Cloning and characterization of a gene encoding a malic enzyme involved in anaerobic growth in Mucor circinelloides.

A 3193 bp contiguous sequence has been cloned from the oleaginous fungus Mucor circinelloides, that contains a full-length gene encoding a putative NADP+: dependent malic enzyme (EC. 1.1.

Biochemical events leading to the diversion of carbon into storage lipids in the oleaginous fungi Mucor circinelloides and Mortierella alpina.

The biochemical events associated with the onset of lipid accumulation in Mucor circinelloides and Mortierella alpina, under conditions of nitrogen-limited growth, have been elucidated; they differ in key aspects from those described in oleaginous yeasts. The NAD+:isocitrate dehydrogenases of Mc. circinelloides and Mort.

A pre-genetic study of the isoforms of malic enzyme associated with lipid accumulation in Mucor circinelloides.

The oleaginous fungus Mucor circinelloides possesses at least six isoforms of malic enzyme (EC 1.1.1.

Evidence that the rate-limiting step for the biosynthesis of arachidonic acid in Mortierella alpina is at the level of the 18:3 to 20:3 elongase.

Mortierella alpina, a fungus used commercially as a source of arachidonic acid, 20:4(n-6), has been examined to see if growth on lipid-based carbon sources leads to repression of either fatty acid biosynthesis and/or fatty acid desaturation and elongation. Changes in the activities of ATP:citrate lyase, isocitrate lyase, carnitine acetyltransferase, malic enzyme, glucose-6-phosphate dehydrogenase and pyruvate kinase when the fungus was grown on fatty-acid-based (Tween) carbon sources were consistent with (i) the cells using the fatty acyl portion of the substrate as the sole carbon source, (ii) pyruvate kinase being the source of pyruvate for biosynthesis under these conditions and (iii) malic enzyme's major function being as a provider of NADPH for lipid biosynthesis. The abolition of fatty acid synthase activity when cells were grown on Tweens indicated the cessation of de novo fatty acid biosynthesis under these conditions.

The role of malic enzyme in the regulation of lipid accumulation in filamentous fungi.

The hypothesis is advanced that NADP(+)-malic enzyme (ME; EC 1.1.1.

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

Malic enzyme was shown to be a major source of NADPH for the synthesis of storage lipid by A previously produced mutant lacking malic enzyme activity (K248) accumulated only half the lipid (12%, w/w, of cell dry weight) accumulated by strains of possessing malic enzyme. When cultivated under conditions designed not to promote the production of storage lipid all three strains of 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.