Abstract

Three Gram-staining negative, facultatively anaerobic, rod-shaped and motile strains, FJAT-51800(T), FJAT-52962(T) and FJAT-54481(T) were isolated from the sediment samples of Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. The 16S rRNA gene sequencing results indicated they could be novel members of the genus Shewanella. The optimum temperature for growth was 30 degrees C. The respiratory quinones of the strains were ubiquinone Q-7 or Q-8, and menaquinone MK-7. Polar lipids of the strains FJAT-52962(T) and FJAT-51800(T) were phosphatidyl glycerol, phosphatidyl ethanolamine, and unidentified aminophospholipids while strain FJAT-54481 consist of phosphatidylglycerol, phosphatidylethanolamine, unidentified aminophospholipids, two unidentified aminolipids and four unidentified lipids. The major fatty acid of the three strains was iso-C-15:0. The genomic DNA G + C contents of strains FJAT-51800(T), FJAT-52962(T) and FJAT-54481(T) were 48.2, 55.3 and 48.1%, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strains FJAT-51800(T), FJAT-52962(T) and FJAT-54481(T) and other closely related Shewanella members were below the cut-off level (95-96%) for species identification. Genome analysis showed that these strains encode genes for osmo-regulation. Based on the results of phenotypic, chemotaxonomic and genome analyses, strains FJAT-51800(T), FJAT-52962(T) and FJAT-54481(T) represent three novel species of the genus Shewanella, for which the names Shewanella avicenniae sp. nov., Shewanella sedimentimangrovi sp. nov., and Shewanella yunxiaonensis sp. nov., are proposed. The type strains are FJAT-51800(T) (= GDMCC 1.2204(T) = KCTC 82448(T)), FJAT-52962(T) (= MCCC 1K05496(T) = KCTC 82445(T)) and FJAT-54481(T) (= GDMCC 1.2348(T) = KCTC 82646(T)).