Methylarcula

Abstract

Me.thyl.ar.cu' la. Fr. méthyle the methyl radical; L. fem. n. arcula small box; M.L. fem. n. Methylarcula methyl‐using small box. Proteobacteria / Alphaproteobacteria / Rhodobacterales / Rhodobacteraceae / Methylarcula Rods 0 . 5–0 . 8 × 0 . 8–2 . 0 μ m . Nonmotile . Gram negative. Poly ‐β‐ hydroxybutyrate granules are formed . Endospores and prosthecae are not formed. Colonies are white or pale pink. Do not produce pyocyanin and fluorescein. Aerobic , having a strictly respiratory type of metabolism with oxygen as the terminal electron acceptor. Moderately halophilic ; NaCl is required for growth. Ectoine is accumulated intracellularly as the main osmoprotectant. Growth does not occur on peptone/yeast extract medium, with or without NaCl. Nitrate is not reduced to nitrite. Chemoorganotrophic. Facultatively methylotrophic . Assimilate C 1 compounds via the isocitrate lyase‐negative ( icI − ) serine pathway . Methylamine , sugars , and some organic acids are used as carbon and energy sources . Ammonium salts, some amino acids, and methylamine are used as nitrogen sources. Growth factors are not required. Oxidase positive . Acids are produced from sugars oxidatively. Acetoin, hydrogen sulfide, and ammonium are not formed. Indole is formed from l ‐tryptophan. The major ubiquinone is Q‐10. The dominant phospholipids are phosphatidylethanolamine and phosphatidylcholine. The predominant cellular fatty acids are straight‐chain unsaturated (C 18:1 ), saturated (C 18:0 ), and cyclopropane (C 19:0 ) acids. Belongs to the Alphaproteobacteria . The mol % G + C of the DNA is : 57–60. Type species : Methylarcula marina Doronina, Trotsenko and Tourova 2000a, 1858.