Thalenfeld B, Epstein I, Grossowicz N
Biochim Biophys Acta. 1977 Mar 29;497(1):112-21. doi: 10.1016/0304-4165(77)90143-x.
A direct correlation between the absorbance of a thermophilic bacillus and specific amidase activity was observed, which was found to depend on the cell density of the culture rather than on the time of contact of the culture with the inducer. Dilution of high density cultures caused the specific amidase activity to decrease. Environmental factors such as pH, concentration of inducer or degree of aeration, and level of NH+4 and glutamate had no effect on amidase synthesis. The decrease in amidase activity upon dilution could not be ascribed to destruction by oxygen or by inactivation or decay. Several lines of evidence suggest that catabolite repression is responsible for the phenomenon described. Succinate-grown cultures gave a stronger dilution effect thatn glutamate-grown cells. The mutant strain E-21, relatively resistant to catabolite repression, did not show the characteristic dilution effect nor the direct correlation between absorbance and specific amidase activity.
观察到嗜热芽孢杆菌的吸光度与特定酰胺酶活性之间存在直接相关性，发现这种相关性取决于培养物的细胞密度，而非培养物与诱导剂接触的时间。高密度培养物的稀释会导致特定酰胺酶活性降低。诸如pH值、诱导剂浓度或通气程度以及NH⁺₄和谷氨酸水平等环境因素对酰胺酶的合成没有影响。稀释后酰胺酶活性的降低不能归因于氧气的破坏、失活或衰变。几条证据表明，分解代谢物阻遏是造成所述现象的原因。以琥珀酸盐为生长底物的培养物比以谷氨酸为生长底物的细胞产生更强的稀释效应。相对抗分解代谢物阻遏的突变菌株E-21既未表现出特征性的稀释效应，也未表现出吸光度与特定酰胺酶活性之间的直接相关性。
