Pseudoxanthomonas kaohsiungensis, sp nov., a novel bacterium isolated from oil-polluted site produces extracellular surface activity

During screening for biosurfactant-producing bacteria, a strain designated J36(T) was isolated from oil-polluted site near Kaohsiung city located in southern Taiwan. Cells of this organism were Gram-negative rods motile by means of a single polar flagellum. Strain J36(T) grew well in complex media under optimum conditions of 35 degrees C and pH 7. The extracellular products of the strain expressed emulsification activity. During cultivation on olive oil as the sole carbon and energy source, the culture supernatant of strain J36(T) reduced surface tension of the medium from 68 to 32.6 dyne/cm. The 16S rRNA gene sequence analysis indicates that strain J36(T) is a member of Xanthomonas group within the gamma-Proteobacteria. The organism belongs to the genus Pseudoxanthomonas and represents a novel species within this genus according to phylogenetic analysis of 16S rDNA sequences, DNA DNA similarity data, whole-cell protein analysis, physiological and biochemical characteristics, as well as fatty acid compositions. The predominant cellular fatty acids of strain J36(T) were 15:0 iso (about 26%), 17:1 iso omega 9c (about 25%), and 15:0 anteiso (about 10%). Its DNA base ratio was 60.1 mol% G+C. We propose to classify strain J36(T) ( = BCRC 17375(T) = LMG 22530(T)) as Pseudoxanthomonas kaohsiungensis sp. nov. (c) 2004 Elsevier GmbH. All rights reserved.