Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam.
FEMS Microbiol Lett. 2019 Jul 1;366(14). doi: 10.1093/femsle/fnz174.
2-chloro-4-nitroaniline is a nitroaromatic compound widely used in industrial and agricultural sectors, causing serious environmental problems. This compound and some of its analogs were utilized by two Fe3+-reducing microbial strains Geobacter sp. KT7 and Thauera aromatica KT9 isolated from contaminated sediment as sole carbon and nitrogen sources under anaerobic conditions. The anaerobic degradation of 2-chloro-4-nitroaniline by the mixed species was increased approximately by 45% compared to that of individual strains. The two isolates' crossfeeding, nutrient sharing and cooperation in the mixed culture accounted for the increase in degradation rates. The determination of degradation pathways showed that Geobacter sp. KT7 transformed the nitro group in 2-chloro-4-nitroaniline to the amino group following by the dechlorination process, while T. aromatica KT9 dechlorinated the compound before removing the nitro group and further transformed it to aniline. This study provided an intricate network of 2-chloro-4-nitroaniline degradation in the bacterial mixture and revealed two parallel routes for the substrate catabolism.
2-氯-4-硝基苯胺是一种广泛应用于工业和农业领域的硝基芳香族化合物，会造成严重的环境问题。两种从污染沉积物中分离出的铁还原微生物菌株 Geobacter sp. KT7 和 Thauera aromatica KT9 将这种化合物及其一些类似物用作在厌氧条件下唯一的碳氮源。与单一菌株相比，混合菌对 2-氯-4-硝基苯胺的厌氧降解率提高了约 45%。两种分离物在混合培养中的交叉喂养、营养共享和合作解释了降解率的提高。降解途径的确定表明，Geobacter sp. KT7 将 2-氯-4-硝基苯胺中的硝基转化为氨基，随后进行脱氯过程，而 T. aromatica KT9 在去除硝基之前对化合物进行脱氯，然后进一步将其转化为苯胺。本研究提供了细菌混合物中 2-氯-4-硝基苯胺降解的复杂网络，并揭示了两种平行的底物分解途径。
