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

A Gram-negative, short-rod-shaped, motile, non-spore-forming and poly-beta-hydroxybutyrate-accumulating bacterial strain, designated wsw-7(T), 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-7(T) were Delftia lacustris 332(T), Delftia tsuruhatensis T7(T) and Delftia acidovorans ATCC 15668(T), with sequence similarities of 98.5, 98.4 and 97.9 To, respectively. Phylogenetic trees obtained with 16S rRNA gene sequences or the polyhydroxyalkanoate synthase (phaC) gene sequences revealed that strain wsw-7(T) and these three closest relatives formed an independent phylogenetic clade within the order Burkholderiales. Strain wsw-7(T) contained summed feature 3 (comprising C-16:1 omega 7c and/or C-16:1 omega c), C-16:0 and C-18:1 omega 7c 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-7(T) represents a novel species in the genus Delftia, for which the name Delftia litopenaei sp. nov. is proposed; the type strain is wsw-7(T) (=BCRC 80212(T)=LMG 25724(T)).