有色金属矿区植物根际耐镉菌的分离鉴定与镉吸附特性  

Isolation,Identification and Adsorption Characteristics of Cd-Resistant Rhizobacteria in a Nonferrous Metal Mine

作　　者：汪婵娟 熊治廷[1] 徐仲瑞[1] 刘荣相 WANG Chan-juan;XIONG Zhi-ting;XU Zhong-rui;LIU Rong-xiang(School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, Chin)

机构地区：[1]武汉大学资源与环境科学学院,湖北武汉430079

出　　处：《生态与农村环境学报》2018年第5期448-455,共8页Journal of Ecology and Rural Environment

基　　金：国家重点研发计划(2017YFD0801502)

摘　　要：从湖南宝山有色金属矿区采集4种优势植物及根部土壤,经鉴定分别为瞿麦(Dianthus superbus)、兰香草(Caryopteris incana var.incana)、野菊(Dendranthema indicum)和败酱(Patrinia villosa)。测定植株和根部土壤的重金属含量,发现野菊、瞿麦从土壤吸收转运镉的能力比兰香草、败酱强,可作为人工生态修复系统的优势物种。从植物根际土壤中分离得到3株耐镉菌(BS1、BS2、BS3),结合形态学、RDP-Ⅱ数据库和16S rDNA基因序列分析,3者分别属于Sphingomonas echinoides、Massilia flava和阿氏芽孢杆菌(Bacillus aryabhattai),对Cd^(2+)的最低抑菌质量浓度分别为300、100和80 mg·L^(-1)。吸附性能试验结果表明,在镉初始质量浓度为50 mg·L^(-1)条件下,3种菌株吸附Cd^(2+)的最适温度为30℃,且随着吸附时间的延长,吸附率总体呈上升趋势,在30～36 h时吸附达到饱和。菌株BS2对镉的吸附效果最显著,在pH值为5.5和6.5时,最大吸附率可达57.32%和54.15%;菌株BS1的最大吸附率为18.83%～29.14%。BS3仅在pH值为6.5时有明显吸附,最大吸附率为40.66%。Four dominant plant species and their rhizosphere soil samples were collected from the nonferrous metal mine of Baoshan,Hunan Province. The plant species were identified as Dianthus superbus,Caryopteris incana var. incana,Dendranthema indicum and Patrinia villosa. Concentrations of Cd in the plants and soil were determined,and it was found that Dendranthema indicum and Dianthus superbus had the stronger ability to absorb Cd from soil than Caryopteris incana var.incana and Patrinia villosa. Due to its high-metal accumulation capacity,Dendranthema indicum and Dianthus superbus showed a potential ability to apply in artificial ecological restoration system. Based on morphology,RDP-Ⅱ identification system and 16S rDNA gene sequence analysis,three Cd-resistant strains of bacteria（BS1,BS2,BS3） isolated from the rhizospheric soil were finally confirmed as Sphingomonas echinoides,Massilia flava and Bacillus aryabhattai. Their minimal inhibitory concentration levels against cadmium were up to 300,100,80 mg·L^-1,respectively. Three factors,including temperature,adsorption time and pH may influence their Cd^2＋ absorption ability. The results show that,under the condition of initial concentration of 50 mg·L^-1 Cd exposure,the optimal growth temperature of three bacterial strains was 30 ℃,and their biosorption amounts of Cd^2＋increased slowly with time going on. The adsorption reached saturation when the strains were cultured for 30 to 36 h. Strain BS2 exhibited higher Cd adsorption rates of 57. 32% and 54. 15% under the condition of pH 5. 5 and 6. 5 than others. The Cd^2＋ adsorption rate of strain BS1 reached 18. 83% to 29. 14%,under three pH conditions. Strain BS3 showed the maximum adsorption rate of 40. 66% only at pH 6. 5.

关 键 词：有色金属矿区 镉 根际细菌 吸附 

分 类 号：X172[环境科学与工程—环境科学] X53