Matsumura P, Marquis R E
Appl Environ Microbiol. 1977 Apr;33(4):885-92. doi: 10.1128/aem.33.4.885-892.1977.
Growth of Streptococcus faecalis in complex media with various fuel sources appeared to be limited by the rate of supply of adenosine-5' -triphosphate (ATP) at 1 atm and also under 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 weight) per mol of 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 ribonucleic acid (RNA) did not appear to be significant causes of growth inefficiency under pressure. In addition, 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 did those growing at 1 atm. Pressure did stimulate the membrane adenosine triphosphatase (ATPase) or S. faecalis at ATP concentrations greater than 0.5 mM. Intracellular ATP levels were found to vary during the culture cycle from about 2.5 mumol/ml of cytoplasmic water for lag-phase or stationary-phase cells to maxima for exponentially growing cells of about 7.5 mumol/ml at 1 atm and 5.5 mumol/ml at 408 atm. N,N'-dicyclohexylcarbodiimide at a 10 muM concentration improved growth efficiency under pressure, as did Mg(2+) or Ca(2+) ions 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. In all, it appeared that S. faecalis growing under pressure has somewhat reduced ATP supply but significantly increased demand and that the inhibitory effects of pressure can be interpreted largely in terms of ATP supply and demand.
粪肠球菌在含有各种燃料源的复杂培养基中的生长似乎受到1个大气压以及408个大气压静水压力下三磷酸腺苷（ATP）供应速率的限制。压力下的生长在能量利用方面效率低下，指数生长培养物的平均细胞产量表明，每产生1摩尔ATP，细胞干重仅为10.7克，而在1个大气压下该值为15.6克。将ATP用于压力-体积功或用于蛋白质、肽聚糖或稳定核糖核酸（RNA）的周转，似乎并不是压力下生长效率低下的主要原因。此外，似乎也没有因离子摄取而增加ATP需求，因为在408个大气压下生长的细胞其内部钾离子水平明显低于在1个大气压下生长的细胞。当ATP浓度大于0.5 mM时，压力确实会刺激粪肠球菌的膜三磷酸腺苷酶（ATPase）。发现细胞内ATP水平在培养周期中有所变化，从对数期或稳定期细胞的约2.5 μmol/ml胞质水，到指数生长细胞的最大值，在1个大气压下约为7.5 μmol/ml，在408个大气压下为5.5 μmol/ml。10 μM浓度的N,N'-二环己基碳二亚胺可提高压力下的生长效率，50 mM浓度的镁离子或钙离子也有同样效果。这些试剂还增强了ATP的聚集，似乎压力下生长效率低下至少部分是由于ATPase活性增加所致。总体而言，似乎压力下生长的粪肠球菌ATP供应有所减少，但需求显著增加，压力的抑制作用在很大程度上可以从ATP的供需角度来解释。
