Distinctive characters: Develops in inorganic media and oxidizes thiosulfate and sulfur to sulfate. Media with slightly alkaline reactions most favorable for growth.
Source: Isolated from coprolite rock material from Triassic period (Arizona).
Habitat: Unknown.
5. Thiobacillus denitrificans Beijerinck, 1904. (Beijerinck, Cent. f. Bakt., II Abt., 11, 1904, 597; Sulfomonas denitrificans Orla-Jensen, Cent. f. Bakt., II Abt., 22, 1909, 314.)
de.ni.tri′fi.cans. L. pref. de off, removed; M.L. noun niter saltpeter, nitrate; M.L. v. nitrifico to make nitrate, to nitrify; M.L. denitrifico to denitrify; M.L. part. adj. denitrificans denitrifying.
Short rods, 0.5 by 1 to 3 microns. Motile by means of a single polar flagellum (Tjulpanova-Mossevitch, Arch. d. Sci. Biol., U.S.S.R., 30, 1930, 203).
Inorganic broth: Growth with production of gas, predominantly nitrogen.
Thiosulfate agar colonies: Thin; clear or weakly opalescent.
Optimum reaction: Neutral or slightly alkaline.
Autotrophic, utilizing carbon from CO2, carbonates and bicarbonates. Considered to be strictly autotrophic by Lieske (Ber. d. deutsch. botan. Gesell., 30, 1912, 12) and facultatively by Tjulpanova-Mossevitch (op. cit., 30, 1930, 203). Beijerinck stated (Kon. Akad. v. Wetenschappen Amsterdam, 42, 1920, 899) that whereas the organism developed initially in an inorganic medium, it lost the autotrophic habit by cultivation in an organic medium.
Facultatively anaerobic. Can live in the absence of free O2 in the presence of nitrate.
Distinctive characters: Oxidizes thiosulfate to sulfate under anaerobic conditions using nitrate as the hydrogen acceptor which is reduced to N2 . Also oxidizes sulfide, elemental sulfur and dithionate.
Habitat: Canal and river water, salt water, soil, peat, composts and mud.
6. Thiobacillus neapolitanus Parker, nom. nov. (Neue Gruppe von Schwefelbakterium, Nathansohn, Mitt. Zool. Sta., Neapel, 15, 1902, 655; Thiobacillus X, Parker, Jour. Gen. Microbiol., 8, 1953, 344.)
ne.a.po.li.ta′nus. L. adj. neapolitanus pertaining to Naples.
Short rods, 0.5 by 1.0 to 1.5 microns. Non-motile. Gram-negative.
Thiosulfate agar colonies: Small (1 to 2 mm in diam.) circular, convex; whitish yellow due to precipitated sulfur.
Thiosulfate liquid medium; Uniform turbidity with pellicle which contains free sulfur. pH drops to 3.0.
Sulfur liquid medium: Very slight, uniform turbidity.
Optimum pH, about 6.0; growth occurs between pH 8.5 to 3.0.
Temperature relations: Optimum, 28° C; slow growth at 10° and 37° C; death occurs at 55° C.
Strictly autotrophic. Derives energy by the oxidation of thiosulfate, tetrathionate, elemental sulfur and hydrogen sulfide. Thiosulfate is oxidized to tetrathionate, sulfate and sulfuric acid; tetrathionate is oxidized to sulfate and sulfuric acid while free sulfuric acid only is formed from elemental sulfur and hydrogen sulfide. Utilizes atmospheric CO2 as a source of carbon.
Nitrogen sources: Ammonium; nitrate- and nitrite-nitrogen.
Aerobic.
Comments: It has not been clear until recently (Parker, Jour. Gen. Microbiol., 8, 1953, 344) that this organism is a species separate from Thiobacillus thioparus Beijerinck. The isolation and detailed study of an organism from concrete identical in most respects with Nathansohn's description of his isolate but different from Beijerinck's and Starkey's description of Thiobacillus thioparus makes it clear that two separate species are involved. Thiobacillus neapolitanus produces tetrathionate and sulfate from thiosulfate and oxidizes H2S and tetrathionate whereas Thiobacillus thioparus produces sulfur and sulfate from thiosulfate and does not oxidize H2S or tetrathionate.
Source: Originally isolated by Nathansohn from sea water at Naples, Italy. Isolated by Parker from early stages of the corrosion of concrete sewers and other concrete structures.
Habitat: Presumably widely distributed in soil and water, including sea water.
7. Thiobacillus concretivorus Parker,
