Genus I. Alcaligenes Castellani and Chahners, 1919* (Manual Trop. Med., 3rd ed., 1919, 936.) Al.ca.li'ge.nes. Arabic al the; Arabic noun gaily the ash of saltwort; French noun alcali alkali; English alkali; Gr. v. gennaio to produce; M.L. mas.n. Alcaligenes alkali-pro- ducing (bacteria). Rods which are either motile by means of peritrichous flagella or non-motile. Gram-neg- ative. May or may not liquefy gelatin and solidified blood serum. Litmus milk turned alka- line, with or without peptonization. Carbohydrates not utilized. Acetylmethylcarbinol not produced. Chromogenesis, when it occurs, is grayish yellow, brownish yellow or yellow. Generally found in the intestinal tracts of vertebrates or in dairy products. The type species is Alcaligenes faecalis Castellani and Chalmers. I. Gelatin not liquefied. A. Motile. B. Non-motile. 1. Produces ropiness in milk. Key to the species of genus Alcaligenes. 1 . A Icaligenes faecalis . 2. Alcaligenes viscolactis. 2. Found in the intestinal tract. 3. Alcaligenes metalcaligenes . II. Gelatin liquefied. A. Motile. 1. Milk peptonized; blood serum liquefied. 4. Alcaligenes bookeri. 2. Milk not peptonized; blood serum not liquefied. 5. Alcaligenes recti. B. Non-motile. 6. Alcaligenes marshallii. 1. Alcaligenes faecalis Castellani and Chalmers, 1919. {Bacillus faecalis alcaligenes Petruschky, Cent. f. Bakt., I Abt., 19, 1896, 187; Bacterium alcaligenes Mez,t Mikro- skopische Wasseranalyse, Berlin, 1898, 63; Castellani and Chalmers, Manual Trop. Med., 1919, 936.) fae.ca'lis. L. noun faex,faecis dregs; M.L. adj. faecalis fecal. Description from Petruschky (op. cit., 1896, 187) as supplemented by Dr. Einar Leifson and Dr. Rudolph Hugh, Loyola University, Chicago, Illinois. Rods, 0.5 by 1.0 to 2.0 microns, occurring singly, in pairs and chains. Normally not encapsulated. Motile by means of peritri- chous flagella. Gram-negative. Gelatin colonies: Circular, grayish, trans- lucent. Gelatin stab: Gray surface growth. No liquefaction. Agar colonies: Opaque, entire, non-chro- mogenic. Agar slant: White, glistening, non-chro- mogenic.
- Revised by Prof. H. J. Conn, New York State Experiment Station, Geneva, New York,
June, 1938; further revision by Prof. Robert S. Breed, New York State Experiment Station, Geneva, New York, October, 1954. t While Mez (1898) proposed the binomial Bacterium alcaligenes earlier than Castellani and Chalmers (1919) proposed the binomial Alcaligenes faecalis, the specific epithet al- caligenes is unusable when the genus Alcaligenes is recognized. The use of the specific epi- thet alcaligenes in the latter genus produces a tautonym, and tautonyms are illegitimate under the Bacteriological Code of Nomenclature (Sect. 5, Rule 18).
