Characterization of Potential Polysaccharide Utilization Systems in the Marine JLT2011 Using a Multi-Omics Approach.

Members of phylum are distributed across diverse marine niches and is often the predominant bacterial class decomposing algae-derived polysaccharides. Here, we report the complete genome of JLT2011 () isolated from surface water of the southeastern Pacific. A remarkable genomic feature is that the number of glycoside hydrolase (GH) genes in the genome of JLT2011 is more than 2-fold higher than that of other species. The functional profiles of the GHs suggest extensive variation in species. Growth experiments revealed that JLT2011 has the ability to utilize a wide range of polysaccharides for growth such as xylan and homogalacturonan in pectin. Nearly half of all GH genes were located on the multi-gene polysaccharide utilization loci (PUL) or PUL-like systems in JLT2011. This species was also found to harbor the two xylan PULs and a pectin PUL, respectively. Gene expression data indicated that more GHs and sugar-specific outer-membrane systems were found in the presence of xylan than in the presence of pectin, suggesting a different strategy for heteropolymeric xylan and homoglacturonan utilization. Multi-omics data (transcriptomics, proteomics, and metabolomics) indicated that xylan PULs and pectin PUL are respectively involved in the catabolism of their corresponding polysaccharides. This work presents a comparison of polysaccharide decomposition within a genus and expands current knowledge on the diversity and function of PULs in marine , thereby deepening our understanding of their ecological role in polysaccharide remineralization in the marine system.