PRECISE MEASUREMENT OF THE CHANGE OF STATISTICAL DISTRIBUTION OF CELL SIZE OCCURRING DURING THE SYNCHRONOUS CULTURE OFCHLORELLA

摘要

Change of statistical distribution of cell size occurring in the synchronous culture ofChlorella ellipsoideawas followed by using a COULTER counter. The culture was started using a population of D-cells which showed a sharp distribution of cell size. During the growth phase, there occurred characteristic changes in the height and shape of the distribution curve; namely, the height first decreased with broadening of the distribution and then increased to the level even higher than the original peak. The broadening of the curves, which indicates the lowering of degree of homogeneity of population, occurred during the period of most active growth, and the homogeneity was restored at later stages of ripening where the growth became sluggish. When the ripened cells (L3) were transferred to the darkness their volume decreased to some extent before the occurrence of cellular division. It was assumed that the shrinkage of cells observed may be partly due to exudation of water from the cells and partly to the consumption of fuel material caused by enhanced respiration, both having been shown to occur at the stage of cell maturation.