Title of article :
Microbial production of N-acetylneuraminic acid by genetically engineered Escherichia coli Original Research Article
Author/Authors :
Mari Ishikawa، نويسنده , , Satoshi Koizumi، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2010
Pages :
5
From page :
2605
To page :
2609
Abstract :
Previously, we described the production of N-acetylneuraminic acid (NeuAc) from N-acetylglucosamine (GlcNAc) in a system combining recombinant Escherichia coli expressing GlcNAc 2-epimerase (slr1975), E. coli expressing NeuAc synthetase (neuB), and Corynebacterium ammoniagenes. However, this system was unsuitable for large-scale production because of its complexity and low productivity. To overcome these problems, we constructed a recombinant E. coli simultaneously overexpressing slr1975 and neuB. This recombinant E. coli produced 81 mM (25 g/L) NeuAc in 22 h without the addition of C. ammoniagenes cells. For manufacturing on an industrial scale, it is preferable to use unconcentrated culture broth as the source of enzymes, and therefore, a high-density cell culture is required. An acetate-resistant mutant strain of E. coli (HN0074) was selected as the host strain because of its ability to grow to a high cell density. The NeuAc aldolase gene of E. coli HN0074 was disrupted by homologous recombination yielding E. coli N18-14, which cannot degrade NeuAc. After a 22 h reaction with 540 mM (120 g/L) GlcNAc in a 5 L jar fermenter, the culture broth of E. coli N18-14 overexpressing slr1975 and neuB contained 172 mM (53 g/L) NeuAc.
Keywords :
Sialic acid , Escherichia coli , Whole cell biocatalysis , N-Acetylneuraminic acid
Journal title :
Carbohydrate Research
Serial Year :
2010
Journal title :
Carbohydrate Research
Record number :
966786
Link To Document :
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