抗镉细菌对镉胁迫辣椒幼苗生长的影响

Effects of Cadmium-Resistant Bacterium on Hot Pepper Seeding Growing under Cadmium Stress

旨在筛选分离可用于镉污染土地栽培农作物根际的抗镉细菌接种物。从辣椒耕地土样分离纯化出4株抗镉细菌,通过16SrRNA基因序列分析鉴定为嗜线虫沙雷氏菌Cd-r-11、吡咯伯克霍尔德菌Cd-r-A、无色杆菌Cd-r-C和Cd-r-D;采用平皿滤纸片法种子萌发试验筛选出对辣椒种子发芽抑制作用较小的是菌株Cd-r-11;采用辣椒幼苗盆栽试验显示菌株Cd-r-11对镉胁迫(20mg/kg基质)辣椒幼苗的生长无显著性抑制作用;通过含镉离子(100mg/L^400mg/L)牛肉膏蛋白胨培养液振荡培养菌株Cd-r-11,火焰原子吸收分光光度法检测显示它能吸附去除超过50%的镉离子。研究结论认为嗜线虫沙雷氏菌Cd-r-11有用做辣椒根际接种物来处理镉污染土壤的应用潜力。

It is aimed to isolate cadmium-resistant bacteria to be utilized as rhizosphere microbial inoculants when crops grow at the cadmium-polluted soil.Four cadmium-resistant bacteria were isolated from the soil sample of hot pepper(Capsicum annuum L.)field.Based on partial sequence of the 16SrRNA gene,they were identified as Serratia nematodiphila Cd-r-11,Burkholderia pyrrocinia Cd-r-A,Achromobacter sp.Cd-r-C and Achromobacter sp.Cd-r-D respectively.The strain Cd-r-11 was screened out with the least inhibitory effect on the hot pepper sprouting seeds placed on the filter paper absorbing cadmium ion in Petri dishes.The strain Cd-r-11 has no significant inhibitory effect on the hot pepper seedlings growing under the cadmium ion(20 mg/kg media)stress in pot test.After inoculating in beef extract-peptone broth containing 100 mg/L to 400 mg/L of cadmium ion,the strain Cd-r-11 could adsorb and remove more than 50%of cadmium ion detected with flame atomic absorption spectrophotometric method.It is concluded that the S.nematodiphila Cd-r-11 has the potential to be utilized as inoculum at the rhizosphere of hot pepper to treat the cadmium-polluted soil.