GABRIEL A. ZAINESCU, LUMINITA ALBU, RODICA ROXANA CONSTANTINESCU STUDY OF COLLAGEN HYDROGEL BIODEGRADABILITY OVER TIME Hydrogels have drawn the interest of researchers over the past decade, due to their intrinsic properties for applications in medicine, agriculture <1,2>, food industry, pharmaceuticals, environmental protection and biomaterials, etc. Obtaining hydrogels with collagen structure by hydrolyzing pelt waste and using them for applications in agriculture is a novelty, considering that the collagen structure is currently used only in medicine. The paper presents an experimental model for obtaining hydrogels with collagenous structure from pelt waste resulting from the liming process. As a biological material, the hydrogel with collagen structure is a complex medium, optimal for the development of a variety of biodeteriogenic organisms due to a considerable amount of protein as well as the presence of lipids and carbohydrates that provide an excellent nutrient substrate for many biological species. During the phase of incorporation into the soil of the collagen hydrogel, proteolytic bacteria develop particularly, stimulated by humidity and possibly by temperature, thus producing biodegradation.The paper presents the methodology for studying the biodegradability of collagen hydrogel with encapsulated nutrients.