Uptake of L-[ 14C]-alanine by glutaraldehyde-treated and untreated spores of Bacillus subtilis

Abstract

The effect of glutaraldehyde on the uptake of L-alanine, and subsequent germination, in spores of Bacillus subtilis NCTC 8236 was examined. Germination was induced by single amino acids, D-glucose and phosphate buffer at 37°C. L-alanine was the best germinant of all amino acids tested. Pretreatment of spores with low concentrations of acid and alkaline glutaraldehyde inhibited subsequent germination, complete inhibition being observed at concentrations of 0.1% (w/v). This concentration also prevented the loss of heat resistance or spores placed in germination medium and exposed to 75°C. Radioactive studies indicated that maxium uptake of L-alanine occurred after ca. 30 min at 37°C. Only 1.2% of available L-alanine was taken up during germination. Pre-treatment of spores with glutaraldehyde did not interfere with L-alanine uptake at aldehyde concentrations up to 0.5% (w/v). However, this was significantly reduced at a glutaraldehyde concentration of 1.0% (w/v). Minimal differences were observed between acid and alkaline forms of the aldehyde. The results are discussed in terms of the mode of action of glutaraldehyde.