[2S00a] 01. ASBA - Part 5

2:35 PM - 2:50 PM JST(5:35 AM - 5:50 AM UTC)

[2ASBA-09] Refactoring of Aureothin Biosynthesis via Biosensor-guided Enzyme Engineering

○Bong Hyun Sung^1,2,3, Yurim Kim^1,2 (1. Korea Research Institute of Bioscience and Biotechnology (Korea), 2. Korea University of Science and Technology (Korea), 3. Korea Advanced Institute of Science and Technology (Korea))

Keywords:

Synthetic Biology,Aureothin,Biosensor

Aureothin, a natural nitro-aromatic compound, exhibits a broad range of biological activities such as nematocidal and antitumor activities. It is synthesized by type I modular polyketide synthases from Streptomyces thioluteus. Aureothin is produced from chorismate through various intermediates such as para-aminobenzoate (pABA) and para-nitrobenzoate using aureothin biosynthetic enzymes (AurABCDEFGHI). However, productivity is not high enough in natural strain and biosynthetic gene cluster (BGC) information is not fully elucidated. In order to increase the productivity of aureothin, we devised a method for rapid identification of a mutant enzyme with increased catalytic activity by screening a mutant library based on a biosensor in heterogeneous host, Escherichia coli. After identifying a transcription-factor-based biosensor to detect pABA, we screened mutant pABA synthases with enhanced catalytic activity. In addition, we revealed that AurBGC did not have a gene required for aureothin production in E. coli research. The selected mutation and missing gene were applied to heterologous aureothin production in Streptomyces, resulting in increase of aureothin production. This study can be applied to improvement of the secondary metabolite production gene difficult to manipulate.