Proposal for reclassification of the species Hungatella xylanolytica as Lacrimispora xylanisolvens nom. nov. and transfer of the genus Hungatella to the family Lachnospiraceae.

Hungatella xylanolytica X5-1T is an anaerobic, xylan-fermenting bacterium first isolated from methane-producing cattle manure. Initially identified as Bacteroides xylanolyticus, this species was later reclassified as H. xylanolytica in 2019. Although this reclassification found support through Genome blast Distance Phylogeny analysis which placed H. xylanolytica X5-1T into the same clade as Hungatella effluvii DSM 24995T, it was contradicted by 16S rRNA gene phylogenetic analysis, which associated it with a set of misnamed Clostridium species later reassigned into the genus Lacrimispora. To ascertain its taxonomic position, comparative analyses were performed to re-examine the relationship between H. xylanolytica X5-1T and all species of the genera Hungatella and Lacrimispora. The ranges of 16S rRNA gene sequence similarity, average amino acid identity, and percentage of conserved protein prediction values were higher between H. xylanolytica X5-1T and species of the genus Lacrimispora than Hungatella. In addition, H. xylanolytica X5-1T was found to harbour genes and pathways conserved and exclusive to species within the genus Lacrimispora but not Hungatella. Essentially, in both the 16S rRNA gene phylogenetic tree and the core-genome phylogenomic tree, H. xylanolytica X5-1T clustered into the same clade as species of the genus Lacrimispora, distinct from species of the genus Hungatella. It is thus clear that H. xylanolytica X5-1T represents a species within the genus Lacrimispora, which we propose to reclassify as Lacrimispora xylanisolvens nom. nov. Finally, based on the results from the phylogenetic and comparative analyses, the genus Hungatella was transferred to the family Lachnospiraceae.

Anaerolentibacter hominis gen. nov. sp. nov., Diplocloster hominis sp. nov. and Pilosibacter fragilis gen. nov. sp. nov., isolated from human faeces.

Three Gram-positive, obligately anaerobic bacterial strains, namely CSJ-1T, CSJ-3T, and CSJ-4T, were isolated from faeces of healthy persons. They were characterized through a combination of whole-genome sequencing, phenotypic traits, and metabolomic analysis. The genome sizes of CSJ-1T, CSJ-4T, and CSJ-3T were 3.3, 3.8, and 6.1 Mbp, with DNA G+C contents of 47.2, 48.3, and 48.8 mol%, respectively. Strain CSJ-3T was identified as representing a novel species, Diplocloster hominis (type strain CSJ-3T=CGMCC 1.18033T=JCM 36512T) of the genus Diplocloster. The 16S rRNA gene sequence similarity and whole genome average nucleotide identity (gANI) of CSJ-4T to its closest related species, Diplocloster modestus ASD 4241T, were 98.3 and 91.4 %, respectively. Comparative analysis of 16S rRNA gene sequences showed 91.6 % similarity between CSJ-1T and its closest phylogenetic neighbour, Catenibacillus scindens DSM 106146T, and 93.3 % similarity between CSJ-4T and its closest relative strain, Clostridium fessum SNUG30386T. Based on the polyphasic taxonomic results, we proposed two novel genera and three novel species. Strain CSJ-1T was identified as representing a novel species of novel genus, Anaerolentibacter hominis gen. nov. sp. nov. (type strain CSJ-1T=CGMCC 1.18046T=JCM 36511T) of the family Lachnospiraceae, and strain CSJ-4T was identified as representing a novel species of novel genus Pilosibacter fragilis gen. nov. sp. nov. (type strain CSJ-4T=CGMCC 1.18026T= JCM 36513T) of the family Clostridiaceae.

Lutispora saccharofermentans sp. nov., a mesophilic, non-spore-forming bacterium isolated from a lab-scale methanogenic landfill bioreactor digesting anaerobic sludge, and emendation of the genus Lutispora to include species which are non-spore-forming and mesophilic.

A novel anaerobic, mesophilic, non-spore-forming bacterium (strain m25T) was isolated from methanogenic enrichment cultures obtained from a lab-scale methanogenic landfill bioreactor containing anaerobic digester sludge. Cells were Gram-stain-negative, catalase-positive, oxidase-negative, rod-shaped, and motile by means of a flagellum. The genomic DNA G+C content was 40.11 mol%. The optimal NaCl concentration, temperature and pH for growth were 2.5 g l-1, 35 °C and at pH 7.0, respectively. Strain m25T was able to grow in the absence of yeast extract on glycerol, pyruvate, arginine and cysteine. In the presence of 0.2 % yeast extract, strain m25T grew on carbohydrates and was able to use glucose, cellobiose, fructose, raffinose and galactose. The novel strain could utilize glycerol, urea, pyruvate, peptone and tryptone. The major fatty acids were iso-C15  :  0, C14  :  0, C16  :  0 DMA (dimethyl acetal) and iso-C15 : 0 DMA. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolate was closely related to Lutispora thermophila EBR46T (95.02 % 16S rRNA gene sequence similarity). Genome relatedness was determined using both average nucleotide identity and amino acid identity analyses, the results of which both strongly supported that strain m25T belongs to the genus Lutispora. Based on its unique phylogenetic features, strain m25T is considered to represent a novel species within the genus Lutispora. Moreover, based on its unique physiologic features, mainly the lack of spore formation, a proposal to amend the genus Lutispora is also provided to include the non-spore-forming and mesophilic species. Lutispora saccharofermentans sp. nov. is proposed. The type strain of the species is m25T (=DSM 112749T=ATCC TSD-268T).

Causal associations between gut microbiome and cardiovascular disease: A Mendelian randomization study.

Background: Observational studies have shown gut microbiomes were associated with cardiovascular diseases (CVDs), but their roles remain controversial, and these associations have not yet been established causally. Methods: Two-sample Mendelian randomization (MR) was used to investigate whether gut microbiome had a causal effect on the risk of CVDs. To obtain comprehensive results, we performed two sets of MR analyses, one with single nucleotide polymorphisms (SNPs) that smaller than the genome-wide statistical significance threshold (5 × 10-8) as instrumental variables, and the other with SNPs that lower than the locus-wide significance level (1 × 10-5). Summary-level statistics for CVDs, including coronary artery disease (CAD), myocardial infarction, heart failure, atrial fibrillation, stroke and its subtypes were collected. The ME estimation was performed using the inverse-variance weighted and Wald ratio methods. Sensitivity analysis was performed using the weighted median, MR-Egger, leave-one-out analysis, MR pleiotropy residual sum and outlier and MR Steiger. Results: Based on the locus-wide significance level, genetically predicted genus Oxalobacter was positively associated with the risk of CAD (odds ratio (OR) = 1.06, 95% confidence interval (CI), 1.03 - 1.10, P = 1.67 × 10-4), family Clostridiaceae_1 was negatively correlated with stroke risk (OR = 0.83,95% CI, 0.75-0.93, P = 7.76 × 10-4) and ischemic stroke risk (OR = 0.823,95% CI, 0.74-0.92, P = 4.15 × 10-4). There was no causal relationship between other genetically predicted gut microbiome components and CVDs risk. Based on the genome-wide statistical significance threshold, the results showed that the gut microbiome had no causal relationship with CVDs risk. Conclusion: Our findings reveal that there are beneficial or adverse causal effects of gut microbiome components on CVDs risk and provide novel insights into strategies for the prevention and management of CVDs through the gut microbiome.

The root zone of graminoids: A niche for H2-consuming acetogens in a minerotrophic peatland.

The importance of acetogens for H2 turnover and overall anaerobic degradation in peatlands remains elusive. In the well-studied minerotrophic peatland fen Schlöppnerbrunnen, H2-consuming acetogens are conceptualized to be largely outcompeted by iron reducers, sulfate reducers, and hydrogenotrophic methanogens in bulk peat soil. However, in root zones of graminoids, fermenters thriving on rhizodeposits and root litter might temporarily provide sufficient H2 for acetogens. In the present study, root-free peat soils from around the roots of Molinia caerulea and Carex rostrata (i.e., two graminoids common in fen Schlöpnnerbrunnen) were anoxically incubated with or without supplemental H2 to simulate conditions of high and low H2 availability in the fen. In unsupplemented soil treatments, H2 concentrations were largely below the detection limit (∼10 ppmV) and possibly too low for acetogens and methanogens, an assumption supported by the finding that neither acetate nor methane substantially accumulated. In the presence of supplemental H2, acetate accumulation exceeded CH4 accumulation in Molinia soil whereas acetate and methane accumulated equally in Carex soil. However, reductant recoveries indicated that initially, additional unknown processes were involved either in H2 consumption or the consumption of acetate produced by H2-consuming acetogens. 16S rRNA and 16S rRNA gene analyses revealed that potential acetogens (Clostridium, Holophagaceae), methanogens (Methanocellales, Methanobacterium), iron reducers (Geobacter), and physiologically uncharacterized phylotypes (Acidobacteria, Actinobacteria, Bacteroidetes) were stimulated by supplemental H2 in soil treatments. Phylotypes closely related to clostridial acetogens were also active in soil-free Molinia and Carex root treatments with or without supplemental H2. Due to pronounced fermentation activities, H2 consumption was less obvious in root treatments, and acetogens likely thrived on root organic carbon and fermentation products (e.g., ethanol) in addition to H2. Collectively, the data highlighted that in fen Schlöppnerbrunnen, acetogens are associated to graminoid roots and inhabit the peat soil around the roots, where they have to compete for H2 with methanogens and iron reducers. Furthermore, the study underscored that the metabolically flexible acetogens do not rely on H2, potentially a key advantage over other H2 consumers under the highly dynamic conditions characteristic for the root-zones of graminoids in peatlands.

Performance of stacked microbial fuel cells with barley-shochu waste.

The treatment of barley-shochu waste combined with electricity generation was examined using stacked microbial fuel cells (SMFCs). The maximum chemical oxygen demand (CODCr) removal efficiency and maximum power density were achieved at 36.7 ± 1.1% and 4.3 ± 0.2 W m⁻³ (15.7 ± 0.9 mW m-2). The acetic acid concentration in effluent increased, whereas the citric acid, ethanol and sugar concentrations decreased during the operation. Microbial community analysis of the anode cell suspension and raw barley-shochu waste revealed that Clostridiaceae, Acetobacteraceae, and Enterobacteriaceae became predominant after the operation, implying that microorganisms belonging to these families might be involved in organic waste decomposition and electricity generation in the SMFCs.

Enhanced Microbial Interactions and Deterministic Successions During Anoxic Decomposition of Microcystis Biomass in Lake Sediment.

Microcystis biomass remineralization after blooming represents a hotspot of nutrient recycling in eutrophic lakes. Because Microcystis blooms are massively deposited on lake sediments, resulting in anoxic conditions, it is important to understand the response and role of benthic microbial communities during the anoxic decomposition of Microcystis in freshwater lakes. In the present study, we employed a microcosm method, combined with high-throughput sequencing, functional prediction, and network analysis, to investigate microbial succession during the short-term (30 days) anaerobic decomposition of Microcystis in a eutrophic sediment. Continuous accumulation of CH4 and CO2 and increasing relative abundance of methanogens were observed during the incubation. The microbial community composition (MCC) significantly changed after addition of Microcystis biomass, with a shift in the community from a stochastic to a functional, deterministic succession. Families, including Clostridiaceae, Rhodocyclaceae, Rikenellaceae, Peptostreptococcaceae, Syntrophomonadaceae, Lachnospiraceae, and Methanosarcinaceae, were predominantly enriched and formed diverse substitution patterns, suggesting a synergistic action of these family members in the decomposition of Microcystis biomass. Importantly, intense species-to-species interactions and weak resistance to disturbance were observed in the microbial community after Microcystis biomass addition. Collectively, these results suggest that the addition of Microcystis induce phylogenetic clustering and structure instability in the sediment microbial community and the synergistic interactions among saprotrophic bacteria play a key role in Microcystis biomass remineralization.

Phosphorus recovery as vivianite from waste activated sludge via optimizing iron source and pH value during anaerobic fermentation.

This study presented an innovative method for phosphorus (P) recovery as vivianite from waste activated sludge (WAS) via optimizing iron dosing and pH value during anaerobic fermentation (AF). The optimal conditions for vivianite formation were in the pH range of 6.0-9.0 with initial PO43- >5 mg/L and Fe/P molar ratio of 1.5. Notably, FeCl3 showed advantages over ZVI for the simultaneous release of Fe2+ and PO43- during WAS fermentation, especially in acidic conditions. The FeCl3 dosing at pH 3.0 could contribute to 78.81% Fe2+ release and 85.69% of total PO43- release from WAS. They were ultimately recovered in the form of high-purity vivianite (93.67%). Clostridiaceae (40.25%) was the predominant bacteria in FeCl3-pH3 reactors, which played key roles in inducing dissimilatory iron reduction for Fe2+ formation. Therefore, P recovery as vivianite from WAS fermentation might be a promising and highly valuable approach to relieve the P crisis.

Thermotolerant cellulolytic Clostridiaceae and Lachnospiraceae rich consortium enhanced biogas production from oil palm empty fruit bunches by solid-state anaerobic digestion.

Thermotolerant cellulolytic consortium for improvement biogas production from oil palm empty fruit bunches (EFB) by prehydrolysis and bioaugmentation strategies was investigated via solid-state anaerobic digestion (SS-AD). The prehydrolysis EFB with Clostridiaceae and Lachnospiraceae rich consortium have maximum methane yield of 252 and 349 ml CH4 g-1 VS with total EFB degradation efficiency of 62% and 86%, respectively. Clostridiaceae and Lachnospiraceae rich consortium augmentation in biogas reactor have maximum methane yield of 217 and 85.2 ml CH4 g-1 VS with degradation efficiency of 42% and 16%, respectively. The best improvement of biogas production was achieved by prehydrolysis EFB with Lachnospiraceae rich consortium with maximum methane production of 113 m3 CH4 tonne-1 EFB. While, Clostridiaceae rich consortium was suitable for augmentation in biogas reactor with maximum methane production of 70.6 m3 CH4 tonne-1 EFB. Application of thermotolerant cellulolytic consortium into the SS-AD systems could enhance biogas production of 3-11 times.

A Diet-Sensitive Commensal Lactobacillus Strain Mediates TLR7-Dependent Systemic Autoimmunity.

Western lifestyle is linked to autoimmune and metabolic diseases, driven by changes in diet and gut microbiota composition. Using Toll-like receptor 7 (TLR7)-dependent mouse models of systemic lupus erythematosus (SLE), we dissect dietary effects on the gut microbiota and find that Lactobacillus reuteri can drive autoimmunity but is ameliorated by dietary resistant starch (RS). Culture of internal organs and 16S rDNA sequencing revealed TLR7-dependent translocation of L. reuteri in mice and fecal enrichment of Lactobacillus in a subset of SLE patients. L. reuteri colonization worsened autoimmune manifestations under specific-pathogen-free and gnotobiotic conditions, notably increasing plasmacytoid dendritic cells (pDCs) and interferon signaling. However, RS suppressed the abundance and translocation of L. reuteri via short-chain fatty acids, which inhibited its growth. Additionally, RS decreased pDCs, interferon pathways, organ involvement, and mortality. Thus, RS exerts beneficial effects in lupus-prone hosts through suppressing a pathobiont that promotes interferon pathways implicated in the pathogenesis of human autoimmunity.

Effects of molecular hydrogen-dissolved alkaline electrolyzed water on intestinal environment in mice.

Increasing evidence indicates that molecular hydrogen-dissolved alkaline electrolyzed water (AEW) has various physiological activities such as antioxidative activity. Gut microbiota are deeply associated with our health through a symbiotic relationship. Recent reports have described that most gastrointestinal microbial species encode the genetic capacity to metabolize molecular hydrogen, meaning that molecular hydrogen might affect the gut microbial composition. Nevertheless, AEW effects on gut microbiota remain unknown. This study investigated AEW effects on the intestinal environment in mice, including microbial composition and short-chain fatty acid contents. After mice were administered AEW for 4 weeks, 16S rRNA gene sequencing analyses revealed their fecal microbiota profiles. Organic acid concentrations in cecal contents were measured using an HPLC system. Compared to the control group, AEW administration mice had significantly lower serum low-density lipoprotein cholesterol level and alanine aminotransferase activity. Organic acid concentrations of propionic, isobutyric, and isovaleric acids were higher in AEW-administered mice. Results of 16S rRNA gene sequencing analyses showed that the relative abundances of 20 taxa differed significantly in AEW-administered mice. Although the definitive role of gut microbes of AEW-administered mice remains unknown, our data demonstrate the possibility that AEW administration affects the gut microbial composition and that it has beneficial health effects in terms of cholesterol metabolism and liver protection.

Short-Term Exposure of Paddy Soil Microbial Communities to Salt Stress Triggers Different Transcriptional Responses of Key Taxonomic Groups.

Soil salinization due to seawater intrusion along coastal areas is an increasing threat to rice cultivation worldwide. While the detrimental impact on rice growth and yield has been thoroughly studied, little is known about how severe salinity affects structure and function of paddy soil microbial communities. Here, we examined their short-term responses to half- and full-strength seawater salinity in controlled laboratory experiments. Slurry microcosms were incubated under anoxic conditions, with rice straw added as carbon source. Stress exposure time was for 2 days after a pre-incubation period of 7 days. Relative to the control, moderate (300 mM NaCl) and high (600 mM NaCl) salt stress suppressed both net consumption of acetate and methane production by 50% and 70%, respectively. Correspondingly, community-wide mRNA expression decreased by 50-65%, with significant changes in relative transcript abundance of family-level groups. mRNA turnover was clearly more responsive to salt stress than rRNA dynamics. Among bacteria, Clostridiaceae were most abundant and the only group whose transcriptional activity was strongly stimulated at 600 mM NaCl. In particular, clostridial mRNA involved in transcription/translation, fermentation, uptake and biosynthesis of compatible solutes, and flagellar motility was significantly enriched in response salt stress. None of the other bacterial groups were able to compete at 600 mM NaCl. Their responses to 300 mM NaCl were more diverse. Lachnospiraceae increased, Ruminococcaceae maintained, and Peptococcaceae, Veillonellaceae, and Syntrophomonadaceae decreased in relative mRNA abundance. Among methanogens, Methanosarcinaceae were most dominant. Relative to other family-level groups, salt stress induced a significant enrichment of transcripts related to the CO dehydrogenase/acetyl-coenzyme A synthase complex, methanogenesis, heat shock, ammonium uptake, and thermosomes, but the absolute abundance of methanosarcinal mRNA decreased. Most strikingly, the transcriptional activity of the Methanocellaceae was completely suppressed already at 300 mM NaCl. Apparently, the key taxonomic groups involved in the methanogenic breakdown of plant polymers significantly differ in their ability to cope with severe salt stress. Presumably, this different ability is directly linked to differences in their genetic potential and metabolic flexibility to reassign available energy resources for cellular adaptation to salt stress.

Decreased Taxon-Specific IgA Response in Relation to the Changes of Gut Microbiota Composition in the Elderly.

Gut microbiota is known to change with aging; however, the underlying mechanisms have not been well elucidated. Immunoglobulin A (IgA) is the dominant class of antibody secreted by the intestinal mucosa, and are thought to play a key role in the regulation of the gut microbiota. T cells regulate the magnitude and nature of microbiota-specific IgA responses. However, it is also known that T cells become senescent in elderly people. Therefore, we speculated that the age-related changes of IgA response against the gut microbiota might be one of the mechanisms causing the age-associated changes of gut microbiota composition. To prove our hypothesis, fecal samples from 40 healthy subjects (adult group: n = 20, an average of 35 years old; elderly group: n = 20, an average of 76 years old) were collected, and the gut microbiota composition and the response of IgA to gut microbiota were investigated. The relative abundance of Bifidobacteriaceae was significantly lower, whereas those of Clostridiaceae, Clostridiales;f__ and Enterobacteriaceae were significantly higher in the elderly group than in the adult group. There was no significant difference in the fecal IgA concentration between the adult and elderly groups. However, the taxon-specific IgA response to some bacterial taxa was different between the adult and elderly groups. To evaluate inter-group differences in the taxon-specific IgA response to each bacterial taxon, the IgA-indices were calculated, and the IgA-indices of Clostridiaceae and Enterobacteriaceae were found to be significantly lower in the elderly group than the adult group. In addition, Clostridiales;f__ and Enterobacteriaceae were significantly enriched in the IgA+ fraction in the adult group but not in the elderly group, whereas Clostridiaceae was significantly enriched in the IgA- fraction in the elderly group but not in the adult group. Some species assigned to Clostridiaceae or Enterobacteriaceae are known to be pathogenic bacteria. Our results suggest the possible contribution of decreased IgA response in the increased abundance of bacterial taxa with potential pathogenicity in the intestinal environment of the elderly. Our findings contribute to the understanding of the regulatory factor for the changes in the gut microbiota composition with aging.

Genome sequence and description of Anaerosalibacter massiliensis sp. nov.

Anaerosalibacter massiliensis sp. nov. strain ND1(T) (= CSUR P762 = DSM 27308) is the type strain of A. massiliensis sp. nov., a new species within the genus Anaerosalibacter. This strain, the genome of which is described here, was isolated from the faecal flora of a 49-year-old healthy Brazilian man. Anaerosalibacter massiliensis is a Gram-positive, obligate anaerobic rod and member of the family Clostridiaceae. With the complete genome sequence and annotation, we describe here the features of this organism. The 3 197 911 bp long genome (one chromosome but no plasmid) contains 3271 protein-coding and 62 RNA genes, including six rRNA genes.

Avaliação da microbiota intestinal em adultos com esofagite erosiva / Assessment of the intestinal microbiota in adults with erosive esophagitis

ABSTRACT BACKGROUND: The intestinal microbiota influences the appropriate function of the gastrointestinal tract. Intestinal dysbiosis may be associated with a higher risk of esophageal lesions, mainly due to changes in gastroesophageal motility patterns, elevation of intra-abdominal pressure, and increased frequency of transient relaxation of the lower esophageal sphincter. OBJECTIVE: The aim of this study was to evaluate the intestinal microbiota in individuals with erosive esophagitis and in healthy individuals using metagenomics. METHODS: A total of 22 fecal samples from adults aged between 18 and 60 years were included. Eleven individuals had esophagitis (eight men and three women) and 11 were healthy controls (10 men and one woman). The individuals were instructed to collect and store fecal material into a tube containing guanidine solution. The DNA of the microbiota was extracted from each fecal samples and PCR amplification was performed using primers for the V4 region of the 16S rRNA gene. The amplicons were sequenced using the Ion Torrent PGM platform and the data were analyzed using the QIIME™ software version 1.8. Statistical analyses were performed using the Mann-Whitney non-parametric test and the ANOSIM non-parametric method based on distance matrix. RESULTS: The alpha-diversity and beta-diversity indices were similar between the two groups, without statistically significant differences. There was no statistically significant difference in the phylum level. However, a statistically significant difference was observed in the abundance of the family Clostridiaceae (0.3% vs 2.0%, P=0.032) and in the genus Faecaliumbacterium (10.5% vs 4.5%, P=0.045) between healthy controls and esophagitis patients. CONCLUSION: The findings suggest that reduced abundance of the genus Faecaliumbacterium and greater abundance of the family Clostridiaceae may be risk factors for the development of erosive esophagitis. Intervention in the composition of the intestinal microbiota should be considered as an adjunct to current therapeutic strategies for this clinical condition.

RESUMO CONTEXTO: A doença do refluxo gastroesofágico (DRGE) é uma das enfermidades mais comuns na prática clínica e possui fisiopatologia multifatorial. Disbiose da microbiota intestinal pode ter influência em mecanismos envolvidos nesta doença, como mudanças nos padrões motores gastrointestinais, elevação da pressão intra-abdominal e aumento da frequência de relaxamentos transitórios do esfíncter esofágico inferior. Contudo, a avaliação da microbiota intestinal, neste contexto, ainda é pouco documentada. OBJETIVO: Este estudo avaliou a microbiota bacteriana intestinal, em indivíduos com doença do refluxo gastroesofágico erosivo e em indivíduos saudáveis, utilizando técnicas de metagenômica. MÉTODOS: Estudo incluiu amostras fecais de 22 adultos, com idades entre 18 e 60 anos: 11 com esofagite erosiva (oito homens e três mulheres) e 11 controles saudáveis (dez homens e uma mulher). Os pacientes foram orientados a coletar e armazenar o material fecal em tubo contendo solução de guanidina. O DNA da microbiota foi extraído das amostras de fezes e amplificação por PCR foi realizada usando iniciadores para a região V4 do gene 16S rRNA. Os amplicons foram seqüenciados usando a plataforma Ion PGM Torrent e os dados foram analisados usando o software QIIME™ versão 1.8 (Quantitative Insights Into Microbial Ecology). Análise de estatística foi realizada utilizando-se o teste não paramétrico de Mann-Whitney e o teste ANOSIM, método não paramétrico baseado em matriz de distância. RESULTADOS: Os índices de alfa-diversidade e beta-diversidade foram semelhantes entre os dois grupos, sem diferença estatisticamente significante. Não houve diferença estatisticamente significante no nível de filo, classe e ordem. Entretanto, observou-se diferença estatisticamente significante na abundância da família Clostridiaceae (0,3% vs 2,0%, P=0,032) e no gênero Faecaliumbacterium (10,5% vs 4,5%, P=0,045) entre controles saudáveis e pacientes com DRGE erosiva, respectivamente. CONCLUSÃO: Os achados sugerem que menor abundância do gênero Faecaliumbacterium e maior abundância da família Clostridiaceae, nos pacientes com DRGE, podem influenciar na fisiopatologia desta doença.

Abyssisolibacter fermentans gen. nov. sp. nov., isolated from deep sub-seafloor sediment.

A Gram-staining-negative, thin rod-shaped, anaerobic bacterium designated MCWD3(T) was isolated from sediment of the deep sea in Ulleung Basin, East Sea, Korea. The ranges of temperature, pH and NaCl for growth of this strain were 15-40°C (optimum 29°C), 5.0-10.0 (optimum pH 6.5), and 1-5%, respectively. The major fatty acids were iso-C(15:0) (30%) and iso-C(15:0) dimethyl acetal (17%). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and unidentified aminophospholipids, phospholipids, and aminolipids. The fermentation product from yeast extract was acetate. Phylogenetic analysis based on 16S rRNA genes indicated that the isolate was related to Sporosalibacterium faouarense (92.8% sequence identity), Clostridiisalibacter paucivorans (92.6%), and Brassicibacter mesophilus (92.4%). However, the isolate was differentiated from these genera by both physiological and chemotaxonomical properties. On the basis of a polyphasic taxonomic analysis, we propose that MCWD3(T) represents a novel taxon with the name Abyssisolibacter fermentans gen. nov. sp. nov.

Characterization of Electricity Generated by Soil in Microbial Fuel Cells and the Isolation of Soil Source Exoelectrogenic Bacteria.

Soil has been used to generate electrical power in microbial fuel cells (MFCs) and exhibited several potential applications. This study aimed to reveal the effect of soil properties on the generated electricity and the diversity of soil source exoelectrogenic bacteria. Seven soil samples were collected across China and packed into air-cathode MFCs to generate electricity over a 270 days period. The Fe(III)-reducing bacteria in soil were enriched and sequenced by Illumina pyrosequencing. Culturable strains of Fe(III)-reducing bacteria were isolated and identified phylogenetically. Their exoelectrogenic ability was evaluated by polarization measurement. The results showed that soils with higher organic carbon (OC) content but lower soil pH generated higher peak voltage and charge. The sequencing of Fe(III)-reducing bacteria showed that Clostridia were dominant in all soil samples. At the family level, Clostridiales Family XI incertae sedis were dominant in soils with lower OC content but higher pH (>8), while Clostridiaceae, Lachnospiraceae, and Planococcaceae were dominant in soils with higher OC content but lower pH. The isolated culturable strains were allied phylogenetically to 15 different species, of which 11 were Clostridium. The others were Robinsoniella peoriensis, Hydrogenoanaerobacterium saccharovorans, Eubacterium contortum, and Oscillibacter ruminantium. The maximum power density generated by the isolates in the MFCs ranged from 16.4 to 28.6 mW m-2. We concluded that soil OC content had the most important effect on power generation and that the Clostridiaceae were the dominant exoelectrogenic bacterial group in soil. This study might lead to the discovery of more soil source exoelectrogenic bacteria species.

Three-dimensional assessment of enamel and dentine in mouse molar teeth during masseter muscle hypofunction / Evaluación tridimensional del esmalte y la dentina de dientes molares de ratones durante la hipofunción del músculo masetero

Background: Mouse molar is a widely used model for teeth development. However, the effect of masticatory function on enamel and dentine in adult individuals remains poorly understood. As reported, the unilateral masseter hypofunction induced by botulinum toxin type A (BoNTA) resulted in mandibular bone damage and signs of unilateral chewing in adult mice. Objective: We aimed to assess the amount of enamel and dentine in the first molar (M1) during the unilateral masseter hypofunction in mice, using high-resolution X-ray microtomography (µCT) as threedimensional approach. Materials and methods: Mandibles of adult BALB/c mice, located either in a Control-group (without intervention) or a BoNTA-group, were ex-vivo scanned using µCT. Treated individuals received each one BoNTA intervention in the right masseter, and saline solution in the left masseter (intra-individual control). Enamel and dentine from M1 were segmented, and volume, thickness and mesial root length were quantified. Results: Enamel volume from treated side resulted unchanged after 2 weeks of unilateral masseter hypofunction. No differences for enamel volume were found between both sides of control individuals, and between these and samples from hypofunctional side in BoNTA-group. Enamel volume from saline-injected side was reduced when compared with experimental side (p<0,01). No differences in dentine volume, thickness of enamel and dentine, and mesial root length were found for any group. Conclusion: The amount of enamel in hypofunctional molars remains unaffected after unilateral BoNTA intervention in the masseter, but contralateral side showed reduced enamel volume. Therefore, increased functional wearing during unilateral chewing after BoNTA intervention should be considered.

Introducción: El molar de ratón es utilizado como modelo de estudio en el desarrollo dental. El efecto de la función masticatoriasobre el tejido dental en individuos adultos aún se comprende. En ratones adultos, la hipofunción unilateral del masetero inducida por toxina botulínica tipo A (BoNTA) resultó en daño óseo mandibular y signos de masticación unilateral. Objetivo: Evaluamos la cantidad de esmalte y dentina en el primer molar (M1) durante la hipofunción unilateral del músculo masetero en ratones mediante análisis con microtomografía (µCT). Materiales y métodos: Las mandíbulas de ratones BALB/c adultos, del grupo Control (sin intervención) o el grupo BoNTA, fueron escaneadas ex-vivo con µCT. Los individuos tratados se inyectaron con BoNTA en el masetero derecho y con solución salina en el masetero izquierdo (control intra-individuo). El volumen y grosor de esmalte y dentina del M1, y la longitud de la raíz mesial fueron medidos. Resultados: No hubo cambios en el volumen del esmalte del lado tratado con BoNTA y en ambos lados del grupo Control, 2 semanas post-intervención. El esmalte del lado control intra-individuo se redujo comparado con el lado experimental (p< 0,01). No hubo cambios en el volumen de dentina, el grosor de esmalte y dentina o en longitud de la raíz mesial de ambos grupos. Conclusión: La cantidad de esmalte en los molares hipofuncionales no se afecta después de la inyección unilateral de BoNTA en masetero, pero si se reduce en el lado contralateral. Por lo tanto, se debe considerar un desgaste dental asimétrico durante esta intervención.