Lampropedia aestuarii sp. nov., isolated from the estuary of a freshwater river.

Abstract

A Gram-stain-negative, strictly aerobic, catalase-positive and oxidase-positive bacterium, designated strain YIM MLB12T, was isolated from estuary sediment sampled at Maliao River where it flows into a plateau lake (Dianchi) in Yunnan, south-west PR China. Cells were non-motile and rod-shaped. Growth was observed at 15-35 °C (optimum, 25-30 °C), pH 6.0-10.0 (optimum, pH 7.0-8.0) and in the presence of 0-7 % (w/v) NaCl (optimum, 0.5-2 %). Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM MLB12T formed a tight phylogenic lineage with members of the genus Lampropedia and was closely related to 'Lampropedia puyangensis' 2-bin with 98.3 % sequence similarity and had low similarities to the type strains of Lampropediahyalina ATCC 11041T (96 %) and Lampropedia cohaerens CT6T (95.5 %). Average nucleotide identity and in silico DNA-DNA hybridization values between strain YIM MLB12T and 'L. puyangensis' KCTC 32235 were 76.5 and 22.6 %, respectively. Strain YIM MLB12T contained ubiquinone-8 as the major quinone. The predominant cellular fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0, C10 : 0 3-OH, summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C12 : 0 3-OH and C14 : 0. The polar lipid profile of strain YIM MLB12T was composed predominantly of diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The major polyamine was spermidine. The genomic DNA G+C content of strain YIM MLB12T was 56.8 mol%. Based on its genotypic and chemotaxonomic features and results of phenotypic analyses, strain YIM MLB12T represents a novel species of the genus Lampropedia, for which the name Lampropediaaestuarii sp. nov. is proposed. The type strain is YIM MLB12T (=KCTC 42886T=CGMCC 1.17071T).