Methylotrophs are a diverse group of microorganisms that can use reduced one-carbon compounds, such as methanol or methane, as the carbon source for their growth; and multi-carbon compounds that contain no carbon-carbon bonds, such as dimethyl ether and dimethylamine. This group of microorganisms also includes those capable of assimilating reduced one-carbon compounds by way of carbon dioxide using the ribulose bisphosphate pathway. These organisms should not be confused with methanogens which on the contrary produce methane as a by-product from various one-carbon compounds such as carbon dioxide. Some methylotrophs can degrade the greenhouse gas methane, and in this case they are called methanotrophs. The abundance, purity, and low price of methanol compared to commonly used sugars make methylotrophs competent organisms for production of amino acids, vitamins, recombinant proteins, single-cell proteins, co-enzymes and cytochromes.
Pink-Pigmented Facultative Methylotrophs, commonly abbreviated to PPFMs, are bacteria that are members of the genus Methylobacterium and are commonly found in soil, dust, various fresh water supplies and on plant surfaces. Although Gram negative, Methylobacteria often stain gram variable and are easily isolated using methanol-based mineral medium. Their pigmentation, which is frequently pink but may also be yellow or orange, is thought to provide protection from solar UV radiation which damages the DNA of bacteria at low doses because of their small cell size. This color is present due to the carotenoid pigments within the cell.
Methylorubrum extorquens is a Gram-negative bacterium. Methylorubrum species often appear pink, and are classified as pink-pigmented facultative methylotrophs, or PPFMs. The wild type has been known to use both methane and multiple carbon compounds as energy sources. Specifically, M. extorquens has been observed to use primarily methanol and C1 compounds as substrates in their energy cycles. It has been also observed that use lanthanides as a cofactor to increase its methanol dehydrogenase activity
Methylocella silvestris is a bacterium from the genus Methylocella spp which are found in many acidic soils and wetlands. Historically, Methylocella silvestris was originally isolated from acidic forest soils in Germany, and it is described as Gram-negative, aerobic, non-pigmented, non-motile, rod-shaped and methane-oxidizing facultative methanotroph. As an aerobic methanotrophic bacteria, Methylocella spp use methane (CH4), and methanol as their main carbon and energy source, as well as multi compounds acetate, pyruvate, succinate, malate, and ethanol. They were known to survive in the cold temperature from 4° to 30° degree of Celsius with the optimum at around 15° to 25 °C, but no more than 36 °C. They grow better in the pH scale between 4.5 to 7.0. It lacks intracytoplasmic membranes common to all methane-oxidizing bacteria except Methylocella, but contain a vesicular membrane system connected to the cytoplasmic membrane. BL2T (=DSM 15510T=NCIMB 13906T) is the type strain.
Hyphomicrobium sulfonivorans is a bacterium from the genus of Hyphomicrobium which was isolated from garden soil in Warwickshire in England.
Arthrobacter methylotrophus is a bacterium species from the genus Arthrobacter which has been isolated from soil around the roots of the plant Tagetes minuta.
Methylobacterium gossipiicola is a Gram-negative, aerobic, facultatively methylotrophic bacteria from the genus of Methylobacterium which has been isolated from cotton in Coimbatore in India.
Methylobacterium jeotgali is a Gram-negative, strictly aerobic, motile and rod-shaped bacteria from the genus of Methylobacterium which has been isolated from fermented seafood jeotgal in Korea.
Methylobacterium marchantiae is a facultatively methylotrophic facultative methylotrophy bacteria from the genus of Methylobacterium which has been isolated from the moos Marchantia polymorpha in Bergpark Wilhelmshöhe near Kassel in Germany.
Methylobacterium oryzae is a facultatively methylotrophic and aerobic bacteria from the genus of Methylobacterium which has been isolated from tissues of the rice plant Oryza sativa in Cheongwon in Korea. Methylobacterium oryzae can utilize 1-aminocyclopropane 1-carboxylate. Methylobacterium oryzae can promote plant growth.
Methylobacterium persicinum is a facultatively methylotrophic and aerobic bacteria from the genus of Methylobacterium which has been isolated from the rice plant Oryza sativa in Iksan in Korea.
Methylobacterium phyllostachyos is a Gram-negative, non-spore-forming, aerobic and facultatively methylotrophic bacteria from the genus Methylobacterium which has been isolated from the surface of a bamboo leaf.
Methylorubrum podarium is a Gram-negative bacteria from the genus Methylorubrum which has been isolated from a human foot in the United Kingdom.
Methylorubrum salsuginis is a facultatively methylotrophic bacteria from the genus Methylorubrum which has been isolated from seawater.
Methylobacterium thuringiense is a Gram-negative, aerobic, facultatively methylotrophic and rod-shaped bacteria from the genus of Methylobacterium.
Methylobacterium trifolii is a Gram-negative, aerobic, facultatively methylotrophic and rod-shaped bacteria from the genus of Methylobacterium.
Methylorubrum suomiense is a facultatively methylotrophic and aerobic bacteria from the genus Methylorubrum which has been isolated from forest soil in Finland.
Methylorubrum pseudosasae is a Gram-negative, aerobic, facultatively methylotrophic bacteria from the genus Methylorubrum which has been isolated from bamboo leaves.
Methylophaga thiooxydans is a methylotrophic bacterium that requires high salt concentrations for growth. It was originally isolated from a culture of the algae Emiliania huxleyi, where it grows by breaking down dimethylsulfoniopropionate from E. hexleyi into dimethylsulfide and acrylate. M. thiooxydans has been implicated as a dominant organism in phytoplankton blooms, where it consumes dimethylsulfide, methanol and methyl bromide released by dying phytoplankton. It was also identified as one of the dominant organisms present in the plume following the Deepwater Horizon oil spill, and was identified as a major player in the breakdown of methanol in coastal surface water in the English channel.
Ann Patricia Wood is a retired British biochemist and bacteriologist who specialized in the ecology, taxonomy and physiology of sulfur-oxidizing chemolithoautotrophic bacteria and how methylotrophic bacteria play a role in the degradation of odour causing compounds in the human mouth, vagina and skin. The bacterial genus Annwoodia was named to honor her contributions to microbial research in 2017.
