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Forest musk deer is the most important animal for natural musk production, and the musk composition changes periodically during musk secretion, accompanied by variation in the com-position of deer-symbiotic bacteria. GC-MS and 16S rRNA sequencing were conducted in this study, the dynamic changes to correlated chemical composition and the microbiota across musk secretion periods (prime musk secretion period, vigorous musk secretion period and late musk secretion period) were investigated by integrating its serum testosterone level in different mating states. Results showed that the testosterone level, musk composition and microbiota changed with annual cycle of musk secretion and affected by its mating state. Muscone and the testosterone level peaked at vigorous musk secretion period, and the microbiota of this stage was distinct from the other 2 periods. Actinobacteria, Firmicutes and Proteobacteria were dominant bacteria across musk secretion period. PICRUSt analysis demonstrated that bacteria were ubiquitous in musk pod and involved in the metabolism of antibiotics and terpenoids in musk. "Carbohydrates and amino acids," "fatty acids and CoA" and "secretion of metabolites" were enriched at 3 periods, respectively. Pseudomonas, Corynebacterium, Clostridium, Sulfuricurvum were potential biomarkers across musk secretion. This study provides a more comprehensive understanding of genetic mechanism during musk secretion, emphasizing the importance of Actinobacteria and Corynebacterium in the synthesis of muscone and etiocholanone during musk secretion, which required further validation. [ABSTRACT FROM AUTHOR]

Simple Summary: The human gastrointestinal tract harbors a complex and dynamic population of microorganisms (mostly bacteria and viruses) that are called the gut microbiota. This microbial community is known to exert a marked influence on the host health. Among the different bacterial families present in the gut microbiota, Enterobacteriaceae represents only a small fraction of total bacteria in healthy individuals, whereas it can abnormally proliferate in the gut of individuals affected by intestinal or extra-intestinal diseases such as obesity, inflammatory bowel disease or metabolic disorders. Our review explores the recent knowledge discussing the dynamics of Enterobacteriaceae in the human gut in healthy or disease-associated conditions. We also describe emerging mechanistic studies that could explain how Enterobacteriaceae proliferate in cases of gut microbiota imbalance in patients as well as the consequences such expansions could have on host health. The human gut microbiota plays a crucial role in maintaining host health. Our review explores the prevalence and dynamics of Enterobacteriaceae, a bacterial family within the Proteobacteria phylum, in the human gut which represents a small fraction of the gut microbiota in healthy conditions. Even though their roles are not yet fully understood, Enterobacteriaceae and especially Escherichia coli (E. coli) play a part in creating an anaerobic environment, producing vitamins and protecting against pathogenic infections. The composition and residency of E. coli strains in the gut fluctuate among individuals and is influenced by many factors such as geography, diet and health. Dysbiosis, characterized by alterations in the microbial composition of the gut microbiota, is associated with various diseases, including obesity, inflammatory bowel diseases and metabolic disorders. A consistent pattern in dysbiosis is the expansion of Proteobacteria, particularly Enterobacteriaceae, which has been proposed as a potential marker for intestinal and extra-intestinal inflammatory diseases. Here we develop the potential mechanisms contributing to Enterobacteriaceae proliferation during dysbiosis, including changes in oxygen levels, alterations in mucosal substrates and dietary factors. Better knowledge of these mechanisms is important for developing strategies to restore a balanced gut microbiota and reduce the negative consequences of the Enterobacteriaceae bloom. [ABSTRACT FROM AUTHOR]

The skin of fish contains a diverse microbiota that has symbiotic functions with the host, facilitating pathogen exclusion, immune system priming, and nutrient degradation. The composition of fish skin microbiomes varies across species and in response to a variety of stressors, however, there has been no systematic analysis across these studies to evaluate how these factors shape fish skin microbiomes. Here, we examined 1922 fish skin microbiomes from 36 studies that included 98 species and nine rearing conditions to investigate associations between fish skin microbiome, fish species, and water physiochemical factors. Proteobacteria, particularly the class Gammaproteobacteria, were present in all marine and freshwater fish skin microbiomes. Acinetobacter, Aeromonas, Ralstonia, Sphingomonas and Flavobacterium were the most abundant genera within freshwater fish skin microbiomes, and Alteromonas, Photobacterium, Pseudoalteromonas, Psychrobacter and Vibrio were the most abundant in saltwater fish. Our results show that different culturing (rearing) environments have a small but significant effect on the skin bacterial community compositions. Water temperature, pH, dissolved oxygen concentration, and salinity significantly correlated with differences in beta-diversity but not necessarily alpha-diversity. To improve study comparability on fish skin microbiomes, we provide recommendations for approaches to the analyses of sequencing data and improve study reproducibility. [ABSTRACT FROM AUTHOR]

Simple Summary: The blowfly, Aldrichina grahami, is widely recognized as a highly significant insect in forensic investigations. Despite the pivotal role of gut microbes in various facets of insect biology, limited knowledge exists regarding the gut microbiome of A. grahami. To investigate the gut bacterial community of A. grahami and explore its stability, diet and developmental stage were selected as the two variables. Larvae were reared on bovine liver, swine manure, and chicken manure, and high-throughput sequencing was performed on the 1st, 2nd, and 3rd instar larvae and the newly emerged adults. Our results revealed that the dominant genera Vagococcus, Providencia, Lactobacillus, and Morganella were present in more than 80% of gut samples. The alpha and beta diversity of the gut bacterial community do not vary significantly across different diets and developmental stages. Our results indicated that the bacterial community in the gut of A. grahami exhibits remarkable stability, and the dominant genera Vagococcus, Providencia, Lactobacillus, and Morganella might be potential core microbes in the gut microbial community. The blowfly, Aldrichina grahami (Diptera: Calliphoridae), is a well-known forensically important insect. Basic data related to A. grahami have been well documented; but despite the pivotal role of gut microbes in various facets of insect biology, little is known about its gut microbiome. To investigate the gut bacterial community of A. grahami and explore its stability, diet and developmental stage were selected as the two variables. Larvae were reared on bovine liver, swine manure, and chicken manure, and high-throughput sequencing of the 1st, 2nd, and 3rd instar larvae and the newly emerged adults was performed. According to our results, the alpha diversity of the gut bacterial community did not significantly vary among different diets and developmental stages. Principal coordinate analysis revealed that the gut microbiome of A. grahami clustered together among different diets and developmental stages. The main phyla in the gut microbial community of A. grahami were Firmicutes and Proteobacteria, and the dominant genera were Vagococcus, Providencia, Lactobacillus, and Morganella. These findings characterized the gut microbiome of A. grahami and demonstrated that the gut bacterial community is fairly stable. The dominant genera Vagococcus, Providencia, Lactobacillus, and Morganella have the potential to serve as core microbiomes within the gut microbial community of A. grahami. [ABSTRACT FROM AUTHOR]

The gut microbiome (GMB) has been extensively reported to be associated with the development and prognosis of human diseases. This study aims to investigate the relationship between GMB composition and chemotherapy efficacy in diffuse large B-cell lymphoma (DLBCL). We demonstrated that DLBCL patients at diagnosis have altered GMB compositions. Significant enrichment of the Proteobacteria phylum in DLBCL patients was observed. Gene analysis showed a high abundance of virulence factors genes. We found baseline GMB to be associated with clinical outcomes. The emergence of Lactobacillus fermentum was correlated with better treatment outcome. Our pilot results suggested a correlation between GMB composition and DLBCL development and prognosis. Clues from our study, together with previous research, provided a rational foundation for further investigation on the pathogenesis, prognosis value, and targeted therapy of GMB in DLBCL. [ABSTRACT FROM AUTHOR]

The early phase of bacterial division involves four major core functions: chromosome coordination, Z-ring stabilization, Z-ring anchoring, and regulation of the initiation of late division. Core functions of the early divisome are generally conserved across the Proteobacteria, not necessarily genes. Gene conservation and essentiality cannot be used to define the core early divisome due to the strong epistatic nature of this network and its coevolution with other critical cellular processes. Variation within the early divisome can inform fundamental principles about division and the evolutionary constraints that have shaped division in each lineage. The bacterial divisome is a complex nanomachine that drives cell division and separation. The essentiality of these processes leads to the assumption that proteins with core roles will be strictly conserved across all bacterial genomes. However, recent studies in diverse proteobacteria have revealed considerable variation in the early divisome compared with Escherichia coli. While some proteins are highly conserved, their specific functions and interacting partners vary. Meanwhile, different subphyla use clade-specific proteins with analogous functions. Thus, instead of focusing on gene conservation, we must also explore how key functions are maintained during early division by diverging protein networks. An enhanced awareness of these complex genetic networks will clarify the physical and evolutionary constraints of bacterial division. [ABSTRACT FROM AUTHOR]

As the number of Covid-19 cases has increased, the production and use of face masks have also increased accordingly. This widespread use of face masks generates millions of tons of mask waste. This study analyzed the bacterial community composition of discarded masks from landfills (Piyungan, Jatibarang, Burangkeng); mangroves (Wanatirta, Tirang, Teluk Naga); and beaches (Parangtritis, Marina, Tanjung Pasir) in Yogyakarta, Semarang, Bekasi, and Tangerang, Java, Indonesia using 16S rRNA sequencing. Analyzing all samples from landfills, mangroves, and beaches revealed that the Proteobacteria phylum is the predominant. In addition, Firmicutes was the second-highest phylum in the samples from landfills and mangroves. In the meantime, Actinobacteria and Cyanobacteria dominated the phyla found in samples from beaches. Analyses at the genus level revealed that Bacillus members predominated in samples of discarded face masks from landfills. In addition, the most prevalent genus found in samples from mangroves and beaches was Vibrio. According to the findings, the distribution of bacterial communities differed among the various regions. Dissimilar bacterial communities and gradient distributions were found among discarded face masks in landfills, mangroves, and beaches. It was the first examination of bacterial distribution in discarded disposable face masks from various locations. [ABSTRACT FROM AUTHOR]

Calf intestines are colonized by rich and complex microbial communities, playing a crucial role in animal physiology, metabolism, nutrition, and immune function. In this study, we provide insight into the composition of fecal microbial bacteria and fungi, respectively, as well as the cross-kingdom interactions. We investigated the intestinal microbiota of different breeds of calves by characterizing the bacterial and fungal communities in the rectal feces of Holstein calves and German Simmental × Holstein cross F1 generation (GXH) using 16S rRNA and ITS amplicon sequencing techniques. PICRUSt2 (version 2.2.0) were used to determine microbial diversity and function and explore the reasons why Holstein calves are more susceptible to diarrhea. The results revealed no significant difference in the diversity of fecal microbiota among the groups (p > 0.05). We identified Firmicutes, Bacteroidetes, and Proteobacteria as the dominant bacterial phyla in the fecal bacterial communities of the two breeds of calves. Ascomycota and Basidiomycota play important roles in the fungal community but differ in relative abundance. Bacteroides was the dominant genus at the group level for calf fecal microbiota in both breeds. The relative abundance of Prevotella, Escherichia-Shigella, Peptostreptococcus, and Butyricicoccus was higher in Holstein calves, and the relative abundance of Faecalibacterium, Megamonas, Butyricicoccus, and Alloprevotella was lower than GXH group. Aspergillus and Cladosporium were the dominating genera of fecal fungi in both groups of calves. LEfSe analysis revealed 33 different bacteria and 23 different fungi between the two groups, with more differential strains found in GXH. In addition, the feces fungi-bacteria interkingdom interactions varied among breeds. Thus, the composition and structure of bacterial and fungal communities in calf feces varied by breed, indicating a potential association between breed and microbial communities. We also found differences in the network between bacterial–fungal kingdoms. We explain the reasons for Holstein calves being more prone to diarrhea. This indicated that breed makes differences in calf diarrhea rates by influencing gut microbial composition and interactions. [ABSTRACT FROM AUTHOR]

Plastics in the ocean create the "plastisphere", a diverse habitat hosting various life forms. Other than the pollution induced by plastics, the co-occurrence of primary producers, symbiotic organisms, decomposers, and pathogens within the plastisphere raises questions about how they influence the dynamics of marine ecosystems. Here, we used a shotgun DNA-sequencing approach to describe the species thriving on floating plastics collected in two Mediterranean sites. Our findings revealed many species of bacteria, eukaryotes, viruses, and archaea on each plastic. Proteobacteria was dominant (70% of reads in the entire dataset), with other groups such as Ascomycota fungi (11%) and Bacteroidetes (9%) also being represented. The community structure was not affected by the polymeric composition or the plastic shape. Notably, pathogenic Vibrio species, including V. campbelli, V. alginolyticus, and V. coralliilyticus, were among the most abundant species. Viruses, despite showing lower relative abundances, occurred in all samples, especially Herpesvirales, Caudovirales, and Poxviridae groups. A significant finding was the presence of the White Spot Syndrome virus (WSSV). This pathogen, responsible for devastating outbreaks in aquaculture systems, had not been previously reported in the marine plastisphere. Our study emphasizes the need for further investigation into the ecological and economic impacts of plastisphere organisms in the ocean. [ABSTRACT FROM AUTHOR]

Decabromodiphenyl ether (BDE-209) is recognized as an emerging and hazardous pollutant in numerous ecosystems. Despite this, only a few studies have concurrently investigated the biodegradation of BDE-209 by a microbial consortium comprising both bacteria and fungi. Consequently, the interactions between bacterial and fungal populations and their mutual effects on BDE-209 degradation remain unclear. Our main objective was to concurrently assess the changes and activity of bacterial and fungal communities during the biodegradation of BDE-209 in a real soil matrix. In the present study, various organic substrates were employed to promote soil biomass for the biodegradation of BDE-209. Soil respiration and molecular analysis were utilized to monitor biological activity and biomass community structure, respectively. The findings revealed that the use of wheat straw in the soil matrix resulted in the highest soil respiration and microbial activity among the treatments. This approach obviously provided suitable habitats for the soil microflora, which led to a significant increase in the biodegradability of BDE-209 (49%). Biomass survival efforts and the metabolic pathway of lignin degradation through co-metabolism contributed to the biodegradation of BDE-209. Microbial community analysis identified Proteobacteria (Alphaproteobacteria-Betaproteobacteria), Firmicutes, Bacteroides (bacterial phyla), as well as Ascomycota and Basidiomycota (fungal phyla) as the key microorganisms in the biological community involved in the biodegradation of BDE-209. This study demonstrated that applying wheat straw can improve both the biological activity and the biodegradation of BDE-209 in the soil of polluted sites. [ABSTRACT FROM AUTHOR]

Introduction: Rhinitis is one of the most prevalent chronic respiratory diseases worldwide. There is emerging evidence suggesting that the indoor microbiome may contribute the onset and exacerbation of rhinitis symptoms, but comprehensive studies on this topic remain scarce. Methods: In this study, we assessed the microbiome assemblage of settled air dust collected in Petri dishes in 86 dormitory rooms of Shanxi University, China using 16s rRNA sequencing. A self-administered questionnaire, including questions about rhinitis symptoms and personal information, was completed by 357 students residing in these dormitories. Logistic and linear regression model was applied to examine the associations between environmental characteristics, indoor microbiome, and rhinitis. Results: The most abundant genera in the dormitories were Ralstonia (15.6%), Pelomonas (11.3%), Anoxybacillus (9.3%) and Ochrobactrum (6.2%). Taxa richness in the class of Actinobacteria and Fusobacteriia was negatively/protectively associated with rhinitis (p<0.05). Six bacterial genera, including those from Actinobacteria (Actinomyces), Fusobacteriia (Fusobacterium), and Bacteroidetes (Prevotella and Capnocytophaga), were negatively/protectively associated with rhinitis. Conversely, seven genera, predominantly from Alphaproteobacteria and Betaproteobacteria (Sphingomonas, Caulobacter, uncharacterized Caulobacteraceae and Comamonadaceae), were positively associated with rhinitis. Living in higher floor level and higher indoor PM2.5 concentrations were associated with a higher abundance of taxa potentially protective against rhinitis and a lower abundance of taxa potentially increasing the risk of rhinitis (P<0.01). However, having curtain indoor and higher indoor CO2 concentrations were associated with a lower abundance of taxa potentially protective against rhinitis and a higher abundance of taxa potentially increasing the risk of rhinitis (P<0.01). Discussion: This study enhances our understanding of the complex interactions between environmental characteristics, indoor microbiomes, and rhinitis, shedding light on potential strategies to manipulate indoor microbiome for disease prevention and control. [ABSTRACT FROM AUTHOR]

With the development of modern sheep raising technology, the increasing density of animals in sheep house leads to the accumulation of microbial aerosols in sheep house. It is an important prerequisite to grasp the characteristics of bacteria in aerosols in sheep house to solve the problems of air pollution and disease prevention and control in sheep house. In this study, the microorganisms present in the air of sheep houses were investigated to gain insights into the structure of bacterial communities and the prevalence of pathogenic bacteria. Samples from six sheep pens in each of three sheep farms, totaling 18, were collected in August 2022 from Ningxia province, China. A high-volume air sampler was utilized for aerosol collection within the sheep housing followed by DNA extraction for 16S rRNA sequencing. Employing high-throughput 16S rRNA sequencing technology, we conducted an in-depth analysis of microbial populations in various sheep pen air samples, enabling us to assess the community composition and diversity. The results revealed a total of 11,207 operational taxonomic units (OTUs) within the bacterial population across the air samples, encompassing 152 phyla, 298 classes, 517 orders, 853 families, 910 genera, and 482 species. Alpha diversity and beta diversity analysis indicated that differences in species diversity, evenness and coverage between different samples. At the bacterial phylum level, the dominant bacterial groups are Firmicutes, Proteobacteria, and Actinobacteria, among which Firmicutes (97.90-98.43%) is the highest. At the bacterial genus level, bacillus, Bacteroides, Fusobacterium, etc. had higher abundance, with Bacillus (85.47-89.87%) being the highest. Through an in-depth analysis of microbial diversity and a meticulous examination of pathogenic bacteria with high abundance in diverse sheep house air samples, the study provided valuable insights into the microbial diversity, abundance, and distinctive features of prevalent pathogenic bacteria in sheep house air. These findings serve as a foundation for guiding effective disease prevention and control strategies within sheep farming environments. [ABSTRACT FROM AUTHOR]

Background: Demodex blepharitis (DB) is a common disease of the ocular surface. The characteristics of the bacterial community in eyelash roots after Demodex infestation are still unknown. Knowledge of the characteristics of the bacterial community of eyelash follicles in patients with DB can provide valuable insights for guiding the diagnosis and treatment of DB. Methods: Twenty-five patients with DB (DB group) and 21 non-DB volunteers (control group) were enrolled in the study. Eyelashes from the upper eyelid of the right eye were sampled, and 16S ribosomal DNA (rDNA) sequencing was performed to determine the V3-V4 regions of the microbial 16S rDNA gene within 1 month of infestation. The sequencing data of the two groups were analyzed and compared. The effect of the bacterium Burkholderia on the survival of Demodex mites was evaluated using Demodex obtained from 12 patients with DB other that the patients in the DB group. Results: A total of 31 phyla and 862 genera were identified in the DB and control groups. The five most abundant phyla in the two groups were Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Cyanobacteria. The abundance of Actinomycetes was significantly higher in the DB group than in the control group. At the genus level, the five most abundant genera in the two groups were Pseudomonas, Burkholderia-Caballeronia-Paraburkholderia, Rolstonia and Acinetobacter; Clostridium sensu stricto 1 was abundant in the control group and Corynebacterium_1 was abundant in the DB group. Compared with the control group, the abundance of Burkholderia-Caballeronia-Paraburkholderia was 2.36-fold lower in the DB group. Linear discriminant analysis Effect Size (LEfSe) analysis revealed Burkholderia-Caballeronia-Paraburkholderia, SC84_unclassified, Nonmyxobacteria and Succinvibrio to be the major biomarkers in the control group and Catenibacterium and Lachnospiraceae NK4A136 group to be the major biomarkers in the DB group. To explore the performance of these optimal marker models, receiver operational characteristic curve analysis was performed, and the average area under the curve value of Burkholderia-Caballeronia-Paraburkholderia was 0.7448. Burkholderia cepacia isolated from normal human eyelashes was fermented, and the Demodex mites isolated from patient eyelashes were cultured together with its fermented supernatant. The results showed that the fermentation supernatant could significantly reduce the survival time of the Demodex mites, suggesting the potential therapeutic value of this bacterium against Demodex. Conclusions: The composition of the bacterial community in the eyelashes of DB patients differed from that in eyelashes of healthy volunteers, revealing a decrease in bacterial diversity in infested eyelashes. This decrease may be related to the occurrence and development of DB. The supernatant of Burkholderia cepacia culture medium was found to inhibit the growth of Demodex in eyelash hair follicles, providing a new insight with potential applications for the clinical treatment of Demodex infestation. [ABSTRACT FROM AUTHOR]

Escalating proportions of industrially contaminated sites are one of the major catastrophes faced at the present time due to the industrial revolution. The difficulties associated with culturing the microbes, has been circumvent by the direct use of metagenomic analysis of various complex niches. In this study, a metagenomic approach using next generation sequencing technologies was applied to exemplify the taxonomic abundance and metabolic potential of the microbial community residing in Amlakhadi canal, Ankleshwar at two different seasons. All the metagenomes revealed a predominance of Proteobacteria phylum. However, difference was observed within class level where Gammaproteobacteria was relatively high in polluted metagenome in Summer while in Monsoon the abundance shifted to Betaproteobacteria. Similarly, significant statistical differences were obtained while comparing the genera amongst contaminated sites where Serratia, Achromobacter, Stenotrophomonas and Pseudomonas were abundant in summer season and the dominance changed to Thiobacillus, Thauera, Acidovorax, Nitrosomonas, Sulfuricurvum, Novosphingobium, Hyphomonas and Geobacter in monsoon. Further upon functional characterization, the microbiomes revealed the diverse survival mechanisms, in response to the prevailing ecological conditions (such as degradation of aromatic compounds, heavy metal resistance, oxidative stress responses and multidrug resistance efflux pumps, etc.). The results have important implications in understanding and predicting the impacts of human-induced activities on microbial communities inhabiting natural niche and their responses in coping with the fluctuating pollution load. [ABSTRACT FROM AUTHOR]

Chlorophenols are persistent environmental pollutants used in synthesizing dyes, drugs, pesticides, and other industrial products. The chlorophenols released from these processes seriously threaten the environment and human health. The present study describes 4-chlorophenol (4-CP) degradation activity and metagenome structure of a bacterial consortium enriched in a 4-CP-containing medium. The consortium utilized 4-CP as a single carbon source at a wide pH range, temperature, and in the presence of heavy metals. The immobilized consortium retained its degradation capacity for an extended period. The 4-aminoantipyrine colorimetric analysis revealed complete mineralization of 4-CP up to 200 mg/L concentration and followed the zero-order kinetics. The addition of glycerol and yeast extract enhanced the degradation efficiency. The consortium showed both ortho- and meta-cleavage activity of catechol dioxygenase. Whole genome sequence (WGS) analysis revealed the microbial compositions and functional genes related to xenobiotic degradation pathways. The identified genes were mapped on the KEGG database to construct the 4-CP degradation pathway. The results exhibited the high potential of the consortium for bioremediation of 4-CP contaminated sites. To our knowledge, this is the first report on WGS analysis of a 4-CP degrading bacterial consortium. [ABSTRACT FROM AUTHOR]

Ticks host different pathogens as endosymbiont and nonpathogenic microorganisms and play an important role in reproductive fitness and nutrient provision. However, the bacterial microbiomes of white-tailed deer ticks have received minimal attention. This study aimed to examine the bacterial microbiome of ticks collected from Odocoileus virginianus on the Mexico-United States border to assess differences in microbiome diversity in ticks of different species, sexes, and localities. Five different tick species were collected: Rhipicephalus microplus, Dermacentor nitens, Otobius megnini, Amblyomma cajennense, and A. maculatum. The tick microbiomes were analyzed using next-generation sequencing. Among all tick species, the most predominant phylum was Proteobacteria, followed by Actinobacteria and Firmicutes. The ticks from Tamaulipas and Nuevo León presented the highest bacterial species diversity. Acinetobacter johnsonii and A. lwoffii were the common bacterial species in the microbiome of all ticks, Coxiella were present in R. microplus, and Dermacentor nitens also exhibited a Francisella-like endosymbiont. The microbiome of most females in D. nitens was less diverse than that of males, whereas R. microplus occurs in females, suggesting that microbiome diversity is influenced by sex. In the bacterial communities of A. maculatum and O. megnini, Candidatus Midichloria massiliensis, and Candidatus Endoecteinascidia fumentensis were the most predominant endosymbionts. These results constitute the initial report on these bacteria, and this is also the first study to characterize the microbiome of O. megnini. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the impact of in vitro rumen fermentation (IVRF) on the microbiome structure and composition of rumen fluid before and after fermentation assays. Methods and Results: Six separate fermentation batches were run for 48 h using maize silage as the basal feed. Rumen fluid samples were analyzed before (RF; only rumen fluid inoculant) and after 48 h fermentation assay (MS; maize silage as the substrate) and further processed for microbiome analysis using amplicon sequencing targeting the V4 region of the bacterial 16S rRNA gene. Bacterial alpha diversity revealed that the Shannon index and observed index were similar between MS and RF fluid. The core microbiome was detected in 88.6% of the amplicon sequence variants in MS and RF. Taxonomic analysis at the phylum level showed similar abundances of Bacteroidetes, Proteobacteria, Firmicutes, Verrucomicrobiota, Spirochaetota, Patescibacteria, and Campilobacterota in MS and RF. The Bray–Curtis distance matrix showed similar bacterial community structure among MS and RF samples. Conclusion: Our results indicated that the in vitro procedure did not affect the bacterial community structure compared to the original rumen fluid inoculum. It should be noted that assessing the microbiome at a single endpoint (i.e., 48 h) may not provide a comprehensive understanding of the microbiome profile dynamics. However, the findings of this study provide a basis for future microbiome-based in vitro fermentation tests and confirm that the technique allows a high degree of species diversity that approximates the rumen function in vivo. [ABSTRACT FROM AUTHOR]

Yangcheng Lake, a typical fishery lake in the middle and lower reaches of the Yangtze River, is threatened by eutrophication. As the main performers of biogeochemical cycles, microorganisms affect the ecological stability of the lake. To study the structural characteristics of the microbial community in Yangcheng Lake and rivers entering Yangcheng Lake and the response relationship with environmental factors, the microbial community was categorized based on the contour of Yangcheng Lake, the major rivers entering Yangcheng Lake, and the pollution sources. The distribution characteristics of seven physicochemical indices were analyzed, including total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), water temperature (WT), pH, dissolved oxygen (DO), and ratio of total nitrogen to total phosphorus (TN/TP). Characterization of microbial community structure based on 16S rRNA high-flux sequencing technology and ANOSIM analysis were used to explore the differences in the relative abundance of microorganisms at each sampling point in the lake and rivers, and redundancy analysis (RDA) was used to analyze the relationship between the microbial community and physicochemical factors. The results showed that the dominant phyla, genera of microorganisms, and the total number of OTUs in the lake and rivers were similar. The dominant phyla included Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, and Verrucomicrobia; the dominant genera included the hgcI clade, CL500-29 marine group, Microcystis PCC-7914, Chloroplast_norank, Clade III_norank, and Flavobacterium. ANOSIM analyses revealed that the microbial community of Yangcheng Lake exhibited an association with geographical space, while the microbial community in the rivers that was linked to the type of pollution source. Redundancy analysis (RDA) indicated that dissolved oxygen (DO), total nitrogen (TN), and pH were significantly correlated with the dominant phyla in Yangcheng Lake (p < 0.05), while total nitrogen (TN), water temperature(WT), and the ratio of total nitrogen to total phosphorus (TN/TP) were significantly related with the dominant genera in Yangcheng Lake (p < 0.05). Total nitrogen (TN) was also significantly linked to the dominant phyla and genera of the tributaries (p < 0.05). Despite the structural similarities in microbial communities between Yangcheng Lake and its inflowing rivers, environmental factors demonstrated significant associations with these communities, providing crucial data support for pollution prevention and the ecological restoration of Yangcheng Lake. [ABSTRACT FROM AUTHOR]

Methane-oxidizing bacteria (MOB) is a group of planktonic microorganisms that use methane as their primary source of cellular energy. For tropical lakes in monsoon Asia, there is currently a knowledge gap on MOB community diversity and the factors influencing their abundance. Herewith, we present a preliminary assessment of the MOB communities in three maar lakes in tropical monsoon Asia using Catalyzed Reporter Deposition, Fluorescence In-Situ Hybridization (CARD-FISH), 16S rRNA amplicon sequencing, and pmoA gene sequencing. Correlation analysis between MOB abundances and lakes’ physicochemical parameters following seasonal monsoon events were performed to explain observed spatial and temporal patterns in MOB diversity. The CARD-FISH analyses detected the three MOB types (I, II, and NC10) which aligned with the results from 16S rRNA amplicons and pmoA gene sequencing. Among community members based on 16S rRNA genes, Proteobacterial Type I MOB (e.g., Methylococcaceae and Methylomonadaceae), Proteobacterial Type II (Methylocystaceae), Verrucomicrobial (Methylacidiphilaceae), Methylomirabilota/NC10 (Methylomirabilaceae), and archaeal ANME-1a were found to be the dominant methane-oxidizers in three maar lakes. Analysis of microbial diversity and distribution revealed that the community compositions in Lake Yambo vary with the seasons and are more distinct during the stratified period. Temperature, DO, and pH were significantly and inversely linked with type I MOB and Methylomirabilota during stratification. Only MOB type I was influenced by monsoon changes. This research sought to establish a baseline for the diversity and ecology of planktonic MOB in tropical monsoon Asia to better comprehend their contribution to the CH4 cycle in tropical freshwater ecosystems.

Background Psilocybin and related tryptamines have come into the spotlight in recent years as potential therapeutics for depression. Research on the mechanisms of these effects has historically focused on the direct effects of these drugs on neural processes. However, in addition to such neural effects, alterations in peripheral physiology may also contribute to their therapeutic effects. In particular, substantial support exists for a gut microbiome-mediated pathway for the antidepressant efficacy of other drug classes, but no prior studies have determined the effects of tryptamines on microbiota. Methods To address this gap, in this preliminary study, male Long Evans rats were treated with varying dosages of oral psilocybin (0.2 or 2 mg/kg), norbaeocystin (0.25 or 2.52 mg/kg), or vehicle and their fecal samples were collected 1 week and 3 weeks after exposure for microbiome analysis using integrated 16S ribosomal DNA sequencing to determine gut microbiome composition. Results We found that although treatment with neither psilocybin nor norbaeocystin significantly affected overall microbiome diversity, it did cause significant dose- and time-dependent changes in bacterial abundance at the phylum level, including increases in Verrucomicrobia and Actinobacteria, and decreases in Proteobacteria. Conclusion and Implications These preliminary findings support the idea that psilocybin and other tryptamines may act on the gut microbiome in a dose- and time-dependent manner, potentially identifying a novel peripheral mechanism for their antidepressant activity. The results from this preliminary study also suggest that norbaeocystin may warrant further investigation as a potential antidepressant, given the similarity of its effects to psilocybin.

Background and Objectives: TB infection is one of the most challengeable epidemiological issues. Complex interactions between microbiota and TB infection have been demonstrated. Alteration in microbial population during TB infection may act as a useful biomarker. The present study examined the microbiota patterns of blood and sputum samples collected from Afghan immigrants and Iranian patients with active TB. Materials and Methods: Sixty active pulmonary TB patients were enrolled in the study. Blood and sputum samples were collected. To detect phylum bacterial composition in the blood and sputum samples, bacterial 16S rRNA quantification by Real-Time qPCR was performed. Results: A significant decrease in Bacteroidetes in Iranian sputum and blood samples of Afghan immigrants and Iranian TB active subjects were seen. While, sputum samples of Afghan immigrants showed no significant differences in Bacteroidetes abundance among TB active and control. Firmicutes were also presented no significant difference between sputum samples of the two races. Actinobacteria showed a significant increase in Iranian and Afghan sputum samples while this phylum showed no significant abundance in Iranian and Afghan TB positive blood samples. Proteobacteria also showed an increase in sputum and blood samples of the two races. Conclusion: An imbalance in Bacteroidetes and Firmicutes abundance may cause an alteration in the microbiota composition, resulting in dysregulated immune responses and resulting in the augmentation of opportunistic pathogens during TB infection, notably Proteobacteria and Actinobacteria. Evaluation of human microbiota under different conditions of TB infection can be critical to a deeper understanding of the disease control.

Abstract Background Giardia duodenalis (Gd) causes intestinal parasitosis. The involvement of the intestinal microbiome in determining the infection's clinical phenotype is unknown. Objective Investigate the fecal microbiome features in dogs with giardiasis. Animals and Methods Cross‐sectional study, including fecal samples of kenneled dogs with Gd diagnosed by fecal Giardia antigen dot ELISA. The fecal microbial compositional characteristics and dysbiosis index (DI) were compared between diarrheic and nondiarrheic dogs. Results Fecal samples of 38 Gd‐infected dogs (diarrheic, 21; nondiarrheic, 17) were included. No differences were found in Faith's phylogenic diversity and beta diversity (weighted UniFrac distances) and in specific taxa abundances at the phylum, genus, and species levels, as well as in alpha and beta diversities between diarrheic and nondiarrheic dogs, and also when divided by sex or age. Among diarrheic dogs, alpha diversity was higher in males than in females (pairwise Kruskal‐Wallis, q = 0.01). Among males, fecal abundances of the genus Clostridium (W = 19) and Clostridium spiroforme species (W = 33) were higher in diarrheic compared to nondiarrheic dogs. In diarrheic dog fecal samples, Proteobacteria were more prevalent (W = 1), whereas Verrucomicrobia were less prevalent in dogs

The microbiota of the gastrointestinal tract influences gut health, which in turn strongly impacts the general health and productivity of laying hens. It is essential to characterise the composition and temporal development of the gut microbiota in healthy layers raised under different management systems, to understand the variations in typical healthy microbiota structure, so that deviations from this might be recognised and correlated with production and health issues when they arise. The present investigation aimed to study the temporal development and phylogenetic composition of the gut microbiota of four commercially raised layer flocks from hatch to end of the production cycle. Non-intrusive faecal sampling was undertaken as a proxy to represent the gut microbiota. Sequencing of 16S rRNA gene amplicons was used to characterise the microbiota. Beta diversity analysis indicated that each faecal microbiota was different across the four flocks and had subtly different temporal development patterns. Despite these inter-flock differences, common patterns of microbiota development were identified. Firmicutes and Proteobacteria were dominant at an early age in all flocks. The microbiota developed gradually during the rearing phase; richness and diversity increased after 42 d of age and then underwent significant changes in composition after the shift to the production farms, with Bacteroidota becoming more dominant in older birds. By developing a more profound knowledge of normal microbiota development in layers, opportunities to harness the microbiota to aid in the management of layer gut health and productivity may be more clearly seen and realised.

El maíz es un cereal de importancia en términos de nutrición humana y animal a nivel mundial. En el presente estudio se comparó el microbioma bacteriano de la rizosfera del suelo entre tres razas criollas de maíz (Zea mays L.), forrajero (C1), doble propósito (C2) y grano (C3); asimismo se determinó su impacto sobre el rendimiento. Se trabajó en parcelas ubicadas en el Campo Experimental El Retiro de la Universidad Autónoma Agraria Antonio Narro (UAAAN). El muestreo de suelo se efectuó el 13 de junio del 2021, 51 días después de la siembra. El DNA se extrajo a partir de tres muestras de cada tipo de raza de maíz. Se amplificó la región V3-V4 del gen 16S rRNA y se realizó secuenciación masiva de siguiente generación con Illumina; el análisis bioinformático se desarrolló en QIIME utilizando la referencia taxonómica bacteriana EzBioCloud. El phylum Proteobacteria, la clase Phycisphaerae, los órdenes Shingomonadales, Micrococcales y Phycisphaerales, las familias Moroxellaceae, Micrococcaceae, Chitinophagaceae, Shingobacteriaceae y Enterobacteriaceae, así como los géneros Acinetobacter, Shingobacterium y Cryseobacterium, fueron los taxa bacterianos que difirieron en abundancia relativa entre las tres razas (P < 0.05, prueba Kruskal-Wallis y una disimilitud promedio > 0.10 en el análisis SIMPER). Dentro de los taxa mencionados se detectaron bacterias promotoras de crecimiento vegetal (BPCV) como Acinetobacter y Sphingobacterium. Se concluye que, de las razas analizadas, la C2 mostró los mejores rendimientos de peso del grano (15.56 Mg ha-1) y peso seco en forraje (10.61 Mg ha-1), la cual representa una buena opción para preservar la semilla y realizar investigaciones posteriores bajo diferentes condiciones.

Abstract Fish aquaculture has become the fastest growing sector in global food production. Thus, ensuring the sustainability of aquaculture practices is of the utmost importance. Studies in higher vertebrates (i.e. mammals) have demonstrated the role of the host microbiome in physiological processes from nutrient acquisition to pathogen protection. Therefore, analysis of fish microbiomes is an important factor to consider with regard to overall animal health and welfare. Rainbow trout (Oncorhynchus mykiss) are an economically valued fish cultured worldwide. Several studies have identified microbial constituents inhabiting the intestinal tract of rainbow trout. To better elucidate some of the core constituents of the rainbow trout intestinal microbiome, this systematic literature review analysed the relative abundance results from 25 articles published on the rainbow trout intestinal microbiome from 2017 to 2021. Bacteria classified within the phyla Firmicutes and Proteobacteria were observed in every study. At the family level, Lactobacillaceae was consistently observed. Additionally, bacteria in the Actinobacteria, Bacteroides, and Tenericutes phyla were identified in at least 50% of the studies. Interestingly, Mycoplasma spp. were occasionally the most dominant organisms present in the microbiome. Overall, the results here identify bacteria that are commonly found members of the rainbow trout intestinal microbiome.

Abstract Background Sahiwal cattle is an indigenous cattle breed of Pakistan and mastitis is one of the major problems faced by Sahiwal cattle which hinders its production potential. The study was designed to investigate the milk microbiota of healthy and mastitic Sahiwal cattle as part of a multistep project to develop probiotics for the mitigation and control of mastitis. Milk samples of Sahiwal cattle (healthy clinical mastitis and subclinical mastitis) reared under similar husbandry and management practices were processed for 16S rRNA gene base metagenomics analysis. Results Results revealed that Proteobacteria were dominant in the healthy group and subclinical mastitis group (56.48% and 48.77%, respectively) as compared to the clinical mastitis group (2.68%). In contrast, Firmicutes were abundant in the clinical mastitis group (64%) as compared to the healthy and subclinical mastitis groups (15.87% and 38.98%, respectively). Dominant species assigned in the healthy group were Ignavibacterium album, Novosphingobium capsulatum, Akkermansia muciniphila and Lactobacillus fermentum.The clinical mastitis group was dominated by Streptococcus dysgalactiae and Corynebacterium bovis, while subclinical mastitis group included Lactobacillus fermentum and uncultured acidobacteriales and Akkermansia muciniphila as dominant species. Alpha diversity indices showed higher microbial diversity in the healthy group compared to the clinical and sub-clinical mastitis groups. Conclusion It is concluded that the milk microbiota of healthy sahiwal cattle has higher diversity and dominant taxa in the different groups may be used as signature microbes for mastitis susceptibility. Akkermansia muciniphila is one of candidate specie that was identified and may be used for development of probiotics.

Abstract Drying and rewetting (DRW) events cause the release of colloidal phosphorus (Pcoll, 1–1000 nm) in leachate, and biochar is considered an effective inhibitor; however, the microbial mechanism remains elusive. In this study, three successive DRW cycles were performed on the soil columns to assess the effect of biochar addition on Pcoll content and its possible associates, including phosphatase-producing microbial populations (phoD- and phoC-harboring microbial communities) and alkaline/acid phosphatase (ALP/ACP) activities. Results showed that the biochar addition significantly decreased the Pcoll by 15.5–32.1% during three DRW cycles. The structural equation model (SEM) confirmed that biochar addition increased phoD- and phoC-harboring microbial communities and ALP/ACP activities, which reduces the release of Pcoll into leachate. In addition, the manure biochar was more effective than the straw biochar in promoting competition and cooperation in the co-occurrence network (2–5% nodes increased on average), and the key taxa Proteobacteria and Cyanobacteria were identified as the dominant species of potential ALP/ACP activities and Pcoll content. Our findings provide a novel understanding of biochar reducing Pcoll loss from the phosphatase perspective by regulating the phoD- and phoC-harboring communities during DRW events. Graphical abstract

Abstract Gut microbiota impacts fish metabolism, nutrient utilization, and health. We know little about how temperature and diet interact with rainbow trout gut microbes. A total of 288 fish (average body weight: 45.6 g) fed four iso‐caloric, ‐lipidic, and ‐nitrogenous diets comprised crude protein (40%) and lipid (20%) manufactured as 100% animal‐based protein (AP) and blend of 50 fish oil (FO)/50 camelina oil (CO), 100% AP and 100% CO, 100% plant‐based protein (PP) and blend of 50 FO/50 CO or 100% PP and 100% CO at 14 or 18°C water temperature. Gut content was analyzed using 16S rRNA gene and shotgun sequencing. Alpha‐diversity did not change significantly. Regardless of diet, Tenericutes, Firmicutes, Proteobacteria, Spirochaetes, Bacteroidetes, and Actinobacteria dominated. At family level, Aeromonadaceae and Enterobacteriaceae dominated at 18°C, while Mycoplasmataceae dominated at 14°C. Moreover, genes relating to amino acid, carbohydrate, fat, and energy metabolisms and fatty acid biosynthesis significantly increased at 18°C. Functional profiles did not vary significantly among diets, except for a higher methionine and cysteine metabolism in fish fed plant ingredient compared animal diet, suggesting trout fed plant‐derived protein mixed with CO could be as effective as those fed fish meals mixed with 50/50 FO and CO.

Pulp-paper mills (PPMs) are known for consistently generating a wide variety of pollutants, that are often unidentified and highly resistant to environmental degradation. The current study aims to investigate the changes in the indigenous bacterial communities profile grown in the sediment co-contaminated with organic and inorganic pollutants discharged from the PPMs. The two sediment samples, designated PPS-1 and PPS-2, were collected from two different sites. Physico-chemical characterization of PPS-1 and PPS-2 revealed the presence of heavy metals (mg kg−1) like Cu (0.009–0.01), Ni (0.005–0.002), Mn (0.078–0.056), Cr (0.015–0.009), Pb (0.008–0.006), Zn (0.225–0.086), Fe (2.124–0.764), Al (3.477–22.277), and Ti (99.792–45.012) along with high content of chlorophenol, and lignin. The comparative analysis of organic pollutants in sediment samples using gas chromatography–mass spectrometry (GC–MS) revealed the presence of major highly refractory compounds, such as stigmasterol, β-sitosterol, hexadecanoic acid, octadecanoic acid; 2,4-di-tert-butylphenol; heptacosane; dimethyl phthalate; hexachlorobenzene; 1-decanol,2-hexyl; furane 2,5-dimethyl, etc in sediment samples which are reported as a potential toxic compounds. Simultaneously, high-throughput sequencing targeting the V3–V4 hypervariable region of the 16S rRNA genes, resulted in the identification of 1,249 and 1,345 operational taxonomic units (OTUs) derived from a total of 115,665 and 119,386 sequences read, in PPS-1 and PPS-2, respectively. Analysis of rarefaction curves indicated a diversity in OTU abundance between PPS-1 (1,249 OTUs) and PPS-2 (1,345 OTUs). Furthermore, taxonomic assignment of metagenomics sequence data showed that Proteobacteria (55.40%; 56.30%), Bacteoidetes (11.30%; 12.20%), and Planctomycetes (5.40%; 4.70%) were the most abundant phyla; Alphproteobacteria (20.50%; 23.50%), Betaproteobacteria (16.00%; 12.30%), and Gammaproteobacteria were the most recorded classes in PPS-1 and PPS-2, respectively. At the genus level, Thiobacillus (7.60%; 4.50%) was the most abundant genera grown in sediment samples. The results indicate significant differences in both the diversity and relative abundance of taxa in the bacterial communities associated with PPS-2 when compared to PPS-1. This study unveils key insights into contaminant characteristics and shifts in bacterial communities within contaminated environments. It highlights the potential for developing efficient bioremediation techniques to restore ecological balance in pulp-paper mill waste-polluted areas, stressing the importance of identifying a significant percentage of unclassified genera and species to explore novel genes.

Abstract: This study investigates the presence of bacterial dominance in one of the most studied sewage-driven eutrophic coastal lagoons, the Imboassica Lagoon in Macaé (RJ), Brazil, utilizing high-throughput sequencing of 16S rDNA. Water samples were collected from three sites within the lagoon. Total microbial DNA was extracted, and the V3-V4 region of the 16S rRNA gene was amplified and sequenced on the Illumina MiSeq platform. A total of 744,879 partial 16S rRNA sequences were clustered, revealing the absence of a single bacterial dominance in the sewage-driven eutrophic coastal lagoon. The prominent phyla detected in the lagoon were Cyanobacteria (27.8%), Proteobacteria (23.7%), and Actinobacteria (14.6%). Proteobacteria emerged as the most abundant phylum in the sewage-impacted lagoon site, whereas Cyanobacteria dominated the other two sampling sites. Among families, Synechococcaceae predominated with genus Synechococcus exhibited the highest prevalence. Families of potentially toxic Cyanobacteria represented less than 1% of the total families. The sewage-impacted lagoon section displayed greater bacterial diversity and richness. The dominance of bacterial communities associated with raw sewage, such as members of the Enterobacteriaceae family, was not confirmed, constituting only 0.75% of the families in the most affected site. This study presents the initial analysis of the bacterial community in the Imboassica Lagoon and suggests that dominance in the lagoon responds to the eutrophication and sewage discharge.

ABSTRACTDuring their long evolution, anoxygenic phototrophic bacteria have inhabited a wide variety of natural habitats and developed specific strategies to cope with the challenges of any particular environment. Expression, assembly, and safe operation of the photosynthetic apparatus must be regulated to prevent reactive oxygen species generation under illumination in the presence of oxygen. Here, we report on the photoheterotrophic Sediminicoccus sp. strain KRV36, which was isolated from a cold stream in north-western Iceland, 30 km south of the Arctic Circle. In contrast to most aerobic anoxygenic phototrophs, which stop pigment synthesis when illuminated, strain KRV36 maintained its bacteriochlorophyll synthesis even under continuous light. Its cells also contained between 100 and 180 chromatophores, each accommodating photosynthetic complexes that exhibit an unusually large carotenoid absorption spectrum. The expression of photosynthesis genes in dark-adapted cells was transiently downregulated in the first 2 hours exposed to light but recovered to the initial level within 24 hours. An excess of membrane-bound carotenoids as well as high, constitutive expression of oxidative stress response genes provided the required potential for scavenging reactive oxygen species, safeguarding bacteriochlorophyll synthesis and photosystem assembly. The unique cellular architecture and an unusual gene expression pattern represent a specific adaptation that allows the maintenance of anoxygenic phototrophy under arctic conditions characterized by long summer days with relatively low irradiance.IMPORTANCEThe photoheterotrophic bacterium Sediminicoccus sp. KRV36 was isolated from a cold stream in Iceland. It expresses its photosynthesis genes, synthesizes bacteriochlorophyll, and assembles functional photosynthetic complexes under continuous light in the presence of oxygen. Unraveling the molecular basis of this ability, which is exceptional among aerobic anoxygenic phototrophic species, will help to understand the evolution of bacterial photosynthesis in response to changing environmental conditions. It might also open new possibilities for genetic engineering of biotechnologically relevant phototrophs, with the aim of increasing photosynthetic activity and their tolerance to reactive oxygen species.

The Cavendish banana (Musa cavendishii L.) is one of the main perennial crops grown in Dak Lak Province of Vietnam. However, data on the endophytic bacterial community of this plant are unknown. In this work, a representative sample, mixing from 5 root samples collected from five banana gardens (the Dwarf Cavendish cultivar) in Dak Lak, was used for analyzing the endophytic microbiome using 16S rRNA gene metabarcoding. Results showed that 5 phyla, 7 classes, 20 orders, 31 families, and 47 genera of endophytic bacteria were identified from the sample. Bacteria belonging to phylum Proteobacteria were the most predominant, with 72.64%, and functions involved in biosynthesis were the most abundant, with 75.35%, of the endophytic bacterial community. Data help to understand the endophytic bacterial community of the Cavendish banana cultivated in Dak Lak, Vietnam. These data can be useful for further experiments concerning relationships between the growth of the Cavendish banana and endophytic bacteria. This is the first report on the endophytic bacteria of the Cavendish banana cultivated in Dak Lak, Vietnam.

Vietnam is currently one of the largest producers and exporters of cashew nuts in the world. Cashew (Anacardium occidentale L.) is one of the main industrial crops cultivated in Dak Lak Province of Vietnam. Comprehending the endophytic bacteria of this plant, a new biofertilizer for sustainable cashew nut production can be progressed. In this report, the cashew root sample was collected from cashew fields in 2021 in Dak Lak. The DNeasy Powersoil kit was used to extract the genomic DNA of endophytic bacteria from the root sample. The 16S rRNA genes (V1–V9 regions) were amplified by PCR, and libraries of amplicons were prepared using the Swift amplicon 16S plus ITS panel kit. The Illumina MiSeq platform was applied to sequence amplicon libraries using 16S rRNA metagenomics. Taxonomic analyses showed that Gammaproteobacteria (38.77 %) and Alphaproteobacteria (37.76 %) were the predominant classes among the endophytic bacteria. Functional analyses revealed that biosynthesis (72.78 %) was the primary function of the endophytic bacterial community. Raw sequences (Fastq files) have been deposited in Mendeley Data [1]. The obtained data provide insight into the endophytic bacterial community of cashews cultivated in Dak Lak Province of Vietnam. The data are valuable for further developing a new biofertilizer for cashew nut production using endophytic bacteria. Ours is the first report about endophytic bacterial communities of cashews cultivated in this province as well as the Central Highlands of Vietnam.

Red calcified non-geniculate coralline algae (NGCA) provide habitat structures, stabilize reef structures, and foster coral larval settlement and metamorphosis. Moreover, the microbes associated with NGCA are dependent on the NGCA host species and are affected by environmental factors; however, little is known about the influence of reef conditions and depth gradients on the associated microbial communities and NGCA. In this study, we collected NGCA under different reef conditions and depth gradients and characterized the microbial communities using the V3–V4 hypervariable regions of the 16S rRNA gene. Metagenomic analysis revealed 2 domains, 51 phyla, 123 classes, and 210 genera. The NGCA-associated bacterial communities were dominated by Proteobacteria, Bacteroidetes, Chloroflexi, Actinobacteria, and Acidobacteriota. Gammaproteobacteria and Alphaproteobacteria were the most abundant bacterial classes. Differences in microbial diversity and richness were not apparent between reef conditions and depth gradients. However, there was a significant difference in bacterial evenness among the depth gradients. The bacterial abundance associated with NGCA was greater in deep zones than in shallow zones. The shallow zone exhibited a greater relative abundance of all gene functions than the deep zone, indicating differences in the distribution of gene functions. This study showed that the microbial communities associated with red calcified NGCA are diverse, and that the depth gradient affects their abundance and evenness, highlighting the need for further research to understand the functional roles of these microbial communities in coral reef conservation.

BcsD is broadly present throughout Proteobacteria and is predicted to contribute to cellulose crystallinity via interaction with BcsH. However, new work shows that, in non-crystalline forming Proteobacteria, BcsD contains an amino-terminal a1-helix, forms a tetrahedron-like structure, and interacts with alternative proline-rich protein partners. [ABSTRACT FROM AUTHOR]

Smear-ripened cheeses are characterized by a viscous, red-orange surface smear on their rind. It is the complex surface microbiota on the cheese rind that is responsible for the characteristic appearance of this cheese type, but also for the wide range of flavors and textures of the many varieties of smear-ripened cheeses. The surface smear microbiota also represents an important line of defense against the colonization with undesirable microorganisms through various types of interaction, such as competitive exclusion or production of antimicrobial substances. Predominant members of the surface smear microbiota are salt-tolerant yeast and bacteria of the phyla Actinobacteria, Firmicutes, and Proteobacteria. In the past, classical culture-based approaches already shed light on the composition and succession of microorganisms and their individual contribution to the typicity of this cheese type. However, during the last decade, the introduction and application of novel molecular approaches with high-resolution power provided further in-depth analysis and, thus, a much more detailed view of the composition, structure, and diversity of the cheese smear microbiota. This led to abundant novel knowledge, such as the identification of so far unknown community members. Hence, this review is summarizing the current knowledge of the diversity of the surface smear microbiota and its contribution to the quality and safety of smear-ripened cheese. If the succession or composition of the surface-smear microbiota is disturbed, cheese smear defects might occur, which may promote food safety issues. Hence, the discussion of cheese smear defects in the context of an increased understanding of the intricate surface smear ecosystem in this review may not only help in troubleshooting and quality control but also paves the way for innovations that can lead to safer, more consistent, and higher-quality smear-ripened cheeses. [ABSTRACT FROM AUTHOR]

Mammary gland infections occur due to bacterial changes in the mammary tissue. Studies conducted in recent years have reported variations in the most common bacteria differ according to geographical locations. California mastitis test (CMT), somatic cell count (SCC), and aerobic colony count (ACC) analyses were performed on approximately 50 mL of hygienically collected raw milk samples. Raw milk was also subjected to conventional bacteriological isolation and identification. Bacterial diversity and rates in raw milk were compared through metagenome analysis. Two samples, one from healthy milk and another from subclinical milk with mastitis, were independently tested to determine whether there were differences in the percentages (%) of bacterial phylum and genera detected as a result of metagenome analysis. As a result of the conventional isolation and identification of raw milk, Escherichia-Shigella, Acinetobacter, Vibrio, Streptococcus, Pseudomonas, Lactococcus, Glutamicibacter and Bacillus genera, and Enterobacteriaceae family were frequently detected, respectively. As a result of metagenome analysis, the following phyla were detected in healthy raw milk: Firmicutes and Proteobacteria (7/7), Bacteroidota (6/7), and Actinobacteriota (4/7). In raw milk with subclinical mastitis, the detected phyla were Firmicutes and Proteobacteria (27/29), Actinobacteriota (11/29), and Bacteroidota (10/29). As a result of the statistical analysis, the frequency of Bacteriodata in healthy milk samples, as well as Enhydrobacter, Enterobacteriaceae, Paenibacillus, Macrococcus, Spingobacterium, and "Others", were significantly higher than the incidence in milk samples with subclinical mastitis. The only exception was observed in Escherichia-Shigella genera, where the opposite situation was evident. As a result of metagenome studies conducted on the raw milk of animals with both healthy and subclinical mastitis, significant differences were detected in some phyla and genera. The findings of our study will shed light on mastitis treatment studies by improving the microbiota. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are a global concern regarding environmental pollution. This study evaluated the impacts of MPs with two sizes (5 µm and 0.5 µm) on hatching performance and microbiota of Sepiella japonica. The presence of MPs increased the hatching rate at some stages of the fertilization process and reduced the oxygen consumption rate at the gastrula stage. No size-dependent impact was observed. The 16S rRNA gene was sequenced to identify the flora. Clustering tags assessed species diversity in the samples with 97% similarity. Proteobacteria was the most abundant phylum in all three groups. MPs publicity appreciably modified flower structure. The most variable genera were Ralstonia, Methylophilus, and Pseudorhodoferax, which can furnish nutrients and modify the host's immune response. MPs exposure appeared to enrich beneficial bacteria in this study. The presence of MPs with a size of 5µm played a greater role in this process, which is supported by presumptive functions. However, since the adsorption of suspended MPs on aquatic eggs can have cascading effects on specific life stages of oviparous animals, regular monitoring of microbial communities is necessary after juvenile S. japonica formation to prevent disease outbreaks. [ABSTRACT FROM AUTHOR]

[Objective] The purpose of this experiment was to explore the effects of potato stem and leaf returning on the physiochemical properties of soil and the structure of the bacterial community. [Method] Differences in soil physiochemical properties and bacterial communities were compared between soil samples with (treatment group R) and without (treatment group NR) potato stem and leaf returning using soil physiochemical analysis and Illumina high-throughput sequencing techniques. [Result] Compared to CK treatment, potato stem and leaf returning significantly increased soil pH, organic matter, alkali-hydrolysable nitrogen, available phosphorus and available potassium content, particularly the available potassium content with an increases from 42. 36 to 141.53 mg/kg. Potato stem and leaf returning significantly affected the structure of the soil bacterial community, with a significant increase in the abundance of 12 bacterial taxa in the R treatment group (on the 45th and 90th day). In addition, the diversity of soil bacterial species was significantly higher in the R treatment group compared to the NR treatment group. Co-occurrence network analysis indicated that the inter-species interactions of bacteria occurred primarily in the Acidobacteria, Actinobacteria, and Proteobacteria phyla. The strength of the interaction was significantly higher in the potato stem and leaf returning treatment compared with the non-returning treatment. Correlation analysis revealed a highly significant negative correlation between Latescibacterota and Desulfobacterota with available phosphorus content and a significant positive correlation with alkali hydrolysable nitrogen and organic matter content. Furthermore, significant positive correlations were observed between Myxococcota, Bdelloyibrionota, Patescibacteria, Entotheonellaeota, Gemmatimonadota, Nitrospirota, Proteobacteria and available potassium content. [Conclusion] The findings indicated that the returning of the potato stem and leaf could significantly improve the soil nutrient content, the diversity of bacterial species and the strength of interspecies interactions in the soil bacterial community. There were significant correlations between the physiochemical properties of the soil and the composition of the bacterial community of the soil. [ABSTRACT FROM AUTHOR]

[Objective] Analyzing the changes of microbial community and enzyme activities in the rhizospheric soil of Paeonia lactiflora with root rot and understanding the relationship between soil environmental factors, microbial community and root rot of P. lactiflora would provide the scientific basis for controlling root rot of P. lactiflora. [Method] Illumina high throughput sequencing technology and soil physicochemical property method were employed to investigate soil bacterial and fungal communities, soil nutrients and enzyme activities of rhizosphere soil of healthy and root rot diseased plants of P. lactiflora. [Result] The content of soil organic matter in the rhizosphere of diseased plants significantly increased, the content of available potassium significantly decreased, and the content of soil alkaline phosphatase and peroxidase significantly increased, compared with healthy plants of P. lactiflora. The richness and diversity of bacteria decreased, but the richness and diversity of fungi increased in the rhizosphere soil of root rot diseased plants of P. lactiflora. The relative abundance of Proteobacteria, Bacteroidota and Sumerlaeota in the rhizosphere soil of root rot diseased plants of P. lactiflora was significantly higher than that of healthy plants, but Chloroflexi, Actinobaciota, Ethylomirabilota and Firmicutes decreased significantly. Sphingomonas, Chtoniobacter, Subgroup7 and Saccharimondales in the rhizosphere soil of root rot diseased plants of P. lactiflora was higher than that of healthy plants. The relative abundance of Ascomycota increased and Basidiomycota decreased in the rhizosphere soil of root rot diseased plants of P. lactiflora, and Zygomycota was significantly higher than that of healthy plants. The pH, organic matter, available phosphorus, available potassium, water-soluble salt, alkaline phosphatase, peroxidase, urease and sucrase were important factors that affected the changes of microbial community in the rhizosphere soil of P. lactiflora, which were mainly related to the changes of dominant bacterial phyla, Chloroflexi, Metromirabilota, Actinobacteriota, and dominant fungal phyla, Chytridiomycota, Basidiomycota, Ascomycota. [Conclusion] The relative abundance of harmful fungi such as Ilyonia, Erysiphe and Fusarium increases significantly. The accumulation of pathogenic bacteria, the changes of enzyme activities, and the nutrient imbalance are the important reasons for the occurrence of root rot of P. lactiflora. [ABSTRACT FROM AUTHOR]

[Objective] The study aimed to understand the response of rhizosphere bacterial community structure and function to drought stress in cucumber seedlings. [Method] Potted water control method was used to set up drought treatment D and normal treatment N, and the rhizosphere bacteria community structure and diversity in cucumber seedlings were determined by Illumina NovaSeq sequencing. [Result] The contents of chlorophyll and soluble sugar in treatment (N) were 2.440 and 10. 380 mg/g, respectively, which were significantly higher than that of drought treatment (D), which was 1.547 and 8. 356 mg/g (P<0.05). The contents of proline and malondialdehyde in treatment D was 51.807 µg/g and 54.848 mol/g, respectively, which were significantly higher than those of treatment N (32.628 µg/g and 29.005 mol/g). The root activity of treatment N was 32.670 µg/(g·h), which was significantly higher than that of treatment D with 20.714 µg/(g·h). Superoxide dismutase (SOD) content of treatment N was 324. 826 U/g, which was significantly lower than that of treatment D with 578. 363 U/g. In the rhizosphere bacterial community of cucumber seedlings, the top five in abundance at the taxonomic level were Proteobacteria, Gemmatimonadota, Bacteroidota, Acidobacteriota and Actinobacteriota. There was no significant difference among treatments in a diversity index (Chaol, Shannon, Simpson). But PCoA analysis showed that there was significant difference in bacterial community structure between the two treatments. Comparing to treatment D, Gemmatimonadota of treatment N was obviously up-regulated, while Bacteroidota and Firmicutes were obviously down-regulated (P<0.05). LEfSe results showed that beneficial bacteria such as Muribaculaceae, Clostridia, Bacilli, etc. which mainly belonging to Bacteroidota and Firmicutes, were significantly enriched in treatment D. The functional analysis of rhizosphere bacterial community showed that the abundance of RNA processing and modification, chromatin structure and dynamics, transcription, amino acid transport and metabolism, carbohydrate transport and metabolism and other related functions of treatment D significantly increased. Furthermore the synthetic pathway related to secondary metabolites such as thiamine and the degradation metabolic pathway dominated by sugars and amino acids were up-regulated. [Conclusion] Drought stress had significant impact on the rhizosphere bacterial community structure of cucumber seedlings, which promoted the significant enrichment of beneficial microorganisms in rhizosphere soil, mainly Bacteroides and Sclerotinia, inducing and promoting the life activities of bacterial community, and significantly increased the abundance of secondary metabolites related to thiamine and degradation metabolic pathways mainly composed of sugars and amino acids. It was expected to provide new ideas for exploring the interaction mechanism of beneficial bacteria in soil that might have a positive impact on cucumber seedlings growth under drought stress. [ABSTRACT FROM AUTHOR]

Ecological restoration has notably impacted microbe and soil characteristics in abandoned open pit mines, especially in alpine regions. Yet, the adaptive responses of microbial communities in the initial years of mine site restoration remain largely unexplored. This study endeavors to offer a thorough comprehension of soil properties and microbial dynamics during the initial phases of alpine mining land reclamation. It places emphasis on physicochemical properties and microbial community composition and evaluates the feasibility of phytoremediation, along with proposing subsequent measures. Our study employs spatial sequence instead of time-sequenceal sequence to investigate early-stage changes in soil microbes and physicochemical properties in alpine mining land reclamation. We used high-throughput sequencing for the 16S rRNA amplicon study. Over time, soil physicochemical properties improved noticeably. Soil pH shifted from neutral to alkaline (7.04–8.0), while soil electrical conductivity (EC) decreased to 77 μS·cm−1 in R_6a. Cation exchange capacity (CEC) initially decreased from R_2a (12.30–27.98 cmol·kg−1) and then increased. Soil organic matter increased from 17.7 to 43.2 g·kg−1 over time during mine reclamation and restoration. The dominant bacterial community consisted of Proteobacteria (33.94% to 52.09%), Acidobacteriota (4.94% to 15.88%), Bacteroidota (6.52% to 11.15%), Actinobacteriota (7.18% to 9.61%), and Firmicutes (4.52% to 16.80%) with varying relative abundances. Gene annotation of sequences from various reclamation years revealed general function prediction, translation, ribosome structure, cell wall/membrane/envelope biogenesis, nucleotide translocation, and metabolism, along with other related functions. Mine reclamation improved soil fertility and properties, with the R_6a treatment being the most effective. Starting in the 2nd year of reclamation, the effective phosphorus content and the dominance of microbial bacteria, notably the Bacillus content, decreased. Firmicute fertilization promoted phosphorus and bacterial growth. In conclusion, employing a blend of sequencing and experimental approaches, our study unveils early-stage enhancements in soil microbial and physicochemical properties during the reclamation of alpine mining areas. The results underscore the beneficial impacts of vegetation restoration on key properties, including soil fertility, pore structure, and bacterial community composition. Special attention is given to assessing the effectiveness of the R_6a treatment and identifying deficiencies in the R_2a treatment. It serves as a reference for addressing the challenges associated with soil fertility and microbial community structure restoration in high-altitude mining areas in Qinghai–Tibet. This holds great significance for soil and water conservation as well as vegetation restoration in alpine mining regions. Furthermore, it supports the sustainable restoration of local ecosystems. [ABSTRACT FROM AUTHOR]

Candidatus Liberibacter asiaticus (CLas) is associated with Citrus Huanglongbing (HLB), a devastating disease in the US. Previously, we conducted a two-year-long monthly HLB survey by quantitative real-time PCR using root DNA fractions prepared from 112 field grapefruit trees grafted on sour orange rootstock. Approximately 10% of the trees remained CLas-free during the entire survey period. This study conducted 16S metagenomics using the time-series root DNA fractions, monthly prepared during twenty-four consecutive months, followed by microbial co-occurrence network analysis to investigate the microbial factors contributing to the CLas-free phenotype of the aforementioned trees. Based on the HLB status and the time when the trees were first diagnosed as CLas-positive during the survey, the samples were divided into four groups, Stage H (healthy), Stage I (early), II (mid), and III (late) samples. The 16S metagenomics data using Silva 16S database v132 revealed that HLB compromised the diversity of rhizosphere microbiota. At the phylum level, Actinobacteria and Proteobacteria were the predominant bacterial phyla, comprising >93% of total bacterial phyla, irrespective of HLB status. In addition, a temporal change in the rhizosphere microbe population was observed during a two-year-long survey, from which we confirmed that some bacterial families differently responded to HLB disease status. The clustering of the bacterial co-occurrence network data revealed the presence of a subnetwork composed of Streptomycetaceae and bacterial families with plant growth-promoting activity in Stage H and III samples. These data implicated that the Streptomycetaceae subnetwork may act as a functional unit against HLB. [ABSTRACT FROM AUTHOR]

The complete removal of bacterial and fungal communities found in natural water sources by drinking water treatment plants (DWTPs) is a global issue of concern as many of these microbes are passed down to the end users through the drinking water distribution systems (DWDSs). An overview of the bacterial and fungal communities present in natural water sources is provided. The abundance of the bacterial and fungal communities in the final water exiting DWTPs and tap water from DWDSs provides an insight into the treatment plants' effectiveness. Information on the different technologies including artificial intelligence (AI) used in the water treatment plants was collated to elucidate their role in drinking water treatment. Based on previous studies, Proteobacteria, Firmicutes, Nitrospirae, and Actinobacteria are the predominant bacterial phyla while Aspergillus, Cladosporium and Penicillium, Fusarium and Trichoderma are the predominant fungal phyla identified in the final water and tap water. Information on the performance of advanced treatment shows the positive impact of the technology in bacteria and fungi removal. Furthermore, the application of AI in water treatment for the determination of coagulant dosages and prediction of the disinfectant is also promising. Research gaps were identified, and future studies were recommended to address water treatment concerns. [ABSTRACT FROM AUTHOR]

Three new strains of dissimilatory perchlorate-reducing bacteria (DPRB), QD19-16, QD1-5, and P3-1, were isolated from an active sludge. Phylogenetic trees based on 16S rRNA genes indicated that QD19-16, QD1-5, and P3-1 belonged to Brucella, Acidovorax, and Citrobacter, respectively, expanding the distribution of DPRB in the Proteobacteria. The three strains were gram-negative and facultative anaerobes with rod-shaped cells without flagella, which were 1.0–1.6 μm long and 0.5–0.6 μm wide. The three DPRB strains utilized similar broad spectrum of electron donors and acceptors and demonstrated a similar capability to reduce perchlorate within 6 days. The enzyme activity of perchlorate reductase in QD19-16 toward chlorate was higher than that toward perchlorate. The high sequence similarity of the perchlorate reductase operon and chlorite dismutase genes in the perchlorate reduction genomic islands (PRI) of the three strains implied that they were monophyletic origin from a common ancestral PRI. Two transposase genes (tnp1 and tnp2) were found in the PRIs of strain QD19-16 and QD1-5, but were absent in the strain P3-1 PRI. The presence of fragments of IR sequences in the P3-1 PRI suggested that P3-1 PRI had previously contained these two tnp genes. Therefore, it is plausible to suggest that a common ancestral PRI transferred across the strains Brucella sp. QD19-16, Acidovorax sp. QD1-5, and Citrobacter sp. P3-1 through horizontal gene transfer, facilitated by transposases. These results provided a direct evidence of horizontal gene transfer of PRI that could jump across phylogenetically unrelated bacteria through transposase. Key points: • Three new DPRB strains can effectively remove high concentration of perchlorate. • The PRIs of three DPRB strains are acquired from a single ancestral PRI. • PRIs are incorporated into different bacteria genome through HGT by transposase. [ABSTRACT FROM AUTHOR]

High-performance sequencing of the 16S rRNA gene (V4 region) was used to reveal the most widespread groups of microorganisms in the bottom sediments of the Barents and Kara seas. In the Barents Sea, these were uncultured bacteria of the families Hyphomicrobiaceae, Anaerolineaceae, Desulfobulbaceae, and Desulfosarcinaceae (Sva0081 sediment group), actinobacteria of the genus Rhodococcus, and proteobacteria of the genus Woeseia. In the Kara Sea the most represented groups were uncultured bacteria of the order Sedimentisphaerales (the SG8-4 cluster, class Phycisphaerae, phylum Planсtomycetota), bacteria of the family Anaerolineaceae, the family Desulfosarcinaceae (the SEEP-SRB1 cluster), the deep phylogenetic cluster NB1-j, organotrophic proteobacteria of the genera Woeseia and Pseudomonas, and sulfate reducers of the genus Desulfatiglans. The patterns of microbial distribution were analyzed depending on the depth from the bottom surface and the presence of fluid discharge zones. It was found that according to analysis of the core microbiome, uncultured bacteria of the SG8-4 cluster and uncultured bacteria of the family Anaerolineaceae predominated in the methane discharge zones in the Barents and Kara seas. [ABSTRACT FROM AUTHOR]

Inhaled corticosteroids (ICS) are the most commonly used anti-inflammatory drugs for the treatment of COPD. COPD has been previously described as a “corticosteroid-resistant” condition, but current clinical trial evidence shows that selected COPD patients, namely those with increased exacerbation risk plus higher blood eosinophil count (BEC), can benefit from ICS treatment. This review describes the components of inflammation modulated by ICS in COPD and the reasons for the variation in response to ICS between individuals. There are corticosteroid-insensitive inflammatory pathways in COPD, such as bacteria-induced macrophage interleukin-8 production and resultant neutrophil recruitment, but also corticosteroid-sensitive pathways including the reduction of type 2 markers and mast cell numbers. The review also describes the mechanisms whereby ICS can skew the lung microbiome, with reduced diversity and increased relative abundance, towards an excess of proteobacteria. BEC is a biomarker used to enable the selective use of ICS in COPD, but the clinical outcome in an individual is decided by a complex interacting network involving the microbiome and airway inflammation. [ABSTRACT FROM AUTHOR]

Heavy metal(loid)s pose a concern that has drawn significant attention on a worldwide scale due to their persistence, toxicity, and bioaccumulation. For instance, research estimates that globally, the environment has been exposed to around 800,000 t of lead (Pb) and 30,000 t of chromium (Cr) over the course of the last 50 years. In response to this global problem, several techniques such as electrokinetic extraction, surface capping, encapsulation, soil flushing, soil washing, and chemical immobilization have been applied for the remediation of metal-contaminated soils. However, many of these have been classified as expensive, non-ecofriendly and time-consuming. Research has shown that proteobacteria is one of the most abundant phyla in metal-contaminated soils. Proteobacteria are well known for their pathogenic potential, but little is known about their potential for cleaning up contaminated soil. This study assessed the remediation potentials of the proteobacteria consortium on leachate-contaminated soil. About 18 bacterial species that were isolated from the leachate-contaminated soil were reintroduced to the soil. The metals with the highest levels of bioreduction activity in the microcosm modified with proteobacteria isolates were As (61%), Cu (64%), Zn (53%), Mn (47%), and Cr (61%). The shortest bioreduction time detected during remediation by proteobacteria isolates is 69.3 days, which is related to Cu reduction at a rate of 0.01 day−1. It is inferred that the selective blending of proteobacteria isolates promotes the bioreduction of metals in contaminated systems by manipulating microbial diversity. Therefore, it is possible to exploit a potential synergy toward metal reduction through microbial interaction. [ABSTRACT FROM AUTHOR]

Conventional sewage treatment plants aim to minimize environmental impacts, but generate by-products, such as sludge, which also must be properly treated and dewatered. From the resource recovery perspective, a promising alternative is a reuse as fertilizer in agriculture, due to the nutrients in its composition, but the feasibility of this reuse depends on sludge treatment technologies that, in addition to promoting dewatering, treat toxic pollutants, pathogens and metals. Many techniques have been employed in an attempt to promote effective dewatering and remove pollutants from sludge, but the high cost of physicochemical treatments and risk of causing secondary pollution, make it difficult to apply on a larger scale, as well as reuse the sludge. Therefore, biological treatments, such as bioleaching, have become an increasingly popular choice, as they have economic and environmental benefits, which with improvements can enable the use of sludge as a resource. The objective of the present study was to investigate the scientific production of the last twelve years, regarding the microbiology of extracellular polymeric substances influence on sewage sludge dewatering during the bioleaching process. The specific objectives were to elucidate the influence of extracellular polymeric substances fractions on sludge dewatering, to identify the main microorganisms involved in extracellular polymeric substances generation and identify the main microorganisms involved in its removal during bioleaching. This literature review will help to understand the microbiological aspects of dewatering during the bioleaching process and will provide useful information to improve future research on the application of bioleaching in sewage sludge treatment. [ABSTRACT FROM AUTHOR]

Introduction: The gut microbiota closely relates to host health, whereas the relationship between gut microbiota and testosterone during the development of Meishan male pigs remains unclear. This study investigated the fecal microbiota composition and testosterone level during development in Meishan male pigs. Methods: Fresh fecal samples of 20 healthy Meishan male pigs were individually collected at 10 and 22 weeks (wk) of age for testosterone content detection and bacteria pyrosequencing analysis. Anaerobic culture experiment of fecal bacteria in vitro was performed for bacteria pyrosequencing analysis. Results: The fecal testosterone content increased significantly from 10 weeks (wk) to 22 wk of age (P < 0.05). Meanwhile, the boars at 22 wk had a lower abundance of phylum Bacteroidetes and Proteobacteria, and genus Alloprevotella, Prevotella_1, Prevotellaceae_NK3B31_group, and Streptococcus in the fecal microbiota composition (P < 0.05). but higher proportions of the phylum Actinobacteria, Firmicutes, Kiritimatiellaeota, and Tenericutes, and genus Clostridium_sensu_ stricto_1, Muribaculaceae and Terrisporobacter than that at 10 wk (P < 0.05), and the Firmicutes to Bacteroidetes ratio was higher at 22 wk than 10 wk (P < 0.05). Moreover, the fecal testosterone level significantly correlated with the relative abundance of the phylum Actinobacteria, Firmicutes, and Tencuteseri, and genus Alloprevotella, Clostridium_sensu_stricto_1, Muribaculaceae, Prevotella_1 and Streptococcus. Furthermore, the in vitro experiments indicated that the abundance of the phylum Proteobacteria and genus Escherichia-Shigella reduced with the increase of supplemental testosterone level. In contrast, the proportion of Firmicutes phylum increased with additional testosterone levels. Discussion: Testosterone could modulate the microflora structure. Meanwhile, the bacteria could degrade the testosterone in a dose testosterone-dependent manner. These results provide us with new insights into the relationship between the gut microbiome and testosterone and the contributions of the gut microbiome in physiological regulation in response to gonad development. [ABSTRACT FROM AUTHOR]