NAGAI Kazuo Chubu Univ., Fac. of Appl. Biol., Prof., 応用生物学部, 教授 (00011974)
KATSUMATA Ryoichi Tohoku Univ., Grad. School of Agr., Prof., 大学院・農学研究科, 教授 (60292257)
MATSUSHITA Kazunobu Yamaguchi Univ., Fac. of Agr., Prof., 農学部, 教授 (50107736)
KUMAGAI Hidehiko Kyoto Univ., Grad. School of Biostudies, Prof., 大学院・生命科学研究科, 教授 (70027192)
NAKAMORI Shigeru Fukui Pref. Univ., Fac. of Biotechnol, Prof., 生物資源学部, 教授 (00254243)
(1) TOMITA: H^+-ATPase operon genes of Corynebacterium glutamicum were cloned and sequenced. The transformant carrying the atp operon genes showed 2.5-fold higher ATPase activities than the wild type. The transformant did now exhibit a distinct difference in fermentation characteristics. However, the maximum levels of both growth and glutamic acid production were somewhat higher than those of the wild type. Also in the glutamic acid production phase, the transformant showed higher glucose consumption rate, respiration rate, membrane potential, internal pH value than those of the wild type.
(2) MATSUSHITA: Membrane vesicles were successfully prepared from Corynebacterium glutamicum, and energetics of the respiratory chain was analyzed by using the membrane vesicles thus prepared. Furthermore, NADPH oxidase, characteristic in the respiratory chain, was purified and shown to be an NADH dehydrogenase II (ndh), of which the function in the respiratory chain and energy metabolism was examined
by constructing ndh-disrupted strain.
(3) KATSUMATA: Alanine dehydrogenase gene of Corynebacterium glutamicum was cloned and sequenced. A transformant of C. glutamicum expressing the gene was obtained. However, in C. glutamicum, alanine biosynthesis appeared to be performed by transaminase. The amplification of the transaminase gene resulted in the production of alanine 4.5 times higher than that of the parent.
(4) NAGAI: Peptidoglycan synthesis genes, murI, murC, murE, and ftsI, were isolated form coryneform bacteria. ltsA gene encoding a novel amido-transferase involved in the formation of cell surface structure was isolated from Corynebacterium glutamicum by the analysis of lysozyme sensitive mutant. Defects of the ltsA gene induced production of L-glutamic acid.
(5) NAKAMORI: Cysteine metabolism of Brevibacterium flavum (Corynebacterium glutamicum) was investigated and cysteine desulfuhydrase (CD) of this strain was identified. Cysteine production with CD disruptant was performed. Serine acetyltransferase gene of this strain was also identified and characterized.
(6) KUMAGAI: Cloning of γ -glutamyltranspeptidase (GGT) gene of Corynebacterium was carried out but not successful. Active site of E. coli GGT was determined and autoprocessing mechanism was elucidated, α -Galactosidase of Bifidobacterium, a kind of Corynebacterium, was characterized and the gene was cloned. Less