Malic Enzyme is a Major Source of NADPH for Lipid Accumulation by Aspergillus Nidulans

Department of Biological Sciences, University of Hull, Hull HU6 7RX, UK ABSTRACT Malic enzyme was shown to be a major source of NADPH for the synthesis of storage lipid by Aspergillus nidulans. A previously produced mutant lacking malic enzyme activity ( acu K248) accumulated only half the lipid (12%, w/w, of cell dry weight) accumulated by strains of A. nidulans possessing malic enzyme. When cultivated under conditions designed not to promote the production of storage lipid all three strains of A. nidulans studied contained equivalent amounts of lipid (5%, w/w, of cell dry weight). Thus malic enzyme did not appear to be limiting the synthesis of metabolically active lipid (e.g. membrane lipids). No evidence of a role for malic enzyme in the desaturation of fatty acids was found. 1 Author for correspondence: James P. Wynn. Tel: +44 1482 465507. Fax: +44 1482 465458. Keywords: lipid biosynthesis, malic enzyme, Aspergillus nidulans