Nie Zimeng, Yan Binghua, Xu Yunhai, Awasthi Mukesh Kumar, Yang Haijun
College of Resources and Environment, Hunan Agricultural University, Changsha 410128, Hunan Province, China; Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, Yunan Province, China.
College of Plant Protection, Hunan Agricultural University, Changsha 410128, Hunan Province, China.
J Hazard Mater. 2021 Jul 15;414:125577. doi: 10.1016/j.jhazmat.2021.125577. Epub 2021 Mar 4.
In this study, two pyridine-degrading strains namely Enterobacter cloacae complex sp. BD17 and Enterobacter sp.BD19 were isolated from the aerobic tank of a pesticide wastewater treatment plant. The mixed bacteria H4 composed of BD17 and BD19 at a ratio of 1:1 was immobilized by Solidago canadensis L. stem biochar with a dosage of 2 g·L. The highest pyridine removal rate of 91.70% was achieved by the immobilized H4 at an initial pyridine concentration of 200 mg·L, pH of 7.0, temperature of 28 °C and salinity of 3.0% within 36 h. The main intermediates of pyridine degradation by BD17 were pyridine-2-carboxamide, 2-aminopropanediamide, and 2-aminoacetamide, while 2-picolinic acid, isopropyl acetate, isopropyl alcohol, and acetaldehyde were identified with BD19 by adopting GC-MS technique. Interestingly, there was a possibility of totally mineralization of pyridine and the corresponding degradation pathways of BD17 and BD19 were revealed for the first time.
在本研究中，从某农药废水处理厂的好氧池中分离出两株吡啶降解菌，即阴沟肠杆菌复合体BD17菌株和肠杆菌BD19菌株。将BD17和BD19按1:1比例组成的混合菌H4用剂量为2 g·L的加拿大一枝黄花茎生物炭固定化。在初始吡啶浓度为200 mg·L、pH为7.0、温度为28℃、盐度为3.0%的条件下，固定化混合菌H4在36 h内对吡啶的去除率最高可达91.70%。BD17降解吡啶的主要中间产物为吡啶-2-甲酰胺、2-氨基丙二酰胺和2-氨基乙酰胺，而采用气相色谱-质谱联用（GC-MS）技术从BD19中鉴定出了2-吡啶甲酸、乙酸异丙酯、异丙醇和乙醛。有趣的是，吡啶存在完全矿化的可能性，并且首次揭示了BD17和BD19相应的降解途径。
