Summary
The growth of several Pythium species is increased between 65 and 100% if cholesterol is added to the growth medium. The optimum concentration is 15 mcg per ml. Mycelium of Pythium ultimum, in which cholesterol is present, incorporates glucose-U-14C and releases 14CO2 at a faster rate than the corresponding sterol free mycelium. In sterol containing cells, more 14CO2 is produced from a given amount of absorbed glucose-U-14C than in sterol free cells, there is thus in sterol containing hyphae a higher level of energy production. This condition can account for the increase in growth due to cholesterol. Only if sterols are present in the cellular membranes of Pythium species is the optimum synthetic capacity reached.
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Schlösser, E., Gottlieb, D. The effect of sterols on the metabolism of Pythium species. Archiv. Mikrobiol. 61, 246–253 (1968). https://doi.org/10.1007/BF00446610
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DOI: https://doi.org/10.1007/BF00446610