IN VITRO PRODUCTION OF PROPIONIC ACID IN MANTLE MITOCHONDRIA OF THE SEA MUSSEL Mytilus edulis L.

Abstract

This chapter focuses on parasitic organisms that usually live under hypoxic conditions, for example, the adult liver fluke Fasoiola hepatica and the intestinal roundworm Ascavis lumbricoides form volatile fatty acids mainly propionic and acetic acid for their energy supply. Propionic and acetic acid also accumulate as end products of anaerobic energy metabolism in organisms that undergo periods of hypoxia or even anoxia. It presents a study that deals with the in vitro production of propionic acid in the mantle of Mytilus edulis. It was demonstrated that the propionic acid synthesis is localized in the mitochondria. The presence of the enzymes of the pathway can be demonstrated, that is, methylmalonyl-CoA isomerase and racemase, propionyl-CoA carboxylase, and acyl-CoA transferase. The activation of the in vitro propionic acid production by malate is also observed in mantle mitochondria of Mytilus edulis . The in vivo production of propionic acid shows a lag time of approx. 16 h of anaerobiosis at 13°C before the accumulation starts. In vivo , succinate should accumulate to a certain level to induce the propionic acid production by the pathway. The production of ATP coupled to the formation of propionate is investigated.