https://video.igem.org/videos/watch/e512625a-79f4-4055-bc36-e810b59f58b7 Title: ORA-GUARD：Engineered Oral Probiotics for Long-Term Bad Breath Solution Description: ORA-GUARD is a synthetic biology project aimed at developing a long-acting therapeutic product for halitosis using engineered oral probiotics. To address the global prevalence of halitosis (affecting ~30% of the population in the world) and the shortcomings of current remedies—which are short lived and disrupt the oral microbiome—the team selected Streptococcus salivarius K12, a GRAS certified oral commensal, as the chassis. Using CRISPR Cas9 mediated genome integration, the engineered strain stably expresses a codon optimized multi enzyme cascade system that efficiently secretes various VSC degrading enzymes. These enzymes convert malodorous volatile sulfur compounds (hydrogen sulfide, methanethiol, etc.) into odorless sulfate, achieving precise and sustained deodorization. A multi layered biosafety strategy, including auxotrophy and a temperature sensitive kill switch, ensures environmental containment. Through integrated human practices and mathematical modeling to guide design optimization, ORA GUARD not only offers an innovative halitosis treatment but also validates a programmable oral probiotic platform, paving the way for future precision oral healthcare. This work embodies the iGEM spirit of “engineering life for the benefit of society.” Official Page Sat, 29 Aug 2026 17:16:02 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://video.igem.org https://video.igem.org/client/assets/images/icons/icon-1500x1500.png https://video.igem.org/videos/watch/e512625a-79f4-4055-bc36-e810b59f58b7 All rights reserved, unless otherwise specified in the terms specified at https://video.igem.org/about and potential licenses granted by each content's rightholder.