Cell cycle and post cycle changes during continuous phased growth of Candida utilis

Abstract

A modification of the continuous phased culture method is described. This permits examination of changes taking place during the cell cycle (cell cycle changes) to be extended into the following period (postcycle changes).Candida utilis was grown on a glucose medium under conditions of carbon and nitrogen limitation. In nitrogen-limited growth, the size of the amino acid pool changed between the cell cycle and postcycle, but remained relatively constant for both periods in carbon-limited growth. In carbon-limited growth, the carbohydrate composition of the cells was relatively little changed, but considerable changes occurred in nitrogen-limited cells during cell cycle and postcycle periods. Changing patterns in phospholipid contents were also observed during cell cycles and postcycles of both carbon- and nitrogen-limited growths.Qualitative and quantitative changes in various cell components were related to the nutrient limiting to growth and the pattern of its use by the cells. The results illustrate the influence of environmental change upon the cell and are discussed in relation to aspects of primary and secondary metabolism in the cell.