Rapid detection and identification of the metabolically diverse genus Gordonia by 16S rRNA-gene-targeted genus-specific primers

The importance of the emerging genus Gordonia in industrial and environmental biotechnology is evidenced by the recent increase in associated publications and patents. But, investigations into potentially valuable Gordonia members are restricted by the limitations of current isolation and detection techniques. This motivated us to design a genus-specific oligonucleotide primer pair which could assist in rapid detection of species of the genus Gordonia by means of PCR-specific amplification. The Gordonia-specific 16S rDNA fragment (829 bp) was successfully amplified for all the reference Gordonia species with the designed primer pair G268F/G1096R. No amplification was noted for closely related species from other genera. The genus specificity was validated with 47 strains including wild-type isolates. Interestingly, two strains assigned earlier as Gordonia nitida (DSM 777) and Gordonia rubripertinctus (ATCC 21930) failed to produce a Gordonia-specific fragment with this primer pair. Further analysis of these two isolates based on 16S rDNA sequencing and phylogenetic analysis classified them to the genus Rhodococcus. Preliminary screening of soil samples with the Gordonia-specific primers was successful in terms of the rapid detection of nine Gordonia wild-type isolates.