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:Seagrass meadows are highly productive ecosystems that are considered hotspots for carbon sequestration. The decline of seagrass meadows of various species has been documented worldwide, including that of Cymodocea nodosa, a widespread seagrass in the Mediterranean Sea. To assess the influence of seagrass decline on the metabolic profile of sediment microbial communities, metaproteomes from two sites, one without vegetation and one with a declining Cymodocea nodosa meadow, were characterised at monthly intervals from July 2017 to October 2018. The differences in the metabolic profile observed between the vegetated and nonvegetated sediment before the decline were more pronounced in the deeper parts of the sediment and disappeared with the decay of the roots and rhizomes. During the decline, the protein richness and diversity of the metabolic profile of the microbial communities inhabiting the nonvegetated sediment became similar to those observed for the vegetated communities. Temporal shifts in the structure of the metabolic profile were only observed in the nonvegetated sediment and were also more pronounced in the deeper parts of the sediment. The assessment of the dynamics of proteins involved in the degradation of organic matter, such as ABC transporters, fermentation-mediating enzymes, and proteins involved in dissimilatory sulphate reduction, reflected the general dynamics of the metabolic profile. Overall, the metabolic profile of the microbial communities inhabiting the nonvegetated sediment was influenced by the decline of seagrass, with stronger shifts observed in the deeper parts of the sediment.
Project description:The contamination of marine ecosystems with microplastics, such as the polymer polyethylene, a commonly used component of single-use packaging, is of global concern. Although it has been suggested that biodegradable polymers, such as polylactic acid, may be used to replace some polyethylene packaging, little is known about their effects on marine organisms. Blue mussels, Mytilus edulis, have become a “model organism” for investigating the effects of microplastics in marine ecosystems. We show here that repeated exposure, over a period of 52 days in an outdoor mesocosm setting, of M. edulis to polyethylene microplastics reduced the number of byssal threads produced and the attachment strength (tenacity) by ~50%. Exposure to either type of microplastic altered the haemolymph proteome and, although a conserved response to microplastic exposure was observed, overall polyethylene resulted in more changes to protein abundances than polylactic acid. Many of the proteins affected are involved in vital biological processes, such as immune- and stress- regulation, metabolism and cellular and structural development. Our study highlights the utility of mass spectrometry-based proteomics to assess the health of key marine organisms and identifies the potential mechanisms by which microplastics, both conventional and biodegradable, could affect their ability to form and maintain reefs.
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: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)