<p>To enable our engineered bacteria to specifically function at the small intestinal lesions in IBD patients, we designed the colonization system. This system consists of two main components: one is the tetrathionate sensor TtrSR, and the other is the adhesion protein Als3. TtrSR is a two-component system from the marine bacterium Shewanella halifaxensis HAW-EB4, which can detect extracellular tetrathionate chemical signals and promote the expression of downstream genes in the signaling pathway. Als3 is a cell surface protein from Candida albicans, which acts as an adhesin, mediating adhesion to epithelial cells, endothelial cells, and extracellular matrix proteins. We chose Saccharomyces cerevisiae as the chassis organism for engineering the bacteria. By expressing the TtrSR system and Als3 protein in Saccharomyces cerevisiae, we will achieve specific colonization at the small intestinal lesions in IBD patients.</p>
<p>We introduced muscone gas molecule receptors derived from mouse olfactory epithelial cells into chassis bioengineered bacteria. The muscone gas molecule receptor is a G protein coupled receptor in eukaryotic cells, and we chose Saccharomyces cerevisiaet as the chassis bioengineering bacterium. By modifying the mating pathway of Saccharomyces cerevisiae, the muscone gas molecule receptor is integrated into the signaling pathway of Saccharomyces cerevisiae. And downstream of the modified mating pathway, lactate dehydrogenase was introduced to alter the anaerobic metabolism pathway of Saccharomyces cerevisiae, synthesizing lactate for the treatment of IBD disease.</p>
