逆境对GST基因过表达库德毕赤酵母G43生长及脱镉能力的影响

Effects of stress on the growth and cadmium removal ability of Pichia kudriavzevii G43 overexpressed GST gene

中文关键词:  库德毕赤酵母菌  GST基因  重组菌株  培养条件  耐受性  脱镉率

英文关键词:Pichia kudriavzevii  GST gene  recombinant strain  culture conditions  tolerance  cadmium removal rate

中文摘要:

      目的 探究逆境对谷胱甘肽S-转移酶(glutathione S-transferase, GST)基因过表达库德毕赤酵母(Pichia kudriavzevii) G43生长及脱镉能力的影响。方法 以一株高镉抗性和高镉脱除率的GST基因过表达的重组P. kudriavzevii G43为研究对象, 从生物量和脱镉率两方面评价盐、低pH、乙醇及高温逆境条件对其生长和脱镉能力的影响。结果 逆境培养条件对G43的生长和脱镉能力影响较大。与原始菌株P. kudriavzevii A16 (CK)相比, G43对盐、酸、乙醇及热的耐受力均有显著提升: 可耐受质量浓度为120 g/L的NaCl, pH 2.5时仍可正常生长, 培养基乙醇体积分数10%时仍可生长, 可耐受43℃高温。在不同逆境条件下, G43的脱镉能力与原始菌株相当或者有明显提升。结论 重组菌株G43具有优异的耐受性, 不同培养条件对其脱镉效果有很大影响, 此为后续P. kudriavzevii等微生物的镉抗性和脱镉机制研究提供基础数据, 也为其在食品体系镉脱除领域的应用奠定理论基础。

英文摘要:

      Objective To explore the effects of stress on the growth and cadmium removal ability of Pichia kudriavzevii G43 overexpressed glutathione S-transferase (GST) gene. Methods The effects of salt, low pH, ethanol and high temperature on the growth and cadmium removal ability of recombinant P. kudriavzevii G43 overexpressed GST gene with high cadmium resistance and high cadmium removal rate were evaluated from 2 aspect of the biomass and cadmium removal rate. Results Stress culture conditions had great effects on the growth and cadmium removal ability of G43. Compared with the original strain P. kudriavzevii A16 (CK), the tolerances of G43 to salt, acid, ethanol and heat were significantly improved: G43 could tolerate 120 g/L NaCl, pH 2.5, 10% ethanol in the medium, or temperature of 43℃. Under different stress conditions, the cadmium removal capacity of G43 was equivalent to or significantly improved to that of the original strain. Conclusion The recombinant strain G43 has excellent tolerances, and different culture conditions have great influences on its cadmium removal effect, which provides basic data for the subsequent study of cadmium resistance and cadmium removal mechanism of P. kudriavzevii and other microorganisms, and also lays a theoretical foundation for its application in the field of cadmium removal in food system.