Agar slants: Growth variable, ranging from thin, scant, rough and non -spreading to good, opaque, smooth and spreading. Glucose agar slants: Growth usually less than on agar. Glucose asparagine agar slants: Growth variable. Proteose-peptone acid agar slants: No growth. Soybean agar slants: Growth, if any, less than on agar. Stock culture agar slants : Growth usually less than on agar. Broth: Turbidity usually uniform. NaCl broth: Scant, if any, growth in 3 per cent NaCl. Milk agar streak plate: Hydrolysis of casein variable. Tomato yeast milk: Not coagulated in .3 days at 45° to 50° C. (Gordon and Smith, Jour. Bact., 58, 1949, 327). Coagulated at 65° C. (Stark and Tetrault, Sci. Agr., 32, 1952, 81). Potato: Scant, if any, growth. Indole not produced. Acid but no gas (with peptone as source of nitrogen) from glucose. Acid production variable from arabinose and xylose. With ammonium salts as a source of nitrogen, acid production is variable from glucose. Starch is hydrolyzed. Acetjdmethylcarbinol not produced. pH of glucose broth cultures is 4.5 to 6.6. Citrates usually not utilized. Nitrites usually produced from nitrates. Nitrites not produced from nitrates (Donk). Usually no gas produced in nitrate broth under anaerobic conditions. Aerobic, facultatively anaerobic. Usually there is growth in glucose broth under ana- erobic conditions. Temperature relations: Optimum, be- tween 50° and 65° C. Growth variable at 70° C. and 37° C. No growth at 28° C. Source: Isolated from spoiled canned corn and string beans. Habitat: Widely distributed in soil and spoiled food products. 16. Bacillus circulans Jordan, 1890, emend. Ford, 1916. (Jordan, Mass. State Board of Health, Exp. Invest., pt. 2, 1890, 831; Ford, Jour. Bact., 1, 1916, 519.) cir'cu.lans. L. part. adj. circulans circling, making round. Rods, 0.5 to 0.7 by 2.0 to 5.0 microns, some slightly bent, with ends rounded or pointed, usually not in chains. Usually actively motile. Gram-negative. Variations: 0.4 to 0.9 by 1.5 to 5.0 microns. Contain metachro- matic granules. Encapsulated. Spores, 0.8 to 1.4 by 1.1 to 2.4 microns, ellipsoidal, terminal to sub-terminal. Spore wall thick and easily stained. Variations: Kidney-shaped or cylindrical. Lateral or central. Thin-walled. Sporangia definitely swollen and clavate. Gelatin stab: Slow, cone-shaped lique- faction, liquefied portion evaporating (Jor- dan); no liquefaction (Ford). Gelatin agar streak plate : Usually a zone of hydrolj'sis is visible. Agar colonies: Thin, spreading, trans- lucent to transparent, sometimes barely visible or small to medium in size, opaque, entire. Giant colonies: Sometimes there are mo- tile micro-colonies which move from the point of inoculation in a rotating pattern, eventually covering the entire plate (poured agar plates should be allowed to stand 2 or 3 days at room temperature in order to dry the surface somewhat before using). Agar slants: Growth scant, thin, spread- ing, often indistinct. Variations: Growth moderate, entire, dense, coherent. Beef extract agar slants (without pep- tone) : Sporulation usually better than on agar. Glucose agar slants : Growth usually heav- ier than on agar. Variations: Very gummy, opaque. Less growth than on agar. Proteose-peptone acid agar slants: Usu- ally no growth. Soybean agar slants: Growth, if any, less than on agar. Broth: Turbidity light to fair. Sediment flocculent to slimy. No growth by a few strains. NaCl broth: No growth by some strains in 2 per cent NaCl. Growth by other strains in 5 per cent. No grow^th in 7 per cent. Milk: Usually acid; slowly coagulated.
