(480g) Controlling Bacterial Persistence and Biofilm Formation

Biofilms are sessile bacterial communities formed in aquatic environments by the secretion of extracellular polymeric substances. Nearly all bacteria form biofilms, and they are frequently associated with diseases and biofouling. It is very difficult to eliminate bacterial biofilms using conventional antibiotic or disinfectant treatments, because the biofilm matrix formed by the microbial products, the induction of stress-responsive genes in biofilms, and the non-metabolizing nature of some biofilm cells (i.e., persister cells) protect biofilm cells from many antibacterial agents (e.g., biofilms are 1,000-fold more resistant to various antibiotics than the planktonic culture). The persistence and complexity of biofilms have been a critical limitation in controlling biofilms. My research group seeks to understand molecular interactions between biofilm cells and develop novel control strategies. These efforts are to i) investigate molecular interactions in multi-species biofilm communities, ii) engineer antibacterial proteins for use as alternatives to antibiotics, iii) develop living biotherapeutics that can sense, secrete, and kill the target biofilm cells without affecting commensal communities, and iv) utilize functional biofilms for enhanced bioelectrochemical systems. We have identified that extra cellular proteins and antimicrobial chemicals that exhibit anti-biofilm and anti-persister activities and demonstrated that synthetic antimicrobial-producing genetic circuits can be applied for eradicating harmful biofilms. Furthermore, we have created functional engineered biofilms for toxic chemical degradation while facilitating electron transfer in bioelectrochemical systems. These studies will open the development of novel strategies for addressing challenges in numerous biofilm-associated problems in the areas of medical, food processing, agricultural, environmental, and many other industries.