English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Gamma-aminobutylate (GABA) is an important chemical in pharmacetucal field and chemical industry. GABA has mostly been produced in lactic acid bacteria by adding  L -glutamate to the culture medium since  L -glutamate can be converted into GABA by inherent  L -glutamate decarboxylase. Recently, GABA has gained much attention for the application as a major building block for the synthesis of 2-pyrrolidone and biodegradable polyamide nylon 4, which opens its application area in the industrial biotechnology. Therefore,  Corynebacterium glutamicum , the major  L -glutamate producing microorganism, has been engineered to achieve direct fermentative production of GABA from glucose, but their productivity was rather low.    Results  Recombinant  C. glutamicum  strains were developed for enhanced production of GABA from glucose by expressing  Escherichia coli  glutamate decarboxylase (GAD) mutant, which is active in expanded pH range. Synthetic P H36 , P I16 , and P L26  promoters, which have different promoter strengths in  C. glutamicum , were examined for the expression of  E. coli  GAD mutant.  C. glutamicum  expressing  E. coli  GAD mutant under the strong P H36  promoter could produce GABA to the concentration of 5.89 ± 0.35 g/L in GP1 medium at pH 7.0, which is 17-fold higher than that obtained by  C. glutamicum  expressing wild-type  E. coli  GAD in the same condition (0.34 ± 0.26 g/L). Fed-bath culture of  C. glutamicum  expressing  E. coli  GAD mutant in GP1 medium containing 50 μg/L of biotin at pH 6, culture condition of which was optimized in flask cultures, resulted in the highest GABA concentration of 38.6 ± 0.85 g/L with the productivity of 0.536 g/L/h.    Conclusion  Recombinant  C. glutamicum  strains developed in this study should be useful for the direct fermentative production of GABA from glucose, which allows us to achieve enhanced production of GABA suitable for its application area in the industrial biotechnology.

microbial cell factories

Enhanced production of gamma-aminobutyrate (GABA) in recombinant Corynebacterium glutamicum by expressing glutamate decarboxylase active in expanded pH range