Stenotrophomonas maltophilia isolated from gasoline-contaminated soil is capable of degrading methyl tert-butyl ether

Background: Methyl tert-butyl ether (MTBE) is a pollutant that causes deleterious effects on human and environmental health. Certain microbial cultures have shown the ability to degrade MTBE, suggesting that a novel bacterial species capable of degrading MTBE could be recovered. The goal of this study was to isolate, identify and characterize the members of a bacterial consortium capable of degrading MTBE. Results: The IPN-120526 bacterial consortium was obtained through batch enrichment using MTBE as the sole carbon and energy source. The cultivable fraction of the consortium was identified; of the isolates, only Stenotrophomonas maltophilia IPN-TD and Sphingopyxis sp. IPN-TE were capable of degrading MTBE. To the best of our knowledge, this report is the first demonstrating that S. maltophilia and Sphingopyxis sp. are capable of degrading MTBE. The degradation kinetics of MTBE demonstrated that S. maltophilia IPN-TD had a significantly higher overall MTBE degradation efficiency and rate (48.39 \ub1 3.18% and 1.56 \ub1 0.12 mg L-1 h-1, respectively) than the IPN-120526 consortium (38.59 \ub1 2.17% and 1.25 \ub1 0.087 mg L-1 h-1, respectively). The kinetics of MTBE removal by both cultures fit first-order and pseudo-first-order reaction models. Conclusions: These findings suggest that S.maltophilia IPN-TD in axenic culture has considerable potential for the detoxification of MTBE-contaminated water

Biodegradation of Methyl Tertiary Butyl Ether (MTBE) by a Microbial Consortium in a Continuous Up-Flow Packed-Bed Biofilm Reactor: Kinetic Study, Metabolite Identification and Toxicity Bioassays - Fig 2

<p>Scanning electron micrographs of <i>tezontle</i> stones (A) without biofilm (60×) and (B–D) with biofilm (60×, 5000×, and 8000×).</p

Dependence of specific removal rate on volumetric loading rate.

<p>(A) MTBE; (B) COD.</p

Relative germination percentage (RG%), relative growth index (RGI) and germination index (GI) averages and toxicity categories of influent and effluent samples.

<p>Relative germination percentage (RG%), relative growth index (RGI) and germination index (GI) averages and toxicity categories of influent and effluent samples.</p

Toxicity tests on bacterial strains of influent and effluents at different hydraulic retention times.

<p>Toxicity tests on bacterial strains of influent and effluents at different hydraulic retention times.</p

Relative abundance of bacterial strains that constitute IPN-120526 consortium in the inoculum and in the packed-bed bioreactor

<p>Relative abundance of bacterial strains that constitute IPN-120526 consortium in the inoculum and in the packed-bed bioreactor</p

Biomass immobilized on <i>tezontle</i> stone particles and MTBE and COD concentrations of effluents at different hydraulic retention times.

<p>Biomass immobilized on <i>tezontle</i> stone particles and MTBE and COD concentrations of effluents at different hydraulic retention times.</p

Dependence of volumetric removal rate on volumetric loading rate.

<p>(A) MTBE; (B) COD.</p

MTBE- and COD-removal efficiency at different hydraulic retention times.

<p>MTBE- and COD-removal efficiency at different hydraulic retention times.</p

Stenotrophomonas maltophilia isolated from gasoline-contaminated soil is capable of degrading methyl tert-butyl ether

Background: Methyl tert-butyl ether (MTBE) is a pollutant that causes deleterious effects on human and environmental health. Certain microbial cultures have shown the ability to degrade MTBE, suggesting that a novel bacterial species capable of degrading MTBE could be recovered. The goal of this study was to isolate, identify and characterize the members of a bacterial consortium capable of degrading MTBE. Results: The IPN-120526 bacterial consortium was obtained through batch enrichment using MTBE as the sole carbon and energy source. The cultivable fraction of the consortium was identified; of the isolates, only Stenotrophomonas maltophilia IPN-TD and Sphingopyxis sp. IPN-TE were capable of degrading MTBE. To the best of our knowledge, this report is the first demonstrating that S. maltophilia and Sphingopyxis sp. are capable of degrading MTBE. The degradation kinetics of MTBE demonstrated that S. maltophilia IPN-TD had a significantly higher overall MTBE degradation efficiency and rate (48.39 ± 3.18% and 1.56 ± 0.12 mg L-1 h-1, respectively) than the IPN-120526 consortium (38.59 ± 2.17% and 1.25 ± 0.087 mg L-1 h-1, respectively). The kinetics of MTBE removal by both cultures fit first-order and pseudo-first-order reaction models. Conclusions: These findings suggest that S. maltophilia IPN-TD in axenic culture has considerable potential for the detoxification of MTBE-contaminated water