Abstract 1874 Constructing gene deletions of ExbD homologs bt2666, bt2667, and ExbB homolog bt2668 in Bacteroides thetaiotaomicron

Polysaccharide degradation is an important part of digestion. Bacteria in the gut microbiome assist in digestion by breaking down large polysaccharides that are otherwise indigestible. Bacteroides thetaiotaomicron (B. theta) is an abundant bacteria in the microbiome that contributes to degradation of many different polysaccharides. B. theta's role in starch degradation is facilitated by a collection of proteins known as starch utilization systems, Sus for short. The Sus proteins depend on proton motive force activated ExbB and ExbD proteins, whose rotation is thought to be key in the opening of the starch transporter. In B. theta, many suspected ExbD and ExbB homologs are present in the genome. In this research, the role of genes bt2666, bt2667, and bt2668 is investigated by deleting these genes from B. theta's genome using allelic exchange methods and natural bacterial recombination. Mutant strains of B. theta have been created for the deletion of bt2667 and bt2668. Plasmids used in conjugation and allelic exchange have also been constructed for deleting bt2666, bt2666-67, and bt2666-68. From a successful deletion of B. theta's genes, growth patterns and differing morphology will be studied to determine the effect of the deletion and therefore the role of the encoded protein in starch utilization. A better understanding of starch and other polysaccharide uptake will allow us to manipulate the metabolism and abundance of the Bacteroides within the gut to impact human health.