Age-related changes in the pH of the medium, fatty acid composition and biosynthesis of fatty acids in various subcellular fractions have been studied in submerged cultures of P. chrysogenum harvested at pH's 7.2, 4.8, 4.4 and 3.8. 14C - labeled lauric and myristic acids were each incubated with cell fractions prepared by sonification and fractional centrifugation. Products were analyzed by thin layer chromatography, gas liquid scintillation spectrometry. Conversion of labeled precursors into longer chain saturated and unsaturated fatty acids was employed as a measure of the activity of the various cell fractions.It was found that between pH 4.8 and 4.4 of the age of the culture a period of maximum fatty acid synthesis occured at the time when glucose was being taken up to a greatest extent from the medium and when cells start rapidly increasing in growth. This correlated to the increased rate of de novo synthesis in the soluble cytoplasmic fraction.The fermentation products, formic, acetic, proprionic, butyric and gluconic acid, produced at different time points of the age of the culture, accounted for the drop in the pH of the medium.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/181032 |
| Date | 03 June 2011 |
| Creators | Zoghbi, Sami S. |
| Contributors | Bennett, Alice S. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | x, 70 leaves ; 28 cm. |
| Source | Virtual Press |
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