title: [Physiological characteristics of a low-pH tolerant strain Torulopsis glabrata RT-6].
abstract: OBJECTIVE
  With the aim of elucidating the physiological characteristics of a low-pH tolerant strain Torulopsis glabrata RT-6.
  
  
  METHODS
  The intracellular pH, ATP level, the membrane bound H(+)-ATPase activity, the membrane fatty acid composition and the intracellular polyphosphate content of the parent strain CCTCC M202019 and the mutant strain RT-6 were determined and compared under different pH conditions.
  
  
  RESULTS
  Compared to that of the parent strain, the cell growth and pyruvate concentration of the mutant strain RT-6 were increased by 60.6% and 85.4% (56 h), respectively. Similarly, the strain RT-6 had higher intracellular pH compared to the control strain at external pH5.0, 4.5, and 4.0. The ATP content, the membrane bound H(+)-ATPase activity and the intracellular polyphosphate content of the mutant strain RT-6 were increased by 11.7%, 13.6%, and 3.5% at external pH 5.5, while at external pH 4.0, increased by 61%, 38.6%, and 30.8%, respectively. Furthermore, the mutant strain RT-6 exhibited higher content of the unsaturated fatty acids and higher membrane fluidity.
  
  
  CONCLUSIONS
  Discharging more intracellular H+ and inhibiting the intracellular H+ production contributed to the strain RT-6's higher intracellular pH, and therefore the acid tolerance.
authors: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China. wangjunjsdx@163.com
authors: Jun
authors: J
authors: Wang
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