Growth, cell cultivation, cell metabolism, and the cell cycle of Candida utilis as explored by continuous phased culture

Abstract

The problem of microbial growth, centred both on the population and the cell, and studied largely in batch culture, is also accessible by open methods of continuous culture which release such growth studies from restrictions imposed by the traditional methods. Thus, continuous phased (synchrony) culture enables studies of the cell cycle to be conducted systematically under different conditions of nutrient limitation and growth rate, and allows the phenotypic changes of chemostat steady states to be expressed as patterns of "cell cycle" behaviour over the doubling time. Studies conducted with Candida utilis in this way, in carbon-, nitrogen-, phosphorus-, and other nutrient-limited growths, have revealed a variable behaviour in the cell cycle, especially in the G1 period. Such variability in cell cycle behaviour is closely linked to the nutrient control of growth in the culture and generally accords with the Monod growth theory. Such variable behaviours for the cell are examined and assessed in relation to leading contemporary models for the cell cycle.