80 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



3. Thiobacillus novellus Starkey. 

 (Jour. Bact., 28, 1934, 365; Jour. Gen. 

 Physiol., 18, 1935, 325; Soil Sci., 89, 

 1935, 207, 210.) From Latin novellus, 

 new . 



Short rods or ellipsoidal cells : 0.4 to 

 0.8 by 0.6 to 1.8 microns. Non-motile. 

 Gram -negati ve . 



Gelatin stab : Mucoid growth at point 

 of inoculation. Sub-surface growth 

 meager. Slow liquefaction. 



Agar plate: Growth slow, colorless, 

 moist, raised, circular, 1 mm in diameter. 

 Deep colonies tiny, lens-shaped. 



Thiosulfate agar plate: Growth slow, 

 becoming white from precipitated sulfur. 

 Surface colonies small, circular, moist. 

 Crystals of CaS04 appear throughout the 

 agar. 



Agar slant: Growth fairly abundant, 

 soft, somewhat ropy, raised, shining, 

 moderately spreading; whitish in re- 

 flected light, brownish opalescence in 

 transmitted light. 



Thiosulfate agar slant : Growth very 

 thin, practically colorless. No sub-sur- 

 face growth. Sulfur usually precipitated 

 as white frosty film on the surface. 



Agar stab : White to cream-colored 

 growth confined close to point of inocula- 

 tion. Penetrates to bottom of tube. 



Thiosulfate agar stab : No appreciable 

 surface growth. 



Broth: Slightly turbid. Gelatinous 

 pellicle. Forms long streamer-like 

 network extending from surface to the 

 bottom. Some sediment. 



Thiosulfate solution medium : Uniform 

 turbidity. No pellicle. Whitish sedi- 

 ment with thin incomplete membrane 

 on the bottom of the flask. Reaction 

 acid in a few days, changes pH 7.8 to 5.8 

 with decomposition of a small quantity 

 of thiosulfate. 



Sulfur solution medium of slightly 

 alkaline reaction: No growth. 



Potato slant: Growth limited, cream- 

 colored, moist, shining, slightly brown. 



Litmus milk: Slow development of 

 slight alkalinity. 



Facultative autotrophic. 



Optimum reaction : Close to neutrality 

 (limiting reactions pH 5.0 to 9.0). 



Aerobic. 



Distinctive characters : Oxidizes thio- 

 sulfate to sulfate and sulfuric acid. Does 

 not oxidize free sulfur. 



Source: Isolated from soils. 



Habitat: Soils. 



4. Thiobacillus coproliticus Lipman 

 and McLces. (Soil Sci., 50, 1940, 432.) 

 Latinized form of the English word copro- 

 lite, fossil dung. 



Long thin rods: 0.1 to 0.2 by 6 to 

 8 (may measure 3 to 40) microns. 

 Straight, S -shaped, and curved cells. 

 Motile by means of a single polar flagel- 

 lum. 



Peptone soil extract agar : Slight 

 growth. 



Nutrient solution : Little or no growth. 



Thiosulfate agar: Slow development. 

 Produces small watery colonies raised 

 above the agar surface. Colonies have 

 been noted which were white from pre- 

 cipitated sulfur. 



Thiosulfate solution: Thiosulfate is 

 oxidized. Little or no turbidity. No 

 pellicle. No sediment. Change in re- 

 action from pH 7.6 to 6.1. 



Sulfur medium: Sulfur is oxidized. 

 No turbidity. 



Facultative autotrophic. 



Aerobic. 



Distinctive characters: Develops in 

 inorganic media and oxidizes thiosulfate 

 and sulfur to sulfate. Media with 

 slightly alkaline reactions most favorable 

 for growth. 



Source : Coprolite rock material from 

 Triassic period (Arizona). 



Habitat : Unknown. 



5. Thiobacillus denitrificans Beijer- 

 inck. (Cent. f. Bakt., II Abt., 11, 1904, 

 597; Sulfomonas denitrificans Orla-Jen- 

 sen. Cent, f . Bakt., II Abt., 22, 1909, 314.) 

 From Latin, de, from; and M.L. nitrifico, 

 to nitrify. 



Short rods, 0.5 by 1 to 3.0 microns long. 

 Motile by means of a single polar flagel- 



