DNA sequenced based bacterial taxonomy should entail decisive phenotypic remarks: Towards a balanced approach

Phenotypic characteristics while complimenting 16S rRNA gene sequencing in identifying bacteria become decisive in solving conflicts of equal % similarity of a given DNA sequence to more than one classified microorganisms. "Phenotypic light" may also indicate right direction when a new species' 16S rDNA sequence is under consideration. In fact 16S rRNA gene sequences give indication that either a novel species has been isolated or the test organism is identified. In each case additional tests are required for resolving different issues. Predictions of microbial phenotypes from metagenomic data depend heavily on our knowledge of expressed genes. Thus renaissance of microbial phenotypic characterization is likely to emerge at par with genotypic signatures. Interplay of these and other complimentary levels of analyses are likely to lead DNA barcoding for microorganisms as it has provided efficient methods for species-level identifications of animals and plants. In this review, an attempt has been made to realize the reader(s) importance of interplay of genotypic and phenotypic characteristics of bacteria for development of comprehensive and more stable classification schemes. It is expected that future valid classification schemes will be based on the phenetic relationships of microorganisms.