Zhongshania antarctica gen. nov., sp. nov. and Zhongshania guokunii sp. nov., gammaproteobacteria respectively isolated from coastal attached (fast) ice and surface seawater of the Antarctic

Two Gram-negative, motile, aerobic, catalase- and oxidase-positive, rod-shaped strains, designated ZS5-23(T) and ZS6-22(T), were respectively isolated from Antarctic coastal attached (fast) ice and surface seawater samples. Both strains could grow at 4-35 °C (optimum 30 °C) and in the absence of NaCl. Analyses of 16S rRNA gene sequences revealed that strains ZS5-23(T) and ZS6-22(T) were closely related to each other (99.0 % sequence similarity) and belonged to the class Gammaproteobacteria, with their closest relatives being Spongiibacter and Melitea species (93.1-94.3 % sequence similarity). The predominant cellular fatty acids in both strains were C₁₇:₁ω8c, C₁₇:₀ and summed feature 3 (C₁₆:₁ω7c and/or iso-C₁₅:₀ 2-OH). Genomic DNA G+C contents of strains ZS5-23(T) and ZS6-22(T) were 51.5 and 51.8 mol%, respectively. The DNA-DNA relatedness between strains ZS5-23(T) and ZS6-22(T) was 50.9 %. Strains ZS5-23(T) and ZS6-22(T) could be differentiated from each other and from Spongiibacter and Melitea species by differences in a number of phenotypic properties. Based on the data presented, strains ZS5-23(T) and ZS6-22(T) represent two novel species in a new genus in the class Gammaproteobacteria, for which the names Zhongshania antarctica gen. nov., sp. nov. (the type species) and Zhongshania guokunii sp. nov. are proposed. The type strain of Zhongshania antarctica is ZS5-23(T) ( = KACC 14066(T)  = CCTCC AB 209246(T)) and that of Zhongshania guokunii is ZS6-22(T) ( = KACC 14532(T)  = CCTCC AB 209247(T)).