Evaluation of the food grade expression systems NICE and pSIP for the production of 2,5-diketo-D-gluconic acid reductase from Corynebacterium glutamicum

• Published in: AMB Express 2013-01, Vol.3 (1), p.7-7
• Main Authors: Kaswurm, Vanja, Nguyen, Tien-Thanh, Maischberger, Thomas, Kulbe, Klaus D, Michlmayr, Herbert
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Biotechnology; Corynebacterium glutamicum; Escherichia coli; Lactobacillus plantarum; Lactococcus lactis; Life Sciences; Microbial Genetics and Genomics; Microbiology; Original; Original Article
• ISSN: 2191-0855; 2191-0855
• DOI: 10.1186/2191-0855-3-7

2,5-diketo-D-gluconic acid reductase (2,5-DKG reductase) catalyses the reduction of 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-keto-L-gulonic acid (2-KLG), a direct precursor (lactone) of L-ascorbic acid (vitamin C). This reaction is an essential step in the biocatalytic production of the food supplement vitamin C from D-glucose or D-gluconic acid. As 2,5-DKG reductase is usually produced recombinantly, it is of interest to establish an efficient process for 2,5-DKG reductase production that also satisfies food safety requirements. In the present study, three recently described food grade variants of the Lactobacillales based expression systems pSIP ( Lactobacillus plantarum ) and NICE ( Lactococcus lactis ) were evaluated with regard to their effictiveness to produce 2,5-DKG reductase from Corynebacterium glutamicum . Our results indicate that both systems are suitable for 2,5-DKG reductase expression. Maximum production yields were obtained with Lb. plantarum /pSIP609 by pH control at 6.5. With 262 U per litre of broth, this represents the highest heterologous expression level so far reported for 2,5-DKG reductase from C. glutamicum . Accordingly, Lb. plantarum/ pSIP609 might be an interesting alternative to Escherichia coli expression systems for industrial 2,5-DKG reductase production.