Project description:Xiangjiang River (Hunan, China) has been contaminated with heavy metal for several decades by surrounding factories. However, little is known about the influence of a gradient of heavy metal contamination on the diversity, structure of microbial functional gene in sediment. To deeply understand the impact of heavy metal contamination on microbial community, a comprehensive functional gene array (GeoChip 5.0) has been used to study the functional genes structure, composition, diversity and metabolic potential of microbial community from three heavy metal polluted sites of Xiangjiang River.
Project description:Xiangjiang River (Hunan, China) has been contaminated with heavy metal for several decades by surrounding factories. However, little is known about the influence of a gradient of heavy metal contamination on the diversity, structure of microbial functional gene in sediment. To deeply understand the impact of heavy metal contamination on microbial community, a comprehensive functional gene array (GeoChip 5.0) has been used to study the functional genes structure, composition, diversity and metabolic potential of microbial community from three heavy metal polluted sites of Xiangjiang River. Three groups of samples, A, B and C. Every group has 3 replicates.
Project description:Numerous studies signify that diets rich in phytochemicals reduce the risk of inflammatory bowel diseases (IBDs). However, their effects are often not uniform among individuals, possibly due to inter-individual variation in gut microbiota. The host indigenous gut microbiota and their metabolites have emerged as factors that greatly influence the efficacy of dietary interventions. The biological activities, mechanisms of actions and the specific targets of several microbial metabolites are unknown. Urolithin A (UroA) is one such natural microbial metabolite, which showed (including our recent study) anti-carcinogenic, anti-oxidative and anti-inflammatory activities. The goal of the experiment to determine if Urolithin A blocks the genes induced by lipopolysaccharide (mimicking bacterial effects on colon) as well as determine effects of Urolithin A alone.
Project description:We established simple synthetic microbial communities in a microcosm model system to determine the mechanisms that underlay cross-feeding in microbial methane-consuming communities. Co-occurring strains from Lake Washington sediment were used that are involved in methane consumption, a methanotroph and two non-methanotrophic methylotrophs.
Project description:The increased urban pressures are often associated with specialization of microbial communities. Microbial communities being a critical player in the geochemical processes, makes it important to identify key environmental parameters that influence the community structure and its function.In this proect we study the influence of land use type and environmental parameters on the structure and function of microbial communities. The present study was conducted in an urban catchment, where the metal and pollutants levels are under allowable limits. The overall goal of this study is to understand the role of engineered physicochemical environment on the structure and function of microbial communities in urban storm-water canals. Microbial community structure was determined using PhyoChio (G3) Water and sediment samples were collected after a rain event from Sungei Ulu Pandan watershed of >25km2, which has two major land use types: Residential and industrial. Samples were analyzed for physicochemical variables and microbial community structure and composition. Microbial community structure was determined using PhyoChio (G3)
Project description:The increased urban pressures are often associated with specialization of microbial communities. Microbial communities being a critical player in the geochemical processes, makes it important to identify key environmental parameters that influence the community structure and its function.In this proect we study the influence of land use type and environmental parameters on the structure and function of microbial communities. The present study was conducted in an urban catchment, where the metal and pollutants levels are under allowable limits. The overall goal of this study is to understand the role of engineered physicochemical environment on the structure and function of microbial communities in urban storm-water canals. Water and sediment samples were collected after a rain event from Sungei Ulu Pandan watershed of >25km2, which has two major land use types: Residential and industrial. Samples were analyzed for physicochemical variables and microbial community structure and composition. Functional gene abundance was determined using GeoChip.
Project description:To study the responses of microbial communities to short-term nitrogen addition and warming,here we examine microbial communities in mangrove sediments subjected to a 4-months experimental simulation of eutrophication with 185 g m-2 year-1 nitrogen addition (N), 3oC warming (W) and nitrogen addition*warming interaction (NW).
Project description:Colorectal cancer (CRC) incidence is rising globally and anticipated to become the leading cause of cancer death in younger individuals. Potential risk factors are diet induced obesity and altered microbiomes that lead to accumulation of toxic metabolite accumulation. However, how ammonia and other microbial metabolites impact key signaling pathways, such as TGF-β signaling, to promote CRC remains unclear. Our study investigates a critical link between gut microbiome alterations, ammonia, and their toxic effects on the TGF-β signaling pathway, to drive CRC progression. We found that in an obesity induced mouse model of cancer, altered microbial populations and ammonia promote Caspase-3-mediated cleavage of SMAD3 adaptor βII-spectrin (SPTBN1). Cleaved SPTBN1 fragments form adducts with ammonia to induce pro-inflammatory cytokine expression and alter TGF-β signaling driving CRC. Extending on Alphafold docking simulations, we identified that ammonia interacts with six polar residues at SPTBN1 (S553, Y556, S663, Y666, N986, and T1178) of cleaved SPTBN1 fragments to form hydrogen bonds that disrupt downstream SMAD3 signaling, altering TGF-β signaling to a protumorigenic phenotype. Blocking SPTBN1, through an SPTBN1 specific siRNA blocks ammonia toxicity and restore TGF-β signaling by reducing the abundance of SPTBN1 cleaved fragments. Importantly, SPTBN1 siRNA blocks ammonia toxicity and restore normal TGF-β signaling in CRC cells. Moreover, our research establishes crosstalk between TGF-β signaling and a microbial sensor, carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), which is significantly overexpressed in CRC patients. We identified CEACAM1-SPTBN1 interactions at specific residues (E517 and Y520) within the immunoreceptor tyrosine-based inhibitory motif (ITIM) of CEACAM1 cytoplasmic domain, with both molecules playing pivotal roles in CRC progression. Our study identifies mechanistic insights into how microbial metabolites target TGF-β a major signaling pathways to promote CRC.
Project description:The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into the ecotoxicity of complex pollutant mixtures as present, e.g., in freeze-dried whole sediment samples and their corresponding organic extracts in parallel. To this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Microarray analysis revealed several classes of significantly regulated genes which could to a considerable extent be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism. Additionally, different gene expression was shown to be less influenced by the sampling site than by the method of exposure, which could be attributed to differential bioavailability of contaminants. Microarray analyses were performed with early life stages of zebrafish exposed to sediment extracts or freeze-dried sediment from three sampling sites (Ehingen, Lauchert, Sigmaringen) along the Upper part of the Danube River, Germany. The expression profiles were compared within the sampling sites, between the exposure scheme and to the expression pattern of model toxicants, such as 4-chloroaniline, Cadmium, DDT, TCDD, and Valproic acid (Gene Expression Omnibus Series GSE9357). Additionally, mechanism-specific bioassays and chemical analysis of the sediments have been combined and compared to the present gene expression data.