FAMILY VII. SPIRILLACEAE 



249 



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. 



