Title A novel methanotroph in the genus Methylomonas that contains a distinct clade of soluble methane monooxygenase
Author Ngoc-Loi Nguyen1, Woon-Jong Yu1, Hye-Young Yang1, Jong-Geol Kim1, Man-Young Jung2, Soo-Je Park3, Seong-Woon Roh4, and Sung-Keun Rhee1*
Address 1Department of Microbiology, Chungbuk National University, Cheongju 28644, Republic of Korea, 2Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria, 3Department of Biology, Jeju National University, Jeju 63243, Republic of Korea, 4World Institute of Kimchi, Gwangju 61755, Republic of Korea
Bibliography Journal of Microbiology, 55(10),775–782, 2017,
DOI 10.1007/s12275-017-7317-3
Key Words methanotroph, Methylomonas, soluble methane monooxygenase, phylogeny
Abstract Aerobic methane oxidation is a key process in the global carbon cycle that acts as a major sink of methane. In this study, we describe a novel methanotroph designated EMGL16-1 that was isolated from a freshwater lake using the floating filter culture technique. Based on a phylogenetic analysis of 16S rRNA gene sequences, the isolate was found to be closely related to the genus Methylomonas in the family Methylococcaceae of the class Gammaproteobacteria with 94.2–97.4% 16S rRNA gene similarity to Methylomonas type strains. Comparison of chemotaxonomic and physiological properties further suggested that strain EMGL16-1 was taxonomically distinct from other species in the genus Methylomonas. The isolate was versatile in utilizing nitrogen sources such as molecular nitrogen, nitrate, nitrite, urea, and ammonium. The genes coding for subunit of the particulate form methane monooxygenase (pmoA), soluble methane monooxygenase (mmoX), and methanol dehydrogenase (mxaF) were detected in strain EMGL16-1. Phylogenetic analysis of mmoX indicated that mmoX of strain EMGL16-1 is distinct from those of other strains in the genus Methylomonas. This isolate probably represents a novel species in the genus. Our study provides new insights into the diversity of species in the genus Methylomonas and their environmental adaptations.