Pseudomonas guguanensis sp. nov., a gammaproteobacterium isolated from a hot spring

Abstract

An aerobic, Gram-stain-negative, rod-shaped bacterium (designated strain CC-G9AT), motile by a polar-flagellum, was isolated from a hot spring water sample in Taiwan. Strain CC-G9AT could grow at 20–42 °C, pH 6.0–10.0 and tolerate up to 7 % (w/v) NaCl. The 16S rRNA gene sequence analysis of strain CC-G9AT showed pairwise sequence similarity to Pseudomonas mendocina LMG 1223T (97.7 %), Pseudomonas alcaligenes ATCC 14909T (97.8 %), Pseudomonas alcaliphila DSM 17744T (97.8 %), Pseudomonas toyotomiensis JCM 15604T (97.6 %), Pseudomonas oleovorans subsp. lubricantis DSM 21016T (97.6 %) and Pseudomonas argentinensis BCRC 17807T (97.5 %), and lower sequence similarity to other species of the genus Pseudomonas . According to DNA–DNA association analysis, the relatedness of strain CC-G9AT to P. mendocina BCRC 10458T, P. alcaliphila DSM 17744T, P. alcaligenes BCRC 11893T, P. oleovorans subsp. lubricantis DSM 21016T, P. argentinensis BCRC 17807T and P. oleovorans subsp. oleovorans BCRC 11902 was 55.1±3.1, 13.7±1.5, 14.1±1.8, 58.5±1.1, 28.9±2.0 and 28.6±1.8 %, respectively. The evolutionary trees reconstructed based on 16S rRNA, gyrB and rpoB gene sequences revealed varying phylogenetic neighbourhoods of strain CC-G9AT with regard to the most closely related type strains. The predominant quinone system was ubiquinone (Q-9) and the DNA G+C content was 64.3±1.3 mol%. The major fatty acids were C10 : 0 3-OH, C12 : 0, C12 : 0 3-OH, C16 : 0 and summed features 3 and 8 consisting of C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. According to distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-G9AT is proposed to represent a novel species within the genus Pseudomonas for which the name Pseudomonas guguanensis sp. nov. is proposed. The type strain is CC-G9AT ( = BCRC 80438T = JCM 18416T).