Page:Bergey's manual of determinative bacteriology.djvu/109

 1945. (Austral. Jour. Exper. Biol, and Med. Sci., 23, 1945, 81; also see Jour. Gen. Microbiol., 8, 1953, 344.)

con.cre.ti′vo.rus. L. noun concretum firm or solid matter; L. v. voro to devour or destroy; M.L. part. adj. concretivorus concrete-destroying.

Short, straight rods 0.5 by 1.5 to 2.0 microns with square ends. Stain irregularly, showing deeply stained granules in poorly stained slender rods. Motile, presumably polar flagellate. Motility lost in older cultures. Single polar flagellum, two to three times the length of the organism (unpublished data). Gram-negative.

Thiosulfate agar colonies: Minute, water-clear, whitish yellow on prolonged incubation. No confluent growth.

Thiosulfate liquid medium: Uniform turbidity, slight deposit of sulfur. No pellicle.

Sulfur liquid medium: Uniform turbidity; floating sulfur granules fall to the bottom.

Strictly aerobic.

Temperature relations: Optimum, 28° C.; slow growth at 10° and 37° C.; death occurs at 55° C.

Strictly autotrophic, utilizing atmospheric CO2 as the source of carbon; growth inhibited by higher concentrations of glucose, glycerol and lactate. Derives energy from its oxidation of elemental sulfur, thiosulfate and hydrogen sulfide, oxidizing them ultimately to sulfate and sulfuric acid. Thiosulfate is oxidized with the intermediate production of tetrathionate.

Nitrogen sources: Utilizes ammonium- and nitrate-nitrogen equally well. Nitrate is not toxic whereas nitrite is.

Optimum reaction: Growth occurs between pH 6.0 and acid concentrations up to 10 per cent. Sulfuric acid optimum is between pH 2.0 and 4.0.

Distinctive characters: Responsible for the rapid corrosion of concrete sewers and other concrete structures where the sewer air contains hydrogen sulfide.

Habitat: Corroding concrete in sewers; also found in sewage and presumably in soil and fresh water.

8. Thiobacillus thiooxidans Waksman and Joffe, 1922. (Jour. Bact., 7, 1922, 239.)

thi.o.ox′i.dans. Gr. noun thium sulfur; Gr. adj. oxys sharp, acid; M.L. v. oxido to make acid, to oxidize; M.L. part. adj. thiooxidans oxidizing sulfur.

Short rods: 0.5 by 1.0 micron with rounded ends. Occur singly, in pairs or in chains. Motile by means of a single polar flagellum. Gram-negative (Starkey, Soil Sci., 39, 1935, 210).

Thiosulfate agar: Scant growth. Nearly transparent colonies.

Sulfur broth: Uniform turbidity. No sediment or surface growth. Medium becomes very acid (below pH 1.0).

Thiosulfate broth: Uniform turbidity. Medium becomes acid, and sulfur is precipitated.

Nitrogen sources: Utilizes ammonia-nitrogen but not nitrate-nitrogen, which is toxic. Asparagin, urea and peptone not utilized.

Temperature relations: Optimum, between 28° and 30° C. Slow growth at 18° and 37° C. Death occurs between 55° and 60° C.

Optimum reaction, between pH 2.0 and 3.5. (Limiting reactions, pH 6.0 to less than pH 0.5.)

Strictly autotrophic, deriving its energy from the oxidation of elemental sulfur and thiosulfate, o.xidizing these to sulfuric acid. It utilizes the CO2 of the atmosphere as a source of carbon.

Strictly aerobic.

Distinctive characters: This species produces more acid, from oxidation of sulfur, and continues to live in a more acid medium, than any other living organism yet reported, the hydrogen-ion concentration of the medium increasing to a pH 0.6 and less.

Source: Isolated from composts of soil, sulfur and rock phosphate, and soils containing incompletely oxidized sulfur compounds.

Habitat: Soil.

9. Thiobacillus trautweinii Bergey et al., 1925. (Thionsäurebakterium, Trautwein, Cent. f. Bakt., II Abt., 53, 1921, 513; also see ibid., 61, 1924, 1; Bergey et al.. Manual, 2nd ed., 1925, 39; Bacterium thiogenes Lehmann, in Lehmann and Neumann, Bakt. Diag., 7 Aufl., 2, 1927, 516.)

traut.wein′i.i. M.L. gen. noun trautweinii of Trautwein; named for K. Trautwein, who first isolated and studied this species.