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Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp (Litopenaeus vannamei) to utilize Chlorella sorokiniana (CHL), a 3 × 2 factorial design stocking experiment was used in this study. Specifically, shrimp was fed with two dietary protein sources (fishmeal [FM] and CHL) at low (LSD; 100 per m3), medium (MSD; 200 per m3) and high (HSD; 300 per m3) stocking densities for 8 weeks. The growth performance and resistance to Vibrio parahaemolyticus (1.0 × 107 CFU/mL) of shrimp decreased with the increase of stocking density, but dietary CHL improved this result. Differences between the CHL and FM groups for V. parahaemolyticus resistance were significant only under high-density conditions (P

Background and aims: The diversity and stability of belowground microbiota communities influence plant health. However, changes over time in the microbiome composition associated with healthy and diseased trees remains poorly understood. The goal of this study is to understand the changes in belowground microbial community associated with Verticillium wilt of smoke trees to provide a basis for the combination of biological agents and chemical measures to combat Verticillium wilt of smoke trees. Methods: In this study, we used an amplicon-based approach to reveal distinct differences in the diversity, structure and composition of the belowground microbial communities of healthy and diseased smoke trees from June to October. Results: The structure, composition and interactions of the belowground microbial communities are different between healthy and diseased smoke trees from June to October. The co-occurrence networks of the belowground microbial community changed with the severity of the disease over time. Additionally, the structural community of healthy and diseased trees showed a shift in keystone OTUs. Conclusions: This study improves our understanding of the belowground microbial community composition associated with smoke trees in healthy and diseased conditions, offering the potential to both manipulate the plant microbiome to promote plant health and to provide an integrated management strategy of smoke tree. [ABSTRACT FROM AUTHOR]

In order to analyze the effect of baicalin on intestinal microbiota (IM) of obese mice induced by highfat diet (HFD), four groups of mice, i.e., normal control group, HFD group, baicalin-treated group of normal control, and baicalin-treated group of HFD, were set up. After 12 weeks of treatment, the mice's body weight, insulin sensitivity, liver histopathological analysis and immunohistochemical analysis were measured. Combining with high-throughput sequencing of IM 16S rRNA gene, the characteristics of obesity induced by HFD and the therapeutic effect of baicalin on obese mice induced by HFD were explored. HFD significantly increased mice body weight, insulin resistance, liver fat accumulation, and the number of macrophages and T cells in the liver, and significantly changed the structure of obese mice IM. Baicalin treatment significantly reduced the weight and insulin resistance of obese mice induced by HFD, liver fat accumulation, and the number of macrophages and T cells, and significantly changed the structure of IM. This study provided reference data for understanding the effect of baicalin on IM composition and metabolism in the treatment of obesity caused by HFD, and helped us to understand the effect of chemicals on IM and its potential effect on host metabolism. [ABSTRACT FROM AUTHOR]

Objective: To examine gut microbiotal diversity in the Han Chinese and Yugur populations of Sunan County, Gansu Province, living in the same environmental conditions, and to analyze possible causes of differences in diversity. Methods: We selected 28 people, ages 18–45 years old, all of whom were third-generation pure Yugur or Han Chinese from Sunan County. Fresh fecal samples were collected, and total bacterial deoxyribonucleic acid (DNA) was extracted. We performed 16S ribosomal ribonucleic acid (16S rRNA) high-throughput sequencing (HTS) and bioinformatics to study the relationships among between gut microbiota structure, genetics, and dietary habits in Yugur and Han Chinese subjects. Results: We found 350 differential operational taxonomic units (OTUs) in Han Chinese and Yugur gut microbiota, proving that gut microbiota differed between the two populations. That were less abundant among Yugurs than Han Chinese were Prevotella_9 and Alloprevotella. That were more abundant among Yugurs than Han Chinese were Anaerostipes and Christensenellaceae_R-7_group. And they were significantly associated with a high-calorie diet In addition. we found differences in predicted gut microbiota structural functions (The main functions were metabolic and genetic information) between the two populations. Conclusion: Yugur subjects demonstrated differences in gut microbiotal structure from Han Chinese subjects, and this difference influenced by dietary and may be influenced by genetic influences. This finding will provide a fundamental basis for further study of the relationships among gut microbiota, dietary factors, and disease in Sunan County. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chinese steamed bread (CSB) is a popular staple food in China with traditional ethnic characteristics. CSB with traditional starters has good flavor and texture but is unstable and requires a long preparation time. Therefore, it is necessary to analyze the traditional starters (ST) and their influence on the flavor and quality of steamed bread to meet people's requirements as a staple food. RESULTS: The count of yeast, lactic acid bacteria and total microbial population significantly varied in different traditional starters; Saccharomyces and Lactobacillus were the predominant genera. Among the tested samples, fungi were found in ST from Shijiazhuang (SJ), Handan (HD) and Langfang (LF), while bacteria were found in ST from Tangshan (TS) and SJ at sub‐predominant levels. In terms of the bread quality, the highest specific volume and porosity were in XT‐CSB (Xingtai); the highest height/diameter ratio was in SJ‐CSB; and the highest sensory score was in TS‐CSB. A total of 26 aroma compounds (VIP > 1; variable importance for predictive components) were identified to discriminate CSB fermented with different starters, which were separated by stepwise canonical discriminant analysis using two functions. The correlation analysis among microbiota, aroma compounds and bread quality showed a higher contribution of bacteria than of fungi. CONCLUSION: Differences in microbial profiles caused different aroma profiles and quality of CSB; and the CSB fermented with traditional starters were sufficiently separated by stepwise canonical discriminant analysis based on aroma compounds. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Conversion of wastewater treatment plants into biorefineries is a sustainable alternative for obtaining valuable compounds, thus reducing pollutants and costs and protecting the environment and human health. Under specific operating conditions, microbial fermentative products of sewage sludge are volatile fatty acids (VFA) that can be precursors of polyhydroxyalkanoate thermoplastic polyesters. The role of various operating parameters in VFA production has yet to be elucidated. This study aimed to correlate the levels of VFA yields with prokaryotic microbiota structures of sewage sludge in two sets of batch fermentations with an initial pH of 8 and 10. The sewage sludge used to inoculate the batch fermentations was collected from a Sicilian WWTP located in Marineo (Italy) as a case study. Gas chromatography analysis revealed that initial pH 10 stimulated chemical oxygen demands (sCOD) and VFA yields (2020 mg COD/L) in comparison with initial pH 8. Characterization of the sewage sludge prokaryotic community structures—analyzed by next-generation sequencing of 16S rRNA gene amplicons—demonstrated that the improved yield of VFA paralleled the increased abundance of fermenting bacteria belonging to Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes phyla and, conversely, the reduced abundance of VFA-degrading strains, such as archaeal methanogens. [ABSTRACT FROM AUTHOR]

Objective: To reflect the potential and intrinsic association among microbiota structure, antibiotic resistance genes distribution and biological toxicity of landfill-leachate according to seasonal change, and accurately assess the potential threat of leachate to the surrounding environment. Methods: On the basis of the leachate water quality monitoring data from January to December 2020, principal component analysis (PCA) was used to identify the main pollutants in the leachate; Vibrio fischeri luminescence inhibition test was used to detect the comprehensive biotoxicity of the leachate; 16S rDNA amplicon sequencing was used for leachate microbiota. q-PCR was used to detect the class 1 integron (intI1), and eight antibiotic resistance genes (sul1, sul2, tetA, tetB, tetM, tetQ, mefA, and mexF); Canonical correspondence (CCA) analysis was carried out for the association analysis. Result: The biotoxicity of leachate in the second quarter was the highest. The dominant phylum of leachate microbiota from 1st quarters to 4th quarters was Proteobacteria (94.97 %, 85.43 %, 88.20 %, and 84.11 %), and the dominant genera were Thiomonas (60.41 %, 26.83 %, 25.66 %, and 30.51 %), Pseudomonas (5.89 %, 1.86 %, 0.68 %, and 4.72 %), Desulfurella (8.52 %, 0.57 %, 3.81 %, and 8.25 %), and Acidithiobacillus (4.71 %, 0.69 %, 0.87 %, and 5.91 %); Nitrospirillum was negatively correlated with chemical oxygen demand (COD) (R=−0.561, P = 0.008) and five-day biochemical oxygen demand (BOD5) (R=−0.591, P = 0.005); Limnohabitans was positively correlated with pH (R=0.444, P = 0.044). Four AR genes (sul1, sul2，tetM, and tetQ) were detected in all the samples, while the second quarter had the highest concentration of sul1(6.31 ± 0.49 lg copies/ng DNA), tetM (3.01 ± 1.38 lg copies/ng DNA) and tetQ (3.64 ± 0.90 lg copies/ng DNA). Conclusion: As the mature landfill, the quality of this leachate met the pollution control standards for domestic waste landfills. Thiomycetes, Pseudomonas, Desulfurization, and Thiopterus acidophyllum constitute the dominant microbiota. However, leachate in the second quarter had more serious contamination, the higher biotoxicity, higher concentration of AR genes, together with higher microbiota richness and diversity, which deserved more attention for the potential threat to the surrounding environment.

With the rapid development of intensive farming mode and the high price of fishmeal (FM), finding alternatives to FM and exploring the application under different stocking densities has become a focus of current research in aquaculture. In this research, the ability of Pacific white shrimp (Litopenaeus vannamei) to utilize Clostridium autoethanogenum protein (CAP) at different stocking densities was investigated from the aspects of growth, disease resistance, intestinal health and transcriptome response. A 3 × 2 factorial design stocking experiment was conducted, using L. vannamei fed diets of two protein sources (FM and CAP) at three stocking densities with 100 per m3 (low, LSD), 200 per m3 (medium, MSD) and 300 per m3 (high, HSD) for 8 weeks. At the end of the feeding trail, the growth performance and the resistance to Vibrio parahaemolyticus of shrimp decreased with the increase of stocking density, and dietary CAP could promote the effects at the same stocking density when compared with the FM group, with more notable enhancement effect at high stocking density was observed. There was a significant interaction between stocking density and protein source on the activities of alkaline phosphatase (AKP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), catalase (CAT), superoxide dismutase (SOD), lysozyme (LYS), amylase and lipase, most of which were significantly different between CAP and FM groups only at high stocking density. Analysis of 16S rDNA sequencing showed that dietary CAP increased the alpha diversity of intestinal microbiota, inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria. Transcriptomics results showed that DEGs in the FM vs CAP group at the same stocking densities were mainly enriched in immune and metabolism-related pathways including Toll and Imd, PI3K-Akt, and JAK/STAT signaling pathway. Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs, also more were detected under high density situations. In conclusion, dietary CAP could not only promote the growth of shrimp, but also improves the immunity and metabolism, and maintains the intestinal health of shrimp when compared with dietary FM, along with more pronounced improvement effect at high-density stocking. The results implied that CAP had a great potential as a novel protein source in shrimp intensive aquaculture. • Replacement of fishmeal with CAP significantly improved the growth performance of L. vannamei at high stocking densities. • Dietary CAP improves immunity, digestibility and optimizes the structure of the intestinal microbiota of L. vannamei. • Dietary CAP boosted immune/metabolic genes and intestinal bacteria synergy, enhancing L. vannamei health and growth. • CAP can be used as a safe and effective protein source for L. vannamei in intensive farming mode. [ABSTRACT FROM AUTHOR]

Understanding the composition of microorganismal communities hosted by insect pests is an important prerequisite for revealing their functions and developing new pest control strategies. Although studies of the structure of the microbiome of Nilaparvata lugens have been published, little is known about the dynamic changes in this microbiome across different developmental stages, and an understanding of the core microbiota is still lacking. In this study, we investigated the dynamic changes in bacteria and fungi in different developmental stages of N. lugens using high-throughput sequencing technology. We observed that the microbial diversity in eggs and mated adults was higher than that in nymphs and unmated adults. We also observed a notable strong correlation between fungal and bacterial α-diversity, which suggests that fungi and bacteria are closely linked and may perform functions collaboratively during the whole developmental period. Arsenophonus and Hirsutella were the predominant bacterial and fungal taxa, respectively. Bacteria were more conserved than fungi during the transmission of the microbiota between developmental stages. Compared with that in the nymph and unmated adult stages of N. lugens, the correlation between bacterial and fungal communities in the mated adult and egg stages was stronger. Moreover, the core microbiota across all developmental stages in N. lugens was identified, and there were more bacterial genera than fungal genera; notably, the core microbiota of eggs, nymphs, and mated and unmated adults showed distinctive functional enrichment. These findings highlight the potential value of further exploring microbial functions during different developmental stages and developing new pest management strategies. [ABSTRACT FROM AUTHOR]

Although intestinal microbiota is closely related to the growth of the host, it is still unclear how it affects the growth of white shrimp. To elucidate the potential processes of intestinal microbiota affecting white shrimp growth, in this study, we compared the intestinal microbiota compositions and metabolisms of larger (11.11 ± 0.32 g) and smaller (5.30 ± 0.06 g) individuals in the same batch of white shrimp cultured in the same environment through high-throughput sequencing of 16S rRNA gene. Our results showed that there was no significant difference in the composition of intestinal microbiota between larger and smaller white shrimps. However, Shewanella algae and Neptunomonas sp. were significantly enriched in the larger group, while Delftia sp., Hydrogenophaga sp., Pseudomonas sp., Synechococcus sp., Methylibium sp., Acidovorax sp., Limnohabitans sp., Burkholderia sp., Candidatus Koribacter sp., and Vogesella sp. were enriched in the smaller group. Moreover, the intestinal microbiota might promote the energy metabolism and growth of white shrimps through regulating their metabolic characteristics and switching their metabolisms from material synthesis to energy metabolisms. [ABSTRACT FROM AUTHOR]

Conversion of wastewater treatment plants into biorefineries is a sustainable alternative for obtaining valuable compounds, thus reducing pollutants and costs and protecting the environment and human health. Under specific operating conditions, microbial fermentative products of sewage sludge are volatile fatty acids (VFA) that can be precursors of polyhydroxyalkanoate thermoplastic polyesters. The role of various operating parameters in VFA production has yet to be elucidated. This study aimed to correlate the levels of VFA yields with prokaryotic microbiota structures of sewage sludge in two sets of batch fermentations with an initial pH of 8 and 10. The sewage sludge used to inoculate the batch fermentations was collected from a Sicilian WWTP located in Marineo (Italy) as a case study. Gas chromatography analysis revealed that initial pH 10 stimulated chemical oxygen demands (sCOD) and VFA yields (2020 mg COD/L) in comparison with initial pH 8. Characterization of the sewage sludge prokaryotic community structures—analyzed by next-generation sequencing of 16S rRNA gene amplicons—demonstrated that the improved yield of VFA paralleled the increased abundance of fermenting bacteria belonging to Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes phyla and, conversely, the reduced abundance of VFA-degrading strains, such as archaeal methanogens.

Aiming to investigate the impact of different stocking densities on the ability of Pacific white shrimp ( Litopenaeus vannamei ) to utilize Chlorella sorokiniana (CHL), a 3 × 2 factorial design stocking experiment was used in this study. Specifically, shrimp was fed with two dietary protein sources (fishmeal [FM] and CHL) at low (LSD; 100 per m 3 ), medium (MSD; 200 per m 3 ) and high (HSD; 300 per m 3 ) stocking densities for 8 weeks. The growth performance and resistance to Vibrio parahaemolyticus (1.0 × 10 7  CFU/mL) of shrimp decreased with the increase of stocking density, but dietary CHL improved this result. Differences between the CHL and FM groups for V . parahaemolyticus resistance were significant only under high-density conditions ( P  < 0.05). Significant interactions between stocking density and protein source were found on the activities of catalase (CAT), superoxide dismutase (SOD) and phenol oxidase (PO), and the contents of malondialdehyde (MDA) in the hepatopancreas and the activities of intestinal amylase, most of which were significantly different between CHL and FM groups only at high stocking density ( P  < 0.05). Analysis of 16S rDNA sequencing showed that dietary CHL increased the alpha diversity of intestinal microbiota, inhibited the colonization of pathogenic bacteria and enhanced the abundance of beneficial bacteria. Transcriptomic results showed that at high stocking densities, differentially expressed genes (DEGs) in the FM vs CHL group were mostly upregulated and primarily enriched in immune and metabolic related pathways including Toll, immune deficiency (Imd) and glycolysis-gluconeogenesis pathways. Pearson correlation analysis revealed significant correlation between the top ten intestinal bacteria at the genus level and markedly enriched DEGs, also more were detected under high density situations. In conclusion, CHL has great potential as a novel protein source in the intensive farming of shrimp., Competing Interests: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, and there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the content of this paper., (© 2024 The Authors.)

Gut microbes play an important role in host disease and health. The Asian honey bee Apis cerana is an important pollinator of agricultural crops in China. However, there are still few studies on the structure and composition of the microbiota in the intestine of A. cerana, especially A. cerana in Yunnan. To understand the species and composition of the microbiota in the intestine of A. cerana in Yunnan, we used high-throughput sequencing technology to carry out 16S rRNA sequencing on 50 samples from Kunming, Xishuangbanna and Mengzi. The results show that both from the phylum level and the genus level, the structure and abundance of the microbiota in the gut of A. cerana from the three regions tended to be the same. At the phylum level, the abundance of Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Acidobacteria and other species was high in A. cerana from different areas. At the genus level, the abundance of Lactobacillus, Gilliamella, Snodgrassella, Apibacter, Candidatus Schmidhempelia and other species was high in A. cerana from different areas. Due to its unique geographical environment and climatic conditions, at the genus level, the diversity of bacterial communities in Xishuangbanna was significantly lower than that in the other two regions, which was about 100 genera less. In conclusion, our results reveal the composition and structure of the intestinal microbiota of bees in Yunnan and deepen our understanding of the intestinal microbiota of bees. [ABSTRACT FROM AUTHOR]

The structure of intestinal microbiota of black rockfish Sebastes schlegelii in five early development stages were determined in high throughput sequencing with Illumina MiSeq PE300 system. The relationship between intestinal microbial community and the environmental (including culture water and feed) microbiota and the abundance variation trends of core microbiota were investigated, based on which the source of some core microbiota was analyzed in this study. The results show that Proteobacteria and Firmicutes are the most dominant phyla in guts. At the genus level, there are obvious differences between the artificial breeding fish and wild adults in the intestinal microflora structure. The compositions of dominant genera are similar, although the structure of intestinal microbiota gradually changes with the growth of larvae and juveniles. The core microbiota including Bacillus, Acinetobacter, Pseudomonas, Lactobacillus, Lactococcus, Glaciecola, Vibrio, Pseudoalteromonas, Acidovorax, and Aliivibrio were determined in the analysis of dominant and shared species. Compared with the water, the effect of feed microbiota on the structure of the gut microbial community is more obvious. Moreover, the trends of Bacillus, Acinetobacter, Pseudomonas, Lactobacillus, Lactococcus, and Glaciecola were opposite to Vibrio and Pseudoalteromonas in the gut. The correlation analysis suggested that Acidovorax, Glaciecola, Pseudomonas, Lactobacillus, and Acinetobacter might transited from mainly the parents and/or came from the fertilization process. The relative results may provide a theoretical reference for selecting the native probiotics, and supply the basic data for artificially regulating the intestinal microbiota with probiotic during early developmental stage of black rockfish. [ABSTRACT FROM AUTHOR]

Abstract Two oilfield-produced wastewater (OPW) plants, one grown through two-stage aerobic (O 1 /O 2) activated sludge process in North-China Oilfield (NCO) and the other through anaerobic/aerobic/aerobic (An/O 1 /O 2) biofilm process in Liao–He Oilfield (LHO), were used for the analysis of the distribution of bacterial communities systematically by high-throughput sequencing. A large number of halotolerant, thermotolerant, and petrol-degrading microbes, Firmicute , Chloroflexi , Thermotogae , Chlorobi , and SBR1093 , were detected in each plant because of high OPW temperature (43 °C–54 °C) and salinity (6.5–12 g L−1 of Cl−). However, the Shannon and Chao 1 indexes of LHO were higher than that of NCO, indicating greater microbial diversity and richness in biofilm process than in the activated sludge system. The microbiota structures of the two plants also differed, and such difference was significantly induced by various raw wastewater petroleum hydrocarbon constituents and treatment processes. The distance-based redundancy analysis showed that the temperature, DO, Cl−, and organic components in OPW were closely related to bacteria distribution. Interestingly, two same-genus strains, NC(X-6) and LH(X-9) , were isolated from NCO and LHO, respectively. Both strains were identified as Bacillus licheniformis , but showed different colony colors, transparencies, cell surface hydrophobicities, dehydrogenase activities, and biodegradabilities of organic matter, which was probably due to the different gene expression levels caused by environmental change. Graphical abstract Image 1 Highlights • Biofilm process exhibited better performance than activated sludge process in OPW plants. • Different wastewater qualities and treatment processes affected microbiota structure significantly. • Bacteria distribution was closely related to temp., DO, pH, Cl− and organic components. • Performances of two same-genus strains showed great distinction for different OPW. [ABSTRACT FROM AUTHOR]

With the increasing price and demand for fishmeal (FM) in aquaculture feeds, Tenebrio molitor (TM), an insect species known as yellow mealworm, is becoming an attractive alternative to FM in the aquaculture industry. This study investigated the effect on growth, enzyme activity, resistance to Vibrio parahaemolyticus , intestinal microbiota, and hemolymph transcriptome in Litopenaeus vannamei (Pacific white shrimp) of replacing up to 45% of FM with TM. L. vannamei (initial weight: 0.42 ± 0.01 g) were fed with diets that replaced FM with TM at 0% (TM0, control), 15% (TM15), 30% (TM30), and 45% (TM45). The results showed that dietary TM30 significantly increased the final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) of L. vannamei (P < 0.05) when compared with TM0. For the enzyme activity of serum, alkaline phosphatase (AKP), catalase (CAT), superoxide dismutase (SOD), phenoloxidase (PO), and lysozyme (LZM) differed significantly in TM45 compared with TM0 (P < 0.05), and malondialdehyde (MDA) decreased. The trypsin in the intestine significantly increased in TM45 compared with TM0 (P < 0.05). In the shrimps challenged with V. parahaemolyticus (1.3 × 107 CFU/mL), survival rates were not significantly different between groups. The alpha diversity indicators were significantly affected by feeding different levels of TM (P < 0.05), and beta diversity analysis showed that the four groups differed significantly (P < 0.05). Based on IndVal values, eight families were distinguished. RNA-seq analysis showed that the most enriched pathway was 'Metabolism of xenobiotics by cytochrome P450'. Some DEGs (differentially expressed genes) of the cytochrome P450 pathway correlated with the abundance of intestine bacteria at the family level. This study provides an insight into the mechanisms associated with molecular and microbiota responses to the effects of substituting TM for FM on L. vannamei , as well as suggests that TM is a potential protein source for farmed L. vannamei , possibly improving its antioxidant capacity, immunity, and resistance to disease via the cytochrome P450 pathway. • Replacement of 30% of dietary fishmeal by T.molitor meal significantly improved L. vannamei growth performance. • Dietary contained T. molitor meal improved non-specific immunity and antioxidant capacity of L. vannamei. • Dietary T. molitor improves L. vannamei growth and immunity, probably associated with Akkermansiaceae and CYP450 pathway. [ABSTRACT FROM AUTHOR]

Alterations in the composition and function of the gut microbiome have been implicated in a range of conditions and diseases. Culture-dependent and culture-independent studies both showed that older people harbour a gut microbiome that differs in composition from that of younger adults. Detailed analyses have identified discrete microbiota subtypes that characterize intermediates between a high diversity microbiota found in healthy community-dwelling subjects and a low diversity microbiota typical for elderly living in long-term residential care. There are also alterations in the microbiome composition associated with biological age, independent of health status. Even after adjusting for confounding factors such as age and medication, trends in microbiota composition correlate with gradients in clinical metadata particularly frailty and inflammatory status. There are few known mechanisms by which these associations might be causative rather than consequential, and this is a subject of intensive research. The strongest candidate effectors are microbial metabolites that could impact host energy balance, act as signalling molecules to modulate host metabolism or inflammation, and potentially also impact on the gut-brain axis. [ABSTRACT FROM AUTHOR]

High-throughput 16S rRNA gene amplicon sequencing technology is widely applied for environmental microbiota structure analysis to derive knowledge that informs microbiome-based surveillance and oriented bioengineering. However, it remains elusive how the selection of 16S rRNA gene hypervariable regions and reference databases affects microbiota diversity and structure profiling. This study systematically evaluated the fitness of different frequently used reference databases (i.e. SILVA 138 SSU, GTDB bact120&#95;r207, Greengenes 13&#95;5 and MiDAS 4.8) and primers of 16S rRNA gene in microbiota profiling of anaerobic digestion and activated sludge collected from a full-scale swine wastewater treatment plant (WWTP). The comparative results showed that MiDAS 4.8 achieved the highest levels of taxonomic diversity and species-level assignment rate. For whichever sample groups, microbiota richness captured by different primers decreased in the following order: V4 > V4-V5 > V3-V4 > V6-V8/V1-V3. Using primer-bias-free metagenomic data results as the judging standard, V4 region also best characterized microbiota structure and well represented typical functional guilds (e.g. methanogens, ammonium oxidizers and denitrifiers), while V6-V8 regions largely overestimated the archaeal methanogens (mainly Methanosarcina ) by over 30 times. Therefore, MiDAS 4.8 database and V4 region are recommended for best simultaneous analysis of bacterial and archaeal community diversity and structure of the examined swine WWTP., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

Objective: To examine gut microbiotal diversity in the Han Chinese and Yugur populations of Sunan County, Gansu Province, living in the same environmental conditions, and to analyze possible causes of differences in diversity., Methods: We selected 28 people, ages 18-45 years old, all of whom were third-generation pure Yugur or Han Chinese from Sunan County. Fresh fecal samples were collected, and total bacterial deoxyribonucleic acid (DNA) was extracted. We performed 16S ribosomal ribonucleic acid (16S rRNA) high-throughput sequencing (HTS) and bioinformatics to study the relationships among between gut microbiota structure, genetics, and dietary habits in Yugur and Han Chinese subjects., Results: We found 350 differential operational taxonomic units (OTUs) in Han Chinese and Yugur gut microbiota, proving that gut microbiota differed between the two populations. That were less abundant among Yugurs than Han Chinese were Prevotella&#95;9 and Alloprevotella . That were more abundant among Yugurs than Han Chinese were Anaerostipes and Christensenellaceae&#95;R-7&#95;group . And they were significantly associated with a high-calorie diet In addition. we found differences in predicted gut microbiota structural functions (The main functions were metabolic and genetic information) between the two populations., Conclusion: Yugur subjects demonstrated differences in gut microbiotal structure from Han Chinese subjects, and this difference influenced by dietary and may be influenced by genetic influences. This finding will provide a fundamental basis for further study of the relationships among gut microbiota, dietary factors, and disease in Sunan County., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ma, Ci, Zhou, Zhang, Gu, Yang, An, An, Lan and Zhao.)

Pytoremediation was studied in this project to treat swine manure lagoon wastewater characteristic of high concentrations of organic carbon, ammonium (N) and phosphorus (P). The impacts of introducing exogenous microalgae Chlorella into the lagoon wastewater on the removal of major nutrients and the transformation of the native wastewater microbiota structure were explored under two phytoremediation modes (shake flask and CO 2 -air bubbling). The results showed that the inoculation of microalgae could significantly enhance N and P removal. Metagenomic analysis of the native microbiota composition in the wastewater affected by algae inoculation revealed that a substantial population of algicidal bacteria was developed in the shake flask system, while in the CO 2 -air bubbling system, a niche for more mutualistic bacteria was created, which benefited the maximal algal growth with the simultaneous optimal N and P removal. To our knowledge, this study presents, the first reported case of applying metagenomic approach to a phytoremediation system treating real swine lagoon wastewater. [ABSTRACT FROM AUTHOR]

Definition of lichens has evolved from bi(tri)partite associations to multi-species symbioses, where bacteria would play essential roles. Besides, although soil bacterial communities are known to be affected by edaphic factors, when lichens grow upon them these could become less preponderant. We hypothesized that the structure of both the lichen microbiota and the microbiota in the soil underneath lichens is shaped by lichen intrinsic and extrinsic factors. In this work, intrinsic factors corresponded to mycobiont and cyanobiont identities of Peltigera lichens, metabolite diversity and phenoloxidase activity and extrinsic factors involved the site of the forest where lichens grow. Likewise, the genetic and metabolic structure of the lichen and soil bacterial communities were analyzed by fingerprinting. Among the results, metabolite diversity was inversely related to the genetic structure of bacterial communities of lichens and soils, highlighting the far-reaching effect of these substances; while phenoloxidase activity was inversely related to the metabolic structure only of the lichen bacterial microbiota, presuming a more limited effect of the products of these enzymes. Soil bacterial microbiota was different depending on the site and, strikingly, according to the cyanobiont present in the lichen over them, which could indicate an influence of the photobiont metabolism on the availability of soil nutrients. [ABSTRACT FROM AUTHOR]

To reflect the potential and intrinsic association among microbiota structure, antibiotic resistance genes distribution and biological toxicity of landfill-leachate according to seasonal change, and accurately assess the potential threat of leachate to the surrounding environment. On the basis of the leachate water quality monitoring data from January to December 2020, principal component analysis (PCA) was used to identify the main pollutants in the leachate; Vibrio fischeri luminescence inhibition test was used to detect the comprehensive biotoxicity of the leachate; 16S rDNA amplicon sequencing was used for leachate microbiota. q-PCR was used to detect the class 1 integron (intI1), and eight antibiotic resistance genes (sul1, sul2, tetA, tetB, tetM, tetQ, mefA, and mexF); Canonical correspondence (CCA) analysis was carried out for the association analysis. The biotoxicity of leachate in the second quarter was the highest. The dominant phylum of leachate microbiota from 1st quarters to 4th quarters was Proteobacteria (94.97 %, 85.43 %, 88.20 %, and 84.11 %), and the dominant genera were Thiomonas (60.41 %, 26.83 %, 25.66 %, and 30.51 %), Pseudomonas (5.89 %, 1.86 %, 0.68 %, and 4.72 %), Desulfurella (8.52 %, 0.57 %, 3.81 %, and 8.25 %), and Acidithiobacillus (4.71 %, 0.69 %, 0.87 %, and 5.91 %); Nitrospirillum was negatively correlated with chemical oxygen demand (COD) (R=−0.561, P = 0.008) and five-day biochemical oxygen demand (BOD 5) (R=−0.591, P = 0.005); Limnohabitans was positively correlated with pH (R=0.444, P = 0.044). Four AR genes (sul1, sul2 ， tetM, and tetQ) were detected in all the samples, while the second quarter had the highest concentration of sul1 (6.31 ± 0.49 lg copies/ng DNA) , tetM (3.01 ± 1.38 lg copies/ng DNA) and tetQ (3.64 ± 0.90 lg copies/ng DNA). As the mature landfill, the quality of this leachate met the pollution control standards for domestic waste landfills. Thiomycetes , Pseudomonas , Desulfurization , and Thiopterus acidophyllum constitute the dominant microbiota. However, leachate in the second quarter had more serious contamination, the higher biotoxicity, higher concentration of AR genes, together with higher microbiota richness and diversity, which deserved more attention for the potential threat to the surrounding environment. • Seasonal change of landfill-leachate was evaluated by microbiota, antibiotic resistance genes and biotoxicity to reflect potential and intrinsic association. • Thiomycetes, Pseudomonas, Desulfurization , and Thiopterus acidophyllum constitute the dominant leachate microbiota. • Leachate microbiota mainly involved in metabolic degradation of sulfides. • Biotoxicity, antibiotic resistance genes Sul1 , tetM , and tetQ , microbiota of the leachate deserved more attention for potential threat to the surrounding environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The sustainable reuse of sludge and wetland macrophyte litter was realized. • SBC and CBC promoted nutrient removal and reduced N 2 O emissions fluxes in CWs. • Biochar-derived DOM can supplement carbon source for denitrification in CWs. • SBC significantly enhanced the key enzyme activities and ETSA in CWs. • Biochar enhanced the enrichment of nitrogen and phosphorus removing microorganisms. Constructed wetlands (CWs) are widely used to treat the effluent of wastewater treatment plants (WWTPs) due to their energy-saving and environmentally friendly advantages. Wetland macrophyte litter and sludge are wastes produced by CWs and WWTPs, respectively. However, there are few studies on the reuse of sludge and macrophyte litter as CW filling materials. In this study, sewage sludge and cattail litter were selected as raw materials to prepare biochar, which was used as CW filling materials to enhance the advanced treatment of secondary effluent. The results showed that the sludge biochar CWs (SBC-CWs) and the cattail biochar CWs (CBC-CWs) possessed better total nitrogen removal efficiency (91% and 81%, respectively) compared with the control (67%). Furthermore, SBC-CWs significantly improved total phosphorus removal efficiency by 20% than that of the control (p < 0.05), and reduced nitrous oxide emissions by 66% compared with the control (p < 0.05). The dissolved organic matter (DOM) released in the biochar was beneficial to replenish carbon sources and accommodate adaptive microorganisms. Electrochemical characterization and molecular methods revealed that the sludge biochar had stronger electron transfer capacity (ETC) than the cattail biochar, which could better promote the activities of key enzymes of the pollutant removal procedure. High-throughput sequencing showed that microorganisms such as Thaurea , Rhodocyclaceae , Hydrogenophaga and Fusibacter related to nitrogen removal were well enriched in the SBC-CWs and CBC-CWs. This research shows the potential for the simultaneous energy-saving advanced treatment of WWTP tailwater and waste resource recovery. [ABSTRACT FROM AUTHOR]

The composition of the human gut microbiota is related to host health, and it is thought that dietary habits may play a role in shaping this composition. Here, we examined the population size and prevalence of six predominant bacterial genera and the species compositions of genus Bifidobacterium (g-Bifid) and Bacteroides fragilis group (g-Bfra) in 42 healthy Belgian adults by quantitative PCR (qPCR) over a period of one month. The population sizes and prevalence of these bacteria were basically stable throughout the study period. The predominant g-Bifid species were Bifidobacterium adolescentis and Bifidobacterium longum ss. longum, and the predominant g-Bfra species were Bacteroides vulgatus, Bacteroides uniformis, and Bacteroides ovatus. The Belgian gut microbiota data were then compared with gut microbiota data from 46 Japanese subjects collected according to the same protocol (Matsuki et al., Appl. Environ. Microbiol. 70, 167–173, 2004). The population size and prevalence of Bifidobacterium catenulatum group were significantly lower in the Belgian gut microbiota than in the Japanese gut microbiota (P < 0.001); however, the population size and prevalence of g-Bifid did not differ. This species-level qPCR analysis will be helpful for investigating the diversity of gut microbiota among ethnic groups. [Copyright &y& Elsevier]

The major parcel of the degradation occurring along wastewater biotreatments is performed either by the native microbiota or by added microbial inocula. The main aim of this study was to apply two fingerprinting methods, temperature gradient gel electrophoresis (TGGE) and length heterogeneity-PCR (LH-PCR) analysis of 16S rRNA gene fragments, in order to assess the microbiota structure and dynamics during mixed olive oil and winery wastewaters aerobic biotreatment performed in a jet-loop reactor (JLR). Sequence homology analysis showed the presence of bacterial genera Gluconacetobacter, Klebsiella, Lactobacillus, Novosphingobium, Pseudomonas, Prevotella, Ralstonia, Sphingobium and Sphingomonas affiliated with five main phylogenetic groups: alpha-, beta- and gamma-Proteobacteria, Firmicutes and Bacteroidetes. LH-PCR analysis distinguished eight predominant DNA fragments correlated with the samples showing highest performance (COD removal rates of 67 up to 75%). Cluster analysis of both TGGE and LH-PCR fingerprinting profiles established five main clusters, with similarity coefficients higher than 79% (TGGE) and 62% (LH-PCR), and related with hydraulic retention time, indicating that this was the main factor responsible for the shifts in the microbiota structure. Canonical correspondence analysis revealed that changes observed on temperature and O level were also responsible for shifts in microbiota composition. Community level metabolic profile analysis was used to test metabolic activities in samples. Integrated data revealed that the microbiota structure corresponds to bacterial groups with high degradative potential and good suitability for this type of effluents biotreatments. [ABSTRACT FROM AUTHOR]

[Display omitted] • The aroma compounds and the microbial community of oil furu were identified. • Twenty two volatile compounds contributed to the aroma profile of oil furu. • Pre-fermentation and ripening showed different predominant microbiota. • The aroma profiles were strongly influenced by the predominant microbes. • Metabolism showed higher activity during oil furu fermentation. The aroma compounds and the microbial community of oil furu, a specific fermented soybean curd, during fermentation were investigated using HS-SPME-GC/MS and high-throughput sequencing, respectively, and their correlations and the predicted functional roles of the microbiota in oil furu were analyzed. Twenty two volatile flavor compounds (relative odor activity value ≥1) were identified that contributed to the aroma profile, which were mainly associated with the aroma attributes. Lactobacillales , Trichosporon and Mucor racemosus were the predominant genera during pre-fermentation, while Candida and Tetragenococcus were predominant during ripening. Correlation analysis showed significant correlation between the microbiota and aroma profiles, and Candida , Empedobacter , Lactobacillus , Pseudomonas , Stenotrophomonas , Trichosporon and Mucor racemosus were significantly and strongly correlated with the characteristic volatile aroma compounds of oil furu (P < 0.05, r > 0.6). Functional analysis showed that metabolic pathways showed higher activity in oil furu, which mainly included amino acid, lipid and carbohydrate metabolism. The results allowed identification of the important aroma compounds and understanding the contribution of the microbiota, and would be useful for designing starter cultures to produce oil furu with desirable aroma properties and understanding its aroma formation pathways. [ABSTRACT FROM AUTHOR]

Lead contamination is an environmental problem, especially in developing countries; due to the nondegradable characteristics of lead, it is easily deposited in human and animal bodies by the food chain. Probiotics are regarded as a good tool to remove lead ions in the intestine and maintain gut health conditions, but previous studies failed to elucidate the relationship among probiotics, the host and the gut microbiota. In the present study, B. coagulans R11 was employed as the "lead removal tool" in lead-exposed mouse, and the effects of B. coagulans R11 on intestinal cells, the microbiota and faecal microRNAs were tested. The results indicated that B. coagulans R11 had no negative effects on mouse intestine model cells and helped keep cells in a normal proliferation ratio and reduce the reactive oxygen species and apoptosis ratios under lead exposure conditions. An in vivo mouse experiment also showed that B. coagulans R11 feeding could reduce the intestinal villi damage caused by lead through adjusting the microbiota structure and function, such as increasing the genus abundance of Akkermansia and Alistipes , decreasing the genus abundance of Alloprevotella , Lachnospiraceae , Parabacteroides and Ruminiclostridium , and keeping the protein dltD existing. Host faecal microRNAs may be influenced by lead and B. coagulans R11, which may change the microbiota structure. Thus, B. coagulans R11 has the potential to be developed and considered as the probiotic that protects the host gut against villi damage and gut microbiota structure and function disorders during lead exposure. Image 1 • B. coagulans R11 feeding could increase the genus abundance of Akkermansia and Alistipes in lead exposure mouse. • B. coagulans R11 feeding decrease the genus abundance of four potential pathogens in lead exposure mouse. • B. coagulans R11 could keep the protein dltD existing gut microbiota in lead exposure mouse. • B. coagulans R11 and lead exposure all could influence the enrichment function of faecal microRNAs. • B. coagulans R11 be considered as the probiotic for intestinal villi protection in lead exposure. [ABSTRACT FROM AUTHOR]

Alterations in the composition and function of the gut microbiome have been implicated in a range of conditions and diseases. Culture-dependent and culture-independent studies both showed that older people harbour a gut microbiome that differs in composition from that of younger adults. Detailed analyses have identified discrete microbiota subtypes that characterize intermediates between a high diversity microbiota found in healthy community-dwelling subjects and a low diversity microbiota typical for elderly living in long-term residential care. There are also alterations in the microbiome composition associated with biological age, independent of health status. Even after adjusting for confounding factors such as age and medication, trends in microbiota composition correlate with gradients in clinical metadata particularly frailty and inflammatory status. There are few known mechanisms by which these associations might be causative rather than consequential, and this is a subject of intensive research. The strongest candidate effectors are microbial metabolites that could impact host energy balance, act as signalling molecules to modulate host metabolism or inflammation, and potentially also impact on the gut-brain axis.