DEVELOP NEW METHODS TO IMPROVE PRODUCTION OF HYDROPHOBIC MOLECULES IN ESCHERICHIA COLI

Abstract

Microbial fermentation has become a promising approach for sustainable and cost-effective production of value-added chemicals. However, with hydrophobic molecules it is challenging to achieve high titers, especially when those compounds cannot be secreted. Often these molecules cannot cross membranes, and thus their production may be limited by lack of storage space in the host. To address this issue, we demonstrated a novel biopolymer-based approach to improve production of hydrophobic compounds. It is using poly(3-hydroxybutyrate) (PHB) inside engineered E. coli as the intracellular storage vessel to encapsulate hydrophobic molecules. The hydrophobic interaction between lycopene, a chromogenic model compound, and PHB was verified by using in vitro binding test and sucrose density gradient centrifugation. The images under Confocal Microscopy validated the in vivo co-localization of PHB granules and lycopene. We managed to improve titer of lycopene, linalool, geraniol, amorphadiene and squalene (by 20%~200%) via different mechanisms by using the multi-functional co-production system.