A novel biocatalyst for efficient production of 2-oxo-carboxylates using glycerol as the cost-effective carbon source

Yujiao Wang; Yingxin Zhang; Tianyi Jiang; Jingjing Meng; Binbin Sheng; Chunyu Yang; Chao Gao; Ping Xu; Cuiqing Ma

doi:10.1186/s13068-015-0368-y

A novel biocatalyst for efficient production of 2-oxo-carboxylates using glycerol as the cost-effective carbon source

Biotechnol Biofuels. 2015 Nov 25:8:186. doi: 10.1186/s13068-015-0368-y. eCollection 2015.

Authors

Yujiao Wang¹, Yingxin Zhang¹, Tianyi Jiang¹, Jingjing Meng¹, Binbin Sheng¹, Chunyu Yang¹, Chao Gao¹, Ping Xu², Cuiqing Ma¹

Affiliations

¹ State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 People's Republic of China.
² State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 People's Republic of China ; State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 People's Republic of China.

Abstract

Background: The surplus of glycerol has increased remarkably as a main byproduct during the biofuel's production. Exploiting an alternative route for glycerol utilization is significantly important for sustainability of biofuels.

Results: A novel biocatalyst that could be prepared from glycerol for producing 2-oxo-carboxylates was developed. First, Pseudomonas putida KT2440 was reconstructed by deleting lldR to develop a mutant expressing the NAD-independent lactate dehydrogenases (iLDHs) constitutively. Then, the Vitreoscilla hemoglobin (VHb) was heterologously expressed to further improve the biotransformation activity. The reconstructed strain, P. putida KT2440 (ΔlldR)/pBSPPcGm-vgb, exhibited high activities of iLDHs when cultured with glycerol as the carbon source. This cost-effective biocatalyst could efficiently produce pyruvate and 2-oxobutyrate from dl-lactate and dl-2-hydroxybutyrate with high molar conversion rates of 91.9 and 99.8 %, respectively.

Conclusions: The process would not only be a promising alternative for the production of 2-oxo-carboxylates, but also be an example for preparation of efficient biocatalysts for the value-added utilization of glycerol.

Keywords: 2-Oxo-carboxylate; Biocatalyst; Glycerol; NAD-independent lactate dehydrogenase; Pseudomonas putida KT2440.