砷铅耐受性植物内生菌株的筛选与其生物学特征的测定

摘要：重金属铅和有毒砷对土壤的污染，尤其是其在对农作物的污染愈来愈受到人们的重视。使用微生物-植物联合修复重金属污染土壤的方法因其绿色、价格低廉，对环境友好等优点日趋受到关注。活跃在植物体内和根际的微生物可通过改变有毒元素的形态和吸附重金属离子等作用，从而降低土壤中重金属的累积以及植物对其吸收作用，增强植物的抗逆能力。所以，挑选出拥有对重金属有毒物质吸附能力，并且能对植物的生长发育有促进作用的细菌，研究其与植物共同修复重金属污染的机制，对降低土壤污染，提高农作物的品质和其对重金属及有毒物质的抗性有着重要的意义。本文利用细菌产IAA、铁载体和产精氨酸脱羧酶的能力等指标，从加入砷、铅的水稻根茎叶分离出三株菌株F37、I12、T4。3株菌的16SrDNA序列分析表明它们都属于Enterobacter（大肠杆菌属）。我们还研究了该3株菌的生物学特性，包括产IAA、铁载体，H2S能力。除此之外，我们还研究了三株菌对其他重金属的抗性以及抗生素抗性情况，以探索菌株对环境适应能力。在动态摇瓶条件下，我们又对这些菌株对铅、砷的去除率进行了测定。结果表明，菌株F37对砷、铅相对其他两株菌来说具有更好的砷、铅去除率。这些结果给微生物植物联合修复土壤重金属污染提供了一定的参考作用。

关键词：铅污染；砷污染；水稻胁迫；微生物修复；联合修复

Screening of plants endophytic strains of As and Pb tolerant and measuring of their biological characteristics

Abstract： Soil pollution, which caused by heavy metal as lead and toxic arsenic, has got more and more attention in the crops especially. Using microbial-plant remediation method to clear up heavy metal contaminated soil makes an increasing attention due to its green, low cost, environment friendly and other advantages. The microorganisms which are active in plants’ rhizosphere can change the form of toxic elements and adsorption of heavy metal ions, reducing the accumulation of heavy metals in the soil and enhancing the plants’ ability to absorb it, improving plants’ resistance to heavy metals. Thus, it is significance to isolate the bacteria with ability to reduce heavy metals and toxic substances. Furthermore, they also can help plants to grow, decrease solid contaminated-soil and enhance crops to be resistance to heavy metals. In this paper, we use the ability of bacterium product IAA, iron carrier and arginine decarboxylase etc. as indicators, we isolated 3 microorganisms-F37, I12, T4 from rice roots and leaves which treated by Pb and As. The 16SrDNA sequence analysis of three microorganisms shows that all of them belonged to Enterobacter ( Escherichia coli). We also studied the biological characteristics of the three strains, including IAA, iron carrier, H2S capacity. In addition, in order to explore the strain to adapt to the environment, we also studied the resistance of three strains to other heavy metals and antibiotic resistance. In the conditions of dynamic shake flask, the lead, arsenic removal rate of this strains was measured. The results showed that strain F37 had better As and Pb removal rates than other two strains. These results provide a reference for microbial plant to repair soil heavy metal pollution.

Key words: Pd pollution；As pollution；Rice stress； Microbial remediation；Combination remediation

摘要 4

关键词 4

Abstract 4

Key words: 5

引言 5

1 材料与方法 6

1．1 材料砷铅耐受性植物内生菌株的筛选与其生物学特征的测定:http://www.chuibin.com/shengwu/lunwen_205830.html