Bacterial differentiation: Its application on production of useful substances.

点击翻译按钮获取中文摘要

1. Control mechanism of bacterial differentiation (Saito, Sadafe, Fujita, Ikeuchi, Kawamura) (1) Regulatory mechanism of sporulation initiation gene spoOA expression in Bacillus subtilis was studied by the use of lacZ-fusion gene and temperature-sensitive spoOA mutant. It was shown that expression of spoOA gene depends on spoOA, OB, OE, OF, and OH genes and spprulation was not initated unless the function of SpoOA protein is derepressed. (2) spoOA gene was cloned and its gene product was overproduced in Escherichia coli and purified. Purified SpoOA protein has DNA-binding activity. (3)div gene which regulates cell division, sporulation, and protein secretion was cloned. (4) Catabolite-repressible gluconate operon was cloned. The whole nucleotide sequence was determined and the mechanism of catabolite repression of B. subtilis was studied.2. Isolation of regulatory factor of gene expression (Beppu, Nakayama) (1) Streptomycin production and sporulation in Streptomyces griseus is positively controlled by A-factor. A-factor was purified and regulatory network surrounding A-factor was studied. (2) Chromosomal proteins of B. subtilis were isolated and purified and sporulation-specific chromosomal proteins were identified.3. Development of usefulvector (Kobayashi, Yamasaki, Yamane, Kudoh, Tanaka) (1) Isolation and analysis of a temperature-dependent promoter revealed that its expressio is controlled by translational-coupling. Stable promoter-probe vector for B. subtilis was constructed. (2) A commom method to amplify a useful gene in B. Subtilis chromosome was developed. (3) Secretion vector carrying -amylase signal peptide was constructed and improvement of its secretion ability was intended. (4) prtR gene which increases protease production in B. natto was identified and cloned. It was shown that PrtR protein is a positive factor which stimulates the transcription of protease gene.