Ertugay N, Hamamci H, Bayindirli A
Department of Food Engineering, Middle East Technical University, Ankara, Turkey.
Folia Microbiol (Praha). 1997;42(3):214-8. doi: 10.1007/BF02818981.
The physiology of a commercial strain of bakers' yeast was studied in terms of the cell composition under different growth conditions and of its response to stress. The study comprised fed-batch experiments since this is the system used in bakers' yeast industry. The classical fed-batch fermentation procedure was modified in that the yeast cells were continuously grown to a steady-state at a dilution rate of 0.1/h in order to achieve more or less the same initial starting point in terms of cell composition. This steady-state culture was then switched to fed-batch concomitantly with exposure to stress. The highest amount of trehalose accumulation was achieved when nutrient depletion and heat stress were applied concomitantly. The highest amount of trehalose, 12%, was attained in cells stressed by both nitrogen depletion and heat stress. The protein content remained constant, although with some oscillations, at a value of 30% throughout this dual stress experiment.
在不同生长条件下，从细胞组成及其对应激的反应方面对一种商业面包酵母菌株的生理学进行了研究。该研究包括补料分批实验，因为这是面包酵母工业中使用的系统。经典的补料分批发酵程序进行了改进，即酵母细胞以0.1/h的稀释率持续生长至稳态，以便在细胞组成方面或多或少达到相同的初始起点。然后将这种稳态培养物切换到补料分批培养，同时施加应激。当同时施加营养耗尽和热应激时，海藻糖积累量最高。在受到氮耗尽和热应激双重胁迫的细胞中，海藻糖含量最高达到12%。在整个双重胁迫实验中，蛋白质含量保持恒定，尽管有一些波动，其值为30%。
