Mitochondrial Metabolism of Glycolate in the Alga Eremosphaera viridis

Abstract

In Eremosphaera glycolate is synthesized and can either be excreted or metabolized by the cells. All the enzymes required for the conversion of glycolate to glycerate are present in this organism. In contrast to higher plants and also to some other algae the enzymes of glycolate metabolism are located exclusively in the mitochondria. Oxidation of glycolate is catalyzed by a dehydrogenase which also has a high affinity for D-lactate. Glycolate as well as D-lactate supplied in the culture medium can be taken up and metabolized by the whole cells. The metabolism of both substrates causes an increase in respiration activity. With D-lactate the oxygen consumption is much higher than with glycolate.