Fontana R, Canepari P, Satta G, Coyette J
J Bacteriol. 1983 May;154(2):916-23. doi: 10.1128/jb.154.2.916-923.1983.
The effects of variations in growth conditions on the penicillin response of Streptococcus faecium ATCC 9790 were studied. Changes in the growth temperature and medium composition were found to cause striking changes in the bacterial generation time, cellular penicillin sensitivity (minimum inhibitory concentration), sensitivity of peptidoglycan synthesis to inhibition by penicillin, rate of autolysis, and labeling pattern of penicillin-binding proteins. However, no constant relationship between these parameters and the minimum inhibitory concentration could be observed. Similar electrophoretic patterns for penicillin-binding proteins were observed in cells grown in different media at the optimal growth temperature. Inhibition of cell division by penicillin in cells grown at this temperature (but not at higher or lower temperatures) caused filamentation of the bacteria. In cells grown in a chemically defined medium at the optimal temperature (but not at temperatures above or below), complete inhibition of cell division was associated with only partial inhibition (34% after 150 min) of peptidoglycan synthesis. It is suggested that the status and physiological importance of individual penicillin-binding proteins in S. faecium are heavily influenced by growth conditions. Depending on the growth conditions, different penicillin-binding proteins may perform the cellular function, indispensible for bacterial growth.
研究了生长条件变化对屎肠球菌ATCC 9790青霉素反应的影响。发现生长温度和培养基成分的变化会导致细菌世代时间、细胞对青霉素的敏感性（最低抑菌浓度）、肽聚糖合成对青霉素抑制的敏感性、自溶速率以及青霉素结合蛋白的标记模式发生显著变化。然而，这些参数与最低抑菌浓度之间未观察到恒定关系。在最佳生长温度下于不同培养基中生长的细胞中观察到相似的青霉素结合蛋白电泳图谱。在此温度（而非更高或更低温度）下生长的细胞中，青霉素对细胞分裂的抑制导致细菌形成丝状体。在最佳温度（而非高于或低于该温度）下于化学限定培养基中生长的细胞中，细胞分裂的完全抑制仅与肽聚糖合成的部分抑制（150分钟后为34%）相关。提示屎肠球菌中各个青霉素结合蛋白的状态和生理重要性受生长条件的严重影响。根据生长条件，不同的青霉素结合蛋白可能执行对细菌生长不可或缺的细胞功能。
