Sulfitobacter algicola sp. nov., isolated from green algae

Abstract

A novel Gram-stain-negative, aerobic, non-flagellated, non-motile, oval-rod-shaped and light pink to light tawny-pigmented bacterial strain (designated 1151^T) were isolated from marine green algae obtained from the coastal seawater of Weihai, China. Strain 1151^T was found to grow at 15–37 °C (optimum, 33 °C), pH 7.0–9.5 (optimum, 7.5–8.5) and in the presence of 1–6% (w/v) NaCl (optimum, 3%). Cells were oxidase-positive and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 1151^T was a member of the genus Sulfitobacter and exhibited the hightest sequence similarity to Sulfitobacter indolifex DSM 14862^T (96.6%), followed by the sequence similarity to Sulfitobacter aestuarii hydD52^T (96.5%) and Sulfitobacter profundi SAORIC-263^T (96.5%). The average nucleotide identity and digital DDH values between strain 1151^T and Sulfitobacter indolifex DSM 14862^T were 69.9% and 20.9%, respectively. The average amino acid identity between strain 1151^T and Sulfitobacter pontiacus DSM 10014^T (type strain of the type species) was 62.3%. Q-10 was detected as the sole respiratory quinone. The dominant cellular fatty acids were sum feature 8 (C_{18: 1}ω7c; 44.1%), C_{20: 1}ω7c (29.7%) and C_{18: 0} (11.7%). The DNA G + C content of strain 1151^T was 51.8 mol%. The polar lipids included phosphatidylglycerol (PG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), and three unidentified lipids (L1, L2 and L3). Based on the phylogenetic and phenotypic characteristics, strain 1151^T is considered to represent a novel species of the genus Sulfitobacter, for which the name Sulfitobacter algicola sp. nov. is proposed. The type strain is 1151^T (= KCTC 72513^T = MCCC 1H00384^T).