Rapid Biodegradation of Methyl tert-Butyl Ether (MTBE) by Pure Bacterial Cultures

Two pure bacterial strains capable of rapid degrading methyl tert–butyl ether (MTBE) were isolated from an industrial wastewater treatment plant, identified and characterized. These strains are able to grow on MTBE as the sole carbon and energy sources and completely mineralize it to the biomass and carbon dioxide. The strains were identified as Bacillus cereus and Klebsiella terrigena. Both strains are able to grow in the presence of 48 gl -1 MTBE in water, which is almost the maximum concentration of MTBE in the water. They were able to completely degrade 10 gl -1 MTBE in less than a day. The specific degradation rate of MTBE at optimum conditions were 5.89 and 5.78 g(MTBE) g(cells)-1 h-1 for B. cereus and K. terrigena, respectively. The biomass yield was 0.085 and 0.076 gg-1, respectively. The cultivations were carried out successfully at 25, 30 and 37 °C, while they showed the best performance at 37 °C. Neither of the strains was able to grow and degrade MTBE anaerobically.