首页 | 本学科首页   官方微博 | 高级检索  
     


Activity of H(+)-ATPase in ruminal bacteria with special reference to acid tolerance.
Authors:T Miwa   H Esaki   J Umemori     T Hino
Abstract:Batch culture experiments showed that permeabilized cells and membranes of Ruminococcus albus and Fibrobacter succinogenes, acid-intolerant celluloytic bacteria, have only one-fourth to one-fifth as much H(+)-ATPase as Megasphaera elsdenii and Streptococcus bovis, which are relatively acid tolerant. Even in the cells grown in continuous culture at pH 7.0, the acid-intolerant bacteria contained less than half as much H(+)-ATPase as the acid-tolerant bacteria. The amounts of H(+)-ATPase in the acid-tolerant bacteria were increased by more than twofold when the cells were grown at the lowest pH permitting growth, whereas little increase was observed in the case of the acid-intolerant bacteria. These results indicate that the acid-intolerant bacteria not only contain smaller amounts of H(+)-ATPase at neutral pH but also have a lower capacity to enhance the level of H(+)-ATPase in response to low pH than the acid-tolerant bacteria. In addition, the H(+)-ATPases of the acid-intolerant bacteria were more sensitive to low pH than those of the acid-tolerant bacteria, although the optimal pHs were similar.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号