Oanh Nguyen Thi, Duc Ha Danh
Dong Thap University, 783 Pham Huu Lau Street, Cao Lanh City, Dong Thap Province, Vietnam.
Biodegradation. 2025 Jun 21;36(4):53. doi: 10.1007/s10532-025-10148-y.
In this study, two pretilachlor-degrading bacterial strains isolated from soil, Enterobacter sp. Pre1 and Pseudomonas sp. Pre2 completely utilized the compound as a sole carbon, energy and nitrogen source under aerobic conditions. The determination of degradation kinetics revealed that the rates of both isolates followed the Michaelis-Menten model, in which the maximum utilization rates of Enterobacter sp. Pre1 and Pseudomonas sp. Pre2 were 0.010 ± 0.0012 and 0.0060 ± 0.0007 mM/h, respectively. Moreover, Pseudomonas sp. Pre2 exhibited effective degradation of butachlor. Enterobacter sp. Pre1 showed better biofilm formation than the later one. Their immobilized biomass in polyurethane foam (PUF) reached 323.4 ± 35.6 mg/g PUF completely degrading pretilachlor at 0.15 mM within 12 h in a packed bed bioreactor. A metabolite, 2,6-diethylaniline, was produced during the degradation by both strains. Besides, 4-amino-3,5-diethyl phenol and aniline were the metabolites in the degradation by Enterobacter sp. Pre1 and Pseudomonas sp. Pre2, respectively. This study confirmed the efficiency and mechanisms in the degradation of pretilachlor by freely suspended and immobilized cells of the isolated bacteria.
在本研究中，从土壤中分离出的两株降解丙草胺的细菌菌株，即肠杆菌属Pre1和假单胞菌属Pre2，在有氧条件下能完全利用该化合物作为唯一的碳、能量和氮源。降解动力学测定表明，两株菌株的降解速率均符合米氏模型，其中肠杆菌属Pre1和假单胞菌属Pre2的最大利用速率分别为0.010±0.0012和0.0060±0.0007 mM/h。此外，假单胞菌属Pre2对丁草胺也有有效的降解作用。肠杆菌属Pre1的生物膜形成能力比后者更强。在填充床生物反应器中，它们固定在聚氨酯泡沫（PUF）中的生物量在12小时内可将0.15 mM的丙草胺完全降解，达到323.4±35.6 mg/g PUF。两株菌株在降解过程中均产生了一种代谢产物2,6 -二乙基苯胺。此外，肠杆菌属Pre1和假单胞菌属Pre2降解过程中的代谢产物分别为4 -氨基-3,5 -二乙基苯酚和苯胺。本研究证实了分离出的细菌的游离悬浮细胞和固定化细胞对丙草胺降解的效率和机制。
