光滑球拟酵母线粒体抵御乙偶姻胁迫的生理机制解析  

Physiological mechanism of mitochondrion against acetoin stress in Candida glabrata

作　　者：李树波[1] 刘立明[1,2] 陈坚[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,江苏无锡214122 [2]江南大学工业生物技术教育部重点实验室,江苏无锡214122

出　　处：《生物加工过程》2015年第3期1-6,共6页Chinese Journal of Bioprocess Engineering

基　　金：国家自然科学基金重点项目(20836003);全国优秀博士学位论文作者专项基金(200962)

摘　　要：以光滑球拟酵母为出发菌株,利用生化和分子生物学实验研究微生物抵御有机溶剂胁迫的生理机制。首先,添加柠檬酸盐考察能量供给对细胞抵御乙偶姻胁迫的影响。与对照条件(0 mmol/L柠檬酸盐)相比,50 mmol/L柠檬酸盐可使细胞生物量在不同乙偶姻质量浓度(6、10、12和15 g/L)胁迫下分别提高了13.2%、14.2%、17.8%和25.2%。同时,通过表达线粒体融合分裂调控基因fzo1和dnm1,以细胞活力、胞内活性氧(ROS)和三磷酸腺苷(ATP)为研究指标考察调控线粒体融合分裂对乙偶姻胁迫的影响。结果表明:与对照菌株相比,在不同乙偶姻质量浓度胁迫下(12和18 g/L),增强线粒体融合可抑制胞内ROS的产生,使其水平分别降低了9.3%和16.2%;却使胞内ATP水平分别提高了9.7%和36.1%,从而延缓乙偶姻胁迫对细胞活力的影响,使细胞生物量相应地提高了9.1%和29.7%。因此,通过添加柠檬酸或改善线粒体生理功能以提高胞内能量供给,可有效提高微生物细胞抵御乙偶姻等环境胁迫的能力。To elucidate the tolerant mechanism of Candida glabrata against acetoin stress, we studied its physiological and biochemical characteristics through two strategies. First, 50 mmol/L of citrate was added to increase intercellular energy production under different concentrations of acetoin （6, 10, 12 and 15 g/L） , and cell growth increased by 13.2%, 14.2%, 17.8% and 25.2%, respectively, compared to the control condition （without addition of citrate）. Furthermore, the genes offzol and dnml were also over-expressed to regulate mitochondrial function, and some important parameters （the intracellular reactive oxygen species （ROS） and adenosine triphosphate （ATP）） were analyzed. Compared to the control strain, improving mitochondrial fusion （over-expressing fzol ） could effectively decrease intercellular ROS production with 9.3% and 16.2%, respectively, under 12 g/L and 18 g/L of acetoin. Moreover, it could significantly increase intracellular ATP generation with 9.7% and 36. 1%, and DCW 9. 1% and 29.7%, respectively. Based on the above results, increasing intercellular energy levels through adding some citrate and improving mitochondrial fusion function was favorable to enhance the cellular robustness for acetoin stress.

关 键 词：乙偶姻 活性氧 光滑球拟酵母 能力代谢 线粒体融合分裂 

分 类 号：TQ224.22[化学工程—有机化工]