Ochrobactrum

Abstract

O.chro.bac' trum . Gr. adj. ochros pale, colorless; Gr. neut. n. baktron a staff or stick; M.L. neut. n. Ochrobactrum a colorless rod. Proteobacteria / Alphaproteobacteria / Rhizobiales / Brucellaceae / Ochrobactrum Rods with parallel sides and rounded ends , typically 1 . 0 × 1 . 5–2 . 0 µm ; shorter oval forms, 1.0–1.5 µm in length, may occur. Cells usually occur singly. Gram negative . Motile by means of peritrichous flagella. Obligately aerobic , having a strictly respiratory type of metabolism. Optimal growth temperature in the range 20–37°C. Colonies on nutrient agar are smooth, low convex, and translucent (opaque and mucoid, quickly becoming confluent in O . tritici ). Chemoorganotrophic, using a variety of amino acids, organic acids, and carbohydrates as carbon sources. Acid is produced from glucose, arabinose, ethanol, fructose, rhamnose, and xylose. Oxidase positive . Catalase positive . Indole is not formed. Nitrates usually reduced . Growth occurs on MacConkey agar. Urease usually positive. Ornithine decarboxylase (ODC) negative. Occur in human clinical specimens, also in soil samples and wheat roots. Parameters of DNA–rRNA hybrids indicate that Ochrobactrum belongs to the Brucella branch within rRNA superfamily IV. 16S rRNA gene sequence analysis places Ochrobactrum in the group of bacteria known as the α‐2 subclass of the Proteobacteria . At the suprageneric level, Ochrobactrum is related to Brucella , Phyllobacterium , Rhizobium , and Agrobacterium . The mol % G + C of the DNA is : 56–59. Type species : Ochrobactrum anthropi Holmes, Popoff, Kiredjian and Kersters 1988, 412.