Oanh Nguyen Thi, Duc Ha Danh
Dong Thap University, 783 Pham Huu Lau Street, Cao Lanh City, Dong Thap Province, Vietnam.
Curr Microbiol. 2021 Apr;78(4):1499-1508. doi: 10.1007/s00284-021-02419-7. Epub 2021 Mar 5.
The widespread use of the herbicide, propanil, causes severe environmental problems. In this study, the effects of propanil on the bacterial community in a sediment slurry were determined. Moreover, the degradation of the herbicide by pure and mixed cultures was first conducted under anaerobic conditions. The results showed that propanil caused significant changes in the bacterial community under anaerobic conditions. Four bacterial strains, i.e., Geobacter sp. Pr-1, Paracoccus denitrificans Pr-2, Pseudomonas sp. Pr-3, and Rhodococcus sp. Pr-4, isolated from the an enrichment sediment slurry were the first pure cultures that degraded propanil and 3,4-dichloroaniline (3,4-DCA) under anaerobic conditions. Some individual isolates showed the slow degradation of propanil and 3,4-DCA, but the mixture of the four strains increased the degradation rates of both compounds. The mixed culture of these isolates transformed more than 90% of propanil within 10 days in liquid media with the amendment of dextrose, glucose, or acetate. The determination of degradation pathway showed that propanil was transformed to 3,4-DCA and some other products before degrading completely. This study provides valuable information on the effects of propanil on the bacterial community and the synergistic degradation of propanil under anaerobic conditions.
除草剂敌稗的广泛使用引发了严重的环境问题。在本研究中，测定了敌稗对沉积物泥浆中细菌群落的影响。此外，首次在厌氧条件下对纯培养物和混合培养物降解该除草剂的情况进行了研究。结果表明，在厌氧条件下，敌稗导致细菌群落发生了显著变化。从富集的沉积物泥浆中分离出的四株细菌，即地杆菌属菌株Pr-1、反硝化副球菌Pr-2、假单胞菌属菌株Pr-3和红球菌属菌株Pr-4，是首批在厌氧条件下降解敌稗和3,4-二氯苯胺（3,4-DCA）的纯培养物。一些单独的分离菌株对敌稗和3,4-DCA的降解速度较慢，但这四株菌株的混合物提高了两种化合物的降解率。在添加了葡萄糖、右旋糖或乙酸盐的液体培养基中，这些分离菌株的混合培养物在10天内将90%以上的敌稗进行了转化。降解途径的测定表明，敌稗在完全降解之前先转化为3,4-DCA和其他一些产物。本研究为敌稗对细菌群落的影响以及厌氧条件下敌稗的协同降解提供了有价值的信息。
