【作者】 卢显妍；

【导师】 尹华；

【作者基本信息】 暨南大学 ， 环境科学， 2005， 硕士

【摘要】 本研究利用原生质体技术选育高效的重金属吸附工程菌。主要包括工程菌的原生质体诱变、原生质体融合、突变株的筛选、吸附性能、吸附机理、工程菌的毒性实验以及实际废水的处理等。 初步探讨了4株重金属吸附菌——掷孢酵母7-3（Sorobolomycetaceae sp.7-3）、玫瑰掷孢酵母（Sporobolomycetaceae roseus）、解脂假丝酵母（Candida lipolytica）和产朊假丝酵母（Candida utilis）的抗铬机理及Cr⁶⁺对它们的毒性影响,结果表明:假丝酵母的可驯化性较好;Sorobolomycetaceae sp.7-3对高浓度Cr⁶⁺的耐受性最好;Candida utilis的除铬机理是表面吸附和胞内积累并存。 考察了制备上述4株重金属吸附菌原生质体的最佳条件。一方面,选用紫外线和亚硝酸对Candida utils CR-001的原生质体进行诱变,得到了6株具有高重金属抗性的高效重金属吸附菌。另一方面,采用原生质体电融合技术获得高效的重金属吸附菌R₃₂。利用CRC2811-1和R₃₂对实际废水的处理结果表明:2株工程菌对3种工业废水的处理效果普遍好于诱变前或融合前出发菌株。此外,CRC2811-1和R₃₂对多种工业废水都具有较强的适应能力,处理能力和耐冲击能力。 毒性实验结果表明:在吸附Cr⁶⁺以前R₃₂对微生物无致突变性,对藻类、洋葱、斑马鱼和小鼠无急性毒性、慢性毒性和蓄积毒性;吸附Cr⁶⁺后,常规水处理中的各种回收和杀菌措施可以降低出水中R₃₂的量,使出水排入江河后不会对环境中的各种生物产生不良的影响。更多还原

【Abstract】 The protoplast technology was used to breed the effective heavy metal sorption engineering strains in this research, including preparation of parental strains protoplast, protoplast-induction and protoplast-fusion of engineering strains, selection of mutants, capability and mechanism of sorption of mutants, toxicity experiment, and treatment of real wastewater, etc.The Cr6+-resistance mechanisms of four heavy metal sorption strains , namely Sporobolomycetaceae sp. 7-3, Sporobolomycetaceae roseus, Candida lipolytica, Candida utilis, and the toxicity of Cr6+ on them have been discussed elementarily. The results showed that acclimatization of Candida sp. was better than Sporobolomycetaceae sp., and the Cr6+-resistance of Sporobolomycetaceae sp. 7-3 was the best of the four. Removal of Cr6+ by Candida sp. was depended on both surface sorption and intracellular accumulation.The optimal condition of protoplast preparation of those four strains had been studied. Then ultraviolet and HNO2 were selected as the mutagens to perform induction mutation towards Candida utilis protoplast of CR-001. Six mutants which possessed high heavy metal removal efficiency and high resistance to Cr6+ were obtained. On the other hand , protoplast-electricity-induced fusion was used to construct high-efficiency heavy metal sorption strains. CRC2811-1 and R32 were used to treat real wastewater. The results showed that treatment effects of CRC2811-1 and R32 of three kinds of industry wastewater were better than the original strains before indution or fusion, especially of the planting wastewater. Furthermore, CRC2811-1 and R32 possessed adaptability, treatment ability and shock resistant ability to a lot of industry wastewater.The results of toxicity experiments showed that R32 would not cause acute, chronic, cumulative and genetical toxicity effect on algae, Allium cepa, Zebra, fish and mice before it absorbed Cr. The recovery and sterilization measurement in routine water treatment could reduce most of the R32 in effluent. This may ensure that the effluent would not cause any ill effect on all kinds of biology in the environment after it was discharged into the river.更多还原