Klebsiella alba sp. nov., a novel pesticide-tolerant bacterium from a heavily polluted environment.

A novel Gram-negative, aerobic, rod-shaped and pesticide (chlorpyrifos and atrazine) tolerant strain, designated CW-D 3(T), was isolated from a heavily polluted soil sample in Jiangsu Province, China. The strain could tolerate about 800 microg.ml(-1) atrazine or chlorpyrifos when added in TYB medium. A polyphasic taxonomy including phylogenetic and phenotypic analysis was performed on the new isolate. Phylogenetic analysis and chemotaxonomic characteristics revealed that strain CW-D 3(T) belongs to the genus Klebsiella. Its closest phylogenetic neighbors were K. singaporensis (strain LX3(T)), three subspecies of K. pneumoniae (strains ATCC 13883(T), ATCC 13884(T) and ATCC 11296(T)) and K. granulomatis, according to 16S rRNA and rpoB gene analysis. The 16S rRNA gene sequence similarity was about 94.8-97.6% and the rpoB gene sequence similarity was about 96.8-98.6% to its phylogenetic neighbors. Strain CW-D 3(T) also showed low DNA-DNA reassociation values (less than 21%) with respect to the three subspecies of K. pneumoniae and Klebsiella singaporensis. Its major fatty acids were C14:0, C16:0, c-C17:0 and c-C19:0 omega8c. The G+C content of the DNA was 58.3 mol%. Phylogenetic and phenotypic results supported the assignment of CW-D 3(T) as a novel species of the genus Klebsiella, for which the name Klebsiella alba sp. nov. is proposed. The type strain is CW-D 3(T) (=LMG 24441(T)=KCTC 12878(T) =CCTCC AB 206144(T)).