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Identification and characterization of a novel 2,3‐butanediol dehydrogenase/acetoin reductase from C orynebacterium crenatum SYPA 5‐5
Author(s) -
Zhao X.,
Zhang X.,
Rao Z.,
Bao T.,
Li X.,
Xu M.,
Yang T.,
Yang S.
Publication year - 2015
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12495
Subject(s) - acetoin , 2,3 butanediol , diacetyl , dehydrogenase , chemistry , reductase , biochemistry , enzyme , corynebacterium , fermentation , bacteria , biology , genetics
Acetoin and 2,3‐butanediol are widely used in the chemical and pharmaceutical industries. The enzyme, 2,3‐butanediol dehydrogenase/acetoin reductase (2,3‐ BDH / AR ), plays a significant role in the microbial production of acetoin and 2,3‐butanediol by catalysing a reversible reaction between acetoin and 2,3‐butanediol. To date, a 2,3‐ BDH has not been characterized from Corynebacterium crenatum . 2,3 ‐ BDH was cloned from Coryne. crenatum SYPA 5‐5 and expressed in Escherichia coli BL 21. Sequence analysis suggested that the 2,3‐ BDH from Coryne . crenatum SYPA 5‐5 belongs to the short‐chain dehydrogenase/reductase superfamily. Its maximum specific activity was obtained at 35°C, however, it became very unstable when the temperature was above 35°C. Its optimal pH was 4·0 for reduction reaction and 10·0 for oxidation reaction. The 2,3‐ BDH activity was increased to some extent by Ca 2+ , Mg 2+ , Zn 2+ and Mn 2+ ions. In particular, Ca 2+ induced about 1·5‐fold increase. The value of k cat / K m for diacetyl and acetoin are higher than for 2,3‐butanediol indicating that 2,3‐ BDH can easily reduce diacetyl or acetoin to 2,3‐butanediol under lower pH conditions. The characteristics of 2,3‐ BDH from Coryne. crenatum SYPA 5‐5 will give guide to further studies for the production of acetoin and 2,3‐butanediol with engineered Coryne. crenatum SYPA 5‐5. Significance and Impact of the Study Acetoin and 2,3‐butanediol are commonly used as platform chemicals and widely used in pharmaceutical industries. 2,3‐butanediol dehydrogenase/acetoin reductase (2,3‐ BDH / AR ) plays a significant role in the microbial production of acetoin and 2,3‐butanediol. In this study, 2,3‐ BDH was cloned from Corynebacterium crenatum SYPA 5‐5, was expressed in Escherichia coli BL 21 and characterized with respect to the optimal temperature, pH , substrate specificity and kinetics. The results will guide further studies in Coryne. crenatum SYPA 5‐5 for the production of acetoin and 2,3‐butanediol.