Application of Attenuated Total Reflection/Fourier Transform Infrared Spectroscopy in the Screening of Strains Producing Bioactive Molecules: A Metabolomics Approach

Abstract

The Recent developments in infrared spectroscopy have made it a method of choice for metabolomics study as it provides accurate analysis with low operating costs due to availability of spectra processing software and chemometrics analysis. The aim of this work is to demonstrate the high potential application of Attenuated Total Reflection/Fourier Transform Infrared Spectroscopy (ATR/FTIR) in rapid screening of microbial strains producing bioactive molecules. In this work, 101 strains were isolated from soil samples collected from the Algerian Sahara desert. ATR/FTIR spectroscopy was applied to eliminate replicate strains. After initial screening, the obtained spectra were divided into two regions. The first, in region between 4000-2250 cm^-1, contain C-H bond stretching vibrations of methyl and methylene of fatty acid membranes, which is very helpful in discriminating Gram positive from Gram negative bacteria. The second region, between 1800-900 cm^-1(amides I and II), 1800-1500 cm^-1 (peptides and proteins), and 960 cm^-1(nucleic acids) were observed. Applying this method as first step in screening enabled us to reduce the sample number by 71.28%. Combining this technique with antibacterial test of antagonism, further reduction in strain number by 87.12% was obtained. Accordingly, total screening costs as well as time for bioactive metabolite screening program were reduced.