一株溶磷菌对盐地碱蓬修复盐渍土Cd污染的促进效应  

The promoting effect of phosphorus-solubilizing bacteria on remediation of cadmium-contaminated saline soil by Suaeda salsa

作　　者：林欣 王立立 杨平 李取生 徐智敏 魏佳[1] 周婷 LIN Xin;WANG Li-li;YANG Ping;LI Qu-sheng;XU Zhi-min;WEI Jia;ZHOU Ting(Sehool of Environment, Jinan University, Guangzhou 510632, China;Sehool of Life Seienee and Technology, Jinan University, Guangzhou 510632, China)

机构地区：[1]暨南大学环境学院,广州510632 [2]暨南大学生命科学技术学院,广州510632

出　　处：《农业环境科学学报》2018年第5期883-891,共9页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(41673094);广东省科技计划项目(2016A020221015)~~

摘　　要：为提高盐渍土Cd污染植物修复效率,探讨溶磷菌对盐地碱蓬生长和镉提取效果的影响,采用浸根法收集水培(含2%NaCl)盐地碱蓬的根系分泌物,将其作为唯一碳源培养5株具有Cd活化能力的溶磷菌并依据细菌OD值绘制生长曲线。挑选繁殖速度较快且溶磷和活化Cd能力显著性强(P<0.05)的大肠埃希菌(Escherichia)在3个NaCl浓度(0.3、6、12 g·L^(-1))处理下,采用摇瓶实验研究该条件下大肠埃希菌对Ca_3(PO_4)_2和CdCO_3的溶解效应及代谢产物变化。进一步采用Cd平均含量为1.37 mg·kg^(-1)的污灌菜园土,在3个外源NaCl浓度(0、4、8 g·kg^(-1))处理下,利用盆栽实验研究大肠埃希菌对盐地碱蓬修复盐渍土Cd污染的促进效应。结果显示:随盐分增加(0.3、6、12 g·L^(-1)),菌株平均绝对溶磷量(扣除不接菌对照值)分别为80.19、78.79、77.54 mg·L^(-1),平均绝对活化Cd量依次为17.84、17.30、19.73 mg·L^(-1),说明盐分的增加没有阻碍菌株的溶磷功能,且随盐分的增强,可促进Cd的活化。不同盐分下菌株的代谢物组成有明显变化,0.3、6、12 g·L^(-1)盐分处理下菌株分泌的有机酸分别为5、10、13种,分泌的氨基酸分别为4、8、8种。其中缬氨酸的量随盐分增加显著增加(P<0.05)。盆栽实验中,4 g·kg^(-1)盐分胁迫下,接菌处理的生物量和根际土壤溶液Cd含量较不接菌对照显著增加(P<0.05),Cd总活化量平均增加3.17倍,全量和DTPA提取态Cd富集系数平均提高260%。综上,盐分胁迫下大肠埃希菌可正常生长并促进盐地碱蓬Cd富集。In order to improve the efficiency of phytoremediation on cadmium-contaminated saline soil and to explore the effect of phosphorus-solubilizing bacteria on plant growth and cadmium uptake in contaminated soil, root exudates of Suaeda salsa were collected from a sterile hydroponic（with 2% NaCl） culture. Five cadmium-and phosphorus-solubilizing isolates were cultivated using the exudates as a unique carbon source in medium. Their growth curves were obtained by determining their OD values. Escherichia grew faster and had stronger cadmium-and phosphorus-solubilizing abilities than the rest of the isolates（P〈0.05）. Herein, its changes in ability to solubilize P and Cd from Ca3（PO4）2 and CdCO3, respectively, and in its metabolic products in three concentrations of NaCl medium（0.3, 6, 12 g·L^（-1））were studied using a shaking flask experiment. A pot experiment was also conducted in sewage-irrigated garden soil（1.37 mg·kg^（-1） Cd）pretreated with three concentrations of NaCl（0, 4, 8 g·kg^（-1））. The promoting effect of Escherichia on remediation of cadmium-contaminated saline soil by Suaeda salsa was investigated. The results showed that Escherichia produced 80.19, 78.79 mg·L^（-1）, and 77.54 mg·L^（-1） dissolved phosphorus and 17.84, 17.30 mg·L^（-1）, and 19.73 mg·L^（-1） dissolved cadmium, respectively, with the 0.3, 6 g·L^（-1）, and 12 g·L^（-1） salt concentration treatments. This shows that an increasing concentration of salt had no effect on P release and promoted Cd release. There was obvious change in the composition of metabolites of Escherichia under the different salt treatments. With the 0.3, 6 g·L^（-1）, and 12 g·L^（-1） salt treatments, 5, 10 kinds, and 13 kinds of organic acids and 4, 8 kinds, and 8 kinds of amino acids were released, respectively. The valine content increased significantly with increasing salt（P〈0.05）. In the pot experiment, biomass and Cd content in the rhizosphere soil solution of Suaeda salsa with bacterial inoc

关 键 词：溶磷菌 盐地碱蓬 根系分泌物 盐渍地 Cd 修复 

分 类 号：X53[环境科学与工程—环境工程]