Project description:We performed RNA-Seq based gene expression analysis of Arabidopsis Col-0 plants grown under axenic and holoxenic conditions in FlowPot system. Holoxenic plants were grown in the presence of soil slurries containing microbial communities derived from natural soils and under axenic condition in presence of heat-killed soil slurries for three weeks. We identified genes differentially enriched in response to presence of microbial communities. Our results suggested that in presence of microbiota there is a differential expression of immunity/defense-related genes in holoxenic compared to axenic plants.
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.
Project description:Biofilms are ubiquitous in nature, forming diverse adherent microbial communities that perform a plethora of functions. Here, we operated two laboratory-scale sequence batch reactors enriched with Candidatus Accumulibacter phosphatis (Accumulibacter) performing enhanced biological phosphorus removal (EBPR). Reactors formed two distinct biofilms, a floccular biofilm, consisting of small, loose, microbial aggregates, and a granular biofilm, forming larger, dense, spherical aggregates. Using metaproteomic methods we investigated the proteomic differences between these two biofilm communities, identifying a total of 2022 unique proteins. Both biofilms contained proteins that were indicative of core EBPR metabolisms and cellular function. To understand the proteomic differences between floccular and granular biofilm communities, we compared protein abundances that were statistically enriched in both biofilm states (alpha level = 0.05). Floccular biofilms were enriched with pathogenic secretion systems suggesting a previously unrecognized, highly competitive, mixed microbial community. Comparatively, granular biofilms revealed a high stress environment with evidence of nutrient starvation, phage predation pressure, extracellular polymeric substance (EPS) synthesis, and increased cell lysis. Granular biofilms enriched outermembrane transport proteins to scavenge the extracellular milieu for amino acids and other metabolites, likely released through cell lysis, to supplement core EBPR metabolic pathways. This study provides the first detailed proteomic comparison between Accumulibacter–enriched floccular and granular biofilm communities, proposes a conceptual model for the granule biofilm, and offers novel insights into granule biofilm formation and stability.
Project description:Rapid corrosion of magnesium alloys is undesirable in structural and biomedical applications and a general way to control corrosion is to form a surface barrier layer isolating the bulk materials from the external environment. Herein, based on the insights gained from the anticorrosion behavior of corrosion products, a special way to mitigate aqueous corrosion is described. The concept is based on pre-corrosion by a hydrothermal treatment of Al-enriched Mg alloys in water. A uniform surface composed of an inner compact layer and top Mg-Al layered double hydroxide (LDH) microsheet is produced on a large area using a one-step process and excellent corrosion resistance is achieved in saline solutions. Moreover, inspired by the super-hydrophobic phenomenon in nature such as the lotus leaves effect, the orientation of the top microsheet layer is tailored by adjusting the hydrothermal temperature, time, and pH to produce a water-repellent surface after modification with fluorinated silane. As a result of the trapped air pockets in the microstructure, the super-hydrophobic surface with the Cassie state shows better corrosion resistance in the immersion tests. The results reveal an economical and environmentally friendly means to control and use the pre-corrosion products on magnesium alloys.
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:Determining how cells vary with their local signaling environment and organize into distinct cellular communities is critical for understanding processes as diverse as development, aging, and cancer. Here we introduce EcoTyper, a new machine learning framework for large-scale identification and validation of cell states and multicellular communities from bulk, single-cell, and spatially-resolved gene expression data. When applied to 12 major cell lineages across 16 types of human carcinoma, EcoTyper identified 69 transcriptionally-defined cell states. Most states were specific to neoplastic tissue, ubiquitous across tumor types, and significantly prognostic. By analyzing cell state co-occurrence patterns, we discovered 10 clinically-distinct multicellular communities with unexpectedly strong conservation, including four with unique myeloid and stromal elements, one enriched in normal tissue, and two associated with early cancer development. This study elucidates fundamental units of cellular organization in human carcinoma and provides a framework for large-scale profiling of cellular ecosystems in any tissue (https://ecotyper.stanford.edu).
Project description:Cornelia de Lange syndrome (CdLS) is a complex multisystem developmental disorder caused by mutations in cohesin subunits and regulators. While the precise molecular mechanisms are not well defined, they point toward a global deregulation of the transcriptional gene expression program. Indeed, cohesin is associated with the boundaries of chromosome domains in addition to enhancers and promoters connecting the 3D genome organization with transcriptional control and gene expression. Here we show that connected gene communities, built with noncoding regulatory elements and genes physically interacting in the 3D chromosomal space, provide a molecular explanation for the pathoetiology of CdLS. Indeed, NIPBL and cohesin are important constituents of connected gene communities, both being centrally positioned at active noncoding regulatory elements. Interestingly, mutations in SMC1A and NIPBL lead to coordinated gene expression changes in connected communities. Our findings suggest a model where CdLS is explained by coordinated modulation of connected gene communities.