Pedobacter aquae sp. nov., a multi-drug resistant bacterium isolated from fresh water

Abstract

A novel bacterial strain designated CJ43(T) was isolated from fresh water located in Gangwon-do, South Korea, displaying multi-drug resistance. The isolate was Gram-stain-negative, aerobic, orange-pigmented, and rod-shaped. Strain CJ43(T) grew optimally at 30 degrees C and pH 7 on R2A agar in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain CJ43(T) belonged to the genus Pedobacter in the family Sphingobacteriaceae and was most closely related to Pedobacter puniceum HX-22-1( T) and P. glucosidilyticus 1-2( T) (98.3 and 98.1% sequence similarity). The genome size of strain CJ43(T) was 3.9 Mb in a single contig with DNA G + C content of 34.9%. The genome included 3144 predicted protein-coding genes, as well as 55 tRNA, 9 rRNA and 3 ncRNA genes. The genome also contained 128 putative antibiotic resistance genes, reflecting its phenotypes. The average nucleotide identity values between strain CJ43(T) and two closely related strains P. puniceum HX-22-1( T) and P. glucosidilyticus 1-2( T) were 91.0 and 88.7%, respectively. In silico digital DNA-DNA hybridization results between strain CJ43(T) and the related strains were 42.8 and 38.6%, respectively. The major fatty acids of strain CJ43(T) were iso-C-15:0, iso-C-17:0 3-OH, and summed feature 3 (C-16:1 omega 6c and/or C-16:1 omega 7c). Strain CJ43(T) contained phosphatidylethanolamine as the major polar lipid and menaquinone-7 as the sole respiratory quinone. Based on the polyphasic taxonomy data, strain CJ43(T) represents a novel species of the genus Pedobacter, for which the name Pedobacter aquae sp. nov. is proposed with the type strain CJ43(T) (= KACC 21350( T) = JCM 33709( T)).