Project description:Bacteriophage – host dynamics and interactions are important for microbial community composition and ecosystem function. Nonetheless, empirical evidence in engineered environment is scarce. Here, we examined phage and prokaryotic community composition of four anaerobic digestors in full-scale wastewater treatment plants (WWTPs) across China. Despite relatively stable process performance in biogas production, both phage and prokaryotic groups fluctuated monthly over a year of study period. Nonetheless, there were significant correlations in their α- and β-diversities between phage and prokaryotes. Phages explained 40.6% of total prokaryotic community composition, much higher than the explainable power by abiotic factors (14.5%). Consequently, phages were significantly (P<0.010) linked to parameters related to process performance including biogas production and volatile solid concentrations. Association network analyses showed that phage-prokaryote pairs were deeply rooted, and two network modules were exclusively comprised of phages, suggesting a possibility of co-infection. Those results collectively demonstrate phages as a major biotic factor in controlling bacterial composition. Therefore, phages may play a larger role in shaping prokaryotic dynamics and process performance of WWTPs than currently appreciated, enabling reliable prediction of microbial communities across time and space.
Project description:Permafrost soil in high latitude tundra is one of the largest terrestrial carbon (C) stocks and is highly sensitive to climate warming. Understanding microbial responses to warming induced environmental changes is critical to evaluating their influence on soil biogeochemical cycles. In this study, a functional gene array (i.e. GeoChip 4.2) was used to analyze the functional capacities of soil microbial communities collected from a naturally degrading permafrost region in Central Alaska. Varied thaw history was reported to be the main driver of soil and plant differences across a gradient of minimally, moderately and extensively thawed sites. Compared with the minimally thawed site, the number of detected functional gene probes across the 15-65 cm depth profile at the moderately and extensively thawed sites decreased by 25 % and 5 %, while the community functional gene beta-diversity increased by 34% and 45%, respectively, revealing decreased functional gene richness but increased community heterogeneity along the thaw progression. Particularly, the moderately thawed site contained microbial communities with the highest abundances of many genes involved in prokaryotic C degradation, ammonification, and nitrification processes, but lower abundances of fungal C decomposition and anaerobic-related genes. Significant correlations were observed between functional gene abundance and vascular plant primary productivity, suggesting that plant growth and species composition could be co-evolving traits together with microbial community composition. Altogether, this study reveals the complex responses of microbial functional potentials to thaw related soil and plant changes, and provides information on potential microbially mediated biogeochemical cycles in tundra ecosystems.
Project description:Accurate description of a microbial community is an important first step in understanding the role of its components in ecosystem function. A method for surveying microbial communities termed Serial Analysis of Ribosomal DNA (SARD) is described here. Through a series of molecular cloning steps, short DNA sequence tags are recovered from the fifth variable (V5) region of the prokaryotic 16S rRNA gene from microbial communities. These tags are ligated to form concatemers comprised of 20-40 tags which are cloned and identified by DNA sequencing. Four agricultural soil samples were profiled with SARD to assess the method’s utility. A total of 37,008 SARD tags comprising 3,127 unique sequences were identified. Comparison of duplicate profiles from one soil genomic DNA preparation revealed the method was highly reproducible. The large numbers of singleton tags together with non-parametric richness estimates indicated a significant amount of sequence tag diversity remained undetected with this level of sampling. The abundance classes of the observed tags were scale-free and conformed to a power law distribution. Numerically, the majority of the total tags observed belonged to abundance classes that were each present at less than 1% of the community. Over 99% of the unique tags individually made up less than 1% of the community. Therefore, from either numerical or diversity standpoints, low abundant taxa comprised a significant proportion of the microbial communities examined and could potentially make a large contribution to ecosystem function. SARD may provide a means to explore the ecological role of these rare members of microbial communities in qualitative and quantitative terms. Keywords: SARD profiles, culture-independent study, microbial community survey, microbial census
Project description:The microbial community and enzymes in fermented rice using defined microbial starter, containing Rhizopus oryzae, Saccharomycopsis fibuligera, Saccharomyces cerevisiae and Pediococcus pentosaceus, play an important role in quality of the fermented rice product and its biological activities including melanogenesis inhibitory activity. The microbial metaproteome revealed large-scale proteins expressed by the microbial community to better understand the role of microbiota in the fermented rice.
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:<p>Benthic organisms sustain coral reefs through their growth and metabolism, but less is known about how their released metabolites influence reef seawater microorganisms. To investigate metabolite composition of benthic exudates and their ecological significance for reef microbial communities, we harvested exudates from six species of Caribbean benthic organisms including stony corals, octocorals, and an invasive encrusting algae, and subjected these exudates to untargeted and targeted metabolomics approaches using liquid chromatography-mass spectrometry. Incubations with reef seawater microorganisms were conducted to monitor changes in microbial community composition using 16S rRNA gene sequencing and abundance in relation to exudate source and three specific metabolites. Exudates tended to be enriched in amino acids, nucleosides, and vitamins, indicating that benthic organisms contribute labile organic matter to reefs. The phytohormone indole-3-acetic acid was detected in octocoral exudates, suggesting that this metabolite facilitates microbial interactions within and outside of benthic organisms. Exudate compositions were species-specific and significantly enriched in the indole class of metabolites. Microbial abundances and specific microbial taxa responded differently in relation to exudates from stony corals and octocorals, demonstrating the link between benthic organismal composition, metabolite exudates, and microbial growth. Conversely, microbial communities did not respond to additions of the individual metabolites, suggesting that reef microorganisms likely provide diverse metabolite pools that support microbial growth. This work provides novel information about the metabolites released from common Caribbean benthic organisms and indicates that the recent shifts in benthic composition from stony to octocorals alter exudate composition and likely impact microbial community composition and function on coral reefs.</p><p><br></p><p><strong>UPLC-MS Metabolite collection incubation assays</strong> are reported in the current study <strong>MTBLS2855</strong></p><p><strong>UPLC-MS Metabolite uptake incubation assay</strong> is reported in <a href='https://www.ebi.ac.uk/metabolights/editor/study/MTBLS3286' rel='noopener noreferrer' target='_blank'><strong>MTBLS3286</strong></a></p>
Project description:<p>Benthic organisms sustain coral reefs through their growth and metabolism, but less is known about how their released metabolites influence reef seawater microorganisms. To investigate metabolite composition of benthic exudates and their ecological significance for reef microbial communities, we harvested exudates from six species of Caribbean benthic organisms including stony corals, octocorals, and an invasive encrusting algae, and subjected these exudates to untargeted and targeted metabolomics approaches using liquid chromatography-mass spectrometry. Incubations with reef seawater microorganisms were conducted to monitor changes in microbial community composition using 16S rRNA gene sequencing and abundance in relation to exudate source and three specific metabolites. Exudates tended to be enriched in amino acids, nucleosides, and vitamins, indicating that benthic organisms contribute labile organic matter to reefs. The phytohormone indole-3-acetic acid was detected in octocoral exudates, suggesting that this metabolite facilitates microbial interactions within and outside of benthic organisms. Exudate compositions were species-specific and significantly enriched in the indole class of metabolites. Microbial abundances and specific microbial taxa responded differently in relation to exudates from stony corals and octocorals, demonstrating the link between benthic organismal composition, metabolite exudates, and microbial growth. Conversely, microbial communities did not respond to additions of the individual metabolites, suggesting that reef microorganisms likely provide diverse metabolite pools that support microbial growth. This work identifies, quantifies, and compares metabolites released from common Caribbean benthic organisms and indicates that recent shifts in benthic composition from stony to octocorals alter exudate composition and likely impact microbial community composition and function on coral reefs.</p><p><br></p><p><strong>UPLC-MS Metabolite uptake incubation assay</strong> is reported in the current study <strong>MTBLS3286</strong></p><p><strong>UPLC-MS Metabolite collection incubation assays</strong> are reported in <a href='https://www.ebi.ac.uk/metabolights/editor/study/MTBLS2855' rel='noopener noreferrer' target='_blank'><strong>MTBLS2855</strong></a></p>
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)
Project description:To understand microbial community functional structures of activated sludge in wastewater treatment plants (WWTPs) and the effects of environmental factors on their structure, 12 activated sludge samples were collected from four WWTPs in Beijing. GeoChip 4.2 was used to determine the microbial functional genes involved in a variety of biogeochemical processes. The results showed that, for each gene category, such as egl, amyA, nir, ppx, dsrA sox and benAB, there were a number of microorganisms shared by all 12 samples, suggestive of the presence of a core microbial community in the activated sludge of four WWTPs. Variance partitioning analyses (VPA) showed that a total of 53% of microbial community variation can be explained by wastewater characteristics (25%) and operational parameters (23%), respectively. This study provided an overall picture of microbial community functional structures of activated sludge in WWTPs and discerned the linkages between microbial communities and environmental variables in WWTPs.
Project description:To understand microbial community functional structures of activated sludge in wastewater treatment plants (WWTPs) and the effects of environmental factors on their structure, 12 activated sludge samples were collected from four WWTPs in Beijing. GeoChip 4.2 was used to determine the microbial functional genes involved in a variety of biogeochemical processes. The results showed that, for each gene category, such as egl, amyA, nir, ppx, dsrA sox and benAB, there were a number of microorganisms shared by all 12 samples, suggestive of the presence of a core microbial community in the activated sludge of four WWTPs. Variance partitioning analyses (VPA) showed that a total of 53% of microbial community variation can be explained by wastewater characteristics (25%) and operational parameters (23%), respectively. This study provided an overall picture of microbial community functional structures of activated sludge in WWTPs and discerned the linkages between microbial communities and environmental variables in WWTPs. Four full-scale wastewater treatment systems located in Beijing were investigated. Triplicate samples were collected in each site.