大宝山矿区耐Cd^(2+)细菌的分离鉴定及其生物学特性  

Isolation and identification,and biological characteristics of cadmium-tolerant bacteria from the Dabao Mine

作　　者：陈美标[1] 郭建华[1] 姚青[2] 段锦梅[1] 冯广达[1] 蔡卓平[1] 朱红惠[1] 

机构地区：[1]广东省微生物研究所 广东省菌种保藏与应用重点实验室 广东省微生物应用新技术公共实验室 广东省华南应用微生物重点实验室-省部共建国家重点实验室培育基地,广东广州510070 [2]华南农业大学园艺学院,广东广州510642

出　　处：《微生物学通报》2012年第12期1720-1733,共14页Microbiology China

基　　金：国家自然科学基金项目(No.31070103);广东省自然科学基金重点项目(No.10251007002000001);广东省科技攻关项目(No.2009B030802013)

摘　　要：【目的】从Cd2+污染土壤中分离获取强耐Cd2+微生物,研究其生物学特性。【方法】采用选择性培养基TSA对广东省大宝山重金属污染土壤中耐镉(Cd2+)细菌进行分离筛选,结合细菌形态观察、生理生化检测、16S rRNA基因序列分析等方法确定了它们的分类地位,并开展了细胞形态、Cd2+耐受性、Cd2+吸附性、对不同pH和盐度适应性、以及对抗生素的抗性等生物学特性的研究。【结果】从土壤中分离到8株具有强耐Cd2+能力的细菌(YN-6、YN-7、YN-8、YN-9、YN-16、YN-17、YN-18、YN-19),初步鉴定其分别属于Rhizobium、Roseateles、Cupriavidus、Methylobacterium、Variovorax、Rhizobium、Achromobacter和Leifsonia属。细菌生物学特性研究表明,8株耐Cd2+细菌的形态存在一定的差异,其中YN-6、YN-8、YN-9、YN-16、YN-17和YN-18菌体为短杆状,而YN-7和YN-19菌体为长杆状。它们对Cd2+的最低抑制浓度均在3 mmol/L以上,且每克细胞吸附1 mg以上的Cd2+。其中,菌株YN-8对Cd2+的耐受性最强(9 mmol/L),菌株YN-9对Cd2+的吸附能力最强(316.7 mg Cd2+/g cells)。不同pH、盐度和抗生素对8株细菌生长的影响存在较大差异。【结论】菌株YN-8和YN-9对环境的适应性较强,可以作为较好的试验材料应用于生物修复重金属Cd2+污染土壤的研究。[Objective] To isolate and obtain cadmium-tolerant bacteria from polluted soil by cadmium and to study their biological characteristics. [Methods] The cadmium-tolerant bacte-ria were isolated from the heavy metals contaminated soil around the Dabao Mine, Guangdong Province by the selective TSA medium, and identified based on morphological observation, physiological-biochemical test and 16S rRNA gene sequence analysis. Their biological char-acteristics including morphology, Cd^2＋ tolerance and absorption, the growth range of pH and salinity as well as antibiotic resistance were investigated. [Results] Eight cadmium-tolerant isolates （YN-6, YN-7, YN-8, YN-9, YN-16, YN-17, YN-18 and YN-19） belonged to the genus of Rhizobium, Roseateles, Cupriavidus, Methylobacterium, Variovorax, Rhizobium, Achro-mobacter and Leifsonia. They were different in the morphology, with YN-6, YN-8, YN-9, YN-16, YN-17 and YN-18 being short rod sharp, while YN-7 and YN-19 being long rod sharp. Their minimum inhibitory concentrations （MIC） of Cd^2＋ were 3 mmol/L or above, and 1 g cells could at least adsorb 1 mg Cd^2＋. Among these strains, YN-8 was the most tolerant to Cd2＋ （9 mmol/L） while YN-9 showed the highest adsorbing capacity of Cd^2＋ （316.7 mg Cd^2＋/cells）. The eight bacteria differed in the response to pH, salinity and antibiotic. [Conclusion] YN-8 and YN-9 were much more adaptive to the environment, which could be used for further stud-ies on soil bioremediation polluted by cadmium.

关 键 词：矿区 耐Cd2+细菌 分离鉴定 生物学特性 

分 类 号：X172[环境科学与工程—环境科学]