Project description:Humans harbor numerous species of colonic bacteria that digest the fiber polysaccharides in commonly consumed terrestrial plants. More recently in history, regional populations have consumed edible seaweeds (macroalgae) containing unique polysaccharides. However, it remains unclear how extensively gut bacteria have adapted to digest these novel nutrients. Here, we show that the ability of gut bacteria to digest seaweed polysaccharides is considerably more pervasive than previously appreciated. Using culture-based approaches, we show that known Bacteroides genes involved in seaweed degradation have mobilized into many members of this genus. We also identify new marine bacteria-derived genes, and their corresponding mobile DNA elements, that are involved in degrading several seaweed polysaccharides. Some of these new genes reside in gut-resident, Gram-positive Firmicutes, for which phylogenetic analysis suggests an origin in the Epulopiscium gut symbionts of marine fishes. Our results are important for understanding the metabolic plasticity of the human gut microbiome, the global exchange of genes in the context of dietary selective pressures and identifying new functions that can be introduced or engineered to design and fill orthogonal niches for a future generation of engineered probiotics.
Project description:This study aimed at identification of genetic regulations for desiccation tolerance in intertidal seaweed species Ulva lactuca most commonly experienced phenomenon of intertidal communities.
Project description:This study aimed at identification of genetic regulations for desiccation and submergence tolerance in intertidal seaweed species Ulva lactuca which arisies periodically due to tidal rhythms.
Project description:Purpose: Examining the transcriptome of human gut bacteria that grow on seaweed polysaccharides as a sole carbon source Methods: Strains were grown on 5 mg/ml seaweed polysaccharides (carrageenan, agarose and/or poprhyran respective to strain) or galactose as a sole carbon source in vitro. Fold change was calculated as seaweed polysaccharide over galactose with n=2 biological replicates. Once cells reached an optical density corresponding to mid-log phase growth, RNA was isolated and rRNA depleted. Samples were multiplexed for sequencing on the Illumina HiSeq platform at the University of Michigan Sequencing Core. Data was analyzed using Arraystar software (DNASTAR, Inc.) Genes with significant up- or down-regulation were determined by the following criteria: genes with an average fold-change >10-fold and with both biological replicates with a normalized expression level >1% of the overall average RPKM expression level. READS WERE ANALYZED .......GABRIEL FILL IN Results: We identified novel polysaccharide utiilization loci in 5 strains of human gut bacteria
