title: Ergosterol synthesis and population analysis of a fed-batch fermentation in Saccharomyces cerevisiae.
abstract: Saccharomyces cerevisiae with an increased content of ergosterol or delta 5,7-sterols, growing on a molasses medium with a feed of ethanol and (NH4)2HPO4, was analyzed as to the age of cell population. The analysis was done by centrifugation in a dextran gradient and by a fluorescence-microscopic technique. In the phase of batch fermentation at a mean specific growth rate of 0.22 h-1 daughter cells contained less than 1% ergosterol while the ergosterol content of mother cells depended on the time of cultivation, a maximum level (4%) being found after two generation times. In the fed-batch phase at a mean growth rate of 0.052 h-1, both daughter and mother cells contained about the same amount of ergosterol (4.7-5.5%). Differences between daughter and mother cells are discussed in view of the relationship between the growth rate and the growth cycle.
mesh_terms: D004875:Ergosterol / Q000096:biosynthesis*; D005285:Fermentation; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D013997:Time Factors
chemical_list: D004875:Ergosterol