A motile, rod-shaped, pink-orange pigmented bacterium, designated strain DW01(T), was isolated from the gut microflora of abalone collected from the South Sea (Republic of Korea). Cells were Gram-negative, facultatively anaerobic, catalase- and oxidase-positive. The major fatty acids were iso-C(15 : 0) (17.7 %), C(16 : 0) (13.4 %), iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c (12.5 %) and C(17 : 1)omega8c (10.7 %). The DNA G+C content was 53.7 mol%. A phylogenetic tree based on the 16S rRNA gene sequences showed that strain DW01(T) forms a lineage of the genus Shewanella and is closely related to Shewanella algae ATCC 51192(T) (98.3 % sequence similarity) and to other members of the genus Shewanella (91.0-94.9 %). The phenotypic characteristics and DNA-DNA hybridization relatedness data indicate that strain DW01(T) should be distinguished from S. algae ATCC 51192(T). On the basis of the data presented in this study, strain DW01(T) represents a novel species, for which the name Shewanella haliotis sp. nov. is proposed. The type strain is DW01(T) (=KCTC 12896(T)=JCM 14758(T)).

Genetic and phenotypic studies on the strains biochemically identified as Shewanella putrefaciens, which had a G+C content ranging from 52 to 54 mol% were conducted. The moles percent G+C of the type strain of S. putrefaciens is 46. Surprisingly, DNA homology experiments revealed that all these strains are genetically related to Shewanella alga (which was reported to produce tetrodotoxin), not to the type strain of S. putrefaciens. In this study, we reidentified clinical strains of S. putrefaciens which have a high range of moles percent G+C, as does S. alga. We also characterized the reidentified strains and found that the original description of S. alga (U. Simidu, K. Kita-Tsukamoto, T. Yasumoto, and M. Yotsu, Int. J. Syst. Bacteriol. 40:331-336, 1990) is insufficient to identify this strain. An emended description of S. alga is given.

Four strains of tetrodotoxin-producing bacteria isolated from a red alga and from pufferfish were characterized. Two of these strains are members of the genus Listonella MacDonell and Colwell. The phenotypic characteristics, guanine-plus-cytosine contents, and base sequences of the 16S rRNAs of these organisms indicated that they are members of Listonella pelagia (Vibrio pelagius) biovar II. The other two strains are members of the genus Alteromonas Baumann et al. and the genus Shewanella MacDonell and Colwell. These two strains are mutually distinct and distinct from the previously described Alteromonas and Shewanella species and therefore are placed in new species. The names Shewanella alga and Alteromonas tetraodonis are proposed for these organisms; the type strains are strains OK-1 and GFC, respectively.