Rapid Methods for Isolation and Screening of Methane Degrading Bacteria

Abstract

There are only few microbial strains available world over having capacity to degrade methane due to lack of rapid methodology for their isolation and efficiency studies. In present study we have isolated five methane degrading bacterial strains by enrichment of soil samples in the flasks containing methane as sole source of carbon in its head space and water as basal medium. Moreover their survival in the evacuated tubes containing methane and presence of soluble methane monooxygenase enzyme by colorimetric plate assay was studied which represents a simplest method of screening of methane utilizing microbial strains as compared to conventional gas liquid chromatographic technique as well as enzymatic assay and molecular detection of the genes encoding methane monooxygenase and methanol dehydrogenase genes. In addition to this presence of a key methane metabolism enzyme methane monooxygenase and ethanol dehydrogenase enzyme was confirmed by detection of genes encoding the enzymes as well as qualitative detection of the enzyme activities in the isolates to provide strong support to the methane degrading capacity of the isolates and to validate the method used in this study to isolate methanotrophs.