Identifikasi Bakteri Pengoksidasi Metana dan Gen Fungsional Isolat dari Tanah Sawah dan Gambut

Abstract

Methane is one of green house gases. Methanotrophic bacteria can use methane as their carbon sources, therefore this bacteria has important role to reduce methane emission from soil and wet land. This research aim to isolate methane oxidizing bacteria and identify genes responsible for methane oxidation. Seven isolates of methanotrophic bacterias (AM1, AM2, AM3, AM4, AM5, AM6, dan AM7) were isolated from rice field and wet land through sub-culture in NMS (nitrate mineral salts) added by methane gases method. All of isolates could use 15 mL of methane gases at the third weeks of incubation and 0,7 mL per day in average. Identification of methane monooxygenase (pmoA) gene used two sets primer, 189f - 682r and 189f - 650r. The results showed isolates AM1, AM2, AM4, AM5, and AM6 had pmoA genes. All of the isolates also had functional methanol dehydrogenase (mxaF) gene. The result of 16S rRNA and blast analysis confirmed that six isolates were identified as Methylocystis and one isolate was Mesorhizobium. Phylogenetic analysis shows all strains would be novel species.