石油污染土壤生物修复中试系统对微生物特性的影响

The Influence of the Microbial Properties of Oil Contaminated Soils in the Bioremediation Pilot Systems

微生物作为土壤石油烃生物降解的主体,其活性是提高石油降解效率的关键要素.在石油污染土壤生物修复过程中,环境条件的改变造成微生物特性及其降解活性的相应变化.与现场调研的土壤相比,生物修复中试系统中微生物密度提高了1个数量级,FDA活性提高了1.5倍.由于环境胁迫产生的诱导作用,除油微生物优势明显.中试系统运行稳定后,除油微生物密度比微生物总密度低1个数量级,污染土壤中微生物的活性与除油微生物的密度变化更趋于一致.扫描电镜和显微镜观察结果表明,生物修复系统微生物以杆菌、球菌为主,革兰氏染色呈阳性.生物修复不同时期土壤与现场土样相比,其种群构成呈现各自的特点.在生物修复后期,微生物种群多样性有所降低,在强化生物修复中试系统中更为明显.这主要是因为随着反应的进行,环境胁迫对微生物的种群多样性及其相对丰度都产生了诱导.

The activities of microbial play an important role in biodegradat＇ion efficiency of oil in soils. During the bioremediation of polluted soils, microbial properties and the degrading activities would be changed by environmental intimidation. Compared with the initial soil in the polluted site, the microbial amount in pilot-scale bioremediation system increased by 10 times, and the microbial activities increased by 1.5 times. According to the inducement of environmental stress, the oil degrading bacteria hold dominant position. After stabilized in pilot system, the oil degrading microbes was 10 percent of the total microbes, and the microbial activities were more consistent with the degrading microorganism. It can be obtained from the SEM and microscope investigation that the dominant G^＋ bacteria in bioremediation were mainly bacillus and coccus. The microbial communities in polluted site and bioremediation presented quite deferent properties. Through the bioremediation in two months, the microbial diversity decreased, and the reduction was especially distinguished in the enhanced bioremediation pilot system. Possibly, during the biodegradation, the microbial diversity and communities were induced by the environmental stress.