Delftia litopenaei sp. nov., a poly-β-hydroxybutyrate-accumulating bacterium isolated from a freshwater shrimp culture pond

Abstract

A Gram-negative, short-rod-shaped, motile, non-spore-forming and poly-β-hydroxybutyrate-accumulating bacterial strain, designated wsw-7T, was isolated from a freshwater shrimp culture pond in Taiwan and was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain wsw-7T were Delftia lacustris 332T, Delftia tsuruhatensis T7T and Delftia acidovorans ATCC 15668T, with sequence similarities of 98.5, 98.4 and 97.9 %, respectively. Phylogenetic trees obtained with 16S rRNA gene sequences or the polyhydroxyalkanoate synthase (phaC) gene sequences revealed that strain wsw-7T and these three closest relatives formed an independent phylogenetic clade within the order Burkholderiales . Strain wsw-7T contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as predominant fatty acids. The major isoprenoid quinone was Q-8 and the DNA G+C content was 67.6 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminolipid and several uncharacterized phospholipids. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain wsw-7T represents a novel species in the genus Delftia , for which the name Delftia litopenaei sp. nov. is proposed; the type strain is wsw-7T ( = BCRC 80212T = LMG 25724T).