GROWTH DEPENDENT LUMINESCENCE FROM CULTURES OF NORMAL and RESPIRATORY DEFICIENT SACCHAROMYCES CEREVISIAE

Abstract

Abstract—Luminescence was detected from oxygenated, liquid cultures of the yeast Saccharomyces cerevisiae with a photon counter sensitive between 200 and 600 nm. Four periods of emission were observed: (1) during the late exponential phase (137 ± 6 counts s−1); (2) during the early stationary phase (118 ± 24 counts s−1); (3) during the late stationary phase (ca. 1000 counts s−1); and (4) during the very late stationary phase (ca. 1000 counts s−1). Emissions (3) and (4) have not been previously reported. Experiments in which the yeast was temporarily separated from the nutrient medium suggested that all of the luminescences arose from within the yeast cell. Respiratory deficient (“petite”) mutants of S. cerevisiae gave similar emissions, except that the first and third emission peaks were more intense and an early shoulder appeared on the first peak. All of the emissions from normal and “petite” cultures disappeared when the yeast was grown anaerobically. It was concluded that the luminescences do not arise from any of the reactions in the fermentative and respiratory pathways and that O−2, may be involved in the processes leading to emission.