Efficient production of gamma-aminobutyric acid by engineered Saccharomyces cerevisiae with glutamate decarboxylases from Streptomyces.
Biotechnol Appl Biochem
; 67(2): 240-248, 2020 Mar.
Article
em En
| MEDLINE
| ID: mdl-31625206
ABSTRACT
Gamma-aminobutyric acid (GABA) is an industrially valuable natural product. This study was aimed to establish an efficient food-grade production process of GABA by engineering Saccharomyces cerevisiae that is generally recognized as safe (GRAS). GABA can be produced by catalytic decarboxylation of l-glutamate (l-Glu) by glutamate decarboxylase (GAD, EC4.1.1.15). Two GADs, SsGAD from Streptomyces sp. MJ654-NF4 and ScGAD from Streptomyces chromofuscus ATCC 49982, were heterologously expressed in S. cerevisiae BJ5464. The engineered yeast strains were used as whole-cell biocatalysts for GABA production. S. cerevisiae BJ5464/SsGAD exhibited significantly higher efficient catalytic activity than that of S. cerevisiae BJ5464/ScGAD. The optimal bioconversion system consisted of a cell density of OD600 30, 0.1 M l-Glu, and 0.28 mM pyridoxal phosphate in 0.2 M Na2 HPO4 -citric acid buffer with pH 5.4, and the reactions were performed at 50 °C for 12 H. S. cerevisiae BJ5464/SsGAD cells can be reused, and the accumulated GABA titer reached 62.6 g/L after 10 batches with an overall molar conversion rate of 60.8 mol%. This work thus provides an effective production process of GABA using engineered yeast for food and pharmaceutical applications.
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01-internacional
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MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Streptomyces
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Engenharia Genética
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Ácido gama-Aminobutírico
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Glutamato Descarboxilase
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article