Rapid determination of total biomass from a yeast fermentation using sequential injection

Abstract

An assay for the measurement of the total biomass in an unfiltered fermentation sample has been developed using a simple sequential injection system, with either total transmitted light or light scattered at 90° as the analytical signal. The biomass is determined without pre-treatment or dilution of the original sample. In the past, the use of unfiltered bioprocess samples in flow injection has been avoided due to problems associated with a complex sample matrix, e.g., cell aggregation, clogging of the flow system, cells sticking to tubing walls and cross contamination. The sample range for the assay is 0.2 to at least 80 g l–1 biomass with relative standard deviations of <3%. The results from a single assay are available 3 min after assay initiation.