Lacibacter luteus sp. nov., isolated from a freshwater river

Abstract

An isolate, designated TTM-7^T, recovered from a freshwater river in Taiwan, was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain TTM-7^T is affiliated with species in the genus Lacibacter. Strain TTM-7^T was most closely related to Lacibacter cauensis NJ-8^T with a 98.2 % 16S rRNA gene sequence similarity, followed by Lacibacter daechungensis H32-4^T (97.4 %) and Lacibacter nakdongensis SS2-56^T (96.3 %). Cells were Gram-stain-negative, aerobic, motile by gliding, rod-shaped and formed orange colonies. Optimal growth occurred at 25 °C, pH 7 and 0 % NaCl. The major fatty acids of strain TTM-7^T were iso-C_{15 : 0}, summed feature 3 (comprising C_{16 : 1}ω7c/C_{16 : 1}ω6c and/or iso-C_{15 : 0} 2-OH) and iso-C_{15 : 1} G. The predominant hydroxy fatty acid was iso-C_{17 : 0} 3-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, two unidentified aminoglycolipids, five unidentified aminophospholipids and one unidentified lipid. The major isoprenoid quinone was MK-7. Genomic DNA G+C content of strain TTM-7^T was 40.6 mol%. Strain TTM-7^T showed 83.6 % average nucleotide identity and 16.0 % digital DNA-DNA hybridization identity with Lacibacter cauensis NJ-8^T. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TTM-7^T should be classified in a novel species of the genus Lacibacter, for which the name Lacibacter luteus sp. nov. is proposed. The type strain is TTM-7^T (=BCRC 81159^T=LMG 30926^T=KCTC 62870^T).

Keywords: Chitinophagaceae; Chitinophagales; Chitinophagia; Lacibacter luteus sp. nov..