Enhanced anaerobic biodegradation of OCDD-contaminated soils by Pseudomonas mendocina NSYSU: Microcosm, pilot-scale, and gene studies

• Published in: Journal of hazardous materials Vol. 278; pp. 433 - 443
• Main Authors: Tu, Y.T., Liu, J.K., Lin, W.C., Lin, J.L., Kao, C.M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.08.2014; Elsevier
• Subjects: Anaerobiosis; Applied sciences; Biodegradation; Biodegradation, Environmental; Bioreactors; Dechlorination; Decontamination. Miscellaneous; Degradation; Denaturing Gradient Gel Electrophoresis; Dioxin; Dioxygenases - genetics; DNA, Bacterial - analysis; Exact sciences and technology; Genes; Genes, Bacterial; Hydrolases - genetics; Lecithin; Lecithins - chemistry; Microorganisms; Octachlorinated dibenzo-p-dioxin; Pilot Projects; Pollution; Polychlorinated Dibenzodioxins - chemistry; Polychlorinated Dibenzodioxins - metabolism; Polymerase Chain Reaction; Pseudomonas; Pseudomonas mendocina; Pseudomonas mendocina - genetics; Pseudomonas mendocina - metabolism; Pseudomonas mendocina NSYSU; Soil and sediments pollution; Soil Microbiology; Soil Pollutants - chemistry; Soil Pollutants - metabolism; Soils; Solubilization; Biodegradation; Lecithin; Pseudomonas mendocina NSYSU; Dioxin; Octachlorinated dibenzo-p-dioxin; Pseudomonadales; Dioxin derivatives; Dehalogenation; Pollutant behavior; Soil pollution; Pseudomonas; Solubilization; Salinity; Persistent organic pollutant; Dechlorination; Decontamination; Anaerobe; Bacteria; Pseudomonadaceae; Cleavage; Bioremediation; Organic compounds
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.06.014

•P. mendocina NSYSU can biodegrade OCDD effectively under reductive dechlorinating conditions.•Lecithin could serve as the solubilization agent enhancing the dechlorination of OCDD.•Ring-cleavage dioxygenase and hydrolase genes in P. mendocina NSYSU are identified.•The growth of P. mendocina NSYSU is inhibited when salinity is higher than 7%. In this study, microcosm and pilot-scale experiments were performed to investigate the capability and effectiveness of Pseudomonas mendocina NSYSU (P. mendocina NSYSU) on the bioremediation of octachlorodibenzo-p-dioxin (OCDD)-contaminated soils. The objectives were to evaluate the (1) characteristics of P. mendocina NSYSU, (2) feasibility of enhancing OCDD biodegradation with the addition of P. mendocina NSYSU and lecithin, and (3) variation in microbial diversity and genes responsible for the dechlorination of OCDD. P. mendocina NSYSU was inhibited when salinity was higher than 7%, and it could biodegrade OCDD under reductive dechlorinating conditions. Lecithin could serve as the solubilization agent causing the enhanced solubilization and dechlorination of OCDD. Up to 71 and 62% of OCDD could be degraded after 65 days of incubation under anaerobic conditions with and without the addition of lecithin, respectively. Decreased OCDD concentrations caused significant increase in microbial diversity. Results from the pilot-scale study show that up to 75% of OCDD could be degraded after a 2.5-month operational period with lecithin addition. Results from the gene analyses show that two genes encoding the extradiol/intradiol ring-cleavage dioxygenase and five genes encoding the hydrolase in P. mendocina NSYSU were identified and played important roles in OCDD degradation.