PHOTON-EMISSION FROM CHEMICALLY PERTURBED YEAST-CELLS

Photon emission (PE) rom yeast cells Saccharomyces cerevisiae strain S P-4 in normal conditions and in conditions perturbed by the addition o f formaldehyde was investigated using single-photon counting equipment . PE from yeast cells, growing in a standard nutrient medium (YPG) the n centrifuged and resuspended in a phosphate buffer (pH = 6.5), was me asured in the presence of oxygen or argon. The solution of formaldehyd e (2%) was injected into the sample. The intensity of PE increased and reached a maximum, then slowly decreased to a level which was higher than the PE level without the perturbing factor. The kinetics of PE wa s found to be strongly dependent upon the presence of oxygen. The mode l of formation and recombination of free radicals was tested. The resu lts indicate that PE can arise during the recombination reactions of f ree radicals like R. + R., RO. + RO., RO2. + RO2. which are formed in the enzymatic oxidative reactions.