sp. nov., sp. nov., sp. nov. and sp. nov., type I methane-oxidizing bacteria isolated from a freshwater creek and the deep terrestrial subsurface.

Four methane-oxidizing bacteria, designated as strains WSC-6, WSC-7, SURF-1, and SURF-2, were isolated from Saddle Mountain Creek in southwestern Oklahoma, USA, and the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. The strains were Gram-negative, motile, short rods that possessed intracytoplasmic membranes characteristic of type I methanotrophs. All four strains were oxidase-negative and weakly catalase-positive.