Milk: Unchanged. Milk agar streak plate: Casein not hj-- drolyzed. Potato: No growth. Indole not produced. Acid but no gas (with peptone as source of nitrogen) from arabinose, xylose and glucose. Ammonium salts not utilized as source of nitrogen. Starch is hydrolyzed. Acetj'lmethylcarbinol not produced. pH of glucose broth cultures is not less than 6.2. Citrates not utilized. Nitrites not produced from nitrates. No gas produced in nitrate broth under anaer- obic conditions. Accessory growth factors essential. Lecithinase reaction doubtful. Urease produced. Aerobic. No growth in glucose broth under anaerobic conditions. Temperature relations: Optimum, be- tween 28° and 33° C. No growth at 45° C. Source: Isolated from soil. Habitat: Probably common in soil. 12. Bacillus polymyxa (Prazmowski, 1880) ^Migula, 1900. {Clostridium polymyxa Prazmowski, Inaug. Diss., Leipzig, 1880, 37; Migula, Syst. d. Bakt., 2, 1900, 638.) po.ly.my'xa. Or. pref. poly- much, many; Gr. noun myxa slime or mucus; M.L. poly- myxa much slime. Rods, 0.6 to 1.0 by 2.0 to 7.0 microns, not in chains. Motile. Gram-variable. Spores, 1.2 to 1.5 by 1.5 to 2.5 microns, ellipsoidal, central to sub-terminal. Spore wall usually thick and easily stained. Freely formed. Sporangia definitely bulged, spindle- shaped or clavate. Gelatin stab: Slow liquefaction. Gelatin agar streak plate: Usually there is a wide zone of hj^drolysis (in the case of widely spreading cultures, the zone of hy- drolysis sometimes extends only slightly beyond the limits of growth). Agar colonies: Usually thin, translucent, spreading, lobate or fimbriate. Rough stage small, round, whitish, sometimes adherent. Agar slants: Growth scant to moderate. restricted or spreading, indistinct to whit- ish. Glucose agar slants: Growth usually much thicker than on agar, raised, glistening, gummy, with production of gas. Variation: Growth thin and not gummy. Glucose nitrate agar slants: Usually good growth, gummy. Proteose-peptone acid agar slants: Good growth, usually no gas. Soybean agar slants: Good growth, usu- ally with the production of gas. Stock culture agar slants: Slightly' heavier grow^th than on agar. No gas. Broth: Turbidity uniform to granular. Gummy sediment. Sometimes a pellicle is formed. NaCl broth: No growth in 5 per cent NaCl. Milk: Usually coagulated with the pro- duction of gas. Milk agar streak plate: Casein hydro- lyzed. Potato: Growth moderate to abundant, slimy, whitish to light tan. Potato decom- posed with the production of gas. Growth of rough strains thicker and heaped up. Indole not produced. Acid and usually gas and gum (with am- monium salts as source of nitrogen) from arabinose, xylose, rhamnose, glucose, lac- tose, mannitol and sorbitol (the production of gas can best be demonstrated by growing the cultures on one of the following media: agar plus 1 per cent potato starch, potato plugs or wheat mash as used for the produc- tion of crystalline dextrins). Starch hydrolyzed. Crystalline dextrins not produced from starch. Hemicellulose and pectin attacked (An- kersmit, Cent. f. Bakt., I Abt., Orig., J^0, 1905, 100). Acetylmethylcarbinol is produced. Eth- anol, butylene-glycol and small amounts of acetone and butanol are also produced. pH of glucose broth cultures is 4.8 to 7.2. Citrates usually not utilized. Methylene blue reduced; not reoxidized in 21 daj'S. Nitrites produced from nitrates. No gas produced in nitrate broth under anaerobic conditions.
