Effect of substrate interaction on oxidation of methane and benzene in enriched microbial consortia from landfill cover soil

Abstract

The interaction of methane and benzene during oxidation in enriched methane-oxidizing consortium (MOC) and in benzene-oxidizing consortium (BOC) from landfill cover soil was characterized. Oxidation of both methane and benzene occurred in the MOC due to the coexistence of bacteria responsible for benzene oxidation, as well as methanotrophs, whereas in the BOC, only benzene was oxidized, not methane. Methane oxidation rates in the MOC were decreased with increasing benzene/methane ratio (mol/mol), indicating its methane oxidation was inhibited by the benzene coexistence. Benzene oxidation rates in the MOC, however, were increased with increasing benzene/methane ratio. The benzene oxidation in the BOC was not affected by the coexistence of methane or by the ratio of methane/benzene ratio (mol/mol). No effect of methane or benzene was found on the dynamics of functional genes, such as particulate methane monooxygenase and toluene monooxygenase, in association with oxidation of methane and benzene in the MOC and BOC.

Keywords:

• Methane
• benzene
• biodegradation
• particulate methane monooxygenase (pmoA)
• toluene monooxygenase (tmoA)
• interaction

Acknowledgments

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) (NRL program, R0A-2008-000-20044-0). It was also supported through the Advanced Environmental Biotechnology Research Center at Pohang University of Science and Technology (2009-0079504) by the NRF, MEST.

Notes

^aInjection amount per serum bottle.

¹Unit, μmol·g-biomass⁻¹·h⁻¹.

²Unit, μmol·mL⁻¹·d⁻¹.

³N.D., not determined.

¹Unit, μmol·g-biomass⁻¹·h⁻¹.

²Unit, μmol·mL⁻¹·d⁻¹.

³N.D., not determined.