高生物量富铬酵母发酵工艺的研究

Study on the preparation of a high-biomass, chromium-enriched yeast strain

【目的】研究高含量富铬酵母的选育及其高浓度发酵工艺。【方法】通过Cr3+抗性培养基筛选和亚硝基胍诱变确定酵母菌株,通过对铬吸收的影响选择最佳铬盐,采用葡萄糖流加和铬盐添加策略在5 L发酵罐中进行培养。【结果】经过抗性筛选和亚硝基胍诱变获得了耐受1 000 mg/L CrCl3的菌株GC9,在3种铬盐CrCl3、Cr2(SO4)3、Cr(NO3)3中以添加Cr2(SO4)3所获得的铬吸收最高。在对数生长后期加入铬浓度为400 mg/L的Cr2(SO4)3,培养42 h后细胞干重达到(96.1±0.4)g/L,铬含量达到(2 390±32)μg/g(其中有机铬含量为94%)。【结论】本研究为工业快速制备富铬酵母提供了一种参考方法。

[Objective] To select the chromium-enriched yeast with high content of organic chromium and its fermentation process. [Methods] The yeast strain was selected by primary screening and mutagenesis. The optimal chromium salt was determined by measuring the chromium absorbtivity of CrCl3, Cr2（SO4）3, and Cr（NO3）3. The culture was performed by flowing addition of glucose and the use of chromium salt in a 5 L fermenter, [ Results] A yeast strain GC9 resisting 1 000 mg/L of CrCl3 was selected, and Cr2（SO4）3 was determined as the chromium salt for addition. The culture of strain GC9 was added with Cr2（SO4）3 containing 400 mg/L of chromium at the late logarithmic phase. After incubating for 42 h, the cell dry weight reached to（96.1 ± 0.4）g/L, and the chromium absorption was （2 390 ± 32） ug/g with 94% of organic chromium. [Conclusion] This study provided an effective approach for the preparation of high-biomass, chromium-enriched yeast for food and drug industry.