| Rhodococcus |
| Morphology | Rhodococcus |
| CELLULAR |
| Staining | Gram-positive. Partially acid-alcohol fast at some state of growth. |
| Morphology | Rods to extensively branched substrate mycelium may be formed. In all strains the morphogenetic cycle is initiated with the coccus or short rod state, with different organisms showing a succession of more or less complex morphological stages by which the completion of the growth cycle is achieved. Thus, cocci may merely germinate into short rods, form filaments with side projections, show elementary branching or, in the most differentiated forms, produce extensively branched hyphae. The next generation of cocci or short rods are formed by the fragmentation of the rods, filaments, and hyphae. Some strains produce feeble microscopically visible aerial hyphae, which may be branched, or aerial synnemata consisting of unbranched filaments that coalesce and project upward |
| Motility | nonmotile |
| Specialized structures | neither conidia nor endospores |
| Division |
| COLONIAL |
| Solid surface | Colonies may be rough, smooth, or mucoid and pigmented buff, cream, yellow, orange, or red, although colourless variants do occur |
| Liquid |
| Growth Parameters | Rhodococcus |
| PHYSIOLOGICAL |
| Tropism | Chemoorganotrophic |
| Oxygen | Aerobic oxidative type of metabolism |
| pH | |
| Temperature | |
| Requirements | Most strains grow well on standard laboratory media at 30`C, although some require thiamin. use a wide range of organic compounds as sole sources of carbon for energy and growth |
| Products | unable to degrade casein, cellulose, chitin, elastin, or xylan. |
| Enzymes | Catalase positive arylsulfatase negative, |
| Unique features | . Rhodococci are sensitive to lysozyme The cell wall peptidoglycan contains major amounts of meso-diaminopimelic acid (meso- DAP), arabine, and galactose. The organisms contain diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylinositol mannosides, dehydrogenated manaquinones with either eight or nine isoprene units as the major isprenolog, large amounts of straight-chain, unsaturated,and tuberculostearic acids, and mycolic acids with 32-66 carbons and up to four double bonds. The fatty acid esters released on pyrolysis gas chromatography of mycolic esters contain 12-18 carbons. |
| ENVIRONMENTAL |
| Habitat | |
| Lifestyle | |
| Pathogenicity |
| Distribution |
| Genome | Rhodococcus |
| G+C Mol % | 63-72% (Tm) |
| Reference | Rhodococcus |
| First citation | Zopf, W 1889 Uber das Mikrochemische Verhalten
Von Fettfarbstoff-haltigen Orgenen. Z. Wiss Mikrosk 6:
172-177 Bergey's systematic cites Zopf, W. (1891) |
| The Prokaryotes | p |
| Bergey's Systematatic | p 1472 M. Goodfellow |
| Bergey's Determinative | p 626 |
| References |