Development of a rapid and highly sensitive biochemical method for the measurement of fungal spore viability. An alternative to the CFU method

Abstract 1 A biochemical method, based on dehydrogenase activity (DHA) measurement, has been developed as an alternative to colony forming unit (CFU) enumeration, for assessing the viability of fungal spores. In viable cells, a tetrazolium salt (MTT) is reduced to a coloured formazan (MTTf) by cellular dehydrogenase enzymes. From the colorimetric assay developed by Mosmann for mammalian cells, the procedure has been adapted and optimised using P. digitatum spores as a model. Propan-2-ol has been selected as the best solvent to extract the MTTf from the spores. The sensitivity of the method has been considerably increased by determining the optimal conditions of incubation for the MTT reduct…