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Bioscience, Biotechnology, and... Jul 2019The basic functions of a propionate-oxidizing bacterium flagellum, such as motility and chemotaxis, have not been studied. To investigate its motility, we compared with...
The basic functions of a propionate-oxidizing bacterium flagellum, such as motility and chemotaxis, have not been studied. To investigate its motility, we compared with that of , an aflagellar propionate-oxidizing bacterium, in soft agar medium. cells spread, while cells moved downward slightly, indicating flagellum-dependent motility in SI. The motility of was inhibited by the addition of carbonyl cyanide m-chlorophenyl hydrazone, a proton uncoupler, which is consistent with the fact that stator protein, MotB of , shared sequence homology with proton-type stators. In addition, 5-N-ethyl-N-isopropyl amiloride, an Na channel blocker, showed no inhibitory effect on the motility. Furthermore, of complemented the defective swimming ability of ∆. These results suggest that the motility of SI depends on the proton-type flagellar motor.
Topics: Deltaproteobacteria; Escherichia coli; Flagella; Peptococcaceae
PubMed: 30919743
DOI: 10.1080/09168451.2019.1597618 -
Environmental Science & Technology Jun 2021Reliance on bioremediation to remove benzene from anoxic environments has proven risky for decades but for unknown reasons. Research has revealed a strong link between...
Reliance on bioremediation to remove benzene from anoxic environments has proven risky for decades but for unknown reasons. Research has revealed a strong link between anaerobic benzene biodegradation and the enrichment of highly specific microbes, including in the family and the deltaproteobacterial Candidate Sva0485 clade. Using aquifer materials from Canadian Forces Base Borden, we compared five bioremediation approaches in batch microcosms. Under conditions simulating natural attenuation or sulfate biostimulation, benzene was not degraded after 1-2 years of incubation and no enrichment of known benzene-degrading microbes occurred. In contrast, nitrate-amended microcosms reported benzene biodegradation coincident with significant growth of spp., along with a functional gene presumed to catalyze anaerobic benzene carboxylation (). Inoculation with 2.5% of a methanogenic benzene-degrading consortium containing Sva0485 ( ORM2) resulted in benzene biodegradation in the presence of sulfate or under methanogenic conditions. The presence of other hydrocarbon co-contaminants decreased the rates of benzene degradation by a factor of 2 to 4. Tracking the abundance of the gene and 16S rRNA genes specific for benzene-degrading and Sva0485 is recommended to monitor benzene bioremediation in anoxic groundwater systems to further uncover growth-rate-limiting conditions for these two intriguing phylotypes.
Topics: Anaerobiosis; Benzene; Biodegradation, Environmental; Canada; RNA, Ribosomal, 16S
PubMed: 34041904
DOI: 10.1021/acs.est.1c00508 -
Bioresource Technology Mar 2022Reducing health risk of mercury (Hg)/methylmercury (MeHg) in sewage sludge is vital to its land application. This study revealed that thermal hydrolysis reduced MeHg...
Reducing health risk of mercury (Hg)/methylmercury (MeHg) in sewage sludge is vital to its land application. This study revealed that thermal hydrolysis reduced MeHg content both during pretreatment process and subsequent anaerobic digestion (AD), which resulted in decrease of MeHg content from 4.24 ng/g to 0.95 ng/g after thermal hydrolysis (150 ℃) and further decreased to 0.39 ng/g after AD. Notably, thermal hydrolysis at high temperature (120 ℃ and 150 ℃) promoted both Hg methylation and MeHg demethylation rather than the control or at low temperature (100 ℃). Hg methylation dominated in hydrolysis and acidogenesis stage, whereas MeHg demethylation dominated in methanogenesis stage. Though abundance of related genes (HgcA and merA) was dramatically reduced, Ruminococcaceae, Peptococcaceae, and Lachnospiraceae were potentially Hg methylators in hydrolysis and acidogenesis stage. Whereas, MeHg demethylation dominated in the late period of AD due to the improved syntrophic methanogenesis and possibly reduced Hg biodegradability by precipitation.
Topics: Anaerobiosis; Hydrolysis; Mercury; Methylmercury Compounds; Microbiota; Sewage
PubMed: 34822982
DOI: 10.1016/j.biortech.2021.126394 -
Frontiers in Microbiology 2021Previous work demonstrated that microbial Fe(III)-reduction contributes to void formation, and potentially cave formation within Fe(III)-rich rocks, such as banded iron...
Hydrologic Alteration and Enhanced Microbial Reductive Dissolution of Fe(III) (hydr)oxides Under Flow Conditions in Fe(III)-Rich Rocks: Contribution to Cave-Forming Processes.
Previous work demonstrated that microbial Fe(III)-reduction contributes to void formation, and potentially cave formation within Fe(III)-rich rocks, such as banded iron formation (BIF), iron ore and canga (a surficial duricrust), based on field observations and static batch cultures. Microbiological Fe(III) reduction is often limited when biogenic Fe(II) passivates further Fe(III) reduction, although subsurface groundwater flow and the export of biogenic Fe(II) could alleviate this passivation process, and thus accelerate cave formation. Given that static batch cultures are unlikely to reflect the dynamics of groundwater flow conditions , we carried out comparative batch and column experiments to extend our understanding of the mass transport of iron and other solutes under flow conditions, and its effect on community structure dynamics and Fe(III)-reduction. A solution with chemistry approximating cave-associated porewater was amended with 5.0 mM lactate as a carbon source and added to columns packed with canga and inoculated with an assemblage of microorganisms associated with the interior of cave walls. Under anaerobic conditions, microbial Fe(III) reduction was enhanced in flow-through column incubations, compared to static batch incubations. During incubation, the microbial community profile in both batch culture and columns shifted from a Proteobacterial dominance to the Firmicutes, including Clostridiaceae, Peptococcaceae, and Veillonellaceae, the latter of which has not previously been shown to reduce Fe(III). The bacterial Fe(III) reduction altered the advective properties of canga-packed columns and enhanced permeability. Our results demonstrate that removing inhibitory Fe(II) via mimicking hydrologic flow of groundwater increases reduction rates and overall Fe-oxide dissolution, which in turn alters the hydrology of the Fe(III)-rich rocks. Our results also suggest that reductive weathering of Fe(III)-rich rocks such as canga, BIF, and iron ores may be more substantial than previously understood.
PubMed: 34335526
DOI: 10.3389/fmicb.2021.696534 -
The Science of the Total Environment Apr 2017Microbial communities drive many biogeochemical processes in oil sands tailings and cause greenhouse gas emissions from tailings ponds. Paraffinic solvent (primarily...
Microbial communities drive many biogeochemical processes in oil sands tailings and cause greenhouse gas emissions from tailings ponds. Paraffinic solvent (primarily C-C; n- and iso-alkanes) is used by some oil sands companies to aid bitumen extraction from oil sands ores. Residues of unrecovered solvent escape to tailings ponds during tailings deposition and sustain microbial metabolism. To investigate biodegradation of hydrocarbons in paraffinic solvent, mature fine tailings (MFT) collected from Albian and CNRL ponds were amended with paraffinic solvent at ~0.1wt% (final concentration: ~1000mgL) and incubated under methanogenic conditions for ~1600d. Albian and CNRL MFTs exhibited ~400 and ~800d lag phases, respectively after which n-alkanes (n-pentane and n-hexane) in the solvent were preferentially metabolized to methane over iso-alkanes in both MFTs. Among iso-alkanes, only 2-methylpentane was completely biodegraded whereas 2-methylbutane and 3-methylpentane were partially biodegraded probably through cometabolism. 16S rRNA gene pyrosequencing showed dominance of Anaerolineaceae and Methanosaetaceae in Albian MFT and Peptococcaceae and co-domination of "Candidatus Methanoregula" and Methanosaetaceae in CNRL MFT bacterial and archaeal communities, respectively, during active biodegradation of paraffinic solvent. The results are important for developing future strategies for tailings reclamation and management of greenhouse gas emissions.
Topics: Alkanes; Archaea; Bacteria; Biodegradation, Environmental; Hexanes; Hydrocarbons; Methane; Oil and Gas Fields; Pentanes; Petroleum Pollution; RNA, Ribosomal, 16S
PubMed: 28094047
DOI: 10.1016/j.scitotenv.2017.01.038 -
Toxics Dec 2023Metabolism underlies the pathogenesis of acute myeloid leukemia (AML) and can be influenced by gut microbiota. However, the specific metabolic changes in different...
Metabolism underlies the pathogenesis of acute myeloid leukemia (AML) and can be influenced by gut microbiota. However, the specific metabolic changes in different tissues and the role of gut microbiota in AML remain unclear. In this study, we analyzed the metabolome differences in blood samples from patients with AML and healthy controls using UPLC-Q-Exactive. Additionally, we examined the serum, liver, and fecal metabolome of AML model mice and control mice using UPLC-Q-Exactive. The gut microbiota of the mice were analyzed using 16S rRNA sequencing. Our UPLC-MS analysis revealed significant differences in metabolites between the AML and control groups in multiple tissue samples. Through cross-species validation in humans and animals, as well as reverse validation of Celastrol, we discovered that the Carnosine-Histidine metabolic pathway may play a potential role in the occurrence and progression of AML. Furthermore, our analysis of gut microbiota showed no significant diversity changes, but we observed a significant negative correlation between the key metabolite Carnosine and and . In conclusion, the Carnosine-Histidine metabolic pathway influences the occurrence and progression of AML, while the gut microbiota might play a role in this process.
PubMed: 38250970
DOI: 10.3390/toxics12010014 -
Microbiology Spectrum Mar 2023Undernutrition may change cecal microbiota-epithelium interactions to influence cecal feed fermentation, nutrient absorption and metabolism, and immune function. Sixteen...
Undernutrition may change cecal microbiota-epithelium interactions to influence cecal feed fermentation, nutrient absorption and metabolism, and immune function. Sixteen late-gestation Hu-sheep were randomly divided into control (normal feeding) and treatment (feed restriction) groups to establish an undernourished sheep model. Cecal digesta and epithelium were collected to analyze microbiota-host interactions based on 16S rRNA gene and transcriptome sequencing. Results showed that cecal weight and pH were decreased, volatile fatty acids and microbial proteins concentrations were increased, and epithelial morphology was changed upon undernutrition. Undernutrition reduced the diversity, richness, and evenness of cecal microbiota. The relative abundances of cecal genera involved in acetate production ( dgA-11 gut group, RC9 gut group, and ) and negatively correlated with butyrate proportion ( vadinBB60 group_norank) were decreased, while genera related to butyrate (_uncultured and _uncultured) and valerate (_uncultured) production were increased in undernourished ewes. These findings were consistent with the decreased molar proportion of acetate and the increased molar proportions of butyrate and valerate. Undernutrition changed the overall transcriptional profile and substance transport and metabolism in cecal epithelium. Undernutrition suppressed extracellular matrix-receptor interaction and intracellular phosphatidyl inositol 3-kinase (PI3K) signaling pathway then disrupted biological processes in cecal epithelium. Moreover, undernutrition repressed phagosome antigen processing and presentation, cytokine-cytokine receptor interaction, and intestinal immune network. In conclusion, undernutrition affected cecal microbial diversity and composition and fermentation parameters, inhibited extracellular matrix-receptor interaction and the PI3K signaling pathway, and then disrupted epithelial proliferation and renewal and intestinal immune functions. Our findings exposed cecal microbiota-host interactions upon undernutrition and contribute to their further exploration. Undernutrition is commonly encountered in ruminant production, especially during pregnancy and lactation in females. Undernutrition not only induces metabolic diseases and threatens pregnant mothers' health, but also inhibits fetal growth and development, leading to weakness or even death of fetuses. Cecum works importantly in hindgut fermentation, providing volatile fatty acids and microbial proteins to the organism. Intestinal epithelial tissue plays a role in nutrient absorption and transport, barrier function, and immune function. However, little is known about cecal microbiota and epithelium interactions upon undernutrition. Our findings showed that undernutrition affected bacterial structures and functions, which changed fermentation parameters and energy regimens, and therefore affected the substance transport and metabolism in cecal epithelium. Extracellular matrix-receptor interactions were inhibited, which repressed cecal epithelial morphology and cecal weight via the PI3K signaling pathway and lowered immune response function upon undernutrition. These findings will help in further exploring microbe-host interactions.
PubMed: 36976022
DOI: 10.1128/spectrum.05320-22 -
Journal of Ethnopharmacology Jan 2024Buyang Huanwu decoction (BHD), a famous traditional Chinese medicine (TCM) formula, was first recorded in Qing Dynasty physician Qingren Wang's Yi Lin Gai Cuo. BHD has...
ETHNOPHARMACOLOGICAL RELEVANCE
Buyang Huanwu decoction (BHD), a famous traditional Chinese medicine (TCM) formula, was first recorded in Qing Dynasty physician Qingren Wang's Yi Lin Gai Cuo. BHD has been widely utilized in the treatment of patients with neurological disorders, including Parkinson's disease (PD). However, the underlying mechanism has not been fully elucidated. In particular, little is known about the role of gut microbiota.
AIM OF THE STUDY
We aimed to reveal the alterations and functions of gut microbiota and its correlation with the liver metabolome in the process of improving PD with BHD.
MATERIALS AND METHODS
The cecal contents were collected from PD mice treated with or without BHD. 16S rRNA gene sequencing was performed on an Illumina MiSeq-PE250 platform, and the ecological structure, dominant taxa, co-occurrence patterns, and function prediction of the gut microbial community were analyzed by multivariate statistical methods. The correlation between differential microbial communities in the gut and differentially accumulated metabolites in the liver was analyzed using Spearman's correlation analysis.
RESULTS
The abundance of Butyricimonas, Christensenellaceae, Coprococcus, Peptococcaceae, Odoribacteraceae, and Roseburia was altered significantly in the model group, which was by BHD. Ten genera, namely Dorea, unclassified_Lachnospiraceae, Oscillospira, unidentified_Ruminococcaceae, unclassified_Clostridiales, unidentified_Clostridiales, Bacteroides, unclassified_Prevotellaceae, unidentified_Rikenellaceae, and unidentified_S24-7, were identified as key bacterial communities. According to the function prediction of differential genera, the mRNA surveillance pathway might be a target of BHD. Integrated analysis of gut microbiota and the liver metabolome revealed that several gut microbiota genera such as Parabacteroides, Ochrobactrum, Acinetobacter, Clostridium, and Halomonas, were positively or negatively correlated with some nervous system-related metabolites, such as L-carnitine, L-pyroglutamic acid, oleic acid, and taurine.
CONCLUSIONS
Gut microbiota might be a target of BHD in the process of ameliorating PD. Our findings provide novel insight into the mechanisms underlying the effects of BHD on PD and contribute to the development of TCM.
Topics: Mice; Animals; Gastrointestinal Microbiome; Parkinson Disease; RNA, Ribosomal, 16S; Liver; Metabolome
PubMed: 37423520
DOI: 10.1016/j.jep.2023.116893 -
Frontiers in Microbiology 2019() functions as a probiotic in animals, but the underlying mechanisms remain unclear. We aim to evaluate the protective effects and definite mechanism by which orally...
() functions as a probiotic in animals, but the underlying mechanisms remain unclear. We aim to evaluate the protective effects and definite mechanism by which orally administered prevents D-galactosamine (D-GalN)-induced liver injury in rats. Twenty-one Sprague-Dawley rats were equally assigned into three groups ( = 7 animals per group). ATCC11778 (2 × 10 colony-forming units/ml) was administered to the group via gavage, and phosphate-buffered saline was administered to the positive control (PC) and negative control (NC) groups for 2 weeks. The PC and groups received 1.1 g/kg D-GalN via an intraperitoneal injection to induce liver injury. The blood, terminal ileum, liver, kidney and mesenteric lymph nodes (MLNs) were collected for histological examinations and to evaluate bacterial translocation. Liver function was also determined. Fecal samples were collected for deep sequencing of the 16S rRNA on an Illumina MiSeq platform. significantly attenuated D-GalN-induced liver injury and improved serum alanine aminotransferase (ALT) and serum cholinesterase levels ( < 0.05 and < 0.01, respectively). modulated cytokine secretion, as indicated by the elevated levels of the anti-inflammatory cytokine interleukin-10 (IL-10) in both the liver and plasma ( < 0.05 and < 0.01, respectively) and the substantially decreased levels of the cytokine IL-13 in the liver ( < 0.05). Pretreatment with attenuated anoxygenic bacterial translocation in the veins ( < 0.05) and liver ( < 0.05) and upregulated the expression of the tight junction protein 1. The gut microbiota from the group clustered separately from that of the PC group, with an increase in species of the and families and a decrease in those of the , , and families. The potential probiotic attenuated liver injury by restoring the gut flora balance and enhancing the intestinal barrier function.
PubMed: 31417535
DOI: 10.3389/fmicb.2019.01751 -
Water Research Sep 2021Dichloromethane (DCM) is a toxic industrial solvent frequently detected in multi-contaminated aquifers. It can be degraded biotically or abiotically, and under oxic or...
Dichloromethane (DCM) is a toxic industrial solvent frequently detected in multi-contaminated aquifers. It can be degraded biotically or abiotically, and under oxic or anoxic conditions. The extent and pathways of DCM degradation in aquifers may thus depend on water table fluctuations and microbial responses to hydrochemical variations. Here, we examined the effect of water table fluctuations on DCM biodegradation in two laboratory aquifers fed with O-depleted DCM-spiked groundwater from a well-characterized former industrial site. Hydrochemistry, stable isotopes of DCM (δC and δCl), and bacterial community composition were examined to determine DCM mass removal and degradation pathways under steady-state (static water table) and transient (fluctuating water table) conditions. DCM mass removal was more pronounced under transient (95%) than under steady-state conditions (42%). C and Cl isotopic fractionation values were larger under steady-state (ε = -23.6 ± 3.2‰, and ε= -8.7 ± 1.6‰) than under transient conditions (ε = -11.8 ± 2.0‰, and ε = -3.1 ± 0.6‰). Dual C-Cl isotope analysis suggested the prevalence of distinct anaerobic DCM degradation pathways, with Λ values of 1.92 ± 0.30 and 3.58 ± 0.42 under steady-state and transient conditions, respectively. Water table fluctuations caused changes in redox conditions and oxygen levels, resulting in a higher relative abundance of Desulfosporosinus (Peptococcaceae family). Taken together, our results show that water table fluctuations enhanced DCM biodegradation, and correlated with bacterial taxa associated with anaerobic DCM degradation. Our integrative approach allows to evaluate anaerobic DCM degradation under dynamic hydrogeological conditions, and may help improving bioremediation strategies at DCM contaminated sites.
Topics: Biodegradation, Environmental; Carbon Isotopes; Groundwater; Laboratories; Methylene Chloride; Water Pollutants, Chemical
PubMed: 34388502
DOI: 10.1016/j.watres.2021.117530