石油污染土壤微生物修复过程中植物毒性变化规律

Ecotoxicity monitoring and plant bioindicators screening of oil-contaminated soil during bioremediation

植物幼苗生长发育和叶片的生化指标能综合反映土壤石油污染的程度及其生态毒性的强弱.为探究植物对石油污染土壤生态毒性的指示效果和污染土壤在生物修复过程中毒性的变化规律,本研究采用3株对石油烃具有良好降解效果的降解菌构建混合菌体系,开展石油污染土壤模拟微生物修复实验.文章考察了5种典型植物指示不同修复时期土壤生态毒性强弱的可行性与敏感性,并进一步从生态学角度揭示修复过程中石油污染土壤生态毒性的变化规律.结果表明,小麦和萝卜相对于莴苣、黑麦草和小青菜而言,更适宜作为石油污染土壤的指示生物.石油污染土壤的生态毒性随着微生物修复过程的进行呈先上升后下降的趋势,石油污染土壤生态毒性在修复的第8 d达到最大.不同的供试植物对石油污染的响应存在一定的差异.小麦和萝卜的生长发育指标能较为敏感地指示石油污染土壤在微生物修复过程中的生态毒性,可作为石油污染土壤微生物修复效果的指示生物.

Seedling development and biochemical indexes of plant leaf could collectively reflect the soil health condition. In order to explore the soil ecotoxicity patterns and biological indicator effects, bioremediation of oil-contaminated soil were conducted. Oil degrading bacterial consortium were built with three strains isolated from oil-contaminated soil. Seedling growth status, malonaldehyde content, and superoxide dismutase activity was detected. The results showed that the maximum inhibition of seedling development and biochemical indexes of plant leaf was observed at the initial stage of bioremediation（on the 8th day） and gradually dropped to normal. Compared withAsparagus lettuce,RyegrassandBrassica chinensis,Triticum aestivumL.andRaphanus sativusL. are more suitable as potential indicators for bio-remediation effectiveness of oil-contaminated soil.