General Information: This species was isolated from tissue cultures of Populus, the Poplar tree. Colonies are pink to red, and the red pigment is water insoluble. Species of the genus Methylobacterium are strictly aerobic, facultatively methylotrophic, Gram-negative, rod-shaped bacteria that are able to grow on one-carbon compounds (e.g. methanol or methylamine), as well as on a variety of C2, C3 and C4 substrates. Only the type species, Methylobacterium organophilum, has been shown to use methane as the sole source of carbon and energy. Members of the genus are distributed in a wide variety of natural and man-made environments, including soil, air, dust, fresh- and marine water and sediments, water supplies, bathrooms, air-conditioning systems and masonry, and some are opportunistic human pathogens.