Gelatin: Liquefied.
Beef extract agar colonies: Small, circular, smooth, flat or raised with regular margins, white to pale yellow.
Beef broth: Moderate clouding.
Milk: Clearing after coagulation. Litmus red.
Uschinsky's solution: Good growth.
Cohn's solution: Poor growth.
Potato: Growth smooth, copious and olive-buff.
Nitrites produced from nitrates.
Indole produced.
Hydrogen sulfide produced.
Acid and gas from glucose, sucrose and glycerol. Acid from lactose.
Starch hydrolyzed.
Temperature relations: Optimum, 32° C. Growth above 36° C. and below 2° to 8° C.
Optimum pH, between 6 and 7; no growth below pH 3.
Aerobic.
Relationship to other species: This species closely resembles the species placed in Aeromonas Kluyver and van Niel.
Source: Isolated from leaf spot of Jimson weed. Datura spp.
Habitat: Pathogenic on Datura metel, D. meteloides, D. inermis, tomato and petunia.
20. Xanthomonas holcicola (Elliott, 1930) Starr and Burkholder, 1942. (Bacterium holcicola Elliott, Jour. Agr. Res., 40, 1930, 972; Starr and Burkholder, Phytopath. 32, 1942, 600.)
hol.ci'co.la. Gr. holcus kind of grass; M.L. mas.n. Holcus generic name of velvet grass and sorghum; L. v. cola to dwell; M.L. fem.n. holcicola, Holcus dweller.
Rods 0.75 by 1.58 microns. Motile with 1 or 2 polar flagella. Encapsulated. Gram-negative.
Gelatin: Liquefied.
Beef-infusion peptone agar colonies: Round, umbonate, glistening, smooth, translucent to opaque, wax-yellow, butyrous.
Broth: Trace of growth in 24 hours. Later turbid with a slight ring.
Milk: Casein precipitated and peptonized. Alkaline.
Nitrite production doubtful.
Indole not produced.
Hydrogen sulfide produced.
Lipolytic (Starr and Burkholder, loc. cit.).
Acid but no gas from sucrose.
Starch hydrolyzed.
Temperature relations: Optimum, between 28° and 30° C. Minimum, 4° C. Maximum, between 36° and 37° C.
pH range for growth: pH 5.5 to 9.0. Optimum pH, between 7.0 and 7.5.
Source: Isolated from many collections of sorghum leaves showing a streak disease.
Habitat: Pathogenic on leaves of Holcus sorghum and H. halepensis.
21. Xanthomonas incanae (Kendrick and Baker, 1942) Starr and Weiss, 1943. (Phytomonas incanae Kendrick and Baker, California Bull. 665, 1942, 10; Starr and Weiss, Phytopath., 33, 1943, 316.)
in.ca'nae. L. adj. incanus hoary, gray; from host Matthiola incana.
Rods 0.4 to 0.8 by 0.6 to 2.5 microns. Motile with a polar flagellum. Gram-negative.
Gelatin: Liquefied.
Beef extract agar colonies: Round, smooth, convex or pulvinate, glistening, margin entire, picric-yellow to amber color.
Broth: Turbid.
Milk: No coagulation. A clearing of the medium.
Nitrites not produced from nitrates.
Indole not produced.
Lipolytic (Starr and Burkholder, Phytopath., 32, 1942, 600).
Acid but no gas from glucose, lactose, sucrose, mannitol, d-galactose, xylose, d-mannose, raffinose, trehalose and glycerol. No acid from maltose, l-arabinose or rhamnose.
Starch not hydrolyzed. Starch hydrolyzed (Burkholder).
Pectate medium liquefied.
Tolerates 3 per cent salt.
Growth in beef broth at pH 4.4.
Aerobic.
Distinctive characters: Causes a disease of flowering stock but not of cabbage. Differs from Xanthomonas campestris in that it does not utilize l-arabinose or maltose.
Source: Four isolates from diseased plants of Matthiola incana.
