1. Zymobacterium oroticum Wachs- man and Barker, 1954. (Jour. Bact., 68, 1954, 400.) o.ro'ti.cum. M.L. noun acidum oroticxiyn orotic acid; M.L. adj. oroticus orotic. Rods, 0.35 to 0.60 by 1.2 to 2.0 microns, with tapering ends, usually occurring in long, intertwined chains. Non-motile. Gram-positive. Gelatin: No liquefaction. Tryptone-glucose-yeast extract agar col- onies: Small, round, convex. Tryptone-glucose-yeast extract broth: In young cultures the cells are character- istically short rods with tapering ends, be- coming ovoid in old cultures. Orotic acid-basal medium; Morphologi- cally, the cells are similar to those described directly above. Milk: No growth. Indole not produced. Acid and gas (in 3 to 5 days) from glucose, fructose, sucrose, lactose, maltose, arabi- nose, galactose and mannitol. Lactic and glutamic acids and glycerol not utilized. Glucose fermentation yields predomi- nantly ethanol (1.3 moles per mole of glu- cose) and carbon dioxide with small amounts of acetic and possibly lactic and formic acids. The maximum level of ethanol pro- duction has not 3'et been determined; how- ever, the level must be quite low since glucose is fermented slowly, even under optimum conditions. Orotic acid fermented with the production of ammonia. Starch not hydrolj^zed. Nitrites not produced from nitrates. Catalase-negative. Anaerobic to microaerophilic. Source: Isolated from bay mud. Habitat: Unknown. FAMILY XII. CORYNEBACTERIACEAE LEHMANN AND NEUMANN, 1907.* (Bakt. Diag., 4 Aufl., £, 1907, 500.) Co.ry.ne.bac.te.ri.a'ce.ae. M.L. neut.n. Corynebacterium type genus of the family; -aceae ending to denote a family; M.L. fem.pl. n. Corynebacteriaceae the Corynebacterium family. Usually non-motile rods, frequently banded or beaded with metachromatic granules. May show marked diversity of form. Branching cells have been described in a few species, but these are very uncertain. Generally Gram-positive, some species being partially decolor- ized more easily than others. Where pigment is formed, it is grayish yellow or orange or pink. Gelatin may be liquefied. Nitrites may be produced from nitrates. Aerobic to micro- aerophilic; a few species are anaerobic. Animal and plant parasites and pathogens; also found in dairy products and soil. Key to the genera of family Corynebacteriaceae. I. Primaril}^ pathogenic on animals and plants. A. Aerobic to anaerobic, pleomorphic rods that show the characteristic arrangement produced by snapping division. 1. Animal species are non-motile, but some of the plant pathogens are motile. Genus I. Corynebacterium, p. 579. 2. Animal species are motile by means of peritrichous flagella. Causes a monocytosis in warm-blooded animals, including man. Genus II. Listeria, p. 597. B. Microaerophilic rods to long filaments. Non-motile. Genus III. Erysipelothrix, p. 599.
- Definition and key with arrangement of genera in family prepared by Prof. Robert S.
Breed, Cornell University, Geneva, New York, November, 1954.
