Rhodoligotrophos appendicifer gen. nov., sp. nov., an appendaged bacterium isolated from a freshwater Antarctic lake

Abstract

A Gram-stain-negative, non-spore-forming, non-motile, irregularly circular, aerobic/microaerobic appendaged bacterium (strain 120-1(T)) was isolated from Naga-ike, one of the freshwater lakes in the Skarvsnes ice-free area of Antarctica. Strain 120-1(T) grew between 5 and 35 °C, with optimum growth at 30 °C. The pH range for growth was between 6.0 and 9.0 (optimum of approximately pH 7.0). The range of NaCl concentration allowing growth of strain 120-1(T) was between 0 and 5.0%, with an optimum of 0.5-1.0%. Strain 120-1(T) was able to utilize organic compounds such as glucose, arabinose, gluconate, adipate and malate. Red colonies were formed on plate medium and the carotenoids were present in the cells. Ubiquinones Q-9 and Q-10 were the major respiratory quinones. The major cellular fatty acids were C(16:0), C(18:1)ω9c and C(18:1)ω7c. The G+C content of the genomic DNA was 61.1 mol%. Comparative analyses of 16S rRNA gene sequences and physiological characteristics of strain 120-1(T) indicate that strain 120-1(T) is a phylogenetically novel bacterium, and that it represents a novel species in a new genus, Rhodoligotrophos gen. nov., in the order Rhizobiales, family Rhodobiaceae. The name Rhodoligotrophos appendicifer gen. nov. sp. nov. is proposed as the type species of this new genus, with 120-1(T) ( = JCM 16873(T) = ATCC BAA-2115(T)) as the type strain.