Biodegradation of methyl tertiary butyl ether (MTBE) by a bacterial enrichment consortia and its monoculture isolates.
Methyl tertiary butyl ether (MTBE), an important gasoline additive, is a recalcitrant compound posing serious environmental health problems. In this study, MTBE-degrading bacteria were enriched from five environmental samples. Enrichments from Stewart Lake sediments and an MTBE contaminated soil displayed the highest rate of MTBE removal; 29.6 and 27.8% respectively, in 28 days. A total of 12 bacterial monocultures isolated from enrichment cultures were screened for MTBE degradation in liquid cultures. In a nutrient-limited medium containing MTBE as the sole source of carbon and energy, the highest rate of MTBE elimination was achieved with IsoSL1, which degraded 30.6 and 50.2% in 14 and 28 days, respectively. In a nutrient-rich medium containing ethanol and yeast extract, the bacterium (Iso2A) substantially removed MTBE (20.3 and 28.1% removal in 14 and 28 days, respectively). Based upon analysis of the 16s rRNA gene sequence and data base comparison, IsoSL1 and Iso2A were identified as a Streptomyces sp. and Sphingomonas sp., respectively. The Streptomyces sp. is a new genera of bacteria degrading MTBE and could be useful for MTBE bioremediation.
Okeke
Benedict C
BC
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
Frankenberger
William T
WT
D001673:Biodegradation, Environmental; D003470:Culture Media; D020459:Genes, rRNA; D019015:Geologic Sediments / Q000382:microbiology*; D008738:Methyl Ethers / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology; D020578:Sphingomonas / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D013302:Streptomyces / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*
D003470:Culture Media; D008738:Methyl Ethers; D012336:RNA, Ribosomal, 16S; C043243:methyl tert-butyl ether