aspartic acid, ethanol, propanol, butanol, glycerol, glucose, lactate, succinate and malate known to be utilized as hydrogen donors. Some varieties oxidize H2 . Produces up to 3100 mg HjS per liter. Nitrites not produced from nitrates. Reduces sulfate to hydrogen sulfide; also reduces sulfites, thiosulfates and hyposulfites. Temperature relations: Optimum, be- tween 25° and 30° C. Maximum, between 35° and 40° C. Chemical tolerance: Optimum pH, be- tween 6 and 7.5. Limits for growth, between pH 5 and 9. Cytochrome is produced. Anaerobic. Habitat : Soil, sewage and water.
2. Desulfovibrio aestuarii (van Delden, 1904; ZoBell, 1948. (Microspira aestuarii van Delden, Cent. f. Bakt., II Abt., 11, 1904,81; ZoBell, in Manual, 6th ed., 1948, 208.) aes.tu.a'ri.i. L. noun uestuarium an estuary, inlet; L. gen. noun aestuarii of an estuary. Morphologically indistinguishable from Desulfovibrio desulfuricans described above, although it has a greater tendency to pleo- morphism and is slightly larger. Motile, possessing a polar flagellum. Gram-nega- tive. Gelatin: No liquefaction. Grows preferentially in media prepared with sea water or 3 per cent mineral salt solution enriched with sulfate and peptone. According to Baars (Over Sulfaatreductie door Bakterien, Diss. Delft, 1930, 164 pp.) the marine species can be acclimatized to tolerate hj^potonic salt solutions, but Rit- tenberg (Studies on Marine Sulfate- Reducing Bacteria, Thesis, Univ. of Calif., 1941, 115 pp.) was unable to confirm this observation. Likewise Rittenberg was unable to acclimatize D. aestuarii to tolerate temperatures exceeding 45° C. or to produce endospores. Produces faint turbidity in absence of oxygen in sea water enriched with sulfate and peptone. Organisms most abundant in sediment. Agar colonies: Small, circular, slightly raised, darker centers, entire, soft con- sistency. Peptone, asparagine, glycine, alanine, glucose, fructose, ethanol, butanol, gh^cerol, acetate, lactate and malate known to be utilized in presence of sulfate. Some strains utilize molecular hydrogen as the sole source of energy. Reduces sulfate to hj'drogen sulfide. Also reduces sulfites, thiosulfates and hy- posulfites. Produces up to 950 mg of hydrogen sulfide per liter. Nitrites not produced from nitrates. Temperature relations: Optimum, be- tween 25° and 30° C. Maximum, between 35° and 40° C. Chemical tolerance: Optimum pH, be- tween 6 and 8. Limits for growth, between pH 5.5 and 8.5. Anaerobic. Habitat: Sea water, marine mud, brine and oil wells.
3. Desulfovibrio rubentschikii (Baars, 1930) ZoBell, 1948. {Vibrio riibentschickii (sic) Baars, Over Sulfaatreductie door Bak- terien, Diss. Delft, 1930, 89; ZoBell, in Man- ual, 6th ed., 1948, 208.) ru.ben.tschi'ki.i. M.L. gen. noun ruben- tschikii of Rubentschik; named for Dr. L. Rubentschik. Slightly curved rods, 0.5 to 1.0 by 1 to 5 microns, usually occurring singly, some- times in pairs and short chains. Actively motile, possessing a polar flagellum. Gram- negative. Morphologically indistinguishable from Desulfovibrio desulfuricans. Reduces sulfate to hydrogen sulfide; also reduces sulfites, thiosulfates and hypo- sulfites. Culturally and phj'siologically like D. desulfuricans except that D. rubentschikii utilizes propionic, butyric, valeric, palmitic and stearic acids and galactose, sucrose, lactose and maltose. Anaerobic. Habitat: Soil and ditch water.
