Avtor/Urednik		Nemec, Tamara
Naslov		Vpliv sestave gojišča na metabolizem lipidov v miceliju glive Aspergillus niger
Prevedeni naslov		Influence of substrate composition on lipid metabolism in Aspergillus niger mycelium
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		1998
Obseg		str. 81
Jezik		slo
Abstrakt		A pectolytic-enzime-producing Aspergillus niger strain was cultivated on two different media, medium with glucose and yeast extract (GYM), stimulating fungal growth and the medium optimized for pectolytic enzyme production (P). In fungal mycelia sterols and fatty acids were followed. In the optimized substrate with the addition of the nonionic detergent Teen 80 (PTW), the measured polygalacturonase activity was increased. Synthesis of total lipis on GYM medium was faster than on P and PTW, substrates. Among sterols ergosterol predominated on both media. On GYM medium higher amounts of precursors for ergosterol biosynthesis were observed thanon P and PTW. Their amounts diminished during the course of fermentation. In all lipid extracts sterol with M+376 was present and determined as ergosterol peroxide with MS and NMR for the first time with A. niger. Changes in ergosterol peroxide content during growth indicates that ergosterol peroxide could act as an intermediate in ergosterol biosynthesis or it can be formed by oxidation of ergosterol. mycelia grown on P and PTW incorporated cholesterol from dry whey. During fungal growth, the amount of free sterols was nearly constant, the differences appeared in quantities ofsterol esters. The amount of cholesterol was higher in mycelia cultivated on P substrate, however, more cholesterol was in ester form on PTW medium. Regarding the fatty acid composition, oleic, linoleic and palmitic acid predominated in all mycelial samples tested. Fungus cultivated on P and PTW accepted some fatty acids from dy whey. The oleic acid of Tween 80 was also incorporated into the cell. Only a small part of oleic acid was present as free fatty acid or as acyglycerols and sterol esters.(Abstract truncated at 2000 characters)
Deskriptorji		ASPERGILLUS NIGER CULTURE MEDIA, CONDITIONED LIPIDS STEROLS CHOLESTEROL FATTY ACIDS ERGOSTEROL