Streptococcus faecalis mutants defective in regulation of cytoplasmic pH
نویسندگان
چکیده
منابع مشابه
Lowering of cytoplasmic pH is essential for growth of Streptococcus faecalis at high pH.
The growth of Streptococcus faecalis at high pH was significantly stimulated by carbonate. In the absence of added carbonate the cells were unable to grow at a pH above 9.5, but in media containing 50 mM HCO3- they grew even at pH 10.5. Both rate and yield of growth at pH 9.5 were significantly stimulated by as little as 5 mM carbonate. The cytoplasmic pH in growing cells was maintained at abou...
متن کاملAmplification of the Streptococcus faecalis proton-translocating ATPase by a decrease in cytoplasmic pH.
When Streptococcus faecalis was grown in the presence of protonophores , an ATPase activity of the membrane was increased at a pH below 8.0 but not at a pH above 8.0. Characteristics of this increased ATPase were identical to those of a proton-translocating ATPase (H+-ATPase) located on the membrane of normal cells. The cytoplasmic pH was regulated at 7.6 to 7.8 but was not regulated in the pre...
متن کاملMutants of Streptococcus faecalis sensitive to alkaline pH lack Na(+)-ATPase.
Alkali-sensitive mutants which grow at pH 7.5 but not at pH 9.5 in Na(+)-rich media were isolated from Streptococcus faecalis ATCC 9790. One of the mutants, designated Nak1, lacked activities of both Na(+)-stimulated ATPase and KtrII (active K+ uptake by sodium ATPase). These activities were restored in a spontaneous revertant designated Nak1R. Active sodium extrusion from Nak1 was observed at ...
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An enrichment medium and a new sensitive medium were developed to detect malolactic variants in different strains of lactic bacteria. Factors such as the concentration of glucose and l-malate, pH level, and the type of indicator dye used are discussed with regard to the kinetics of malic acid conversion to lactic acid. Use of these media allowed a rapid and easier screening of mutagenized strep...
متن کاملRegulation of cytoplasmic pH in bacteria.
In the last 30 years, bacteria have provided experimentalists with an easily manipulable system in which to study regulatory phenomena. This has led to a relatively clear understanding of the regulatory mechanisms which operate to control gene expression (35). However, with a few exceptions (e.g., chemotaxis, the control of enzyme activity) regulatory phenomena which primarily involve control o...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 1980
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.143.3.1187-1193.1980