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In the present study, nonrhizobial endophytes were isolated from Pisum sativum and Cicer arietinum from Haryana, India. A total of 355 bacterial endophytes were screened for plant growth promoting traits. Out of all, 96 bacterial endophytes were selected based on morphological characters and multi-PGP traits, and their diversity analyzed by amplified ribosomal DNA restriction analysis. Based on their ARDRA profile, the 25 representative isolates (12 from P. sativum and 13 from C. arietinum), were selected and identified by 16S ribosomal DNA sequencing. Genetic relatedness based on BLAST analysis revealed the similarity of these isolates with members of three prominent phyla, that is, Proteobacteria, Firmicutes, and Actinobacteria. The dominant cluster, Firmicutes, constituted 60% of the isolates, assigned to four different genera, Bacillus, Staphylococcus, Ornithinibacillus, and Lysinibacillus. Phylum α-proteobacteria included two genera, namely Paenochrobactrum and Ochrobactrum and three genera in phylum γ-proteobacteria, namely Pseudomonas, Pantoea and Proteus. The phylum Actinobacteria was constituted of two genera, Microbacterium and Arthrobacter. Bacillus zhangzhouensis, Bacillus safensis, Arthrobacter enclensis from P. sativum and Bacillus haynesii, Paenochrobactrum sp. from C. arietinum are documented as plant growth promoting endophytic bacteria for the first time in the present study. The in vitro and in vivo assessment based on bonitur score revealed that the endophytic isolates Bacillus mojavensis PRN2, Pseudomonas chlororaphis PHN9, B. safensis PRER2, Pseudomonas sp. RCP1, Pseudomonas lini PRN1 and B. haynensii RCP3 from P. sativum and C. arietinum significantly enhanced the plant growth parameters. Therefore, these potential isolates can be further harnessed for preparation of bioformulations to enhance sustainable agriculture.

Stellera chamaejasme has become a problematic weed in northern and south-western grasslands of China. To evaluate a possible role of endophytes in its strong competitive capacity, the endophytic bacterial community of S. chamaejasme was investigated by culture-dependent and independent methods, and the growth-promoting traits of some culturable isolates as well as the benefit of endophyte ST3CS3 (Brevundimonas sp.) on host plants growth were studied. The results showed that 823 OTUs were generated with a 97% similarity level in the culture-independent study. They were classified into 29 phyla, 61 classes, 147 orders, 237 families and 440 genera. Among them, Pseudomonas and Ralstonia were the most dominant genera in belowground parts (G) (64.25%) and aboveground parts (S) (26.54%) respectively. The diversity and species richness of endophytes in S were significantly higher than that of G (P 0.001, t-test). Contrary to this, the number of culturable bacteria in S was a little lower than that of G (P 0.05, t-test). Totally, 176 isolates belonging to 30 morphotypes were obtained in the culture-dependent study. Among them, Acinetobacter was the most dominant genus in G (51.30%), then followed by Pseudomonas (6.09%) and Brevundimonas (6.09%), while Lysinibacillus (21.31%) was the most dominant genus in S, followed by Pseudomonas (11.48%). Growth-promoting trait tests indicated that 93.65% of the tested isolates (63) exhibited nitrogen-fixing, IAA-synthesizing, phosphorus or potassium solubilizing capacity, in which 77.97% belonged to Proteobacteria, a phylum found to contain more active isolates. Pot experiments demonstrated that endophyte ST3CS3 can significantly improve host plants growth and increase its nitrogen and chlorophyll content (P 0.01, t-test). Therefore, we suggest that strong competitiveness of S. chamaejasme may in part be due to possession of high ratios of plant growth-promoting proteobacterial endophytes such as Pseudomonas, Acinetobacter and Brevundimonas.

Summary Faecal Microbiota Transplantation (FMT) is considered as a promising technology to fight against obesity. Wild boar has leanermuscle and less fat in comparison to the domestic pig, which were thought to be related with microbiota. To investigate the function and mechanism of the wild boar microbiota on obesity, we first analysed the wild boar microbiota composition via 16S rDNA sequencing, which showed that Firmicutes and Proteobacteria were the dominant bacteria. Then, we established a high‐fat diet (HFD)‐induced obesity model, and transfer low and high concentrations of wild boar faecal suspension in mice for 9 weeks. The results showed that FMT prevented HFD‐induced obesity and lipid metabolism disorders, and altered the jejunal microbiota composition especially increasing the abundance of the Lactobacillus and Romboutsia, which were negatively correlated with obesity‐related indicators. Moreover, we found that the anti‐obesity effect of wild boar faecal suspension was associated with jejunal N6‐methyladenosine (m6A) levels. Overall, these results suggest that FMT has a mitigating effect on HFD‐induced obesity, which may be due to the impressive effects of FMT on the microbial composition and structure of the jejunum. These changes further alter intestinal lipid metabolism and m6A levels to achieve resistance to obesity., Our results suggest that the fecal bacteria of wild boar have a mitigating effect on HFD‐induced obesity, which may be due to the impressive effects of wild boar fecal microbiota transplantation on the microbial composition and structure of the jejunum. These changes further alter intestinal lipid metabolism and m6A levels to achieve resistance to obesity.

Objectives To characterize the abundance and relative composition of seawater bacterioplankton communities in Changle city using Illumina MiSeq sequencing and bacterial culture techniques. Methods Seawater samples and physicochemical factors were collected from the coastal zone of Changle city on 8 September 2019. Nineteen filter membranes were obtained after using a suction filtration system. We randomly selected eight samples for total seawater bacteria (SWDNA group) sequencing and three samples for active seawater bacteria (SWRNA group) sequencing by Illumina MiSeq. The remaining eight samples were used for bacterial culture and identification. Alpha diversity including species coverage (Coverage), species diversity (Shannon–Wiener and Simpson index), richness estimators (Chao1), and abundance‐based richness estimation (ACE) were calculated to assess biodiversity of seawater bacterioplankton. Beta diversity was used to evaluate the differences between samples. The species abundance differences were determined using the Wilcoxon rank‐sum test. Statistical analyses were performed in R environment. Results The Alpha diversity in the SWDNA group in each index was ACE 3206.99, Chao1 2615.12, Shannon 4.64, Simpson 0.05, and coverage 0.97; the corresponding index was ACE 1199.55, Chao1 934.75, Shannon 3.49, Simpson 0.09, and coverage 0.99. The sequencing results of seawater bacterial genes in the coastal waters of Changle city showed that the phyla of high‐abundance bacteria of both the SWDNA and SWRNA groups included Cyanobacteria, Proteobacteria, and Bacteroidetes. The main classes included Oxyphotobacteria, Alphaproteobacteria, and Gammaproteobacteria. The main genera included Synechococcus CC9902, Chloroplast, and Cyanobium_PCC‐6307. Beta diversity analysis showed a significant difference between the SWDNA and SWRNA groups (P, In the SWDNA and SWRNA groups, the dominance of the phyla were Cyanobacteria, Proteobacteria, and Bacteroides; the main classes were oxygen‐producing photobacteria, α‐proteobacteria, and γ‐proteobacteria. The predominant genera are Synechococcus_CC9902, Chloroplast, Cyanobium_PCC‐6307, Candidatus Actinomarina, Ascidiaceihabitans and HIMB11 in SWDNA; Chloroplast, Synechococcus_CC9902, HIMB11, Cyanobium_PCC‐6307, Ascidiaceihabitans, and Ralstonia in SWRNA.

International audience; Holothurians are marine invertebrates that are among the most widespread benthic megafauna communities by both biomass and abundance in shallow-water and deep-sea ecosystems, their functions supporting important ecological services worldwide. Despite their simple appearance as sea cucumbers, holothurians show a wide range of feeding practices. However, information on what and how these animals eat is scattered and potentially confusing. We provide a comprehensive review of holothurian nutrition in coastal and deep-sea ecosystems. First, we describe morphological aspects of holothurian feeding and the ultrastructure of tentacles. We discuss the two processes for food capture, concluding that mucus adhesion is likely the main method; two mucous cells, type-1 and type-2, possibly allow the adhesion and de-adhesion, respectively, of food particles. Secondly, this review aims to clarify behavioural aspects of holothurian suspensionand deposit-feeding. We discuss the daily feeding cycle, and selective feeding strategies. We conclude that there is selectivity for fine and organically rich particles, and that feeding through the cloaca is also a route for nutrient absorption. Third, we provide a wide description of the diet of holothurians, which can be split into two categories: living and non-living material. We suggest that Synallactida, Molpadida, Persiculida, Holothuriida and Elasipodida, ingest the same fractions, and emphasise the importance of bacteria in the diet of holothurians.

Steroidal oestrogens (C18 ) are contaminants receiving increasing attention due to their endocrine-disrupting activities at sub-nanomolar concentrations. Although oestrogens can be eliminated through photodegradation, microbial function is critical for removing oestrogens from ecosystems devoid of sunlight exposure including activated sludge, soils and aquatic sediments. Actinobacteria were found to be key oestrogen degraders in manure-contaminated soils and estuarine sediments. Previously, we used the actinobacterium Rhodococcus sp. strain B50 as a model microorganism to identify two oxygenase genes, aedA and aedB, involved in the activation and subsequent cleavage of the estrogenic A-ring respectively. However, genes responsible for the downstream degradation of oestrogen A/B-rings remained completely unknown. In this study, we employed tiered comparative transcriptomics, gene disruption experiments and mass spectrometry-based metabolite profile analysis to identify oestrogen catabolic genes. We observed the up-regulation of thiolase-encoding aedF and aedK in the transcriptome of strain B50 grown with oestrone. Consistently, two downstream oestrogenic metabolites, 5-oxo-4-norestrogenic acid (C17 ) and 2,3,4-trinorestrogenic acid (C15 ), were accumulated in aedF- and aedK-disrupted strain B50 cultures. Disruption of fadD3 [3aα-H-4α(3'-propanoate)-7aβ-methylhexahydro-1,5-indanedione (HIP)-coenzyme A-ligase gene] in strain B50 resulted in apparent HIP accumulation in oestrone-fed cultures, indicating the essential role of fadD3 in actinobacterial oestrogen degradation. In addition, we detected a unique meta-cleavage product, 4,5-seco-estrogenic acid (C18 ), during actinobacterial oestrogen degradation. Differentiating the oestrogenic metabolite profile and degradation genes of actinobacteria and proteobacteria enables the cost-effective and time-saving identification of potential oestrogen degraders in various ecosystems through liquid chromatography-mass spectrometry analysis and polymerase chain reaction-based functional assays.

Ectomycorrhiza-associated bacteria, especially endofungal bacterial microbiota (EBM) in the fruiting body, play important roles in driving the establishment and function of ectomycorrhizae. However, the influence of ectomycorrhizal fungus bolete identity on their EBM is still unclear. We analysed the EBM of three different bolete fruiting body species on Thousand Island Lake, including Tylopilus felleus, Tylopilus areolatus and Boletus queletii, and compared them with their corresponding mycosphere soil bacterial microbiota by high-throughput sequencing. The EBM was classified into Bacillus, Pseudomonas, Burkholderia and Stenotrophomonas genera. Proteobacteria, Bacteroidetes and Acidobacteria were predominant in the EBM of bolete fruiting bodies as well as their mycosphere soil, while Firmicutes was significantly higher in the EBM. Moreover, the core microbiome (342 operational taxonomic units) of the EBM was shared among the three bolete fungal species. The relative abundances of gene families related to cell cycle control and nucleotide, coenzyme and lipid metabolism were significantly higher in the EBM than in the corresponding mycosphere soil bacterial microbiota, but there was no difference among the three different boletes. The results suggested that the host identity of ectomycorrhizal fungus boletes could affect the EBM, which might be mainly due to the selection of host fungi for the different functional EBM needed.

The Sansha Yongle Blue Hole is the deepest blue hole in the world discovered so far, while its great potential and values have not been fully exploited regarding microbial communities. A large-scale sampling was performed at different depths (0-270 m) inside the blue hole. Based on high-throughput sequencing, the diversity and richness of bacterial communities were relatively higher in oxic and euphotic layer, and at depths of 180-230 m in anoxic layer. Proteobacteria was dominant with mean relative abundance of 64.7%. As the representative genera, Thiomicrospira and Arcobacter were detected with higher abundances up to 96.1% and 31.5% in the anaerobic environment. Principal co-ordinates analysis, one-way ANOVA and network analysis highlighted the distinctive species at different depths. Correlation analysis illustrated the significant correlations between the bacteria and environmental elements of dissolved oxygen, temperature, salinity, pH, sulphur and nutrient. Phylogenetic analysis indicated that the microbial ecosystem was characterized with infrequent and unidentified microorganisms in the deep layer. This research revealed the unique microbial ecosystem and potential functions in regulating ecosystem productivity and cycling of carbon, sulphur and nitrogen. Comprehensive and long-term investigations in the Sansha Blue Hole should be taken to conserve the peculiar ecosystem.

Microorganisms are widely distributed throughout the built environment and even those found in concealed environments such as sink P‐traps can have an impact on our health. To date, most studies on sink bacterial communities focused on those present in hospitals with no to little information regarding sinks in residential or communal settings. Here, we conducted a characterization using 16S rRNA sequencing of the bacterial communities of communal restroom sinks located on a university campus to investigate the diversity, prevalence, and abundances of the bacteria that reside in this understudied environment. The study found that community composition and structure were highly variable across individual sinks, and there were marginal differences between buildings and the two different parts of sink examined. Proteobacteria were the most abundant phylum in the sink communities, and the families Burkholderiaceae, Moraxellaceae, and Sphingomonadaceae were found to be ubiquitous across all sinks. Notably, human skin was identified as a primary contributor to the below‐strainer sink bacterial community. These data provide novel insight into the sink bacterial communities' constituents and serve as the foundation for subsequent studies that might explore community stability and resilience of in situ sinks.

BACKGROUND Bacteria are the most diverse and abundant group of soil organisms that influence plant growth and health. Bacillus and Trichoderma are commonly used as biological control agents (BCA) that directly or indirectly act on soil bacteria. Therefore, it is essential to understand how the applied microbes impact the indigenous microbial community before exploring their activity in the control of soilborne diseases. RESULTS MiSeq sequencing of the 16S rRNA gene was used to decipher the shift of rhizosphere bacterial community in ginger (Zingiber officinale Roscoe) treated with Bacillus subtilus and Trichoderma harzianum at different concentrations. The dominant phyla in treated and nontreated samples were Proteobacteria, Actinobacteria, Acidobacteria and comprised up to 54.7% of the total sequences. There were significant differences between BCA treated and nontreated samples in the bacteria community. BCA treated plants presented higher bacterial diversity than nontreated and higher dosage of BCA had a larger impact on rhizosphere microbiota, but the 'dose-response relationship' varied in different bacterial groups. Potential biomarkers at genus level were found, such as RB41, Pseudomonas, Nitrospira, Candidatus_Udaeobacter. CONCLUSION The combined use of Bacillus subtilus and Trichoderma harzianum could alter bacterial community structure and diversity in rhizosphere soil. BCA-microbes interactions as well as soil microbial ecology should be noticed in plant disease management. © 2021 Society of Chemical Industry.

Background: Rural communities who consume unpasteurized and traditional fermented milk products on a regular basis, have a low prevalence of allergic diseases. Lactic acid producing bacteria present within these products, is postulated to have an allergy protective role against atopy. Objective: To characterize and compare the bacterial microbiota of fresh unpasteurised cow’s milk and to explore the effect of milk fermentation (commercially and traditionally fermented) on the bovine milk microbiota. Methods: Raw, unpasteurized cow’s milk was collected from urban and rural farms. Another sample, collected from a rural farm, was left to ferment naturally. Three different brands of commercially fermented milk samples were also analysed. The V3 and V4 regions of the 16S rRNA gene were amplified to assess microbiota composition. Results: Urban and rural fresh milk had the highest microbiota alpha diversity, and commercially bought fermented milk products, the least. Commercially fermented milk was consistently dominated by lactic acid producing bacteria, belonging to the phylum Firmicutes, while homemade fermented milk comprised of approximately 50% Firmicutes and 50% Proteobacteria. The relative abundance of several organisms differed between fermented and unfermented milk. Lactococcus lactis dominated all milk products, however its relative abundance was lower in fresh milk compared with fermented milk. Lactobacillus paracasei and Streptococcus infantis were abundant in traditionally fermented milk, but absent in commercially fermented products. Potential pathogens were demonstrated in fresh and home fermented milk. Conclusion: Commercially fermented milk can be promoted as a safe and possible allergy protective complementary feed from 1 year of age.

Microorganisms of plant phyllosphere play an important role in plant health and productivity and are influenced by abiotic and biotic factors. In this study, we investigated the phyllosphere bacterial communities of three cigar tobacco varieties cultivated in Guangcun (GC) and Wuzhishan (WZS), Hainan, China. Metagenomic DNA was extracted from tobacco leaf samples and sequenced by 16S rDNA amplicon sequencing. Our results showed that bacterial communities of cigar tobacco phyllosphere in GC exhibited remarkably higher alpha diversity than that in WZS. There was slight effect of tobacco genotype variations on the alpha diversity in both cultivation sites, and beta diversity and structure of bacterial community were not influenced significantly by the cultivation sites and tobacco varieties. Statistical analyses of species diversity unraveled that the dominant species in bacterial communities of cigar tobacco phyllosphere among all these samples were phylogenetically affiliated to Proteobacteria and Cyanobacteria. At the genus level, the most abundant microorganism was Limnobacter, followed by Brevundimonas, unidentified_Cyanobacteria, and Pseudomonas. Additionally, environmental conditions except for humidity were negatively correlated with the relative abundance of bacterial genera. Further analyses revealed that influence of site‐specific factors on tobacco bacterial community was relatively higher than genotype‐specific factors. In short, this study may contribute to the knowledge base of practical applications of bacterial inoculants for tobacco leaf production., This study provided a theoretical support when applying the phyllosphere bacterial communities to promote tobacco growth, prevent disease, and regulate the tobacco aging process artificially.

Large regions of Earth's surface are underlain by salt deposits that evaporated from ancient oceans and are populated by extreme halophilic microbes. Some of these halophiles may have been preserved over geological timescales within hypersaline fluid inclusions, but ingresses of water and/or anthropogenic activities can lead to the formation of alternative habitats, including NaCl stalactites or speleothems. While the microbiology of ancient evaporites has been well-studied, the ecology of these recently formed structures is less-well understood. Here, the microbiology of a NaCl stalactite ('salticle') in a Triassic halite mine is characterised. The specific aims were to: determine the presence of fluid inclusions; determine the microbial structure of the salticle compared with a nearby brine-pool and surficial soil; and characterise the ecophysiological capabilities of this unique ecosystem. The salticle contained fluid inclusions, and their microbiome was composed of Euryarchaetota, Proteobacteria, and Actinobacteria, with Haloarchaea in greater abundance than brine-pool or soil microbiomes. The salticle metagenome exhibited a greater abundance of genes involved in osmoregulation, anaerobic respiration, UV resistance, oxidative stress, and stress-protein synthesis relative to the soil microbiome. We discuss the potential astrobiological implications of salticles as enclosed salt-saturated habitats that are protected from ionising radiation and have a stable water-activity. This article is protected by copyright. All rights reserved.

According to the appearance and technology, traditional fermented Douchi can be divided into dried Douchi and wet Douchi. However, there are few reports on the difference of bacterial community structure between them or the influence of bacterial community on product flavor. In this study, high‐throughput sequencing technology and electronic nose were used to measure the bacterial diversity and flavor of 40 Douchi samples, and the correlation between them was explored by multivariate statistical means combined with COG database. Results showed that the cumulative average relative abundance of Firmicutes and Proteobacteria in the samples was as high as 95.93%, and the former was the core bacteria phylum. On the whole, the dominant bacteria in Douchi were Bacillus (50.67%), Staphylococcus (14.07%), Enterococcus (2.54%), Proteus (1.61%), Brevibacillus (1.46%), Providencia (1.26%), Weissella (1.24%), and Ureibacillus (1.19%). LEfSe analysis indicated that Bacillus can be used as a biomarker in dried fermented soybeans. Meanwhile, dried samples contained more intensive aromatic substances, but were significantly lower in W6S (selectivity to hydrogen) and W3S (methane‐aliph) compared with the wet samples. Aneurinibacillus and Brevibacillus were helpful to the formation of aromatic flavor in Douchi, but Vagococcus and Corynebacterium were the opposite. Gene and microbial phenotypic prediction showed that microorganisms in dried Douchi use protein more efficiently, while in wet Douchi, microbial energy metabolism was more vigorous. The pathogenic potential of microorganisms in dried samples was higher than that in wet. This study can sound the alarm for improving the safety of home‐brewed Douchi and provide guidance for the subsequent screening of strains that enhance the flavor of fermented soybeans., Bacillus, Staphylococcus, Enterococcus, Proteus, Brevibacillus, Providencia, Weissella, and Ureibacillus were the dominant bacteria of Douchi; Brevibacillus and Aneurinibacillus had significant positive correlations with three aromatic characteristics but Vagococcus and Corynebacterium were the opposite; Microorganisms in dried Douchi use protein more efficiently, while in wet Douchi, microbial energy metabolism was more vigorous.

Host characteristics, such as sex and age, are closely associated with the structure and function of gut microbiota; however, less is known about the effects of age and sex on the gut microbiota of nonhuman primates, and therefore, our knowledge of interindividual variability in host gut microbiota is limited. In this study, 153 fecal samples from rhesus macaques (Macaca mulatta) were analyzed using high‐throughput 16S rRNA sequencing in order to explore associations between age and sex of the host and their gut microbiota. The results indicated that female macaques had higher alpha diversity and a more unique gut microbiota than did males. The proportion of Proteobacteria, Tenericutes, Cyanobacteria, unclassified bacteria, and Verrucomicrobia was higher in females than that in males. We also found that adults of both sexes had a higher alpha diversity, a higher proportion of norank Ruminococcaceae, Oscillospira, norank Lachnospiraceae, norank Clostridiales, and Succinivibrio, and a lower proportion of Enterococcus than immatures. Functional analyses revealed that the richness of metabolic pathways was higher in females than males and in adults compared with immatures. These results could be attributed to differences in the nutritional requirements and hormone levels of macaques of different sex and age classes. We conclude that variation in the gut microbiota of different sex and age classes of rhesus macaques may be linked to age‐ and sex‐specific differences in nutrient requirements and hormone levels. These results highlight the importance of host age and sex on the structure and function of the gut microbiota and the need to consider physiological traits when conducting studies on the gut microbiota., Sex and age were associated with differences in the diversity and relative abundance of gut microbiota in rhesus macaques. These differences could be linked to age‐ and sex‐specific differences in nutrient requirements and hormone levels, highlighting the effects of age and sex on the structure and function of the gut microbiota, as well as the need to consider physiological traits when conducting gut microbiota studies.

Summary Steroidal oestrogens are often accumulated in urban estuarine sediments worldwide at microgram per gram levels. These aromatic steroids have been classified as endocrine disruptors and group 1 carcinogens. Microbial degradation is a naturally occurring mechanism that mineralizes oestrogens in the biosphere; however, the corresponding genes in oestrogen‐degrading actinobacteria remain unidentified. In this study, we identified a gene cluster encoding several putative oestrogen‐degrading genes (aed; actinobacterial oestrogen degradation) in actinobacterium Rhodococcus sp. strain B50. Among them, the aedA and aedB genes involved in oestrogenic A‐ring cleavage were identified through gene‐disruption experiments. We demonstrated that actinobacterial oestrone 4‐hydroxylase (AedA) is a cytochrome P450‐type monooxygenase. We also detected the accumulation of two extracellular oestrogenic metabolites, including pyridinestrone acid (PEA) and 3aα‐H‐4α(3'‐propanoate)‐7aβ‐methylhexahydro‐1,5‐indanedione (HIP), in the oestrone‐fed strain B50 cultures. Since actinobacterial aedB and proteobacterial edcB shared, We identified a gene cluster encoding several putative estrogen‐degrading genes (aed; actinobacterial estrogen degradation) in actinobacterium Rhodococcus sp. strain B50. Among them, the aedA and aedB genes involved in estrogenic A‐ring cleavage were identified through gene‐disruption experiments.

The purpose of this study was to examine the effect of gaseous hydrogen sulphide on growth performance and cecal microbial diversity in weaning pigs. A total of 24 weaning pigs (Landrace × Yorkshire × Duroc; average body weight = 8.55 ± 0.68 kg；weaning at 28 days) were selected and randomly divided into four groups (six replicates in each group). The piglets were exposed to hydrogen sulphide (0, 5, 10 and 15 mg/m3) during the experiment period, which lasted 28 days in four controlled environmental chambers. The results showed that exposure to hydrogen sulphide reduced the average daily gain (ADG), average daily feed intake (ADFI), and increased the diarrhoea rate of piglets. Hydrogen sulphide could increase the abundance and diversity of intestinal microbiota. The abundance of Firmicutes and Proteobacteria increased and Bacteroides decreased in the treatment groups. Five biomarkers, such as Eubacterium_1coprostanoligenes, Clostridiales, Phascolarctobacterium, Acidaminococcaceae and Ruminococcaceae_UCG_002 were selected by Lefse analysis. Our results reveal that hydrogen sulphide damaged the growth performance and destroyed the microbial bacteria balance of weaning pigs. The concentrations of hydrogen sulphide should fall below 5 mg/m3., 24 weaning pigs were exposed to hydrogen sulfide (0, 5, 10 and 15 mg/m3) in 4 controlled environmental chambers for 28 days.The results showed that exposure to gaseous hydrogen sulfide damaged the growth performance and resulted the microbial bacteria imbalance.The concentration of hydrogen sulfide should fall below 5 mg/m3.

In this study, we explored the diversity and community composition of bacteria along a vertical gradient in Lake Issyk Kul, Kyrgyzstan, one of the largest and deepest brackish lakes in in the world. We identified 4904 bacterial ASVs based on analysis of 16S rRNA gene sequences and determined significant changes in the composition responding mainly to the variables depth and salinity. A higher abundance of Proteobacteria and Bacteroidetes was observed in the surface waters and the lake tributaries. Cyanobacteria were more abundant in the deep chlorophyll maximum (28.5 to 128 m), while Planctomycetes and Chloroflexi were dominant at depths between 128 to 600 m. According to our machine learning analysis used for identifying the most critical environmental factors, depth and temperature revealed the strongest effect on members of Proteobacteria, Planctomycetes, and Chloroflexi, while oxygen is associated with the variations in Cyanobacteria. Also, a notable increase in alpha diversity estimations was observed with increasing water depth. This work evidences significant differences in the structure of bacterial communities along the depth gradient in deep, transparent lake ecosystems. Notably, there is a dominance of Planctomycetes and Chloroflexi in the deepest layers, which can only be seen in a few other lakes with similar characteristics as Lake Issyk Kul and raises questions about their ecological role.

Bacterial communities that enrich in high‐temperature Daqu are important for the Chinese maotai‐flavor liquor brewing process. However, the bacterial communities in three different types of high‐temperature Daqu (white Daqu, black Daqu, and yellow Daqu) are still undercharacterized. In this study, the bacterial diversity of three different types of high‐temperature Daqu was investigated using Illumina MiSeq high‐throughput sequencing. The bacterial community of high‐temperature Daqu is mainly composed of thermophilic bacteria, and seven bacterial phyla along with 262 bacterial genera were identified in all 30 high‐temperature Daqu samples. Firmicutes, Actinobacteria, Proteobacteria, and Acidobacteria were the dominant bacterial phyla in high‐temperature Daqu samples, while Thermoactinomyces, Staphylococcus, Lentibacillus, Bacillus, Kroppenstedtia, Saccharopolyspora, Streptomyces, and Brevibacterium were the dominant bacterial genera. The bacterial community structure of three different types of high‐temperature Daqu was significantly different (p, Thermoactinomyces, Staphylococcus, Lentibacillus, Bacillus, Kroppenstedtia, Saccharopolyspora, Streptomyces, and Brevibacterium were the dominant bacterial genera. Bacterial community structure of white Daqu samples and yellow Daqu samples may be more similar, while that of black Daqu samples differs more from the two. Bacteria from different types of high‐temperature Daqu have similar functions as well as phenotypes, and bacterial metabolism was vigorous in the high‐temperature Daqu.

Planktonic microorganisms play a key role in the biogeochemical processes of the aquatic system, and they may be affected by many factors. High-throughput sequencing technology was used in this study to investigate and study the bacterioplankton community of water bodies in the upper reaches of the Heihe River Basin in Qinghai Plateau. Results showed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria are the predominant phyla in this river section, while the main genera are Thiomonas, Acidibacillus, Acidocella, Rhodanobacter, Acidithiobacter and Gallionella, which are autochthonous in the acid-mine drainage. Additionally, total nitrogen, total phosphorus, permanganate index and pH are significantly correlated with the bacterioplankton abundance and are the main limiting factors for the spatial distribution of the bacterioplankton. PICRUSt inferred that the mainstream microbial assemblages had a higher abundance of KOs belong to metabolism of terpenoids and polyketides, while the tributary had higher abundance of KOs belong to the immune system. The relationship between bacterioplankton community composition and environmental factors in the Heihe River basin was discussed for the first time in this study, which provides a theoretical basis for the healthy, orderly development of the water environment in the Heihe River Basin.

Lake Taihu in China has suffered serious harmful cyanobacterial blooms for decades. The algal blooms threaten the ecological sustainability, drinking water safety, and human health. Although the roles of abiotic factors (such as water temperature and nutrient loading) in promoting Microcystis blooms have been well studied, the importance of biotic factors (e.g. bacterial community) in promoting and meditating Microcystis blooms remains unclear. In this study, we investigated the ecological dynamics of bacterial community, the ratio of toxic Microcystis, as well as microcystin in Lake Taihu. High-throughput 16S rRNA sequencing and principal component analysis (PCA) revealed that the bacteria community compositions (BCCs) clustered into three groups, the partitioning of which corresponded to that of groups according to the toxic profiles (the ratio of toxic Microcystis to total Microcystis, and the microcystin concentrations) of the samples. Further Spearman's correlation network showed that the α-proteobacteria Phenylobacterium strongly positively correlated with the toxic profiles. Subsequent laboratory chemostats experiments demonstrated that three Phenylobacterium strains promoted the dominance of the toxic Microcystis aeruginosa PCC7806 when co-culturing with the non-toxic PCC7806 mcyB- mutant. Taken together, our data suggested that the α-proteobacteria Phenylobacterium may play a vital role in the maintenance of toxic Microcystis dominance in Lake Taihu.

As predators of bacteria, amoebae select for traits that allow bacteria to become symbionts by surviving phagocytosis and exploiting the eukaryotic intracellular environment. Soil-dwelling social amoebae can help us answer questions about the natural ecology of these amoeba-bacteria symbioses along the pathogen-mutualist spectrum. Our objective was to characterize the natural bacterial microbiome of phylogenetically and morphologically diverse social amoeba species using next-generation sequencing of 16S rRNA amplicons directly from amoeba fruiting bodies. We found six phyla of amoeba-associated bacteria: Proteobacteria, Bacteroidetes, Actinobacteria, Chlamydiae, Firmicutes, and Acidobacteria. The most common associates of amoebae were classified to order Chlamydiales and genus Burkholderia-Caballeronia-Paraburkholderia. These bacteria were present in multiple amoeba species across multiple locations. While there was substantial intraspecific variation, there was some evidence for host specificity and differentially abundant taxa between different amoeba hosts. Amoebae microbiomes were distinct from the microbiomes of their soil habitat, and soil pH affected amoeba microbiome diversity. Alpha-diversity was unsurprisingly lower in amoebae samples compared with soil, but beta-diversity between amoebae samples was higher than between soil samples. Further exploration of social amoebae microbiomes may help us understand the roles of bacteria, host, and environment on symbiotic interactions and microbiome formation in basal eukaryotic organisms.

Dogs and cats have gained a special position in human society by becoming our principal companion animals. In this context, efforts to ensure their health and well‐fare have increased exponentially, with in recent times a growing interest in assessing the impact of the gut microbiota on canine and feline health. Recent technological advances have generated new tools to not only examine the intestinal microbial composition of dogs and cats, but also to scrutinize the genetic repertoire and associated metabolic functions of this microbial community, revealing that the taxonomic composition and the metabolic repertoire of the intestinal microbial population of dogs and cats may be influenced by several factors, including diet, age and anthropogenic aspects, as well as intestinal dysbiosis., Summary Dogs and cats have gained a special position in human society by becoming our principal companion animals. In this context, efforts to ensure their health and welfare have increased exponentially, with in recent times a growing interest in assessing the impact of the gut microbiota on canine and feline health. Recent technological advances have generated new tools to not only examine the intestinal microbial composition of dogs and cats, but also to scrutinize the genetic repertoire and associated metabolic functions of this microbial community. The application of high‐throughput sequencing techniques to canine and feline faecal samples revealed similarities in their bacterial composition, with Fusobacteria, Firmicutes and Bacteroidetes as the most prevalent and abundant phyla, followed by Proteobacteria and Actinobacteria. Although key bacterial members were consistently present in their gut microbiota, the taxonomic composition and the metabolic repertoire of the intestinal microbial population may be influenced by several factors, including diet, age and anthropogenic aspects, as well as intestinal dysbiosis. The current review aims to provide a comprehensive overview of the multitude of factors which play a role in the modulation of the canine and feline gut microbiota and that of their human owners with whom they share the same environment.

Foraminifera host diverse microbial communities that can shift in response to changing environmental conditions. To characterize climate change impacts on the foraminifera microbiome across life stages, we exposed adult Marginopora vertebralis (Large Benthic Foraminifera) to pCO2 and temperature scenarios representing present-day, 2050 and 2100 levels and raised juveniles under present-day and 2050 conditions. While treatment condition had no significant effect on the seawater microbial communities, exposure to future scenarios significantly altered both adult and juvenile microbiomes. In adults, divergence between present-day and 2050 or 2100 conditions was primarily driven by a reduced relative abundance of Oxyphotobacteria under elevated temperature and pCO2 . In juveniles, the microbial shift predominantly resulted from changes in the proportion of Proteobacteria. Indicator species analysis identified numerous treatment-specific indicator taxa, most of which were indicative of present-day conditions. Oxyphotobacteria, previously reported as putative symbionts of foraminifera, were indicative of present-day and 2050 conditions in adults, but of present-day conditions only in juveniles. Overall, we show that the sensitivity of the M. vertebralis microbiome to climate change scenarios extends to both life stages and primarily correlates with declines in Oxyphotobacteria and shifts in Proteobacteria under elevated temperature and pCO2 .

Magnetotactic bacteria (MTB) are diverse prokaryotes that produce magnetic nanocrystals within intracellular membranes (magnetosomes). Here, we present a large-scale analysis of diversity and magnetosome biomineralization in modern magnetotactic cocci, which are the most abundant MTB morphotypes in nature. Nineteen novel magnetotactic cocci species are identified phylogenetically and structurally at the single-cell level. Phylogenetic analysis demonstrates that the cocci cluster into an independent branch from other Alphaproteobacteria MTB, that is, within the Etaproteobacteria class in the Proteobacteria phylum. Statistical analysis reveals species-specific biomineralization of magnetosomal magnetite morphologies. This further confirms that magnetosome biomineralization is controlled strictly by the MTB cell and differs among species or strains. The post-mortem remains of MTB are often preserved as magnetofossils within sediments or sedimentary rocks, yet paleobiological and geological interpretation of their fossil record remains challenging. Our results indicate that magnetofossil morphology could be a promising proxy for retrieving paleobiological information about ancient MTB.

Although soil microbial communities are central in ecosystem functioning, we know little of their characterization for those associated with grazing‐tolerant host plant species in grassland ecosystems in response to grazing. In this study, we used a high‐throughput sequencing approach to characterize soil microbes from the rhizosphere and bulk soil of grazing‐tolerant grass species, Stipa breviflora, in the Inner Mongolian desert steppe. We found that response mechanisms of soil bacteria distinct from fungal communities, and variance also occur between the rhizosphere and bulk soil communities under long‐term grazing. Soil fungal communities and the co‐occurrence networks in S. breviflora rhizosphere were more sensitive to long‐term grazing than bacteria. We reveal that rhizosphere effects and soil water content were the main drivers of the changes in fungal communities and their co‐occurrence networks. Moreover, the dominant bacterial phyla Bacteroidetes and Proteobacteria and fungal phyla Ascomycota and Glomeromycota might participate in regulating processes of S. breviflora's response to grazing. Overall, these findings give new snapshots of mechanisms of how grazing affects soil microbial communities, in an attempt to contribute to a clearer understanding of grazing‐tolerant mechanism of S. breviflora., In this study, we used a random matrix theory (RMT)‐based network approach to investigate the characterization of soil microbes associated with a grazing‐tolerant grass species, Stipa breviflora. I believe the results would provide new insight into the mechanisms by which grazing affects soil microbial communities, so as to contribute to a better understanding of grazing‐tolerant mechanism of S. breviflora.

Prokaryotes play crucial roles in the rehabilitation process to restore the ecological integrity of disturbed areas. This work reports on the profiles of N‐fixing microorganisms and Actinobacteria, from DGGE, the prokaryotic composition from next‐generation sequencing (NGS) and physicochemical soil characteristics. We compared a deactivated mining site where mining ended about 10 years ago, when the revegetation process was begun (RV), and a reference site, with natural vegetation (NT), both located at Retiro das Almas Mine, in the Quadrilatero Ferrifero region, Minas Gerais, Brazil. In both sites, the most abundant archaeal and bacterial groups included Euryarchaeota, Thaumarchaeota, Proteobacteria, Actinobacteria, Acidobacteria, and Verrucomicrobia and revealed differences in their ecological metrics and distribution. Proteobacteria and Actinobacteria were most abundant in RV sites, while Acidobacteria and Verrucomicrobia were most abundant in NT sites. Less abundant phyla, such as Bathyarchaeota (Archaea) and GAL 15 (Bacteria) were found only in NT, while Gracilibacteria, Ignavibacteriae BJ‐169, and BRC1 were only found in RV. The majority of identified bacterial genera were shared by RV and NT. Soil P, pH, and particle density were most significant (p

This paper describes molecular and functional characterization of a novel dioxygenase enzyme from the aquatic cyanobacterium Anabaena cylindrica. The enzyme showed a strong inhibition by excess of the precursor L‐DOPA. However, its heterologous expression has allowed detecting the formation of the main compounds in the biosynthetic pathway of betalains. The discovery of this novel dioxygenase in the phylum cyanobacteria shows that betalains' formation is more diverse than expected., Summary The biosynthesis of betalamic acid, the structural unit of pigments betalains, is performed by enzymes with 4,5‐DOPA‐extradiol‐dioxygenase activity. These enzymes were believed to be limited to plants of the order Caryophyllales and to some fungi. However, the discovery of Gluconacetobacter diazotrophicus as the first betalain‐forming bacterium opened a new field in the search for novel biological systems able to produce betalains. This paper describes molecular and functional characterization of a novel dioxygenase enzyme from the aquatic cyanobacterium Anabaena cylindrica. The enzyme was found to be a homodimer of a polypeptide of 17.8 kDa that, opposite to previous related enzymes, showed a strong inhibition by excess of the precursor L‐DOPA. However, its heterologous expression has allowed detecting the formation of the main compounds in the biosynthetic pathway of betalains. In addition, phylogenetic analysis has shown that this enzyme is not close related to enzymes from plants, fungi or proteobacteria such as G. diazotrophicus. The presence of enzymes that produce these health‐promoting compounds is more diverse than expected. The discovery of this novel dioxygenase in the phylum cyanobacteria expands the presence of betalamic acid‐forming enzymes in organisms of different nature with no apparent relationship among them.

Understanding soil microbiome responses to different land‐management strategies provides insights into tallgrass prairie restoration. However, few studies have examined these interactions. We addressed this issue by surveying samples from the University of Nebraska at Omaha's Glacier Creek Preserve, where a long‐term burn experiment was established in 1982, with the mow treatments incorporated in 2002. In 2015, we collected 89 soil samples and obtained ~2.3 million bacterial and archaeal 16S rRNA sequence reads and ~2.4 million fungal ITS reads. Analysis of the sequences showed that dominant phyla were Proteobacteria (~30.0%) and Acidobacteria (~22.8%) in bacteria and Ascomycota (~66.2%) in fungi. We found that burning and mowing had a distinct effect on soil bacterial and fungal diversity: soils exposed to the burn treatments possessed a relatively high bacterial diversity but a relatively low fungal diversity. We also observed that burning and mowing had different effects on different microbial groups within bacteria and fungi. The burn treatments led to a relatively high abundance of bacterial groups such as Gemmatimonadetes and Armatimonadetes that prefer dry or warmer soils and arbuscular mycorrhizal (AM) fungi, whereas the mow treatments resulted in increased abundances of Nitrospirae bacteria. Moreover, functional prediction revealed that soil samples from the burn treatments were enriched with AM and plant saprotrophic fungi, and fungal plant pathogens were enriched in the mow samples. Considering soil functional differences between burn and mow treatments and an increased plant production after burning treatments, we speculate that burning could be a better strategy in the tallgrass land restoration, with certain fungal groups as an imperative indicator. HIGHLIGHTS: Understanding soil microbiome responses to different land‐management strategies provides insights into tallgrass prairie restoration We showed differences in the soil bacterial and fungal communities between burn and mow treatments. Soil fungi were enriched in AM fungi and plant saprotroph functions after burning, but fungi with putative plant pathogens after mowing. The burn treatment is a better strategy for tallgrass prairie land restoration in this study region.

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has become a major global challenge. The virus infects host cells using its spike glycoprotein (S‐protein) and has significantly higher infectivity and mortality rates among the aged population. Here, based on bioinformatic analysis, I provide evidence that some members of the upper respiratory tract (URT) commensal bacteria express viral S‐protein ‐binding proteins. Based on this analysis and available data showing a decline in the population of these bacteria in the elderly, I propose that some URT commensal bacteria hamper SARS‐CoV‐2 infectivity and that a decline in the population of these bacteria contributes to the severity of infection. Further studies should provide a better understanding of the interaction of URT bacteria and SARS‐CoV‐2, which may lead to new therapeutic approaches.

Summary The potential utility of black soldier fly larvae (BSFL) to convert animal waste into harvested protein or lipid sources for feeding animal or producing biodiesel provides a new strategy for agricultural waste management. In this study, the taxonomic structure and potential metabolic and nutrient functions of the intestinal bacterial communities of BSFL were investigated in chicken and swine manure conversion systems. Proteobacteria, Firmicutes and Bacteroidetes were the dominant phyla in the BSFL gut in both the swine and chicken manure systems. After the larvae were fed manure, the proportion of Proteobacteria in their gut significantly decreased, while that of Bacteroidetes remarkably increased. Compared with the original intestinal bacterial community, approximately 90 and 109 new genera were observed in the BSFL gut during chicken and swine manure conversion, and at least half of the initial intestinal genera found remained in the gut during manure conversion. This result may be due to the presence of specialized crypts or paunches that promote microbial persistence and bacteria–host interactions. Ten core genera were found in all 21 samples, and the top three phyla among all of the communities in terms of relative abundance were Proteobacteria, Firmicutes and Bacteroidetes. The nutrient elements (OM, TN, TP, TK and CF) of manure may partly affect the succession of gut bacterial communities with one another, while TN and CF are strongly positively correlated with the relative abundance of Providencia. Some bacterial taxa with the reported ability to synthesize amino acids, Rhizobiales, Burkholderia, Bacteroidales, etc., were also observed in the BSFL gut. Functional analysis based on genes showed that intestinal microbes potentially contribute to the nutrition of BSFL and the high‐level amino acid metabolism may partly explain the biological mechanisms of protein accumulation in the BSFL body. These results are helpful in understanding the biological mechanisms of high‐efficiency nutrient conversion in BSFL associated with intestinal microbes., The potential utility of black soldier fly larvae (BSFL) to convert animal waste into harvested protein or lipid sources provides a new strategy for agricultural waste management. In this study, the taxonomic structure and potential metabolic and nutrient functions of the intestinal bacterial communities of BSFL were investigated in chicken and swine manure conversion systems. The results are helpful in understanding the biological mechanisms of high‐efficiency nutrient conversion in BSFL associated with intestinal microbes.

16 Pág. Centro de Biotecnología y Genómica de Plantas, Soil microorganisms surviving in mining sites have developed metal-resistance mechanisms to biotransform metals. Their use as biofertilizers can improve phytoremediation efficiency in contaminated soils by reducing metal toxicity while promoting plant growth. We analysed through whole-metagenome shotgun sequencing the composition, diversity and function of microbial communities present in a contaminated mine soil along a gradient of metals (As, Cu, Fe, Mn, Pb, Zn) to identify tolerant species carrying metal-resistance functional genes that can be used in association with plants for phytoremediation. Soil samples were collected from an abandoned copper mine, across three areas with different levels of metal contamination (unaffected, moderately contaminated and highly contaminated). The relative abundance of Proteobacteria, especially genus Bradyrhizobium, increased in the highly contaminated area, whereas Actinobacteria dominated in the unaffected area. Archaea (Euryarchaeota) predominated in the moderately contaminated area, Haloarcula, Halobacterium and Halorubrum being the most abundant genera. The fungi Basidiomycota did not exhibit differences among the areas, whereas Ascomycota, especially the genus Aspergillus, increased in areas with low metal concentrations. Metal-resistance genes associated with Fe (acn, furA, dpsA), Cu (cop-unnamed, copF, actP, copA, mmco, cutO) and As (arsT, arsC, aioA/aoxB) metabolism were the most abundant and were affected by the gradient of soil contamination. Those associated with Cu predominated in the most contaminated area, whereas As and Fe genes were more abundant in the least contaminated. Among the carriers of these metal-resistance genes, Bradyrhizobium diazoefficiens, Pseudomonas aeruginosa, Halorubrum trapanicum, Aspergillus fumigatus and A. fischeri were dominant in the most contaminated area. These species could give rise to promising biofertilizers to be used in association with suitable plants for the phytoremediation of contaminated mining sites. Highlights: Metals affect differentially abundance, diversity and function of microorganisms in a mine soil. Proteobacteria dominated in contaminated areas and Actinobacteria in the less contaminated. Most abundant metal-resistance genes were associated with Cu, As and Fe. Bradyrhizobium diazoefficiens and other species are promising biofertilizers for phytoremediation., We are grateful to the Comunidad de Madrid (Spain) and Structural Funds 2014‐2020 (ERDF and ESF) for the financial support (project AGRISOST‐CM S2018/BAA‐4330). Also, this research was funded by the Ministerio de Economía y Competitividad (Spain), grant number CTM2013‐47874‐C2‐1‐R. Also, this research was funded by the Ministerio deEconomía y Competitividad (Spain), grant numbers CTM2013‐47874‐C2‐1‐R, and RTI2018‐096975‐B‐100.

The gut microbiota of birds is known to be characterized for different species, although it may change with feeding items. In this study, we compared the gut microbiota of birds with different feeding behaviors in the same habitat. We collected fecal samples from three Arctic species, snow buntings Plectrophenax nivalis, sanderlings Calidris alba, and pink‐footed geese Anser brachyrhynchus that are phylogenetically quite distant in different families to evaluate effects of diet on gut microbiota. Also, we characterized the prevalence of fecal bacteria using the Illumina MiSeq platform to sequence bacterial 16S rRNA genes. Our NMDS results showed that fecal bacteria of snow buntings and sanderlings were significantly distant from those of pink‐footed geese. Although all three birds were occupied by three bacterial phyla, Proteobacteria, Firmicutes, and Bacteroidetes, dominant taxa still varied among the species. Our bacterial sequences showed that snow buntings and sanderlings were dominated by Firmicutes and Bacteroidetes, while pink‐footed geese were dominated by Proteobacteria. In addition, the bacterial diversity in snow buntings and sanderlings was significantly higher than that in pink‐footed geese. Our results suggest that insectivorous feeding diet of snow buntings and sanderlings could be responsible for the similar bacterial communities between the two species despite the distant phylogenetic relationship. The distinctive bacterial community in pink‐footed geese was discussed to be related with their herbivorous diet., We showed that fecal bacteria of snow buntings and sanderlings were distant from those of pink‐footed geese. In addition, the bacterial diversity in snow buntings and sanderlings was significantly higher than that in geese. Our results suggest that diet as well as host phylogeny may affect the gut microbiota of Arctic birds.

Despite the vast carbon (C) stock of crop root residues in arable ecosystems, the microbial assimilation mechanism of crop root derived‐C is poorly understood. In this study, a DNA‐based stable isotope probing (DNA‐SIP) approach was used to explore and characterize the diversity of the soil bacterial community assimilating C derived from ¹³C‐labelled rice root residues during a 90‐day incubation. Overall, ¹³C‐assimilating bacterial groups with various characteristics were identified with the occurrence of strong priming effects on soil native C. Significant increases of Actinobacteria, Proteobacteria and Bacteroidetes abundances within the ¹³C‐assimilating bacterial community were observed. Generally, Streptomyces were the predominant utilizers of ¹³C derived from rice root residues within a 28‐day incubation. The ¹³C‐labelling of Pseudomonas, which was continuously detected during incubation, indicated stronger effects at the later decomposition stage. The role of genera Kitasatospora, Catenulispora, Nocardioides, Flavisolibacter and Niastella in ¹³C‐labelled rice root residues assimilation was also observed. Meanwhile, incorporation of rice root residues stimulated the growth of certain bacterial groups that incorporated unlabelled native soil C, including Chloroflexi, Acidobacteria, Planctomycetes, Verrumicrobia and Nitrospirae. HIGHLIGHTS: The microbial mechanism of the utilization of crop root residues is largely neglected. We explored the diversity of bacterial communities assimilating rice root residues with DNA‐SIP Actinobacteria, Proteobacteria and Bacteroidetes were dominant decomposers of root residues Streptomyces and Pseudomonas were consistently detected as key assimilators during decomposition

Gut microbiota in fish plays an important role in the nutrient digestion, immune responses and disease resistance. To understand the effect of fluoroquinolone antibiotic bath administration on fish gut microbiota, the gut microbiota community in the coral trout Plectropomus leopardus (Lacepède, 1802) was studied after enrofloxacin bathing treatment at two concentrations (5 and 10 mg/L) and 0 mg/L as control. A total of 90 fish were used in this study, and three replicates were used for each treatment. After a 24‐hr bath, the gut bacterial composition was analyzed using high‐throughput Illumina sequencing. The results indicated that the richness, diversity and the dominant bacterial taxa of P. leopardus gut bacteria were not affected by enrofloxacin bathing (p > .05). Proteobacteria and Firmicutes were the dominant phyla, and Exiguobacterium, Citrobacter, Vibrio, Acinetobacter, Pseudomonas were the dominant genus. The findings in the present study provide an understanding on the relationship between fish gut bacteria community and antibiotic bath administration. The findings of this study are instructive on the antibiotic bath administration applied for the management of P. leopardus health in aquaculture., The gut microbiota community in the coral trout Plectropomus leopardus (Lacepède, 1802) was studied after enrofloxacin bathing treatment at two concentrations (5 and 10 mg/L) and 0 mg/L as control. After a 24‐hr bath, the gut bacterial composition was analyzed using high‐throughput Illumina sequencing. The results indicated that the richness, diversity and the dominant bacterial taxa of P. leopardus gut bacteria were not affected by enrofloxacin bathing (p > .05).

Fruit flies usually harbor diverse communities of bacteria in their digestive systems, which are known to play a significant role in their fitness. However, little information is available on Zeugodacus tau, a polyphagous pest worldwide. This study reports the first extensive analysis of bacterial communities in different life stages and their effect on the development and reproduction of laboratory-reared Z. tau. Cultured bacteria were identified using the conventional method, and all bacteria were identified by high-throughput technologies (16S ribosomal RNA gene sequencing of V3-V4 region). A total of six bacterial phyla were identified in larvae, pupae, and male and female adult flies, which were distributed into 14 classes, 32 orders, 58 families and 96 genera. Proteobacteria was the most represented phylum in all the stages except larvae. Enterobacter, Klebsiella, Providencia, and Pseudomonas were identified by conventional and next-generation sequencing analysis in both male and female adult flies, and Enterobacter was found to be the main genus. After being fed with antibiotics from the first instar larvae, bacterial diversity changed markedly in the adult stage. Untreated flies laid eggs and needed 20 days before oviposition while the treated flies showed ovary development inhibited and were not able to lay eggs, probably due to the alteration of the microbiota. These findings provide the cornerstone for unexplored research on bacterial function in Z. tau, which will help to develop an environmentally friendly management technique for this kind of harmful insect.

Background The human skin microbiome is represented by bacteria, fungi, viruses, and mites. Aims Every human being possess their own unique skin microbiome because intrinsic and environmental factors have a significant impact on the quality and quantity of microorganism. Every site of the body is a separate microbial niche. Patients The feet are one of the most unique and heterogeneous microbial niches of human body with areas that differ by skin thickness, anatomical features, distribution of sweat glands, pH, and the availability of oxygen. Results Healthy skin of the foot is inhabited by Corynebacteriaceae, Micrococcaceae, Propionibacteriaceae, Actinobacteria, Clostridiales, Lactobacillaceae, Streptococcaceae, Enterobacteriaceae, Moravellaceae, Neisseriaceae, Pastereullaceae, and Proteobacteria. The most common fungi present on the feet are Malassezzia, Cryptococcus, Aspergillus, Rhodotorula, Epicoccum, Saccharomyces, Candida, Epidermophyton Microsporum, and Trichophyton. Conclusions The disturbance of the foot microbiome causes dysbiosis and may lead to pitted keratolysis, fungal, and viral infections or even to protothecosis.

The intestinal microbiota plays an important role in the health and metabolism of the host. Next‐generation sequencing technology has enabled the characterization of the gut microbiota of several animal species. We analyzed the intestinal microbiota in six different parts of the gastrointestinal tracts (GITs) of five Mongolian horses by sequencing the 16S rRNA gene V3‐V4 hypervariable region. All horses were kept in the natural habitat of the Inner Mongolia grassland. Significant differences were observed among the microbiota compositions of the distinct GIT regions. In addition, while the microbial community structures of the small and large intestine were significantly different, those of the cecum and colon were similar. In the foregut, Firmicutes (65%) and Proteobacteria (23%) were the most abundant, while Firmicutes (45%) and Bacteroidetes (42%) were the most common in the hindgut. At the level of family, Ruminococcaceae (p = .203), Lachnospiraceae (p = .157), Rikenellaceae (p = .122), and Prevotellaceae (p = .068) were predominant in the hindgut, while the relative abundance of the Akkermansia genus (5.7%, p = .039) was higher in the ventral colon. In terms of the putative functions, the ratio of microbial abundance in the different parts of the GIT was similar, the result can help characterize the gut microbial structure of different animals., The microbial communities of the different parts of the Mongolian horse gastrointestinal tracts were significantly different, and there was greater diversity between the lower gut and upper gut. Direct sampling of the different segments of gastrointestinal tracts provided a more complete diagram of the gut microbiota than fecal analysis. The vegetarian diets and adaptability of Mongolian horses were likely related not only to their stable and complicated gastrointestinal microbiota but also to their special herbivorous digestive physiology.

Ocean pollution is a worldwide environmental challenge that could be partially tackled through microbial applications. To shed light on the diversity and applications of the bacterial communities that inhabit the sediments trapped in artificial containers, we analyzed residues (polyethylene terephthalate [PET] bottles and aluminum cans) collected from the Mediterranean Sea by scanning electron microscopy and next generation sequencing. Moreover, we set a collection of culturable bacteria from the plastisphere that were screened for their ability to use PET as a carbon source. Our results reveal that Proteobacteria are the predominant phylum in all the samples and that Rhodobacteraceae, Woeseia, Actinomarinales, or Vibrio are also abundant in these residues. Moreover, we identified marine isolates with enhanced growth in the presence of PET: Aquimarina intermedia, Citricoccus spp., and Micrococcus spp. Our results suggest that the marine environment is a source of biotechnologically promising bacterial isolates that may use PET or PET additives as carbon sources., Financial support by Ministerio de Ciencia e Innovación (grant SETH ref. RTI2018‐095584‐B‐C41‐42‐43‐44 co‐financed by FEDER), the European Union H2020 (BIOROBOOST project ID 210491758; Micro4Biogas project ref.101000470), Agencia Estatal de la Innovación AEI (MIPLACE projectref. PCI2019‐111845‐2), and Agència Valenciana de la Innovación AVI (ENTOMOPLAST project ref. INNEST/2021/334) are acknowl-edged. Àngela Vidal‐Verdú and Esther Molina‐Menor are funded with a Formación del Profesorado Universitario grant from the Spanish Ministerio de Ciencia, Innovación y Universidades with references FPU18/02578 and FPU17/04184, respectively. Adriel Latorre‐Pérezis a recipient of a Doctorado Industrial fellowship from the Spanish Ministerio de Ciencia, Innovación y Universidades (reference DI‐17‐09613).

Ginsenosides, including Rb1 , Rb2 , Rb3 and Rc, belong to protopanaxadiol-type saponins in Panax ginseng C. A. Mey. Their contents are high in P. ginseng. They could inhibit oxidant stress, enhance immunity, lower blood sugar, resist tumor cells and facilitate other physiological activities. This study aimed to explore the interaction between ginsenosides Rb1 , Rb2 , Rb3 and Rc and the intestinal flora of healthy people. It also sought to analyse the biotransformation products and pathways of these ginsenosides in in-vitro human intestinal bacteria and their effects on the diversity of human intestinal flora. Human intestinal bacteria were incubated with ginsenosides Rb1 , Rb2 , Rb3 and Rc at 37 °C under anaerobic conditions. Samples were taken at different timepoints. The transformed products were identified by rapid high-resolution liquid chromatography-quadrupole time-of-flight mass spectrometry. After 48 h of transformation, the transformed product of ginsenosides Rb1 , Rb2 , Rb3 and Rc was ginsenoside compound K. The transformation rates were 83.5 %, 88.7 %, 85.6 %, and 84.2 %. 16S rRNA sequencing technology was applied to the bioinformatic analysis of faecal samples incubated for 48 h. Relative to the blank control, the relative abundance of Firmicutes and Proteobacteria significantly increased at the phylum level. Moreover, the relative abundance of Bacteroidetes significantly decreased in ginsenosides Rb1 , Rb2 , Rb3 and Rc. At the genus level, the relative abundance of Escherichia significantly increased, whereas that of Dorea, Prevotella and Megasphaera significantly decreased in all groups. These results showed that Rb1 , Rb2 , Rb3 and Rc could improve the structure and diversity of human intestinal flora and balance the metabolic process.