Development of Genetically Stable Escherichia coli Strains for Poly(3-Hydroxypropionate) Production |
| |
| Authors: | Yongqiang Gao Changshui Liu Yamei Ding Chao Sun Rubing Zhang Mo Xian Guang Zhao |
| |
| Institution: | 1. CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.; 2. University of Chinese Academy of Sciences, Beijing, China.; 3. Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.; 4. Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao, China.; Louisiana State University and A & M College, United States of America, |
| |
| Abstract: | Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. In our previous study, a pathway for P3HP production was constructed in recombinant Esecherichia coli. Seven exogenous genes in P3HP synthesis pathway were carried by two plasmid vectors. However, the P3HP production was severely suppressed by strain instability due to plasmid loss. In this paper, two strategies, chromosomal gene integration and plasmid addiction system (PAS) based on amino acid anabolism, were applied to construct a genetically stable strain. Finally, a combination of those two methods resulted in the best results. The resultant strain carried a portion of P3HP synthesis genes on chromosome and the others on plasmid, and also brought a tyrosine-auxotrophy based PAS. In aerobic fed-batch fermentation, this strain produced 25.7 g/L P3HP from glycerol, about 2.5-time higher than the previous strain with two plasmids. To the best of our knowledge, this is the highest P3HP production from inexpensive carbon sources. |
| |
| Keywords: | |
|
|
