对镉高抗性及吸附性的鲁氏酵母突变株的选育

利用紫外线诱变选育鲁氏酵母(CICC1379)镉高抗性及其生物吸附能力的菌株。采用最低抑菌浓度(MIC)法测定鲁氏酵母菌的镉抗性,用含Cd2+的平板筛选出3株明显高于亲株镉抗性的突变株,即Cd102、Cd103、Cd104,这些突变体的镉抗性分别为26、12、14 mg/L,明显高于亲株的镉抗性(6 mg/L)。遗传稳定实验证明,突变株Cd102的镉抗性具有较高的遗传稳定性。突变株Cd102的生物吸附性也有相应的提高,并且在中低浓度Cd2+脱除方面表现出更强的吸附能力,对Cd2+浓度为0.775、3.205、6.843、36.335 mg/L溶液的脱除率分别为76.47%、69.99%、64.01%和51.79%,较亲株分别提高了7.01%、12.85%、15.3%和8.65%。突变株Cd102在中低浓度镉溶液的脱除方面表现出更强的吸附能力。

The Breeding of Mutant strains of Zygosaccharomyces rouxii for High Cadmium Resistance and Biosorption Capability

The present study focuses on the improvement of cadmium resistance and biosorption capability in Zygosaccharomyces rouxii utilizing mutagenesis technology.The cadmium resistance level of Z.rouxii is measured by the method of minimum inhibitory concentration(MIC).Using cadmium-containing YEPD petri dishes,three preferred mutants of Z.rouxii CICC1379 were screened out,namely,Cd102,Cd103,Cd104.The cadmium resistance level of these mutants is 26mg/L,10mg/L,14mg/L,respectively,noticeably greater than that of the parent strain(6mg/L).The cadmium resistance level of mutant strain Cd102 has a high genetic stability,and its biosorption capability has also improved correspondingly.The removal efficiency of mutant strain Cd102 for 0.775,3.205,6.843 and 36.335mg/L Cd2+ solutions is 76.47%,69.99%,64.01% and 51.79%,respectively,which has increased by 7.01%,12.85%,15.3% and 8.65% compared with the parent strain.Furthermore,it apparently shows a better ability of biosorption for cadmium solution of median and low concentration.Cd102 is considered a powerful strain for Cd removal studies from food and water environment in the future.