一株耐受低pH光滑球拟酵母RT-6的生理特性  

Physiological characteristics of a low-pH tolerant strain Torulopsis glabrata RT-6

作　　者：汪军[1,2] 秦义[1,2] 赵亮亮[1,2] 陈坚[1,2] 刘立明[1,2] 

机构地区：[1]江南大学,食品科学与技术国家重点实验室,无锡214122 [2]江南大学,工业生物技术教育部重点实验室,无锡214122

出　　处：《微生物学报》2011年第3期340-345,共6页Acta Microbiologica Sinica

基　　金：国家杰出青年基金(20625619);国家自然科学基金重点项目(20836003);国家“973项目”(2007CB714303);全国优秀博士学位论文作者专项基金(200962)~~

摘　　要：【目的】研究一株耐受pH 1.91的光滑球拟酵母(Torulopsis glabrata)RT-6的生理特性。【方法】在不同的pH条件下,对比分析原菌CCTCC M202019和突变株RT-6胞内pH、胞内ATP水平、H+-ATPase酶活、膜脂肪酸组成和聚磷酸盐含量等生理学特性的差异。【结果】与原菌比较,突变株RT-6:(1)生物量和丙酮酸产量分别提高了60.6%和85.4%(56 h);(2)在胞外pH5.0、4.5、4.0时,胞内pH极显著高于原菌;(3)胞内ATP、H+-ATPase酶活和聚磷酸盐含量,在胞外pH 5.5条件下,分别提高了11.8%、13.6%和3.5%,而胞外pH 4.0时,则分别提高了61.1%、38.6%和30.9%;(4)膜脂肪酸不饱和度增强,膜的流动性更强。【结论】突变株RT-6通过促进胞内质子向胞外转运和抑制胞内质子生成,以帮助维持自身胞内pH稳定,适应低pH环境。[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.[Conclusion]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.

关 键 词：光滑球拟酵母 低pH胁迫 生理特性 

分 类 号：TQ920.1[轻工技术与工程—发酵工程]