2. 微生物の高塩濃度環境における応答(セミナー「ストレスと生物のレスポンス」)

概要

論文の詳細を見る
Various responses are observed in bacteria to hyperosmotic pressure. Here, possibilities of some hypotheses for signals and sensors of osmotic pressure, and osmoprotectants were reviewed. Two-component regulatory system of sensor-effector seems plausible to detect any change in extracellular osmotic pressure and transduce it into various adaptational systems in the cells. Although there are many reports of osmoprotectants, it is remained as resolved question how these compounds can support cell growth. And, it was pointed out that gross analysis for them is not helpful for consideration of real situation in the cytoplasm. 'Ectoine', one of excellent osmoprotectants, was found in a moderate halophile, Halomonas sp. Unlike glycine betaine it is not known about the regulatory systems of ectoine accumulation with response to hypersalinity. But, all of the three enzymes, 2,4-diaminobutyric acid (2,4-DABA) transaminase, 2,4-DABA acetyltransferase, and ectoine synthase, were confirmed. The first and the third enzymes were purified and characterized. The results indicated that as a whole the pathway seems capable of synthesis of ectoine at approx. 0.5M NaCl.
低温生物工学会の論文
1993-10-20