Fourier Transform Infrared (FT-IR) Spectroscopy

This research work was performed to examine the feasibility of using Fourier transform infrared (FT-IR) spectroscopy (in the mid-IR range, 4000-400 cm-1) to i) detect and identify bacterial cells. The greatest spectral variation was observed between 1800 cm-1 and 900 cm-1: for amide I band at ~1650 cm-1, amide II band at ~1540 cm-1, CH3 and CH2 of protein components around 1455 cm-1 and 1398 cm-1, P=O of the phosphodiester backbone of nucleic acids around 1242 cm-1 and 1080 cm-1, and polysaccharide compounds around 1050 - 950 cm-1. From the second derivative transformation and loadings plot, FT-IR showed the potential to detect sublethally injured and dead cells and discriminate between different types and degrees of cell injury.