-
The Science of the Total Environment Jan 2024Schwertmannite (Sch) is a highly bioavailable iron-hydroxysulfate mineral commonly found in acid mine drainage contaminated environment rich in sulfate (SO)....
Schwertmannite (Sch) is a highly bioavailable iron-hydroxysulfate mineral commonly found in acid mine drainage contaminated environment rich in sulfate (SO). Microbial-mediated Sch transformation has been well-studied, however, the understanding of how SO availability affects the microbial-mediated Sch transformation and the secondary minerals influence microbes is relatively limited. This study examined the effect of SO availability on the iron-reducing bacteria (FeRB) and SO-reducing bacteria (SRB) consortium-mediated Sch transformation and the resulting secondary minerals in turn on bacteria. Increased SO accelerated the onset of microbial SO reduction, which significantly accelerated Sch reduction transformation. The extent of intermediate products such as lepidocrocite (22.1 % ~ 76.3 %, all treatments) and goethite (15.3 %, 10 mM SO, 5 d) formed by Sch transformation depended on SO concentrations. Vivianite, siderite and iron‑sulfur minerals (e.g., FeS and FeS) were the dominant secondary minerals, in which the relative content of vivianite and siderite decreased while iron‑sulfur minerals increased with increasing SO concentration. Correspondingly, the abundance of FeRB and SRB was negatively and positively correlated with SO concentration, respectively; 1 mM SO promoted the cymA and omcA expression of FeRB, but 10 mM SO lowerd the cymA and omcA expression compared to the 1 mM SO; the dsr expression of SRB related linearly to the SO concentration. These secondary minerals accumulated on the cell surface to form cell encrustations, which limited the growth and gene expression of FeRB and SRB, and even inhibited the activity of SRB in the 10 mM SO treatment group. The 10 mM SO treatment group with low-intensity ultrasound effectively restored the SRB activity for reducing SO by disintegrating the cell-mineral aggregation, further indicating that cell encrustations limited the microbial metabolism. The results highlight the critical role that SO availability can play in controlling microbial transformation of mineral, and the influence of secondary minerals on microbial metabolism.
Topics: Iron; Sulfates; Minerals; Desulfovibrio; Bacteria; Sulfur; Oxidation-Reduction
PubMed: 37820819
DOI: 10.1016/j.scitotenv.2023.167690 -
Clinical and Experimental Rheumatology Jan 2024To assess whether there is a bidirectional causal relationship between the composition of gut microbiota and rheumatoid arthritis (RA), and to identify specific...
OBJECTIVES
To assess whether there is a bidirectional causal relationship between the composition of gut microbiota and rheumatoid arthritis (RA), and to identify specific pathogenic bacterial taxa via the Mendelian randomisation (MR) analysis.
METHODS
We acquired single nucleotide polymorphisms (SNPs) associated with the composition of gut microbiota (n=18,340) and with RA (n=331,313) from publicly available genome-wide association studies (GWAS). The genome-wide threshold was 1 × 10-5 in the forward MR analysis and was 5 × 10-8 in the reverse MR analysis. Inverse variance weighted (IVW) was the main method to analyse causality, and MR results were verified by several sensitivity analyses including weighted median, MR Egger, and MR Pleiotropy Residual Sum and Outlier (PRESSO).
RESULTS
The IVW method suggested that eight taxa were positively correlated with RA, including: MollicutesRF9 (pIVW <0.01), Alphaproteobacteria (pIVW <0.01), Betaproteobacteria (p IVW =0.04), Bacteroidaceae (pIVW <0.01), Adlercreutzia (pIVW <0.01), Bacteroides (pIVW <0.01), Butyricimonas (p IVW =0.03) and Holdemanella (pIVW =0.03). Six bacterial taxa were negatively correlated with RA, including Desulfovibrionales (pIVW = 0.01), Methanobacteriales (pIVW <0.01), Methanobacteria (PIVW <0.01), Desulfovibrionaceae (pIVW <0.01), Methanobacteriaceae (pIVW <0.01) and Butyrivibrio (pIVW =0.02). Heterogeneity (p>0.05) and pleiotropy (p>0.05) analysis confirmed the robustness of the MR results.
CONCLUSIONS
We identified some specific bacterial taxa that were causally associated with the risk of RA, providing new insights into prevention and diagnosis of RA.
Topics: Humans; Gastrointestinal Microbiome; Genome-Wide Association Study; Arthritis, Rheumatoid; Polymorphism, Single Nucleotide
PubMed: 37812479
DOI: 10.55563/clinexprheumatol/p9ig7c -
Revista Espanola de Quimioterapia :... Dec 2023
Identification of curved Gram-negative rods by MALDI-TOF mass spectrometer in a patient with Fournier ́s gangrene. A bacteremia caused by Desulfovibrio desulfuricans and Escherichia coli.
Topics: Humans; Desulfovibrio desulfuricans; Escherichia coli; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Gangrene; Bacteremia; Gram-Negative Bacteria
PubMed: 37767548
DOI: 10.37201/req/026.2023 -
Scientific Reports Sep 2023Sulfate-reducing bacteria (SRB) are terminal members of any anaerobic food chain. For example, they critically influence the biogeochemical cycling of carbon, nitrogen,...
Sulfate-reducing bacteria (SRB) are terminal members of any anaerobic food chain. For example, they critically influence the biogeochemical cycling of carbon, nitrogen, sulfur, and metals (natural environment) as well as the corrosion of civil infrastructure (built environment). The United States alone spends nearly $4 billion to address the biocorrosion challenges of SRB. It is important to analyze the genetic mechanisms of these organisms under environmental stresses. The current study uses complementary methodologies, viz., transcriptome-wide marker gene panel mapping and gene clustering analysis to decipher the stress mechanisms in four SRB. Here, the accessible RNA-sequencing data from the public domains were mined to identify the key transcriptional signatures. Crucial transcriptional candidate genes of Desulfovibrio spp. were accomplished and validated the gene cluster prediction. In addition, the unique transcriptional signatures of Oleidesulfovibrio alaskensis (OA-G20) at graphene and copper interfaces were discussed using in-house RNA-sequencing data. Furthermore, the comparative genomic analysis revealed 12,821 genes with translation, among which 10,178 genes were in homolog families and 2643 genes were in singleton families were observed among the 4 genomes studied. The current study paves a path for developing predictive deep learning tools for interpretable and mechanistic learning analysis of the SRB gene regulation.
Topics: Humans; Transcriptome; Gene Expression Profiling; Desulfovibrio; Food Chain; Sulfates
PubMed: 37758719
DOI: 10.1038/s41598-023-43089-8 -
Frontiers in Microbiology 2023The importance of gut-liver axis in the pathophysiology of metabolic dysfunction-associated fatty liver disease (MAFLD) is being investigated more closely in recent...
Metagenomic signatures reveal the key role of phloretin in amelioration of gut dysbiosis attributed to metabolic dysfunction-associated fatty liver disease by time-dependent modulation of gut microbiome.
The importance of gut-liver axis in the pathophysiology of metabolic dysfunction-associated fatty liver disease (MAFLD) is being investigated more closely in recent times. However, the inevitable changes in gut microbiota during progression of the disease merits closer look. The present work intends to assess the time-dependent gut dysbiosis in MAFLD, its implications in disease progression and role of plant-derived prebiotics in its attenuation. Male C57BL/6J mice were given western diet (WD) for up to 16 weeks and phloretin was administered orally. The fecal samples of mice were collected every fourth week for 16 weeks. The animals were sacrificed at the end of the study and biochemical and histological analyses were performed. Further, 16S rRNA amplicon sequencing analysis was performed to investigate longitudinal modification of gut microbiome at different time points. Findings of our study corroborate that phloretin alleviated the metabolic changes and mitigated circulating inflammatory cytokines levels. Phloretin treatment resists WD induced changes in microbial diversity of mice and decreased endotoxin content. Prolonged exposure of WD changed dynamics of gut microbiota abundance and distribution. Increased abundance of pathogenic taxa like , and was noted. Phloretin treatment not only reversed this dysbiosis but also modulated taxonomic signatures of beneficial microbes like , , and . Therefore, the potential of phloretin to restore gut eubiosis could be utilized as an intervention strategy for the prevention of MAFLD and related metabolic disorders.
PubMed: 37744933
DOI: 10.3389/fmicb.2023.1210517 -
Frontiers in Microbiology 2023Salt marshes are dynamic, highly productive ecosystems positioned at the interface between terrestrial and marine systems. They are exposed to large quantities of both...
Salt marshes are dynamic, highly productive ecosystems positioned at the interface between terrestrial and marine systems. They are exposed to large quantities of both natural and anthropogenic carbon input, and their diverse sediment-hosted microbial communities play key roles in carbon cycling and remineralization. To better understand the effects of natural and anthropogenic carbon on sediment microbial ecology, several sediment cores were collected from Little Sippewissett Salt Marsh (LSSM) on Cape Cod, MA, USA and incubated with either cordgrass or diesel fuel. Resulting shifts in microbial diversity and activity were assessed via bioorthogonal non-canonical amino acid tagging (BONCAT) combined with fluorescence-activated cell sorting (FACS) and 16S rRNA gene amplicon sequencing. Both and diesel amendments resulted in initial decreases of microbial diversity as well as clear, community-wide shifts in metabolic activity. Multi-stage degradative frameworks shaped by fermentation were inferred based on anabolically active lineages. In particular, the metabolically versatile were prominent under both treatments, as were the sulfate-reducing , which may be attributable to their ability to utilize diverse forms of carbon under nutrient limited conditions. By identifying lineages most directly involved in the early stages of carbon processing, we offer potential targets for indicator species to assess ecosystem health and highlight key players for selective promotion of bioremediation or carbon sequestration pathways.
PubMed: 37744927
DOI: 10.3389/fmicb.2023.1235906 -
The Journal of Nutritional Biochemistry Dec 2023Multiple sclerosis (MS) is a disease of the central nervous system that involves the immune system attacking the protective covering of nerve fibers. This disease can be...
Multiple sclerosis (MS) is a disease of the central nervous system that involves the immune system attacking the protective covering of nerve fibers. This disease can be influenced by both environmental and genetic factors. Evidence has highlighted the critical role of the intestinal microbiota in MS and its animal model, experimental autoimmune encephalomyelitis (EAE). The composition of gut microflora is mainly determined by dietary components, which, in turn, modulate host homeostasis. A diet rich in naringenin at 0.5% can effectively mitigate the severity of EAE in mice. However, there is little direct data on the impact of naringenin at optimal doses on EAE development, as well as its intestinal microbiota and metabolites. Our study revealed that 2.0% naringenin resulted in the lowest clinical score and pathological changes in EAE mice, and altered the gene expression profiles associated with inflammation and immunity in spinal cord tissue. We then used untargeted metabolomics and 16S rRNA gene sequences to identify metabolites and intestinal microbiota, respectively. Naringenin supplementation enriched gut microbiota in EAE mice, including increasing the abundance of Paraprevotellaceae and Comamonadaceae, while decreasing the abundance of Deltaproteobacteria, RF39, and Desulfovibrionaceae. Furthermore, the changes in gut microbiota affected the production of metabolites in the feces and brain, suggesting a role in regulating the gut-brain axis. Finally, we conducted a fecal transplantation experiment to validate that gut microbiota partly mediates the effect of naringenin on EAE alleviation. In conclusion, naringenin has potential immunomodulatory effects that are influenced to some extent by the gut microbiome.
Topics: Mice; Animals; Encephalomyelitis, Autoimmune, Experimental; Brain-Gut Axis; RNA, Ribosomal, 16S; Multiomics; Multiple Sclerosis
PubMed: 37741298
DOI: 10.1016/j.jnutbio.2023.109448 -
Polish Journal of Microbiology Sep 2023We aimed to compare the clinical efficacy of fecal microbiota transplantation (FMT) from the same sex on ulcerative colitis (UC) patients. A total of 272 UC patients...
We aimed to compare the clinical efficacy of fecal microbiota transplantation (FMT) from the same sex on ulcerative colitis (UC) patients. A total of 272 UC patients were selected in the prospective clinical study, which incorporated four distinct groups, each comprising male and female patients, who were either receiving FMT or placebo, respectively. FMT was performed by sending the gut microbiota of healthy female or male adolescents to the same gender patients via gastroscope three times (one time/three weeks), and a placebo was used with an equal volume of saline. Abdominal pain, diarrhea, thick bloody stool, intestinal mucosal lesion, and Mayo scores were measured. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were evaluated. The changes of intestinal flora were detected by the 16S rRNA sequencing. FMT reduced the scores of diarrhea, abdominal pain, mucosal lesion, and Mayo, SAS, and SDS in UC patients compared to the placebo group ( < 0.05). Clostridiales and were dominant in gut microbiota from male patients and were reduced after FMT. Meanwhile, the abundance of , , and was increased in the male group. Female patients had a higher abundance of , , and before FMT, and it was reduced after FMT. Meanwhile, the abundance of , , , and was increased in the female group. There were no significant changes for the species in the corresponding placebo groups. FMT improved the UC symptoms of male and female patients, which may be associated with different gut microbiota changes.
Topics: Adolescent; Humans; Female; Male; Colitis, Ulcerative; Fecal Microbiota Transplantation; Prospective Studies; RNA, Ribosomal, 16S; Abdominal Pain; Bifidobacterium; Diarrhea; Fabaceae; Lactobacillus
PubMed: 37725892
DOI: 10.33073/pjm-2023-025 -
Microbiome Sep 2023Gypsum Hill Spring, located in Nunavut in the Canadian High Arctic, is a rare example of a cold saline spring arising through thick permafrost. It perennially discharges...
BACKGROUND
Gypsum Hill Spring, located in Nunavut in the Canadian High Arctic, is a rare example of a cold saline spring arising through thick permafrost. It perennially discharges cold (~ 7 °C), hypersaline (7-8% salinity), anoxic (~ 0.04 ppm O), and highly reducing (~ - 430 mV) brines rich in sulfate (2.2 g.L) and sulfide (9.5 ppm), making Gypsum Hill an analog to putative sulfate-rich briny habitats on extraterrestrial bodies such as Mars.
RESULTS
Genome-resolved metagenomics and metatranscriptomics were utilized to describe an active microbial community containing novel metagenome-assembled genomes and dominated by sulfur-cycling Desulfobacterota and Gammaproteobacteria. Sulfate reduction was dominated by hydrogen-oxidizing chemolithoautotrophic Desulfovibrionaceae sp. and was identified in phyla not typically associated with sulfate reduction in novel lineages of Spirochaetota and Bacteroidota. Highly abundant and active sulfur-reducing Desulfuromusa sp. highly transcribed non-coding RNAs associated with transcriptional regulation, showing potential evidence of putative metabolic flexibility in response to substrate availability. Despite low oxygen availability, sulfide oxidation was primarily attributed to aerobic chemolithoautotrophic Halothiobacillaceae. Low abundance and transcription of photoautotrophs indicated sulfur-based chemolithoautotrophy drives primary productivity even during periods of constant illumination.
CONCLUSIONS
We identified a rare surficial chemolithoautotrophic, sulfur-cycling microbial community active in a unique anoxic, cold, hypersaline Arctic spring. We detected Mars-relevant metabolisms including hydrogenotrophic sulfate reduction, sulfur reduction, and sulfide oxidation, which indicate the potential for microbial life in analogous S-rich brines on past and present Mars. Video Abstract.
Topics: Calcium Sulfate; Canada; Microbiota; Oxygen; Sulfates; Gammaproteobacteria
PubMed: 37697305
DOI: 10.1186/s40168-023-01628-5 -
Journal of Dairy Science Jan 2024The main purpose of the current study was to investigate the ameliorative effects of bovine milk osteopontin (bmOPN) on the gut dysfunction of pregnant rats fed a...
The main purpose of the current study was to investigate the ameliorative effects of bovine milk osteopontin (bmOPN) on the gut dysfunction of pregnant rats fed a high-fat diet (HFD). Bovine milk osteopontin was supplemented at a dose of 6 mg/kg body weight. Bovine milk osteopontin supplementation during pregnancy reduced colonic inflammation of HFD dams, and it also increased the colonic expression of ZO-1 and claudin-4 of HFD dams. Bovine milk osteopontin significantly enriched the relative abundance of Bacteroidetes, whereas it decreased Proteobacteria, Helicobacteraceae, and Desulfovibrionaceae in feces of HFD dams. The levels of isobutyric acid and pentanoic acid in the HFD + bmOPN group were higher than that of the HFD group. Functional predication analysis of microbial genomes revealed that bmOPN supplementation to HFD pregnancies changed 4 Kyoto Encyclopedia of Genes and Genomes pathways including bile acid biosynthesis. Further, bmOPN enriched hepatic taurochenodeoxycholic acid and tauroursodeoxycholic acid plus taurohyodeoxycholic acid in the gut of HFD maternal rats. Our findings suggested that bmOPN improved the gut health of HFD pregnant rats partially through modulating bile acid biosynthesis.
Topics: Female; Pregnancy; Rats; Animals; Mice; Milk; Diet, High-Fat; Osteopontin; Gastrointestinal Microbiome; Bile Acids and Salts; Mice, Inbred C57BL
PubMed: 37690710
DOI: 10.3168/jds.2023-23802