Determination of intracellular dehydrogenase activities using flow injection analysis

Reproducible rapid methods for cell disintegration in miniaturized flow cells were developed. The disintegration of yeast cells by ultrasonics and ultraturrax in a miniaturized flow through chamber was compared with the mixer mill disintegration. The flow through chamber was combined with a sterile on-line sampling device to take samples from yeast cell suspensions and with an automated flow injection analysis (FIA) set-up, to determine the released enzyme activities. The FIA set-up was tested with the sequential determination of malate dehydrogenase, formate dehydrogenase and formaldehyde dehydrogenase in mixtures. The automated FIA determination of the intracellular formate dehydrogenase of yeast cells (Hansenula polymorpha) was performed.