p. 167 - 178 AEROBIC AND ANAEROBIC BIODEGRADATION OF POLLUTANTS UNDER THE ACTION OF BACTERIA ISOLATED FROM THE BLACK SEA WATER (II). TOXICITY OF BIODEGRADATION PRODUCTS ON AQUATIC ORGANISMS Maria Mirza 1), Eliza Leonte 2), Colette Gancevici 3), Dorina Tatu-Chitoiu 3), M. Negut 3), D. Antonescu 4), L. Radu 4) 1) Romanian Marine Research Institute Constanta 2) Research and Design Institute for Wastewater Treatment Bucharest 3) Microbiology Institute "I. Cantacuzino" Bucharest 4) National Institute of Veterinary Science "Pasteur" Bucharest Abstract The acute and chronic toxicity of some final biodegradation products of resorcinol (1,3 dihydroxybenzene), orcinol (3,5 hydroxy toluene), and Black Sea oil by means of Proteus vulgaris and Escherichia coli was determined on Cyprinus carpio, Hipophthalmichthys molitrix and cladocera Daphnia magna.