolphins (Lagenorhynchus obliquidens) and common bottlenose dolphin (Tursiops truncatus) affiliated with family Delphinidae, and Cape fur seals (Arctocephalus pusillus pusillus) affiliated with family Otariidae. Results show significant differences in microbial community composition of whales, dolphins, and fur seals and indicate that host phylogeny (family level) plays the most important role in shaping the microbial communities, rather than food and environment. In general, the gut microbial communities of dolphins had significantly lower diversity compared to that of whales and fur seals. Overall, the gut microbial communities were mainly composed of Firmicutes and Gammaproteobacteria, together with some from Bacteroidetes, Fusobacteria, and Epsilonbacteraeota. However, specific bacterial lineages were differentially distributed among the marine mammal groups. For instance, Lachnospiraceae, Ruminococcaceae, and Peptostreptococcaceae were the dominant bacterial lineages in the gut of belugas, while for Cape fur seals, Moraxellaceae and Bacteroidaceae were the main bacterial lineages. Moreover, gut microbial communities in both Pacific white-sided dolphins and common bottlenose dolphins were dominated by a number of pathogenic bacteria, including Clostridium perfringens, Vibrio fluvialis, and Morganella morganii, reflecting the poor health condition of these animals. Although there is a growing recognition of the role microorganisms play in the gut of marine mammals, current knowledge about these microbial communities is still severely lacking. Large-scale research studies should be undertaken to reveal the roles played by the gut microbiota of different marine mammal species.

Hadal trenches have higher microbial carbon turnover rates as compared to adjacent abyssal plains. However, the source of organic carbon in the trench remains enigmatic. In this study, we show that a fraction of organic carbon is possibly derived in situ and correlated with chemoautotrophic communities supported by the fluid discharge of water-rock interaction in the trench wall, based on analysis of glycerol dialkyl glycerol tetraether (GDGT) membrane lipids, including archaeal isoprenoid GDGTs (IsoGDGTs) and bacterial branched GDGTs (BrGDGTs), in sediments and rocks of the Mariana and Yap Trenches, northwest Pacific Ocean. These trench sediments contained relative higher BrGDGTs ratios, which was a rare observation in the open ocean. The BrGDGT-to-IsoGDGT ratios ranged in 0.02–0.88 (mean = 0.10 ± 0.11) in sediments and 0.09–0.38 (mean = 0.17 ± 0.13) in altered rocks. The calculated values of branched and isoprenoid tetraether (BIT) index ranged from 0.02–0.73 (mean = 0.18 ± 0.11) in sediments and from 0.16–0.9 in altered rocks (mean = 0.37 ± 0.27). Moreover, these GDGTs exhibited similar characteristics to those of altered basalt rocks, indicating inputs of organic carbon from the trench subsurface environment. Thus, in addition to organic-rich material settling, we propose chemoautotrophic activity in oceanic crust could be an additional source of organic carbon in the deepest part of the ocean, with an important role in deep-sea carbon cycles.

The distribution and succession of microbial communities along the dispersion path of hydrothermal plumes has not been well investigated. In this study, we collected several types of samples from the Longqi hydrothermal field located on the Southwest Indian Ridge, including hydrothermal plumes at different stages of formation, a suite of water column samples across the non-buoyant hydrothermal plumes above this field, and a background seawater column approximately 350 km away from the hydrothermal field. Using CH4 concentration anomalies, three non-buoyant plume samples between 2,535 and 2,735 m were identified within the water column. Microbial community compositions within these plumes and background seawater samples were examined based on the 16S rRNA genes and revealed significant variations and successions in community composition between different portions of the hydrothermal plumes. Near the vent orifice, representing the initial stage of plume formation, microbial populations were characterized by abundant and diverse putative vent-associated communities including (hyper)thermophiles such as Aquificaceae and Hydrogenothermaceae within the phylum Aquificae, and some epsilonproteobacterial chemolithoautotrophs such as Sulfurovum, Sulfurimonas, and Caminibacter. By contrast, in the rising buoyant plumes and adjacent seawaters, most vent-associated microbial taxa were still present but made only minor contributions to community composition. Some microbial taxa that are common in seawater columns such as alphaproteobacterial Sphingomonadaceae and SAR11 clade, deltaproteobacterial SAR324 clade, and gammaproteobacterial Pseudomonas, together with Sulfurimonas and SUP05 clade, became predominant. Members within the Sulfurimonas and SUP05 clade flourished with considerable abundance in the non-buoyant plumes, although these plumes were mainly composed of alphaproteobacterial Rhodobacteraceae, gammaproteobacterial Alteromonadaceae and Saccharospirillaceae putatively derived from the surrounding ambient seawater. We also analyzed archaeal components in the initial discharge and rising buoyant plume stages, with both primarily consisting of thaumarchaeal Nitrosopumilales and euryarchaeal Marine Group II. Our results indicated that being characteristic microbial lineages within the hydrothermal plumes of the Southwest Indian Ridge, both Sulfurimonas and SUP05 clade display a common and abundant distribution across the plume path. However, out of these clades, Sulfurimonas is more abundant and widespread.

Orientations, roughnesses, and cavities of crystals are typical factors influencing the servicing reliability of metals in corrosive environments. A phase-field scheme for modeling stress-corrosion coupled damage (SCCD) is developed. The effects of the crystal factors on SCCD are numerically simulated using the incremental-iterative scheme of the user-defined finite elements. The impacts of orientations, roughnesses, and cavities on the corrosion rate of magnesium (Mg) in corrosive environments are discussed quantitatively. It is found that crystal textures and surface roughnesses can significantly influence the diffusion-controlled corrosion rate. Strong basal texture and a smooth surface of the crystal can significantly enhance the corrosion resistance of Mg. The cavity, as a typical crystal defect, is capable of inducing the damage path and modulating the corrosion rate. The design of crystal-scale features, such as orientations, roughnesses, and cavities, is promising for the enhancement of the resistance to SCCD.

Although gut microbes are regarded as a significant component of many mammals and play a very important role, there is a paucity of knowledge around marine mammal gut microbes, which may be due to sampling difficulties. Moreover, to date, there are very few, if any, reports on the gut microbes of melon-headed whales. In this study, we opportunistically collected fecal samples from eight stranded melon-headed whales (Peponocephala electra) in China. Using high-throughput sequencing technology of partial 16S rRNA gene sequences, we demonstrate that the main taxa of melon-headed whale gut microbes are Firmicutes, Fusobacteriota, Bacteroidota, and Proteobacteria (Gamma) at the phylum taxonomic level, and Cetobacterium, Bacteroides, Clostridium sensu stricto, and Enterococcus at the genus taxonomic level. Meanwhile, molecular ecological network analysis (MENA) shows that two modules (a set of nodes that have strong interactions) constitute the gut microbial community network of melon-headed whales. Module 1 is mainly composed of Bacteroides, while Module 2 comprises Cetobacterium and Enterococcus, and the network keystone genera are Corynebacterium, Alcaligenes, Acinetobacter, and Flavobacterium. Furthermore, by predicting the functions of the gut microbial community through PICRUSt2, we found that although there are differences in the composition of the gut microbial community in different individuals, the predicted functional profiles are similar. Our study gives a preliminary inside look into the composition of the gut microbiota of stranded melon-headed whales.

Coral reefs are an important part of the ocean ecosystem and are a vital spawning ground for marine fish. Microorganisms are abundant in this environment and play a key role in the growth and development of host species. Many studies have investigated the microbial communities of fish with a focus on the intestinal microbiome of laboratory-reared adult fish. Little is known about the relationship between fish eggs and their microorganisms, especially as microbial communities relate to wild fish eggs in coral reefs. In this study, we analyzed the microbial communities of two species of coral fish eggs, Acanthopagrus schlegelii and Halichoeres nigrescens, using 16S rRNA gene amplicon sequencing technology. Pseudomonas, Archromobacter, and Serratia were the main bacterial genera associated with these fish eggs and are known to be bacteria with potentially pathogenic and spoilage effects. The microbial community structures of Acanthopagrus schlegelii and Halichoeres nigrescens eggs were separated based on the 30 most abundant operational taxonomic units (OTUs). Principal coordinate analysis (PCoA) and non-metric multidimensional scaling analysis (NMDS) further confirmed that the microbial communities of coral fish eggs differ by species, which may be due to host selection. A functional prediction of the microbial communities indicated that most of the microbial communities were chemoheterotrophic and involved in nitrogen cycling. Our results showed that the microbial communities of coral fish eggs were distinct by species and that key microorganisms were potentially pathogenic, leading to the spoilage of fish eggs, high mortality, and low incubation rates. This study provided new insights for understanding the relationship between microorganisms and wild fish eggs.

Understanding the underlying mechanism that drives the microbial community mediated by substrates is crucial to enhance the biostimulation in trichloroethene (TCE)-contaminated sites. Here, we investigated the performance of stable TCE-dechlorinating consortia by monitoring the variations in TCE-related metabolites and explored their underlying assembly mechanisms using 16S rDNA amplicon sequencing and bioinformatics analyses. The monitoring results indicated that three stable TCE-dechlorinating consortia were successfully enriched by lactate-containing anaerobic media. The statistical analysis results demonstrated that the microbial communities of the enrichment cultures changed along with time and were distinguished by their sample sources. The deterministic and stochastic processes were simultaneously responsible for shaping the TCE-dechlorinating community assembly. The indicator patterns shifted with the exhaustion of the carbon source and the pollutants, and the tceA-carrying Dehalococcoides, as an indicator for the final stage samples, responded positively to TCE removal during the incubation period. Pseudomonas, Desulforhabdus, Desulfovibrio and Methanofollis were identified as keystone populations in the TCE-dechlorinating process by co-occurrence network analysis. The results of this study indicate that lactate can be an effective substrate for stimulated bioremediation of TCE-contaminated sites, and the reduction of the stochastic forces or enhancement of the deterministic interventions may promote more effective biostimulation.

Microbe plays an important role in driving biogeochemical cycles, thus it is of great interest to understand microbial responses and feedbacks to global changes. We have recently analyzed functional potentials of soil microbial community via a high-throughput, microarray-based metagenomic tool named GeoChip 3.0 to illustrate microbial responses to global changes simulated by soil transplant and/or maize cropping. Here we describe detailed experimental design, data collection and pre-processing to support our published studies by Liu et al. [5] and Zhao et al. [14].

Harmful algal blooms occur all over the world, destroying aquatic ecosystems and threatening other organisms. The culture supernatant of the marine algicidal actinomycete BS01 was able to lysis dinoflagellate Alexandrium tamarense ATGD98-006. Physiological and biochemical responses to oxidative stress in A. tamarense were investigated to elucidate the mechanism involved in BS01 inhibition of algal growth. Transmission electron microscope analysis revealed that there were some chloroplast abnormalities in response to BS01 supernatant. The decrease in cellular-soluble protein content suggested that cell growth was greatly inhibited at high concentration of BS01 supernatant. The increase in the levels of reactive oxygen species (ROS) and malondialdehyde contents following exposure to BS01 supernatant indicated that algal cells suffered from oxidative damage. The content of pigment was significantly decreased after 12 h treatment, which indicated that the accumulation of ROS destroyed pigment synthesis. Moreover, the decrease of Fv/Fm ratio suggested that in the photosynthetic system, the dominant sites producing ROS were destroyed by the supernatant of the BS01 culture. The activities of the antioxidant enzymes including superoxide dismutase and peroxidase increased in a short time and decreased slightly with increasing exposure time. A real-time PCR assay showed changes in the transcript abundances of two photosynthetic genes, psbA and psbD. The results showed that BS01 supernatant reduced the expression of the psbA gene after 2 h exposure, but the expression of the psbD gene was increased at concentrations of 1.0 and 1.5%. Our results demonstrated that the expression of the psbA gene was inhibited by the BS01 supernatant, which might block the electron transport chain, significantly enhancing ROS level and excess activity of the antioxidant system. The accumulation of ROS destoryed pigment synthesis and membrane integrity, and inhibited or ultimately killed the algal cells.

With the popularization of late-maturing and high-yielding maize (Zea mays L.) hybrids, high kernel moisture concentration at the usual harvest time has resulted in increased kernel breakage and additional drying costs. To achieve low kernel moisture at harvest in China's maize-growing areas, there is a need for the selection of fast dry-down hybrids and the prediction of the ideal harvest time. During 2014-2017, the time-series kernel moisture concentrations of three maize hybrids were measured in the field in three major maize-producing regions in China. Our goal was to accurately predict maize kernel dry-down in the field. We found that the Logistic Power model M = 90/[1 + (T/a)b] could be used to accurately predict the entire dry-down process of maize kernels across hybrids and regions (concordance correlation coefficient, 0.884-0.996; RMSE, 2.76-5.16%; R², .943-.986; and coefficient of residual mass, -0.09-0.14), where M is the kernel moisture concentration (wet basis), a and b are parameters that reflect the dry-down characteristics of the hybrids, and T is the thermal time (°C d) from silking based on mean daily temperature over the periods of grain-filling and grain-drying. This work provides a new and convenient model for predicting kernel moisture concentration and evaluating the dry-down characteristics of hybrids using parameters a and b. [ABSTRACT FROM AUTHOR]