Oxalate synthesis was rigorously investigated in a wood-decaying fungus, Gloeophyllum trabeum, using 13C metabolic flux analysis, a method not previously explored in this type of system. Peroxisomal glyoxylate dehydrogenase and cytosolic oxaloacetate acetylhydrolase were found to contribute to the majority of oxalate synthesized under low and high nitrogen conditions, respectively.
