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Determination of yeast viability during a stress‐model alcoholic fermentation using reagent‐free microscopy image analysis
Author(s) -
Tibayrenc Pierre,
Ghommidh Charles,
PreziosiBelloy Laurence
Publication year - 2011
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.549
Subject(s) - propidium iodide , yeast , staining , microscopy , biology , saccharomyces cerevisiae , ethanol fermentation , viability assay , fluorescence microscope , microbiology and biotechnology , population , cell , fermentation , programmed cell death , chemistry , pathology , biophysics , biochemistry , medicine , fluorescence , genetics , apoptosis , physics , environmental health , quantum mechanics
A dedicated microscopy imaging system including automated positioning, focusing, image acquisition, and image analysis was developed to characterize a yeast population with regard to cell morphology. This method was used to monitor a stress‐model alcoholic fermentation with Saccharomyces cerevisiae . Combination of dark field and epifluorescence microscopy after propidium iodide staining for membrane integrity showed that cell death went along with important changes in cell morphology, with a cell shrinking, the onset of inhomogeneities in the cytoplasm, and a detachment of the plasma membrane from the cell wall. These modifications were significant enough to enable a trained human operator to make the difference between dead and viable cells. Accordingly, a multivariate data analysis using an artificial neural network was achieved to build a predictive model to infer viability at single‐cell level automatically from microscopy images without any staining. Applying this method to in situ microscope images could help to detect abnormal situations during a fermentation course and to prevent cell death by applying adapted corrective actions. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011