Original Research ARTICLE
Engineering a microbial consortium based whole-cell system for efficient production of glutarate from L-lysine
- 1Nanjing Tech University, China
Glutarate is an important C5 platform chemical produced during the catabolism of L-lysine through 5-aminovalerate (5-AMV) pathway. Here we first established a whole-cell biocatalysis system for the glutarate production from L-lysine with the engineered Escherichia coli (E. coli) that co-expressed DavAB and GabDT. However, the accumulation of intermediate 5-aminovalerate was identified as one important factor limiting glutarate production. Meanwhile, the negative interaction of co-expressing DavAB and GabDT in a single cell was also confirmed. Here we solved these problems through engineering a microbial consortium composed of two engineered E. coli strains, BL21-22AB and BL21-YDT, as the whole-cell biocatalysts, each of which contains a part of the glutarate pathway. After the optimization of bioconversion conditions, including temperature, metal ion additives, pH and cell ratio, 17.2 g/L glutarate was obtained from 20 g/L L-lysine with a yield of 95.1%, which was improved by 19.2% compared with that in a single cell. Little accumulation of 5-aminovalerate was detected. Even at the high substrate concentration, the reduced 5-aminovalerate accumulation and increased glutarate production were achieved. This synthetic consortium produced 43.8 g/L glutarate via a fed-batch strategy, the highest titer reported to date.
Keywords: Glutarate, 5-aminovalerate accumulation, engineering microbial consortium, whole-cell, E. coli
Received: 26 Sep 2018;
Accepted: 08 Feb 2019.
Edited by:Thomas E. Hanson, University of Delaware, United States
Reviewed by:Charilaos Xiros, Research Institutes of Sweden (RISE), Sweden
Jian-Zhong Liu, Sun Yat-sen University, China
Vinod Kumar, Cranfield University, United Kingdom
Copyright: © 2019 Wang, Su, Feng, Chen, Xu and Ouyang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Kequan Chen, Nanjing Tech University, Nanjing, China, email@example.com