OBSERVATIONS ON SPIRILLUM SPUTIGENUM AND ITS RELATIONSHIP TO SELENOMONAS SPECIES WITH SPECIAL REFERENCE TO FLAGELLATION

Two strains of Spirillum sputigenum from the oral cavity were described in detail by Macdonald (1953). The organisms were gramnegative and appeared as either curved or S-shaped spirillar rods from 4 to 50 A long and were apparently peritrichously flagellated. Macdonald (1953) recommended that these forms be included in Bergey's classification as a recognized species of the genus Spirillum, and be listed as (a) one micron or less thick, (b) no volutin granules observed, and (e) having peritrichous flagella. In 1954 Lessel and Breed recommended the recognition of the genus Selenomonas and the inclusion of Spirillum sputigenum as one of three species in this genus under the name of Selenomonas sputigena. The other two species were Selenomonas palpitans, from the intestinal tract of the guinea pig, related rodents, and herbivorous mammals, and Selenomonas ruminantium, from the rumen juice of domestic animals. The former was described first by von Prowazek (1913) and named by Simons (1921). The latter was described by Certes (1889) as a protozoan species, Ancyromonas ruminantium; Wenyon (1926) renamed it Selenomonas. This organism was isolated in pure culture by Huhtanen and Gall (1953) and by Bryant and Small (1956). Bryant (1956) described a number of physiological characteristics of several strains and noted that production of H2S by Selenomonas ruminantium was the only known feature distinguishing it from Spirillum sputigenum. Each of the three organisms has been described by one or more authors as having a flagellum or tuft of flagella attached near the middle of the concave side (Hoffman and von Prowazek, 1906; von Prowazek, 1913; Boskamp, 1922; Certes, 1889; Kerandel, 1909; Woodcock and Lepage,