Chemical fractionation of phosphorus-32 labelled cells of Micrococcus lysodeikticus treated with chlorhexidine

Abstract

Abstract A method for the chemical fractionation of Micrococcus lysodeikticus into “cold trichloroacetic acid soluble”, alcohol soluble, ribonucleic acid and residual fractions is described. The results of applying this method to untreated and chlorhexidine-treated 32P labelled cells are discussed. In untreated cells the 32P content of the “cold trichloroacetic acid soluble” fraction, which constitutes the metabolic pool, increases at a rate dependent on temperature increase and there is a corresponding decrease in the 32P content of the ribonucleic acid fraction. At the highest temperature, 40°, the increase of 32P in the pool is followed by a decrease due to leakage from the pool. The release of 32P from chlorhexidine-treated cells maintained at 1 °, 20°, 30° and 40° has been measured after 0.5, 2 and 13 hr. There is an initial rapid release which is entirely from the “cold trichloroacetic acid soluble” fraction and a slower secondary release from the ribonucleic acid fraction. This secondary release is almost completely inhibited at 1° and by high (64 and 128 μ.g/ml) chlorhexidine concentrations.