THE SUCCINOXIDASE SYSTEM INASPERGILLUS NIGER

Abstract

The succinoxidase system of Aspergillzrs niger differs from that of avian and mammalian tissues in its greater lability during preparation and storage but is similar in its sensitivity to malonate, cyanide, azide, and B.A.L., its association with cell particles, and its single pH optimum a t pH 7.3. T h e system is not inhibited by arsenite in concentrations up to 0.01 M. MethodsAspergillus niger, N.R.C. 233, was grown in 200 ml. lots of a medium containing 3% malt extract, 0.5Yo yeast extract, and ly0 glucose in 1-liter shake flaslts a t 26'. The growth (15-20 gm.) from two 18 to 20 hr. cultures was washed with water by filtration and the pressed pad of mold was then frozen in powdered dry ic% When completely frozen, the pad was ground for 30 min. in a mortar paclted in dry ice, with twice its weight of acid-washed Manzucript

Aconitase and Isocitric Dehydrogenases of Aspergillus niger in Relation to Citric Acid Production

“…It was essentially that used by Martin (1954) and consisted of 1 yo glucose, 8% malt extract, and 0.5% yeast extract dispensed in 100 ml. volumes in 500 ml.…”

THE METABOLISM OF MALONATE BY MYCELIAL SUSPENSIONS OF ASPERGILLUS NIGER

“…It has been shown that the TCA cycle is operative during the growth of cultures of A. niger (Ramakrishnan, 1954;Ramakrishnan and Martin, 1954;Yeoman, i960). Martin (1954) detected a conventional succinoxidase system in this fungus. The conclusion that such a system is operating in the cellular oxidation of sugars and other normal metabolites in this fungus was strengthened by the detection in Experiments C and D of labelled cyclic acids after feeding mycelia with radioactive malonate.…”