MIG1基因和葡萄糖对扣囊复膜孢酵母细胞形态变化的影响及机理探究

【目的】研究MIG1基因和葡萄糖对扣囊复膜孢酵母细胞形态变化的影响及其机理探究。【方法】扣囊复膜孢酵母在不同浓度葡萄糖的YPD培养基中培养,敲除MIG1基因菌株在常规YPD培养基中培养,研究细胞内葡聚糖酶和几丁质酶活性以及细胞壁β-葡聚糖和几丁质含量与细胞形态变化之间的关系。【结果】培养基中葡萄糖浓度越低,扣囊复膜孢酵母菌丝体越少,单细胞酵母越多,且葡聚糖酶和几丁质酶活性越高,β-葡聚糖和几丁质含量越低;葡萄糖浓度对敲除MIG1基因菌株没有显著影响,葡聚糖酶和几丁质酶活性始终保持在较高水平,β-葡聚糖和几丁质含量也较低,菌体多以单细胞酵母形式存在。【结论】MIG1基因和葡萄糖通过葡萄糖阻遏作用调节葡聚糖酶和几丁质酶活性,进而影响细胞壁的葡聚糖和几丁质含量,最终影响扣囊复膜孢酵母细胞的形态变化。

Effects of MIG1 gene and glucose on cell morphology of Saccharomycopsis fibuligera and mechanism exploration

Objective] It was studied that the effects of MIG1 gene and glucose on cell morphology of Saccharomycopsis fibuligera and the mechanism exploration. Methods] S. fibuligera was cultured in YPD mediums with different concentrations of glucose and MIG1 gene knockout strain was in YPD medium. We studied the relationship between intracellular glucanase and chitinase activities and cell wall glucan and chitin contents and cell morphological changes. Results] When the concentration of glucose in the media was lower, the mycelium of S. fibuligera decreased, single-cell yeast increased, glucanase and chitinase activities increased, and then glucan and chitin contents in cell walls reduced. The concentration of glucose had no significant effect on MIG1 gene knockout strain: glucanase and chitinase activities of MIG1 gene knockout strain were remained at a high level, glucan and chitin contents in cell walls was also lower, and most of cells existed as the form of single-cell yeast. Conclusion] MIG1 gene and glucose by multicopy inhibitor of glucose regulated glucanase and chitinase activities which affected glucan and chitin contents in cell walls, so that the cell morphology of S. fibuligera changed.