Jackson Narrett

Poster Presentation

Enzymatic degradation and metabolism of α-linked disaccharides by Cellvibrio japonicus

Trehalose, kojibiose, nigerose, maltose, and isomaltose are disaccharides composed of two glucose molecules joined by an α-linkage. The metabolism of these α-linked diglucosides by bacteria impacts human health and is essential to biotechnological processes that rely on starch as a carbon source. Previous work has identified the genes necessary for the use of maltose as a carbon source by Cellvibrio japonicus while its ability to use the other α-linked diglucosides remained undefined. This investigation evaluates the usage of all five α-linked diglucosides as physiological carbon sources by C. japonicus. In-frame deletion coupled with phenotypic analysis demonstrates that only one of two predicted trehalase genes is necessary for trehalose metabolism. Data show that C. japonicus is capable of using kojibiose, nigerose, and isomaltose as sole carbon sources despite a lack of genes annotated for metabolism of these sugars. Metabolism of kojibiose and isomaltose is dependent on an adaptation event that varies temporally, yet occurs with regularity, during growth curve acquisition. This work has augmented an increasingly broad understanding of carbohydrate metabolism in C. japonicus and provides baseline data for future experimentation. Further characterization of the mechanisms, genes, and enzymes involved in degradation and metabolism of α-linked disaccharides by C. japonicus will improve our understanding of the strategies that microorganisms employ to utilize the diverse carbohydrates in nature.