title: Use of Mycobacterium austroafricanum IFP 2012 in a MTBE-degrading bioreactor.
abstract: Mycobacterium austroafricanum IFP 2012 is able to slowly grow on methyl tert-butyl ether (MTBE), a fuel oxygenate widely used as a gasoline additive. The potential of M. austroafricanum IFP 2012 for aerobic MTBE degradation was investigated in the presence of a secondary carbon source, isopropanol. The strain was then tested for MTBE biodegradation at the laboratory-scale in a fixed-bed reactor using perlite as the matrix, and isopropanol was injected once a week to maintain M. austroafricanum IFP 2012 biomass inside the perlite bed. The biofilter was operated for 85 days at an influent flow rate of 20 ml/h by varying the MTBE concentration from 10 to 20 mg/l. The hydraulic retention time was fixed at 5 days. The removal of MTBE depended on the inlet MTBE concentration and a MTBE removal efficiency higher than 99% was obtained for MTBE concentrations up to 15 mg/l. A set of 16S rRNA gene primers specific for M. austroafricanum species was used to analyze the DNA extracted from the biofilter effluent in order to detect the presence of M. austroafricanum IFP 2012 and to estimate the effect of periodic injections of isopropanol on the release of the strain from the perlite bed. The results demonstrated that the injection of isopropanol served to maintain an active MTBE degrading biomass in the biofilter and that this system could be used to effectively treat MTBE contaminated groundwater.
authors.affiliation: Institut Francais du Petrole, Rueil-Malmaison, France.
authors.forename: Helena
authors.initials: H
authors.lastname: Maciel
authors.forename: Hugues
authors.initials: H
authors.lastname: Mathis
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lopes Ferreira
authors.forename: Darwin
authors.initials: D
authors.lastname: Lyew
authors.forename: Serge
authors.initials: S
authors.lastname: Guiot
authors.forename: Frédéric
authors.initials: F
authors.lastname: Monot
authors.forename: Charles W
authors.initials: CW
authors.lastname: Greer
authors.forename: Françoise
authors.initials: F
authors.lastname: Fayolle-Guichard
mesh_terms: D019840:2-Propanol / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D001709:Biotechnology; D005742:Gasoline; D008738:Methyl Ethers / Q000378:metabolism*; D009161:Mycobacterium / Q000145:classification / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D005742:Gasoline; D008738:Methyl Ethers; D014874:Water Pollutants, Chemical; C043243:methyl tert-butyl ether; D019840:2-Propanol