Quantification of cell size distribution as applied to the growth of Corynebacterium glutamicum

Abstract

It is known that the cell size is related to the physiological state of a cell. Therefore, cell size distribution directly reflects the average physiological properties of the cell culture. Cell size distribution can be enumerated by image analysis, flow cytometry and coulter counter. In this study, image analysis was used to characterize the cell size distribution during the growth of Corynebacterium glutamicum and was further analyzed by a distribution function. The parameters of the distribution function indicate the mean value and spread of the distribution. Analysis demonstrated that the maximum specific growth rate was higher (0.67 h⁻¹) for the growth obtained through serial dilution of seed as compared to growth from a normal seed culture (0.53 h⁻¹). This was due to a greater percentage of the cell population being in the state of division for the growth through serial dilution in the mid-log phase. The measurement of the cell size distribution demonstrated that the average cell size decreased during the course of growth. The distribution function was also used to enumerate the average specific growth rate of both the conditions of the culture. The demonstrated methodology can be used to predict an average growth property of a cell culture.