Aquabacterium limnoticum sp. nov., isolated from a freshwater spring

Abstract

A Gram-negative, facultatively anaerobic, short-rod-shaped, non-motile and non-spore-forming bacterial strain, designated ABP-4T, was isolated from a freshwater spring in Taiwan and was characterized using the polyphasic taxonomy approach. Growth occurred at 20–40 °C (optimum, 30–37 °C), at pH 7.0–10.0 (optimum, pH 7.0–9.0) and with 0–3 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain ABP-4T, together with Aquabacterium fontiphilum CS-6T (96.4 % sequence similarity), Aquabacterium commune B8T (96.1 %), Aquabacterium citratiphilum B4T (95.5 %) and Aquabacterium parvum B6T (94.7 %), formed a deep line within the order Burkholderiales. Strain ABP-4T contained summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c), C18 : 1 ω7c and C16 : 0 as predominant fatty acids. The major cellular hydroxy fatty acid was C10 : 0 3-OH. The major isoprenoid quinone was Q-8 and the DNA G+C content was 68.6 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, diphosphatidylglycerol and several uncharacterized phospholipids. The DNA–DNA relatedness of strain ABP-4T with respect to recognized species of the genus Aquabacterium was less than 70 %. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain ABP-4T represents a novel species in the genus Aquabacterium, for which the name Aquabacterium limnoticum sp. nov. is proposed. The type strain is ABP-4T ( = BCRC 80167T = KCTC 23306T).