氯代硝基苯降解菌Comamonas sp.strain CNB-1对污染土壤生物修复作用的研究

Bioremediation of chloronitrobenzene-polluted soil with Comamonas sp.strain CNB-1

硝基取代芳烃化合物是一类重要的环境污染物,利用微生物降解作用修复被污染的土壤、清除环境中的污染物等具有重要的现实意义(Peresetal.,2000).利用从污水处理厂分离的一株降解氯代硝基苯的丛毛单胞菌(Comamonas sp.)菌株CNB-1进行了消除土壤中氯代硝基苯的试验研究.传统的菌落计数方法和针对氯代硝基苯降解酶基因的竞争性定量PCR技术监测结果表明,菌株CNB-1有效地在土壤中定值和存活,其细胞数量与污染物浓度具有显著的相关性,并能够在2d时间内完全清除土壤中2μg.g-1的氯代硝基苯.利用PCR-DGGE技术对土壤中的微生物群落检测,结果表明,存在污染物氯代硝基苯时可以明显检测到加入的菌株CNB-1的特征性条带,加入菌株CNB-1对土壤中原来微生物群落的影响不大.结论:菌株CNB-1在硝基芳烃污染土壤的生物修复中可能具有良好的应用前景.

Nitroaromatics are widely used in chemical industries and are important environmental pollutants as well. Thus, the development of new technology based on microbial degradation of nitroaromatics is of practical importance. In this study, a chloronitrobenzene-degrading Comamonas sp. strain CNB-1, which was isolated from activated sludge of a wastewater treatment plant, was used to develop new process for bioremediation of chloronitrobenzene-polluted soil. The population of strain CNB-1 was monitored by cultivation method and by quantitative competitive PCR that targeted chloronitrobenzene nitroreductase gene. Results indicated that strain CNB-1 survived in soil and chloronitrobenzene was removed effectively. Up to 2 μg of chloronitrobenzene·g ^-1 of soil was completely removed within 2 days after inoculation of strain CNB-I. The microbial communities were determined with PCR-DGGE technique in soils supplemented with chloronitrobenzene （ as control）, or chloronitrobenezene plus strain CNB-1, or no treatment （ as control）. Results did not show significant changes of microbial community, indicating the introduction of strain CNB-1 did not disturb the original microbial community. Based on these results, it is concluded that the strain CNB-1 has great potential in bioremediation of nitroaromatics-polluted soil.