Emended descriptions of these species and subspecies are given.In 1972, Terasaki (14) published a morphological, physiological, and biochemicd characterization of 49 strains of spirilla, including a number of new strains isolated from putrid infusions of shellfish (13) and a strain isolated from mosses collected in the Antarctic (see Table 1). In 1973, eight of the new strains were placed by T e r d (15) in five new species of Spirillum (S. psychrophilum, S. hiroshimense, S. pelagicum, S. pusillum, and s. multiglobuliferun), and three of the strains were placed in two new subspecies (S. itersonii subsp. nipponicum and S. peregrinum subsp. integrum) of previously established species. In the same year, Hylemon et al. (6) proposed that the genus Spirillum Ehrenberg 1832 be divided into three genera: SpirilZum, Aquaspirillum, and Oceanospirillum. Subsequently, additional characters were determined for the 11 new isolates mentioned above, and the results of both the original and the supplementary tests indicated that the freshwater strains possessed the salient characteristics of the genus Aquaspirillum (6, 9, 10) and that the marine strains possessed those of the genus Oceanospirillum (6,9,10). In the present paper, the new nomenclatural combinations necessitated by the transfer of these organisms and emended descriptions of the species and subspecies are provided.
MATERIALS AND METHODSBacterial strains. The strain designations of the 11 isolates used in this investigation, their identification when they were originally described (15), their sources, and their dates of isolation are listed in Table 1.
Maintenance of cultures.The Spirillum strains were maintained as agar stab cultures at room temperature (15 to 33OC) with monthly transfers, except for strain CA1, which was maintained at 4°C with trimonthly transfers. Freshwater spirilla were maintained on a nutrient agar of the following composition (in grams per liter of distilled water): Arei-peptone (Kyoei Seiyaku & Co., Ltd., Tokyo), 5.0; Arei-meat extract, 3.0; and agar, 15.0. For marine strains, a seawater agar was used, with seawater (drawn from Kairo-en, Itsukaichi-cho near Hiroshima) being substituted for the distilled water in the above nutrient agar. In those cases where the ceUs of certain strains were apt to "straighten out" during maintenance, smooth colonies were occasionally selected so as to maintain stocks of typical morphology. The method used for freeze-drying the spirilla has been reported recently by Terasaki (16).Inocula. With the exception of the tests for determination of substrates that can serve as sole carbon 130