DEGRADATION OF AMINO-ACIDS AT A SIMULATED WATER-SEDIMENT INTERFACE OF A MEDITERRANEAN LAGOON ENVIRONMENT, GOLFE DU LION

The degradation of the labeled amino acids 14C arginine and 3H lysine at the simulated water-sediment interface of a Mediterranean lagoon was studied. The 4 day experiments included respiratory activity measurements using both aerobic and anaerobic sediments and the study of incorporation processes in specific organic fractions. After active mineralization of the 14C arginine, which occurred during the 1st day, the radioactivity in the acid-soluble fraction decreased and polycondensed products were progressively incorporated. The radioactivity of the 3H lysine was included mainly in the acid-soluble fraction. The nature of the substrate, and the reducing conditions in the environment affected the radioactivity distribution in the organic fractions. The identification of amino acids in the acid-soluble and base-soluble fractions shows that the labeled arginine and lysine released from the initial compounds are important quantitatively.