耐镉酵母菌QN-3的基本特性研究  

Cadmium Tolerance and Basic Characterization of a Newly Isolated Strain Yeast QN-3

作　　者：王陶[1] 李文[1] 董玉玮[1] 李同祥[1] 贺羽 WANG Tao;LI Wen;DONG Yuwei;LI Tongxiang;HE Yu(Jiangsu Key Construction Laboratory of Food Resource Development and Quality Safe,Xuzhou University of Technology,Xuzhou 221018,China)

机构地区：[1]徐州工程学院江苏省食品资源开发与质量安全重点建设实验室,江苏徐州221018

出　　处：《徐州工程学院学报（自然科学版）》2022年第3期50-58,共9页Journal of Xuzhou Institute of Technology(Natural Sciences Edition)

基　　金：国家自然科学基金项目(31270577,32102121);江苏省“六大人才高峰”高层次人才项目(SWYY-222);徐州市科技计划项目(KC21296,KC20186)。

摘　　要：微生物在重金属污染治理中具有十分重要的作用,为开发新型重金属生物吸附剂,对前期从化工厂附近土壤中分离获得的一株高耐镉酵母菌Cystobasidium oligophagum QN-3的镉耐受特性及基本特性进行了研究.通过测定其在低镉和高镉条件下的生长曲线来确定它的生长规律,对该菌株培养条件进行优化,采用最优条件的菌体进行镉吸附试验,并通过透射电镜观察镉在菌体表面的沉积作用.结果表明:QN-3在固体培养基中能够最高耐受22000 mg/L Cd^(2+);在镉质量浓度100 mg/L液体培养基中,最佳液体培养条件为NaCl质量浓度0.01 g/mL,温度28℃,接种量6%,装液量50 mL,pH 6.0;菌体吸附性能随着镉质量浓度升高而下降,在镉质量浓度为50 mg/L培养基中其对镉吸附能力最强,吸附率达到49.42%;通过透射电镜分析酵母菌在吸附镉前后的变化,表明在吸附金属镉后,酵母菌QN-3细胞表面出现镉的聚集物,细胞内部物质聚集,产生空泡.Microorganisms play a very important role in the treatment of heavy metal pollution.In order to develop new heavy metal biosorbents,a strain of cadmium-tolerant Cystobasidium oligophagum QN-3 screened from the soil around the chemical plant in the early stage was studied for its cadmium tolerance and basic characteristics.The growth regularity of QN-3 was determined by measuring its growth curve under the condition of low and high concentrations of Cd^(2+).The culture conditions of the strain under Cd^(2+) were optimized,and the Cd^(2+) adsorption test was carried out by using cells under the optimal conditions.Deposition of Cd^(2+) on cell surface was detected by Transmission electron microscopy.The results showed the strain could resist 22000 mg/L Cd^(2+) on PDA plate,the optimum culture conditions under 100 mg/L of Cd^(2+) were as follows:NaCl 1%,temperature 28℃,inoculum 6%,medium 50 mL,pH 6.0;The adsorption ability of QN-3 decreased with the increase of Cd^(2+) concentration.When the concentration of Cd^(2+) was 50mg/L,the adsorption capacity was the strongest,and the adsorption rate was up to 49.4%in the liquid medium.The morphological changes of QN-3 cells before and after Cd^(2+) adsorption were analyzed by transmission electron microscope.It showed that after Cd^(2+) adsorption,Cd^(2+) aggregates appeared on the surface of yeast QN-3 cells,the substances in the cells gathered and vacuoles appeared.

关 键 词：镉污染 酵母菌 耐镉 吸附性能 

分 类 号：TS201.3[轻工技术与工程—食品科学]