Journal
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
Volume 87, Issue 1, Pages 159-165Publisher
SPRINGER
DOI: 10.1007/s00253-010-2493-7
Keywords
Corynebacterium glutamicum; Oxygen deprivation; Amino acid production; Environmentally friendly process
Categories
Funding
- New Energy and Industrial Technology Development Organization (NEDO), Japan
Ask authors/readers for more resources
Corynebacterium glutamicum was genetically engineered to produce l-alanine from sugar under oxygen deprivation. The genes associated with production of organic acids in C. glutamicum were inactivated and the alanine dehydrogenase gene (alaD) from Lysinibacillus sphaericus was overexpressed to direct carbon flux from organic acids to alanine. Although the alaD-expressing strain produced alanine from glucose under oxygen deprivation, its productivity was relatively low due to retarded glucose consumption. Homologous overexpression of the gapA gene encoding glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in the alaD-expressing strain stimulated glucose consumption and consequently improved alanine productivity. In contrast gapA overexpression did not affect glucose consumption under aerobic conditions, indicating that oxygen deprivation engendered inefficient regeneration of NAD(+) resulting in impaired GAPDH activity and reduced glucose consumption in the alanine-producing strains. Inactivation of the alanine racemase gene allowed production of l-alanine with optical purity greater than 99.5%. The resulting strain produced 98 g l(-1) of l-alanine after 32 h in mineral salts medium. Our results show promise for amino acid production under oxygen deprivation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available