Genomic analysis of polysaccharide-producing bacteria from sugarcane processing streams.
Microbes cause economic losses during postharvest processing of both sugar beet and sugarcane by consuming sucrose and producing extracellular polysaccharides (EPS), which negatively affect the purification and crystallization process. Recent research has uncovered a wide diversity of sugar-consuming microbes present in sugar factories, and the structure and composition of the EPS they produce are likely just as diverse. An improved understanding of the microbes in sugar factories will help guide improvements in measures to inhibit microbial growth and remove EPS through the use of hydrolyzing enzymes. Here, we report on the whole-genome sequencing of 24 bacterial strains recently isolated from sugarcane processing streams in Louisiana, which include Leuconostoc, Gluconobacter, and Pantoea species. We were able to identify the EPS-producing enzymes encoded on each genome, which varied in both function and copy number per genome. Finally, the isolated bacteria were spotted on various sugar substrates, revealing a diversity of EPS-producing phenotypes that reflect their genetic diversity. We show that genomics is a powerful tool in predicting the structure and composition of EPS produced by microbes present in sugar factories, which will help guide improvements in enzymatic removal of EPS.