Apparent diameter and cell density of yeast strains with different ploidy

Abstract

Abstract Optical density at 600 nm (OD 600 ) measurements are routinely and quickly taken to estimate cell density in cultivation and to track cell growth. The yeast Saccharomyces cerevisiae is one of the microorganisms most used in industry, and the OD 600 values are frequently adopted as the indicator of yeast cell density, according to the Beer–Lambert law. Because the OD 600 value is based on turbidity measurement, the Beer–Lambert law can be applied only for microbial cultivation with low cell densities. The proportionality constants strongly depend on several parameters such as cell size. Typically, yeast strains are categorized into haploids and diploids. It is well known that cell size of diploid yeasts is larger than haploid cells. Additionally, polyploid (especially triploid and