FTIR microspectroscopic investigation of Lactobacillus paracasei apoptosis induced by cisplatin

Recent studies have shown that bacteria can also undergo apoptosis, which has gradually attracted researchers' attention. Cisplatin is a first-line drug to treat several cancers, but it can damage beneficial bacteria. Hence it is very important to explore the damage mechanism of cisplatin on beneficial bacteria. In this study, Lactobacillus paracasei, one kind of beneficial bacteria, was used as the model to investigate cisplatin damage. Conventional detection showed that cisplatin induced the apoptosis of Lactobacillus paracasei. Then Fourier transform infrared (FTIR) microspectroscopy was used to detect biomacromolecular changes in Lactobacillus paracasei apoptosis, and the following results were obtained: ① Second derivative IR spectra showed the changes of DNA, proteins, polysaccharides and lipids; ② Peak-area ratios suggested the changes of the protein and lipid structure and the decrease of DNA content; ③ Principal component analysis (PCA) further revealed significant changes in the DNA and protein content/structure. This study may have a new insight into the adverse reaction mechanism of cisplatin on Lactobacillus, moreover, it suggests that FTIR microspectroscopy may be a useful supplementary tool for investigating bacterial apoptosis.