gen. nov., sp. nov., a novel haloalkaliphile isolated from a laboratory culture cyanobacterium species and proposals of fam. nov., fam. nov., ord. nov. and ord. nov.

A prosthecate bacterial strain, designated G-192, was isolated from decaying biomass of a haloalkaliphilic cyanobacterium sp. Z-T0701. The cells were aerobic, Gram-negative, non-endospore-forming and dimorphic, occurring either as sessile bacteria with a characteristic stalk or as motile flagellated cells. The strain utilized a limited range of substrates, mostly peptonaceous, but was able to degrade whole proteins. Growth occurred at 5-46 °C (optimum, 35-40 °C), pH 7.3-10.3 (optimum, pH 8.0-9.0), 0-14 % NaCl (v/w; optimum, 2.0-6.0 %, v/w). The G+C content of the genomic DNA of strain G-192 was 66.8%. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain G-192 formed a distinct evolutionary lineage within the family . Strain G-192 showed the highest 16S rRNA sequence similarity to ZYF765 (95.2%), GISW-4 (94.2%) and WD6-1 (95.5%). The major cellular fatty acids (>5% of the total) were C 9, C and 11-methyl-C ω7. The major polar lipids were glycolipids and phospholipids. The only respiratory quinone was ubiquinone-10 (Q-10). Based on polyphasic results including phylogenomic data, the novel strain could be distinguished from other genera, which suggests that strain G-192 represents a novel species of a new genus, for which the name gen. nov., sp. nov. is proposed. The type strain is G-192 (=VKM B-3306=KCTC 72746). The strain is the first representative of the stalked bacteria associated with a haloalkaliphilic cyanobacterium. Based on phylogenomic indices and phenotypic data, it is proposed to evolve two novel families fam. nov. and fam. nov. out of the current family . In addition, it is proposed to place the first two families in the novel order ord. nov. and novel order ord. nov. is proposed to accommodate the family .