Gramella crocea sp. nov., isolated from activated sludge of a seafood processing plant

A novel aerobic Gram-negative strain, designated as YB25^T, was isolated from an activated sludge sample collected from a seafood processing plant in Zhoushan, Zhejiang Province, China, and characterized by using a polyphasic taxonomic approach in this study. Strain YB25^T was motile by gliding, and short-rod-shaped. The isolate grew at 4-37 °C (optimum 28 °C), pH 6.0-9.0 (optimum pH 7.0) and 0.0-10.0% NaCl (optimum 2.0%, w/v). Phylogenetic analysis based on 16S rRNA gene indicated that strain YB25^T belonged to the genus Gramella, and showed the highest sequence similarity of 97.59% to Gramella lutea YJ019^T. The DNA G + C content was 39.5%. In silico DNA-DNA hybridization (DDH) and average nucleotide identity (ANI) values between strain YB25^T with most closely strains were below the threshold, which is considered to the phylogenetic definition of a novel species. Chemotaxonomic analysis indicated that the only respiratory quinone was menaquinone-6 and the major fatty acids were iso-C_15:0, anteiso-C_15:0, iso-C_17:0 3-OH, and summed feature 9 (iso-C_17:1ω9c and C_16:0 10 methyl). The polar lipid profile was composed of phosphatidylethanolamine, an unidentified phospholipid, two unidentified amino lipids, three unidentified glycolipids, and four unidentified lipids. Compared with the reference strains, strain YB25^T contained higher abundance of genes for carbohydrates metabolism,nitrogen metabolism, sulfur metabolism and respiration based on its genomic metabolic pathways and had been found a certain potential in the degradation of pectin. On the basis of the taxonomic evidence, strain YB25^T represents a novel species of the genus Gramella, for which the name Gramella crocea sp. nov. is proposed. The type strain is YB25^T (= KCTC 82680 ^T = MCCC 1K05761^T).