The Daily Bulletin

Dr. Yong Han from the Department of Chemistry and Biochemistry at Ohio University will deliver a research seminar on Thursday, April 3, from 12:15 to 1:30 p.m. in SAMC 151.

Seminar Title: From Bioluminescent Squids to Living Machines: Applications of Microbial Synthetic Biology from the Perspective of Natural Product Chemistry

Abstract: Bacteria communicate through chemical molecules, which function as a "chemical language" for both inter-bacterial signaling and interactions with the host. In this talk, I will present my research in this field, focusing on the discovery and application of microbial biosynthetic pathways and quorum sensing (QS) systems. First, I will introduce the identification of a large NRPS biosynthetic gene cluster in a respiratory tract symbiotic Gordonia species and how its activation and large-scale fermentation led to the production of a rare glycosylated cyclic lipopeptide containing 16 amino acid residues. Further studies demonstrated its anti-lung cancer activity, while transcriptomic analyses revealed extensive interactions with host cells, suggesting that it may exert its effects through regulating host gene expression, showing the therapeutic potential of engineered probiotics. Building on this discovery, I will discuss the reconstruction of biosynthetic pathways for bioactive secondary metabolites within engineered probiotics and the development of a QS-based drug release strategy. This system is designed to respond specifically to the tumor microenvironment, utilizing a dual-input logic gate (AND Gate) that detects tumor-specific lactate concentrations and QS signals. This approach enables precise control over anticancer drug release, improving delivery accuracy while minimizing off-target effects. The "living machine" developed through this strategy allows for in situ synthesis and targeted delivery of bioactive compounds, paving the way for synthetic probiotic-based living therapeutics. To illustrate its potential, I will present two examples demonstrating how this strategy addresses key health challenges. This research integrates natural product chemistry and synthetic biology, expanding the applications of microbial quorum sensing while providing new insights into precision medicine, disease diagnostics, biosensing, and forensic science, ultimately driving innovation in synthetic biology for medical applications.