Real-time monitoring of Bacillus subtilis endospore components by attenuated total reflection Fourier-transform infrared spectroscopy during germination

Chemical changes of particular Bacillus subtilis spore components were monitored by attenuated total reflection Fourier-transform infrared spectroscopy (ATR/FTIR) during spore germination on a ZnSe internal reflection element. Within minutes of the initiation of spore germination, significant changes in the amount of calcium dipicolinate (DPA-Ca) and proteins were noted in the wild-type strain. The changes in a germination mutant (strain 1G9, gerD) were similar to those in the wild-type strain, but the rates of change were slower. The changes in another germination mutant (strain 1G7, gerA) were very different from those in the first two strains: germination was slow and incomplete, and proteins and DPA-Ca remained unaltered throughout the course of the germination study. This technique thus offers a sensitive and non-destructive method for real-time monitoring of various cellular components during spore germination.