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Development of efficient enzymatic production of theanine by γ‐glutamyltranspeptidase from a newly isolated strain of Bacillus subtilis , SK11.004
Author(s) -
Shuai Yuying,
Zhang Tao,
Jiang Bo,
Mu Wanmeng
Publication year - 2010
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.4120
Subject(s) - bacillus subtilis , theanine , ethylamine , glutamine , biochemistry , enzyme , chemistry , hydrolysis , biosynthesis , strain (injury) , amino acid , fermentation , biology , food science , bacteria , organic chemistry , genetics , anatomy , green tea
BACKGROUND: Theanine, a unique amino acid found almost exclusively in tea plants, has various favourable physiological and pharmacological functions in humans. Gamma‐glutamyltranspeptidase (GGT, EC 2.3.2.2) is considered to be the most effective enzyme for the production of theanine. In fact, GGT can catalyse the transfer of γ‐glutamyl moieties from γ‐glutamyl compounds to water (hydrolysis) or to amino acids and peptides (transpeptidation). RESULTS: A novel strain, SK11.004, which produces GGT with high theanine‐forming ability was isolated from fermented shrimp paste and identified as Bacillus subtilis through its physiological and biochemical properties as well as its 16S rDNA sequence analysis. Theanine (18.9 mmol L −1 ) was synthesised by GGT (0.06 U mL −1 ) through transfer reaction in the presence of glutamine (20 mmol L −1 ) as a donor and ethylamine HCl (50 mmol L −1 ) as an acceptor at pH 10 and 37 °C for 4 h, the conversion rate being up to 94%. CONCLUSION: The enzymatic synthesis of theanine using GGT from a newly isolated strain Bacillus subtilis SK11.004 was found to be an efficient method. Moreover, compared with others, the GGT from B. subtilis SK11.004 exhibited the highest ratio of transferring activity to hydrolytic activity using glutamine, suggesting a high potential application in the production of theanine and other functional γ‐glutamyl compounds. Copyright © 2010 Society of Chemical Industry