Broth: Turbid; thin pellicle; viscid sedi- ment. Gives off ammonia. Litmus milk: Alkaline. No other detecta- ble changes. Potato: Scant to abundant, yellowish to brownish growth. No detectable acid or gas produced from carbohydrates. Indole not produced. Nitrites may or may not be produced from nitrates. Urea not hydrolyzed. The growth of this species has been tested on 18 amino acids, 12 aliphatic amines, 4 amides, 5 miscellaneous organic nitrogen compounds and 3 inorganic nitrogen com- pounds. Only aspartic acid, asparagine, histidine and glutathione supported suffi- cient continued growth to give appreciable turbidity in broth and a final pH close to 8.0. Almost all of the aliphatic amines were toxic (Denault, Cleverdon and Kulp, Jour. Bact., 66, 1953, 465). No characteristic odor. Aerobic. Optimum temperature, between 25° and 37° C. Relationships to other species: This pe- ritrichous organism is very frequently con- fused with a polar flagellate organism having almost identical characters. The polar flagellate species has been placed in the genus Vibrio. See discussions under Vibrio percolans Mudd and Warren and Vibrio alcaligenes Lehmann and Neumann. Source: Isolated from feces, abscesses related to the intestinal tract and occasion- ally from the blood stream. Miles (Jour. Gen. Microbiol., 4, 1950, 434) reports that an organism having all the characteristics of this species caused a fatal red leg in a batch of European tree-frogs (Hyla arborea L.) received at the London Zoological Gar- dens. Habitat: Less commonly found in the intestine than is Vibrio alcaligenes Leh- mann and Neumann. Widely distributed in decomposing organic matter. Generally considered to be non-pathogenic. 2. Alcaligenes viscolactis (Mez, Breed, comb, nov.* {Bacillus lactis viscosus Adametz, Milchztg., 18, 1889, 941; also see Landwirtschl. Jahrb., £0, 1891, 185; and Cent. f. Bakt., 9, 1891, 698; Mez, Mikros- kopische Wasseranalyse, Berlin, 1898, 61; Alcaligenes viscosiis Weldin, Iowa State Coll. Jour. Sci., 1, 1927, 186.) vis.co.lac'tis. L. noun viscum glue, bird- lime; L. gen. noun lactis of milk; M.L. viscolactis of slimy milk. Description taken from Long and Ham- mer (Iowa State Coll. Jour, of Sci., 10, 1936, 262), supplemented by Dr. Rudolph Hugh, Loyola University, Chicago, Illinois. Rods, 0.6 to 1.0 by 0.8 to 2.6 microns, occurring singly, in pairs or in short chains. Frequently found as almost spherical cells. Non-motile. Capsules produced in milk cultures. Gram-negative. Gelatin colonies: Small, gray becoming yellowish. Gelatin stab : White surface growth, some- times with villous growth in stab. No lique- faction. Agar colonies: After 3 to 4 days, circular, 4 to 6 mm in diameter, white, viscid, shin- ing, entire. Agar slant: Abundant, white, spreading, viscid, shining growth. Broth: Turbid with thin pellicle and some sediment. Ropiness generally pro- duced. Litmus milk: Ropiness produced. Pellicle formed. Alkaline. No coagulation. Potato: Moderatel}^ heavy, dirty white, spreading, shining growth. Indole not produced. Hydrogen sulfide not produced. Acid production from carbohydrates slight, if at all. Lipolytic. Methyl red test negative. Acetylmethylcarbinol not produced.
- The discovery that Mez (1898) used a binomial for this species before Weldin did in
1927 has made it necessary to propose a new combination. The specific epithet viscolactis, which is derived directly from the epithets in the original trinomial. Bacillus lactis viscosus Adametz, 1889, is in reality to be preferred over the much-used epithet viscosus. In the genus Bacterium, in which Alcaligenes viscolactis is frequently placed, the epithet viscosum has been applied to at least five quite different species of bacteria.
