Shiella aurantiaca gen. nov., sp. nov., a novel bacterium isolated from activated sludge, and proposal of Shiellaceae fam. nov.

Abstract

A novel Gram-stain-negative, long rod-shaped, aerobic, non-motile, non-spore-forming and orange-pigmented bacterium, designated LB-30T, was isolated from activated sludge. Growth was observed at 15-40 °C (optimum 30 °C), pH 6.0-9.0 (optimum 7.0) and salinities of 0-3.0 % (w/v; optimum 2.0 %). LB-30T showed less than 89.9 % sequence similarities to the recognized taxa of the order Cytophagales. The results of phylogenetic analysis based on 16S rRNA gene sequences and phylogenomic tree indicated that LB-30T formed a distinct lineage within the order Cytophagales. The average amino acid identity (AAI) values between LB-30T and members of the related families Cyclobacteriaceae, Fulvivirgaceae, Roseivirgaceae, Reichenbachiellaceae, Cesiribacteraceae, Cytophagaceae and Hymenobacteraceae in the order Cytophagales were 50.5-54.6 %. The sole respiratory quinone of LB-31T was menaquinone 7 (MK-7). The major polar lipids were phosphatidylethanolamine, aminolipid and four unidentified lipids. The major fatty acids were iso-C15 : 0, iso-C15 : 1G and iso-C17 : 0 3-OH. The DNA G+C content was 43.8 mol%, calculated from the genome sequence. On the basis of differences in the phenotypic, physiological and biochemical characteristics, and distinct phylogenetic relationships, strain LB-30T is proposed to represent a novel species in a novel genus for which the name Shiella aurantiaca gen. nov., sp. nov is proposed, within a novel family Shiellaceae fam. nov. of the order Cytophagales. The type strain is LB-30T (=GDMCC 1.3629T= KCTC 92689T).