Pusillimonas maritima sp. nov., isolated from surface seawater

Two Gram-stain-negative, short rod-shaped and non-flagellated strains, designated 17-4A(T )and L52-1-41, were isolated from the surface seawater of the Indian Ocean and South China Sea, respectively. The 165 rRNA genes of the two strains shared sequence similarity of 99.45%. Strain 17-4A(T) shared the highest 16S rRNA gene similarity of 98.02% with Pusillimonas caeni EBR-8-1(T), followed by Pusillimonas noertemannii BN9(T )(97.47%), Pusillimonas soli MJ07(T) (96.93%), Parapusillimonas granuli Ch07(T) (96.68%), Pusillimonas ginsengisoli DCY25(T )(96.65%), Eoetvoesia caeni PB3-7B(T) (96.63%), Paracandidimonas caeni 24(T) (96.34%), Castellaniella defragrans 54Pin(T) (96.28%) and Pusillimonas harenae B201(T) (96.05%). L52-1-41 shared the highest 16S rRNA gene similarity of 97.74% with Pusillimonas caeni EBR-8-1(T), followed by Pusillimonas noertemannii BN9(T) (97.47%), Pusillimonas soli MJ07(T) (96.65%), Parapusillimonas granuli Ch07(T) (96.41%), Pusillimonas ginsengisoli DCY25(T) (96.37%), Eoetvoesia caeni PB3-7B(T) (96.35%), Pusillimonas harenae 6201(T) (96.28%), and Paracandidimonas caeni 24(T) (96.06%). The results of phylogenetic analyses indicated that 17-4A(T) and L52-1-41 formed a stable, distinct and highly supported lineage affiliated to the genus Pusillimonas. The results of the digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses indicated that they represented a single species. They featured similar genomic DNA G+C contents of 53.2-53.4 mol%. Activities of catalase and oxidase were negative for both strains. The fatty acids patterns of 17-4A(T) and L52-1-41 were most similar, mostly comprised of C-16:0, Co-17:0 cycio, C-18:0, C-18:1 omega 9c and summed feature 8 (C-18:1, omega 7c and/or C18:1 omega 6c). The major polar lipids of the two strains were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and unidentified aminolipids. The respiratory quinone of the two strains was Q-8. Hence, on the basis of the phenotypic, chemotaxonomic and genotypic data presented in this study, we proposed the classification of both strains as representatives of a novel species named Pusillimonas maritima sp. nov., with the type strain 17-4A(T) (=MCCC 1A12670(T)=KCTC 62121(T)=NBRC 113794(T)), and another strain L52-1-41 (=MCCC 1A05046=KCTC 52313).