【作者】 邓仁健； 金昌盛； 任伯帜； 黄中杰； Andrew HURSTHOUSE；

【Author】 Ren-jian DENG;Chang-sheng JIN;Bo-zhi REN;Zhongjie Huang;rew HURSTHOUSE;School of Civil Engineering, Hunan University of Science and Technology;

【机构】 湖南科技大学土木工程学院；

【摘要】 水体中重金属污染物锑(Sb)因具有较高的积累毒性和致癌性而受到广泛关注。本研究从锑污染土壤中筛选得到1株高抗锑的菌株,命名为StrainJ5,经形态观察、扫描电镜等特征生理生化试验及18S rRNA序列分析,鉴定为黏红酵母(Rhodotorula glutinis)。运用极限耐受方法测定菌株最小抑菌浓度(MIC)为1200 mg/L,最适宜生长条件为pH5.0、温度28℃、摇床速率150r/min,12～18h为对数增长期。运用SDS法进行质粒消除实验,结果发现处理前后菌株的抗锑性能差异不大,同时质粒提取与检测实验并未发现质粒条带,进而初步推断菌株的抗性基因位于染色体上。基于KEGG数据库分析菌株J5抗锑的分子生物学机制,依据模拟代谢途径和KEGG注释结果推测菌株J5抗锑的功能基因为ABC重金属转运蛋白Hmt1、铁硫簇调控蛋白基因。本研究的耐受性菌株具有高抗锑的能力,在生物重金属污染修复上有较高的潜在应用价值。更多还原

【Abstract】 The pollution of antimony(Sb) species in natural waters has drawn more and more attention due to their high cumulative toxicity and carcinogenicity.In this study, a Gram-positive, aerobic, budding reproduction fungus was isolated from an agricultural soil sample near the north mine smelter in Xikuangshan, Hunan province, named as J5,which was identified as Rhodotorula glutinis according to phylogenetic analysis of the 18 S rRNA gene. The strain isolated could resist antimony and it was able to grow well on solid medium containing 800 mg/L Sb(III). Its liquid minimum inhibition concentration(MIC) is 1200 mg/L, optimum conditions for growth under p H5.0, temperature 28 ℃,table speed 150 r/min, 12～18 h is logarithmic growth period. Five growth curves about the strain were drawn on media with or without antimony(Ⅲ). In addition, it was found that the Sb(III)-resistance of this strain was insignificant and showed instability by applying the method of SDS plasmid elimination test, while the test of plasmid extraction and detection didn’t find any plasmid bands. Therefore, we presented a preliminary view of the strain Sb(III)-resistance gene may be located on chromosome. According to the simulated metabolic pathway and KEGG annotation, the functional genes of strain J5 were assumed to be iron-sulfur cluster assembly protein, cytosolic iron-sulfur protein assembly protein and vacuolar ABC heavy metal transporter Hmt1. The results of this study indicate that this strain has a better potential for antimony resistance compared to other reports. Physiological characterization of the isolates also indicates the possible application of this strain for bioremediation of sites contaminated with antimony.更多还原