Triglyceride degradation in soil

To study the fate of fatty wastes left by food industries in the soil, tristearin was chosen as a model molecular marker and its biodegradation followed in different types of soil in a laboratory experiment. Samples of three soils (controls and treatments) were incubated for periods of 1–4 weeks, at 20°C. A significant disappearance of total free lipids was observed. A detailed study of different lipid classes showed an increased activity by soil microorganisms. This resulted in the oxidation and hydrolysis of the added component, producing free stearic acid and esters (methyl stearate, ethyl stearate and propyl stearate). After 4 weeks, the amounts of these compounds decreased. They are certainly intermediate components in the biodegradation processes of triglycerides. The use of this pathway for the elimination of fatty wastes in soil seems to be all the more important as it is known that fatty acids, mono/diglycerides and glycerol are removed more easily than triglycerides.