Affiliation: | (1) School of Agricultural Biotechnology, and Center for Agricultural Biomaterials, Seoul National University, Seoul, 151-742, Republic of Korea;(2) Department of Food Science and Biotechnology, Kyonggi University, Suwon, 443-760, Republic of Korea;(3) Department of Food and Nutrition, Chosun University, Kwangju, 501-759, Republic of Korea;(4) Division of Applied Life Science, Graduate School, Gyeongsang National University, Jinju, 660-701, Republicof Korea |
Abstract: | A bifunctional alcohol/acetaldehyde dehydrogenase (AdhE) gene (adhE) was cloned from Leuconostoc mesenteroides C7 (LMC7), which is the dominant lactic acid bacterium produced during heterofermentation of kimchi. The nucleotide sequence of the DNA fragment containing putative adhE, which is 2685 bp long and encodes an 886 amino acid polypeptide, exhibits 99% homology with Leu. mesenteroides sp. cremoris. The deduced AdhE comprises two conserved domains: alcohol dehydrogenase (Adh) and acetaldehyde dehydrogenase (Aldh). Moreover, two NAD-binding sites were observed, based on the presence of the GXGXXG motif. A pADHE containing the adhE gene expressed AdhE at the translational level in Escherichia coli BL21, which was at a higher level than in E. coli DH5 and E. coli JM109. The AdhE of LMC7 showed Adh and Aldh activities that, when expressed in E. coli. BL21, were 7.5 and 5.7 U mg-1 , respectively. |