ENERGETICS OF STREPTOCOCCAL GROWTH-INHIBITION BY HYDROSTATIC-PRESSURE
ENERGETICS OF STREPTOCOCCAL GROWTH-INHIBITION BY HYDROSTATIC-PRESSURE
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DOI：
10.1128/aem.33.4.885-892.1977
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发表时间：
1977-01-01
影响因子：
4.4
通讯作者：
MARQUIS, RE
中科院分区：
文献类型：
--
作者：
MATSUMURA, P;MARQUIS, RE
Growth of Streptococcus faecalis in complex media with various fuel sources appeared to be limited by the rate of supply of ATP at 1 atm and 408 atm of hydrostatic pressure. Growth under pressure was energetically inefficient, as indicated by an average cell yield for exponentially growing cultures of only 10.7 g (dry wt/mol ATP produced compared with a 1 atm value of 15.6. Use of ATP for pressure-volume work or for turnover of protein, peptidoglycan or stable RNA did not appear to be significant causes of growth inefficiency under pressure. There did not seem to be an increased ATP requirement for ion uptake because cells growing at 408 atm had significantly lower internal K+ levels than those growing at 1 atm. Pressure stimulated the membrane ATPase of S. faecalis at ATP concentrations > 0.5 mM. Intracellular ATP levels varied during the culture cycle from about 2.5 .mu.mol/ml of cytoplasmic water for lag-phase or stationary-phase cells to maxima for exponentially growing cells of about 7.5 .mu.mol/ml at 1 atm and 5.5 .mu.mol/ml at 408 atm. N,N''-dicyclohexylcarbodiimide at a 10 .mu.M concentration improved growth efficiency under pressure, as did Mg2+ or Ca2+ at 50 mM concentration. These agents also enhanced ATP pooling, and it seemed that at least part of the growth inefficiency under pressure was due to increased ATPase activity. S. faecalis growing under pressure has somewhat reduced ATP supply but significantly increased demand, and the inhibitory effects of pressure can be interpreted largely in terms of ATP supply and demand.
