复合诱变原生质体选育重金属去除菌

选用紫外线和亚硝酸对产朊假丝酵母CR-001进行单因子和多因子诱变处理,通过复合诱变得到了6株具有高重金属抗性的高效重金属去除菌.经过传代后CRC2811-1和CRC7-2的抑菌圈直径减至1.7mm和1.2mm;对Cr⁶⁺的去除率分别从80.2%和81.2%提高到了95.2%和94.7%.其余4株突变株的抗性和除铬性能均可保持稳定.此外,利用扫描电镜、透射电镜和原子力显微镜等仪器对吸附铬前后细胞内外的变化情况进行分析,探讨了突变菌株除铬性能改善的机理.

Improvement of Heavy Metal Removing Strain by Protoplast Combination Mutant

Ultraviolet and HNO₂ were selected as the mutagens to perform the single factor and multi-factor induction mutation towards Candida utilis CR-001. Six mutant strains which possessed high heavy metal removal efficiency and high resistance to Cr⁶⁺ were obtained through combined induction with UV and HNO₂. After they were subcultured for 10 generations,the diameter of bacteriostatic circle of CRC2811-1 and CRC7-2 was reduced to1.7 mm and 1.2 mm respectively, while the Cr⁶⁺ removal efficiency of CRC2811-1 was increased from 80.2% to 95.2%, and that of CRC7-2 was from 81.2% to 94.7%. The stability of the other 4 mutant strains was rather stable. Furthermore,precipitation of chromium outside or inside the cell was studied by using combined technique of scanning electron microscopy(SEM),transmission electron microscopy(TEM),and atomic force microscopy(AFM),and the mechanism of chromium removal improvement by the mutant strains was discussed.