Affiliation:
1. National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
2. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
Abstract
Biofilms enable bacterial cells to adhere and thrive on surfaces, with associated changes in growth and gene expression aiding their survival in challenging environments. While previous research has explored E. coli biofilm formation, there has been limited exploration of its application in industrial production. Prior studies have shown that immobilized fermentation can enhance L-threonine production. This study aims to augment biofilm formation and subsequently increase L-threonine production in E. coli by regulating the quorum sensing system, focusing on key AI-2-related genes, including luxS, lsrB, lsrK, and lsrR. In +pluxS and +plsrB strains, AI-2 levels were significantly altered, resulting in enhanced biofilm formation, increased curli expression, shorter free-cell fermentation periods, and improved production efficiency through immobilized continuous fermentation. In a single batch of free-cell fermentation with E. coli W1688, L-threonine production was 10.16 g/L. However, +pluxS and +plsrB strains achieved L-threonine yields of 15.27 g/L and 13.38 g/L, respectively, after seven fermentation batches. Additionally, the fermentation period was reduced from 36 h to 28 h and 30 h, respectively.
Funder
National Key R&D Program of China
National Natural Science Foundation of China
Jiangsu National Synergetic Innovation Center for Advanced Materials
Key Research and Development Program of Nanjing Jiangbei New Area
Key R&D plan of Jiangsu Province
Youth Fund of Natural Science Foundation of Jiangsu Province
Subject
Plant Science,Biochemistry, Genetics and Molecular Biology (miscellaneous),Food Science