Spongiibacter taiwanensis sp nov., a marine bacterium isolated from aged seawater

A Gram-reaction-negative, heterotrophic, marine bacterium, designated strain SPT1(T), was isolated from an aged seawater sample which was collected from the shallow coastal region of Nanya, Keelung, Taiwan and stored at room temperature for more than 7 years. Strain SPT1(T) was a motile rod which exhibited monotrichous flagellation. It required NaCl for growth and exhibited optimal growth at 30-35 degrees C, 1-3% NaCl and pH 7-8. The strain was a strictly aerobic bacterium, incapable of anaerobic growth by nitrate reduction or denitrification, or by fermenting glucose or other carbohydrates. Cellular fatty acids were dominated by C-16 : 1 omega 7c and/or C-16 : 1 omega 6c (23.4 %), C-17 : 1 omega 8c (18.1 %), C-16 : 0 (8.5 %), C-18 : 1 omega 7c (8.4 %) and C-10 : 0 3-OH (6.3 %). The predominant isoprenoid quinone was Q-8. Polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol and phosphatidic acid. The DNA G+C content was 57.9 mol%. Phylogeny based on 16S rRNA gene sequences showed that strain SPT1(T) formed a distinct species-level lineage within the genus Spongiibacter of the class Gammaproteobacteria and shared sequence similarities of 94.4-96.2% with Spongiibacter marinus and Spongiibacter tropicus, the only two species of the genus Spongiibacter with validly published names. The 16S rRNA gene sequence similarities between strain SPT1(T) and other species were less than 93.1 %. Polyphasic taxonomic data obtained in this study indicated that strain SPT1(T) could be classified as a novel species of the genus Spongiibacter, for which the name Spongiibacter taiwanensis sp. nov. is proposed. The type strain is SPT1(T) (= JCM 31012(T) = BCRC 80916(T)).