Characterization of pyridine biodegradation by two Enterobacter sp. strains immobilized on Solidago canadensis L. stem derived biochar

• Published in: Journal of hazardous materials Vol. 414; p. 125577
• Main Authors: Nie, Zimeng, Yan, Binghua, Xu, Yunhai, Awasthi, Mukesh Kumar, Yang, Haijun
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.07.2021
• Subjects: acetaldehyde; Aerobic bacteria; bacterial strain; bacterium isolation; Bio chars; biochar; Biodegradation; bioremediation; charcoal; concentration (parameter); controlled study; Enterobacter; Enterobacter cloacae; Enterobacter cloacae complex; Enterobacter sp; Environmental; environmental factor; Immobilisation; Immobilization; Intermediate; Intermediates; Mass spectrometry; Metabolic pathway; Metabolic pathways; Mineralisation; Mineralization; Mineralogy; nonhuman; organic compound; pesticide residue; Pesticide wastewater; Pyridine; pyridine derivative; Pyridines; Radioactive waste vitrification; Resource Recovery; Resursåtervinning; salinity; Solidago; Solidago canadensis; temperature; waste component removal; waste water treatment plant; Waste water treatment plants; Wastewater treatment; wastewater treatment plant; Biodegradation; Immobilization; Metabolic pathway; Mineralization; Intermediates
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.125577

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−1. The highest pyridine removal rate of 91.70% was achieved by the immobilized H4 at an initial pyridine concentration of 200 mg·L−1, 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. [Display omitted] •Two Enterobacter sp. strains were first isolated for efficient pyridine degradation.•Degradation mechanisms of pyridine by two Enterobacter sp. strains were revealed.•The mixed bacteria H4 was constructed with two Enterobacter sp. strains at ratio 1:1.•Highest pyridine removal rate of 91.70% was reached by immobilized H4.