Paraflavisolibacter caeni gen. nov., sp. nov., a novel taxon within the family Chitinophagaceae isolated from sludge

A Gram- stain-negative bacterium, designated strain LB -8(T), was isolated from an activated sludge sample collected from a factory in Binzhou city, Shandong province, PR China. Cells of strain LB -8(T) were strictly aerobic, non-motile and rod-shaped. Growth occurred at 15-40 degrees C (optimum, 30 degrees C), at pH 6.0-9.0 (optimum, pH 7.0) and at 0-7.5 % (w/v) NaCl (optimum, 0.5 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LB -8(T) formed a distinct phyletic branch within the family Chitinophagaceae and was most closely related to members of the genera Flavisolibacter, Cnuella and Paracnuella with 92.7-93.3 % 16S rRNA gene sequence similarities. The average amino acid identity values between strain LB -8(T) and its closed phylogenetic neighbours Flavisolibacter, Cnuella and Paracnuella were below 70 % supporting that strain LB -8(T) was a member of a novel genus. The predominant cellular fatty acids of LB -8(T) were iso-C15:0, anteiso-C15:0, summed feature 3 (C-16:1 omega 7c and/or C-16: 1 omega 6c) and iso- C-17:0 3 -OH, and the only isoprenoid quinone was menaquinone- 7 (MK -7). The major polar lipids of strain LB-8(T) were phosphatidylethanolamine, four unidentified aminolipids and two unidentified lipids. The genome size of strain LB-8(T) was 7.01 Mbp with 41.2 mol% G+C content. On the basis of the evidence presented in this study, strain LB -8(T) represents a novel species of a new genus in the family Chitinophagaceae, for which the name Paraflavisolibacter caeni gen. nov., sp. nov. (type strain LB- 8(T)=GDMCC 1.3631(T)=KCTC 92688(T)) is proposed.

Automated summary

In this study, a novel bacterium strain LB-8(T) was isolated from an activated sludge sample in Binzhou city, Shandong province, PR China. The strain belongs to a new genus Paraflavisolibacter caeni within the family Chitinophagaceae, and is most closely related to Flavisolibacter, Cnuella, and Paracnuella genera.