Classification of strain Chj404 using polyphasic taxonomy

Abstract

In order to study a microbial diversity and to find novel bacteria, we isolated 601 strains from various soil and seawater samples collected from several environmental sites including Uleung-Do (Island), tidelands of Western Coast, and contaminated stream near the industrial complex in Chung-ju City. Out of the isolates, 42 strains were identified with 16S rDNA partial sequencing. Among them, 13 strains exhibited less than 97% similarity in their base pair to the best-matched strains conserved in GeneBank database. One of bacteria, Strain Chj404 was subject to polyphasic taxonomy for the precise classification. On the basis of phenotypic characteristics, fatty acid analysis and 16S rDNA sequence analysis, it was considered to be a new species belonging to a new genus. It was a Gram-negative, aerobic, coccoid-rod shaped bacterium. It grew well on nutrient agar medium and utilizes a broad spectrum of carbon source. The G + C content of the DNA is 67%. Main composition of ubiquinone is Q-8 and the residues are composed of Q-7, Q-9, and Q-10. The Major fatty acid is $C_{18:1}$ cultured on TSA agar for 24 hours, but $C_{19:0}$ cycloω8c for 48 hours. The 16S rDNA sequence of strain Chj404 has been deposited at GeneBank as AY039817. Comparative 16S rDNA studies show a clear affiliation of this bacterium to the alpha-2 subgroup of Proteobacteria. Comparison of phylogenetic data indicates that it is most closely related to Chelatococcus asaccharovorans DSM $6462^T$ (90.3% similarity in 16S rDNA sequence). Since strain Chj404 is clearly distinct from closely related species, I propose the name Kaistia adipata gen. nov., sp. nov. for this strain Chj404.