产铁载体菌对龙葵修复土壤Cd污染的促进效应  

Enhancing effect of siderophore-producting bacteria on remediation of cadmium-contaminated soil by Solanum nigrum L

作　　者：王东升 王立立 李取生 周婷 周雪芳 高琼 WANG Dongsheng;WANG Lili;LI Qusheng;ZHOU Ting;ZHOU Xuefang;GAO Qiong(Key Laboratory of Environmental Pollution and Health of Guangdong Province,School of Environment,Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学环境学院,广东省环境污染与健康重点实验室,广州510632

出　　处：《环境工程学报》2018年第8期2311-2319,共9页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划项目(2017YFD0801305); 广东省科技计划项目(2017A010105005)

摘　　要：通过CAS筛选培养基从龙葵根系土中筛选出2株产铁载体菌T1、Y2,经生理生化鉴定和16S r DNA序列分析,初步确定T1、Y2分别为铜绿假单胞菌和阴沟肠杆菌。将2株细菌接种至溶镉溶磷培养基中进行实验室培养,并对溶镉、溶磷结果和2株菌的胞外分泌物进行分析。结果表明,接种T1、Y2菌培养基中的有效镉、有效磷与不接菌对照相比显著增加(P<0.05),2株菌分泌的草酸、丁二酸、甘油酸等有机酸使培养基pH显著降低(P<0.05),促进了碳酸镉和磷酸钙的活化。在受Cd污染的灌溉土中进行龙葵盆栽实验,以灌根的方式分别接种T1、Y2菌,并对龙葵的生物量、龙葵根系土水溶态Cd浓度、龙葵吸收Cd总量及其根系土壤Cd形态的转化进行分析。结果表明:接种T1、Y2菌处理的龙葵根系土溶液Cd浓度比不接菌对照增加4.5、3.6倍,接种T1菌处理的地上部分与地下部分的干重比不接菌对照增加1.55、2.45倍,接种Y2菌处理的地上部分与地下部分的干重比不接菌对照增加1.47、2.28倍,接种T1、Y2菌处理的龙葵地上部分Cd总吸收量比不接菌对照增加1.56、1.69倍;接种T1、Y2菌处理的龙葵富集系数与未接菌对照相比增加,并没有达到显著性差异(P>0.05),接种T1、Y2菌处理的转运系数与未接菌对照相比未显著性变化(P>0.05)。接种菌处理有效促进了龙葵根系土壤难溶性形态Cd向可交换态Cd的转化。同时,研究发现接种T1、Y2菌可显著促进(P<0.05)龙葵对土壤Cd的吸收,强化了龙葵修复土壤镉污染的能力。Two strains of siderophore-producting bacteria T1 and Y2 were isolated from the root system soil of Solanum nigrumL by CAS screening medium. Physiological and biochemical identification and 16 S r DNA sequence analysis confirmed that T1 and Y2 were Pseudomonas aeruginosa and Enterobacter cloacae, respectively. These strains were inoculated into the cadmium and phosphorus-dissolving medium for the determination of cadmium and phosphate dissolution, and the analysis of extracellular secretions. The results showed that the effective cadmium and available phosphorus in the culture medium inoculated with T1 and Y2 were significantly higher than those in the non-inoculated control（P〈0.05）. Organic acids such as oxalic acid, succinic acid and glyceric acid secreted by these strains significantly reduced the pH of the medium（P〈0.05）. The activation of cadmium carbonate and calcium phosphate was promoted. Pot experiment of Solanum nigrumL in Cd-contaminated soil was conducted with strain irrigation at root. The biomass of Solanum nigrumL, the concentration of soluble Cd in root soil, the total amount of Cd absorbed by Solanum nigrumL and the transformation of Cd in root soil were analyzed. The results showed that the concentration of Cd in the root solution treated with T1 and Y2 was 4.5 and 3.6 times higher than that of the non-inoculated control. The dry weight of aerial and underground parts treated with strain T1 was increased by 1.55 and 2.45 times compared with the control. The dry weight ratio of aerial and underground parts treated with strain Y2 was 1.47 and 2.28 times higher than that of the control. The total Cd uptake of aerial parts of Solanum nigrumL treated with T1 and Y2 was 1.56 and 1.69 times higher than that of non-inoculated control.The enrichment coefficient of Solanum nigrumL treated with T1 and Y2 inoculation increased, whereas, it was not significant（P〉0.05）. The transport coefficient of Solanum nigrumL treated with T1 and Y2 inoculation did not change significantly compared with

关 键 词：产铁载体菌 龙葵 胞外分泌物 CD污染 土壤修复 

分 类 号：X53[环境科学与工程—环境工程]