title: The peroxidase-mediated biodegradation of petroleum hydrocarbons in a H2O2-induced SBR using in-situ production of peroxidase: Biodegradation experiments and bacterial identification.
abstract: A bacterial peroxidase-mediated oxidizing process was developed for biodegrading total petroleum hydrocarbons (TPH) in a sequencing batch reactor (SBR). Almost complete biodegradation (>99%) of high TPH concentrations (4g/L) was attained in the bioreactor with a low amount (0.6mM) of H2O2 at a reaction time of 22h. A specific TPH biodegradation rate as high as 44.3mgTPH/gbiomass×h was obtained with this process. The reaction times required for complete biodegradation of TPH concentrations of 1, 2, 3, and 4g/L were 21, 22, 28, and 30h, respectively. The catalytic activity of hydrocarbon catalyzing peroxidase was determined to be 1.48U/mL biomass. The biodegradation of TPH in seawater was similar to that in fresh media (no salt). A mixture of bacteria capable of peroxidase synthesis and hydrocarbon biodegradation including Pseudomonas spp. and Bacillus spp. were identified in the bioreactor. The GC/MS analysis of the effluent indicated that all classes of hydrocarbons could be well-degraded in the H2O2-induced SBR. Accordingly, the peroxidase-mediated process is a promising method for efficiently biodegrading concentrated TPH-laden saline wastewater.
authors.affiliation: Department of Environmental Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Sakine
authors.initials: S
authors.lastname: Shekoohiyan
authors.affiliation: Department of Environmental Health Engineering, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran. Electronic address: moussavi@modares.ac.ir.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Moussavi
authors.affiliation: Department of Environmental Health Engineering, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Naddafi
mesh_terms: D001407:Bacillus / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D006838:Hydrocarbons / Q000378:metabolism*; D006861:Hydrogen Peroxide; D010544:Peroxidases / Q000378:metabolism*; D059392:Petroleum Pollution; D011549:Pseudomonas / Q000378:metabolism; D062065:Wastewater
chemical_list: D006838:Hydrocarbons; D006861:Hydrogen Peroxide; D010544:Peroxidases; D062065:Wastewater
keywords: Biodegradation; Bioreactor; Enzyme; Peroxidase; Petroleum hydrocarbon; Salinity