Comparison of FTIR and 16S rDNA sequencing methods for identification and taxonomy of methylotroph bacteria

Molecular methods such as 16S rDNA sequencing are relatively accurate but are costly and time consuming، therefore new alternative methods have been a matter of interst. FTIR (Fourier Transform Infrared) is one of these methods. It is a physico-chemical method based on measurement of molecular bond vibrations excited by infrared radiation at specific wavelength range. The aim of this study was to assess efficiency of FTIR in identification and taxonomy of methylotroph bacteria (most important group of chlorinated methane derivative degrading bacteria) and comparing it to 16S rDNA sequencing method. Of 30 isolated methylotroph bacteria، 7 were selected. Following amplification of a portion of 16S rDNA gene by PCR and sequencing، a phylogenic tree was constructed. By FTIR method، transmittance spectra of these bacteria were obtained in infrared region 400-4000 cm-1. FTIR data were analyzed by SPSS software. The dendrogram of FTIR data analysis was very similar to dendrogram of 16S rDNA sequencing. Results showed that FTIR can be used as an identification method but not yet for taxonomy. By introducing a standard method for FTIR data analysis، this method can be considered as an alternative to the 16S rDNA sequencing method.