土壤中产酸菌的筛选及其对重金属生物有效性影响

Screening of Organic Acids Producing Microbes and Their Effects on the Phytoremediation of Soils Contaminated with Heavy Metals

文章通过微生物筛选和盆栽模拟实验,研究了污染土壤中产酸菌对印度芥菜吸收重金属的影响,对土壤中筛选出的具有活化或钝化效果的产酸微生物进行菌种鉴定和产物分析。实验共筛选得到产酸菌28株,通过盆栽试验,发现编号为A-4-2、b-1-0、c-5-5、c-4-0的菌株对印度芥菜吸收重金属有很好的促进作用,编号为b-3-7的菌株对印度芥菜吸收重金属有抑制作用。对上述菌株进行生理生化分析和16S r DNA的提取纯化及测序,它们分别为:c-4-0为反硝化利斯特氏菌(Listeria denitrificans),b-1-0为环状芽孢杆菌(Bacillus cirallans),c-5-5为格氏利斯特氏菌(Listeria grayi),b-3-7为干燥奈瑟氏球菌(Neisseria sicca)。将其发酵液经反向高效液相色谱分析,发现这些菌株的发酵液代谢产物中含有草酸、酒石酸、苹果酸等低分子量酸物质,这些酸物质影响了土壤中重金属元素的存在形态,即生物有效性,进而影响了植物对其吸收与利用。

This paper,based on microbial screening and pot experiment,studies the influence of indigenous acid-producing microorganisms on absorption of heavy metal of Brassica juncea in contaminated soil. The selected acid-producing microbes with activation or passivation are strain identified and product analyzed. 28 acid-producing strains are found through screening,and the strains labeled A-4-2,b-1-0,c-5-5,and c-4-0 fairly promote the absorption of heavy metal of Brassica juncea. Meanwhile, strain labeled b-3-7 restrains absorption of heavy metal of Brassica juncea. After phytophysiology and biochemistry analysis and extraction and purification and sequencing of 16 S r DNA,the strains are shown as Listeria denitrificans（c-4-0）,Bacillus cirallans（b-1-0）,Listeria grayi（c-5-5）,and Neisseria sicca（b-3-7）.Analysis with reversed-phase high performance liquid chromatography,indicates that oxalic acid,tartaric acid and malic acid are found in metabolito of zymotic fluid, all of which are low molecular weight organic acids, which would affect the existing form of heavy metal, namely biological effectiveness, and further affect the absorption of plants on heavy metal.