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Diatom blooms can significantly affect the succession of microbial communities, yet little is known about the assembly processes and interactions of microbial communities during autumn bloom events. In this study, we investigated the ecological effects of an autumn diatom bloom on prokaryotic communities (PCCs) and microeukaryotic communities (MECs), focusing on their assembly processes and interactions. The PCCs were largely dominated by Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria, and Flavobacteria, while the MECs primarily included Diatomea, Dinoflagellata, and Chlorophyta. The succession of both PCCs and MECs was mainly driven by this diatom bloom and environmental factors, such as nitrate and silicate. Null modeling revealed that homogeneous selection had a more pronounced impact on the structure of PCCs compared with that of MECs. In particular, drift and dispersal limitation cannot be neglected in the assembly processes of MECs. Co-occurrence network analyses showed that Litorimicrobium, Cercozoa, Marine Group I (MGI), Cryptomonadales, Myrionecta, and Micromonas may affect the bloom process. In summary, these results elucidated the complex, robust interactions and obviously distinct assembly mechanisms of PCCs and MECs during a diatom bloom and extend our current comprehension of the ecological mechanisms and microbial interactions involved in an autumn diatom bloom process. [ABSTRACT FROM AUTHOR]

Probiotics have emerged as promising alternatives to antibiotics for maintaining the health of the Chinese mitten crab (CMC, Eriocheir sinensis). However, the efficacy of probiotic application in CMC culture ecosystems remains uncertain. Intestinal microbiota is often as comprehensive indicators of aquatic animal health, but the effects of probiotics on CMC intestinal microbiota remain poorly understood. In this study, we used 16S rRNA gene amplicon sequencing to investigate the mechanisms underlying the changes of the intestinal microbial communities following short‐term probiotic application in CMC culture. Our data showed there was poor probiotic colonization in the intestines of pond‐cultured CMCs. The short‐term application of probiotics had no significant impact on the alpha‐diversity for the microbial communities; however, it significantly changed the beta‐diversity. Remarkably, the probiotics promoted butanoate metabolism of the CMC intestinal microbiota. According to network analysis, the microbiome of the CMC intestine manifested rapid responses to probiotic application, and cooperation between intestinal microbial communities may have been enhanced. Taken together, our results provide preliminary insights into the roles of probiotics in the CMC intestinal microbial ecosystem. [ABSTRACT FROM AUTHOR]

The survival pattern of Escherichia coli O157:H7 (E. coli O157:H7) and its regulatory factors in natural environments have been widely studied. However, there is little information about the survival of E. coli O157:H7 in artificial environments, especially in wastewater treatment facilities. In this study, a contamination experiment was performed to explore the survival pattern of E. coli O157:H7 and its central control factors in two constructed wetlands (CWs) under different hydraulic loading rates (HLRs). The results showed that the survival time of E. coli O157:H7 was longer in the CW under the higher HLR. Substrate ammonium nitrogen and available phosphorus were the main factors that influenced the survival of E. coli O157:H7 in CWs. Despite the minimal effect of microbial α-diversity, some keystone taxa, such as Aeromonas , Selenomonas , and Paramecium , governed the survival of E. coli O157:H7. In addition, the prokaryotic community had a more significant impact on the survival of E. coli O157:H7 than the eukaryotic community. The biotic properties had a more substantial direct power on the survival of E. coli O157:H7 than the abiotic factors in CWs. Collectively, this study comprehensively disclosed the survival pattern of E. coli O157:H7 in CWs, which is an essential addition to the environmental behavior of E. coli O157:H7, providing a theoretical basis for the prevention and control of biological contamination in wastewater treatment processes. [Display omitted] • It is the first time to study the survival of E. coli O157:H7 in CWs. • The survival time of E. coli O157:H7 is longer in H-CW than in L-CW. • NH 4 +-N and AP essentially impact the survival of E. coli O157:H7 in CWs. • Specific keystone taxa regulate the survival of E. coli O157:H7 in CWs. • The biotic properties more affect the survival of E. coli O157:H7 in CWs. [ABSTRACT FROM AUTHOR]

• A global meta-analysis of microbial community to increased salinity. • Significant reduction of prokaryotic alpha-diversity with increased salinity. • High salt concentrations enhanced Bacteroidetes and Proteobacteria. • Saline environment promoted Ascomycota but restrained Basidiomycota. • Importance of high-salinity microbes in regulating nutrient and energy flow. Soil salinity can affect microbial activities and community structure, with broader implications for carbon storage and mineralization. However, a consensus on how soil microbial communities respond to elevated salinity has yet to be reached. With the increasing salinization of coastal lowlands, a comprehensive assessment of salinity-driven microbial community shifts is crucial for understanding and predicting shifts of biogeochemical processes in response to soil salinization. Here, we conducted a meta -analysis of 21 studies to investigate the changes in soil microbial communities along salinity gradients. We found a significant reduction of prokaryotic alpha-diversity indices with increasing salinity. Prokaryotic beta-diversity was altered by elevated salinity, but significant differences were only found between samples at < 1 and > 10 ppt salinity. Compared to non-saline conditions, high salt concentrations increased the relative abundance of Bacteroidetes and Proteobacteria by 17–19%, especially that of Alphaproteobacteria and Gammaproteobacteria, but generally inhibited the rest of the dominant phyla and classes. For fungi, Ascomycota was 1.3-fold more abundant in saline environments than in non-saline environments, but Basidiomycota was 21% less. This meta-analysis reveals significant changes of microbial community composition responding to environmental salinization. With strong biodiversity reduction under saline conditions, these dominant microbial groups with high-salinity niche preference will play a stronger role in regulating nutrient and energy flow, and constraining SOC dynamics. [ABSTRACT FROM AUTHOR]

• Microbiota and nutrients removal are studied in pilot-scale CWs with two HLRs. • HLR profoundly influences microbiota at the genus level and related removal efficiency. • The co-occurrence network shows microbiota becomes more complex under higher HLR. • A higher level of stochasticity is found in the microbiota under the higher HLR condition. • Pathogens invasion is observed in the endosphere and proved to be affected by HLR. Constructed wetland (CW) is an environment-friendly and low-cost technology for nutrients removal from domestic wastewater. For a well-tuned CW, hydraulic loading rate (HLR) is one of the critical factors, particularly under the challenging circumstance of more frequent heavy rainfall events brought by global warming. In this study, a comprehensive investigation was conducted to explore the influence of different HLRs on the CW's bulk substrate and root-associated microbiota aiming to yield new insight for CW management from a hybrid perspective of environmental microbiology and engineering science. The response of the microbial community and associated nutrients removal performance under different HLR settings were analyzed after a one-year operation. Results showed that the bulk substrate and rhizosphere genera involved in desulfurization and denitrification, such as Ferritrophicum, Sulfurimonas, and Sulfurisoma , were enriched in the higher HLR condition and associated with the higher total nitrogen (TN) and nitrate nitrogen (NO 3 −-N) removal compared to the lower HLR condition. Co-occurrence network analysis demonstrated a more complex network under the higher HLR condition. Besides, it was observed that more stochastic in microbial assembly under the higher HLR condition. Surprisingly, zoonotic pathogens were observed and showed a greater prevalence under the higher HLR condition, indicating the potential correlation between HLR and pathogen intrusion. Collectively, this study revealed that the microbiota could be significantly altered under different HLR conditions, thereby resulting in differences in nutrients removal performance. [Display omitted] [ABSTRACT FROM AUTHOR]