Project description:The plant hemicellulose xyloglucan (XyG) is secreted from the roots of numerous plant species, including cereals, and contributes towards soil aggregate formation in terrestrial systems. Whether XyG represents a key nutrient for plant-associated bacteria is unclear. The phylum Bacteroidota are abundant in the plant microbiome and provide several beneficial functions for their host. However, the metabolic and genomic traits underpinning their success remain poorly understood. Here, we employed whole-cell proteomics to determine the molecular mechanisms responsible for xyloglucan utilisation in two model Flavobacterium species, Flavobacterium johnsoniae DSM2064 and Flavobacterium sp. OSR005. We identified the occurrence of a distinct and conserved gene cluster, referred to as the Xyloglucan Utilisation Loci (XyGUL). Flavobacterium XyGUL is a hybrid of the molecular machinery found in gut Bacteroides spp., Cellvibrio japonicus, and the plant pathogen Xanthomonas. Combining protein biochemistry, computational modelling and phylogenetics, we identified a mutation in the enzyme required for initiating hydrolysis of the XyG polysaccharide, an outer membrane endoxyloglucanase glycoside hydrolase family 5 subfamily 4 (GH5_4), which enhances activity towards XyG.
Project description:The soil bacterium Flavobacterium johnsoniae was grown on agar plates with or without pectin,bacteria were harvested, lysed, and subjected to LC-MS/MS analysis
Project description:Clinical Flavobacterium columnare ATCC 49512 was grown on Flavobacterium columnare growth medium (FCGM). Bacteria from four colonies at mid-exponential phase were harvested, total proteins were isolated, and identified using 2-DE MALDI TOF/TOF MS and 2-D LC ESI MS/MS analyses. The MS/MS spectra for all peptides were analyzed using sequest algorithm
Project description:Columnaris disease is a prevalent disease in freshwater environments worldwide caused by the ubiquitous aquatic bacterium Flavobacterium species. Adhesion to the external mucosal surfaces of fishes is the initial stage of infection, and the gills specifically have been identified as both a primary target and release site for this pathogen. Previous research has indicated that a predominant US aquaculture product, the hybrid striped bass (Morone chrysops x M. saxatilis), is more susceptible to infection with Flavobacterium columnare (covae) than the maternal white bass (M. chrysops) parental species. Therefore, to further elucidate the differences between these fish we conducted a transcriptomic profiling study examining the differences of gene expression in gill mucosal tissue over time after exposure to F. covae isolate LSU-066-04. Combined with previous work, these data provide a greater understanding of host immune response to a common pathogen in moronids.
