p. 81 - 90 THE INFLUENCE OF YEAST EXTRACT ON THE METABOLISM OF CHLORELLA SP. Iulia Voinescu and Pia-Elena Mihnea Romanian Marine Research Institute Constanta Abstract Results are given regarding the influence of yeast extract on the division rate, the synthesis of proteins and carbohydrates, as well as of a and b chlorophyllian fractions in the alga Chlorella sp., isolated from the Black Sea phytoplankton. Concentration of 10 to 300 ml % were tested. The results were positive for all concentrations, the optimum quantity being 110 ml %.