Four new members of the family Cytophagaceae: Chryseosolibacter histidini gen. nov., sp. nov., Chryseosolibacter indicus gen. nov., sp. nov., Dawidia cretensis, gen. nov., sp. nov., and Dawidia soli, gen. nov., sp. nov. isolated from diverse habitat

Four novel strains were isolated: PWU4(T) and PWU20(T) were both from soil in Germany, PWU5(T) was isolated from soil in India and PWU37(T) was obtained from sheep faeces collected on the Island of Crete. Cells of each were observed to be Gram-negative, strictly aerobic, rod shaped, and to grow optimally between 28 and 34 °C, between pH 7.0 and 8.0 and without the addition of NaCl. The strains were found to be catalase and oxidase-negative and able to grow on most mono- and disaccharides, a few polysaccharides and organic acids. Their predominant menaquinone was identified as MK-7. Their major fatty acids were identified as C(16:1) ω7c (PWU4(T) and PWU20(T)) and C(16:1) ω5c (PWU5(T) and PWU37(T)). The DNA G + C contents of strains PWU4(T), PWU20(T), PWU5(T) and PWU37(T) were determined to be 50.2 mol%, 51.6 mol %, 39.8 mol% and 53.8 mol%, respectively. The 16S rRNA gene sequence analysis revealed that the close relatives Ohtaekwangia koreensis 3B-2(T) and Ohtaekwangia kribbensis 10AO(T) share less than 93.8% sequence similarity. The strains were classified in two groups, where PWU4(T) and PWU20(T) share 93.0% sequence similarity, and PWU5(T) and PWU37(T) share 97.5% sequence similarity. However, the members of each group were concluded to represent different species based on the low average nucleotide identity (ANI) of their genomes, 69.7% and 83.8%, respectively. We propose that the four strains represent four novel species of two new genera in the family Cytophagaceae. The type species of the novel genus Chryseosolibacter is Chryseosolibacter histidini gen. nov., sp. nov. with the type strain PWU4(T) (= DSM 111594(T) = NCCB 100798(T)), whilst strain PWU20(T) (= DSM 111597(T) = NCCB 100800(T)) is the type strain of a second species, Chryseosolibacter indicus sp. nov. The type species of the novel genus Dawidia is Dawidia cretensis gen. nov., sp. nov. with the type strain PWU5(T) (= DSM 111596(T) = NCCB 100799(T)), whilst strain PWU37(T) (= DSM 111595(T) = NCCB 100801(T)) is the type stain of a second species, Dawidia soli sp. nov.