THE NEED FOR CONSISTENT NOMENCLATURE AND ASSESSMENT OF GROWTH PHASES IN DIAUXIC CULTURES OF SACCHAROMYCES-CEREVISIAE

The need for consistent nomenclature and accurate assessment of late growth phases in diauxic yeast cultures is highlighted by the substantial variation of stress tolerance in Saccharomyces cerevisiae after the exhaustion of the initial fermentable carbon source. At present, a wide variety of assessment methods and confused terminology exists in the literature, leading to difficulties in the interpretation and comparison of published results. A method based on the depletion of ethanol accumulated during the respiro-fermentative growth phase is suggested as suitable for assessing subsequent growth phases and reporting results. Consistent application of nomenclature for growth phases is recommended to assist the interpretation of published experimental results. It is suggested that the phases of growth in diauxic batch culture should be referred to using the terms (1) initial lag phase, (2) respiro-fermentative phase, (3) diauxic lag phase, (4) respiratory phase, (5) stationary phase, and (6) death phase.