重金属胁迫下土壤微生物和微生物过程研究进展

Advances in the research of soil microorganisms and their mediated processes under heavy metal stress

通过对重金属胁迫下土壤微生物和微生物过程研究的进程和研究进展的归纳综述 ,分析了该研究尚存在的问题 ,并阐述了其可能原因 .认为土壤微生物和微生物学过程的重金属胁迫研究存在如下问题 :一是从实验室、田间试验和实地监测得到的结果间无法进行比较 ,从而使实验室和田间试验的研究丧失了其科学指导意义 ,并且在实地监测研究中缺乏相应的“精确”对照 ;二是在重金属的胁迫下土壤微生物不但数量有消长 ,而且区系结构上也发生了变化 ,但是用于检测微生物区系结构变化的手段 (PLFA、BI OLOG和DNA等方法 )尚处在探索阶段并需要昂贵的设备 ,难以普及 ,需发展一些可广泛普及的新方法来代替传统的平板分离法分析土壤微生物结构 ;三是重金属对土壤微生物和微生物过程产生胁迫的形态、离子效应和根际效应尚未得到有效的研究和探讨 ;四是土壤微生物和微生物过程重金属胁迫的表征体系尚未建立 .

More and more evidence from both laboratory and field experiments suggested that soil microbes were more sensitive to heavy metal stress than soil animals or plants living in the same soil. This understanding has been gradually accepted as a common point in this field. The history and the latest advances in soil microorganisms and its mediated processes under heavy metal stresses in soils were reviewed in this paper. It is difficult to do any comparison among the results from laboratory, field toxicological experiment and environmental monitoring.So far, a relevantly 'accurate' control soil was rarely available in the environmental monitoring. Much of evidence has indicated that not only microbial population/ biomass was changed under heavy metal stress, but also its structure was varied. Although many molecular methods, such as PLFA, BIOLOG and DNA, have been developed to detect this microbial structural change, they always need many expensive instruments and accessories, and only could be done in laboratory. Therefore, some rapid and easy methods are expected to develop to substitute the traditional plate count. The speciation in the solution phase, ion effect and rhizospheric effect of heavy metal on the toxicity to soil microorganisms and its mediated processes need extent studies and discussion. Finally, the microbial indicator system of assessing heavy metal toxicity to soil microorganisms and its mediated processes need to be established.