Characterization of yeast cultivations by steric sedimentation field-flow fractionation.

The characterization and quantification of biomass is often time consuming and dependent on the cultivation media and gives no detailed information between cell size and shape and their productivity. By monitoring the bioprocess with steric sedimentation field-flow fractionation (Sd/StFFF) in combination with laser light scattering, not only cell growth, but also the variation of cell size and shape during the cultivation, can be observed. In this work, the feasibility of separating and characterizing cell populations by steric sedimentation field-flow fractionation is demonstrated by its application to three different yeast cultivation broths. For this purpose samples which were collected at different cultivation times were injected into an FFF system. Fractograms were obtained in less than 4 min. Due to the relatively high resolution of the method, a cell sample could be fractionated in several subpopulations differing in their size as well as in their number of buds.