The investigation sought to determine by means of radioactive tracer techniques, the biochemical mechanisms in the anaerobic degradation of typical organics found in wastes. Two liter laboratory scale digesters were used in all the radioactive tracer work. Substrate and nutrients were slug fed daily while carbon-14 compounds were slug fed one time or daily depending on the type of study being performed. Chemical analyses of the liquid feed and effluent were routinely performed along with identification of gaseous end products. Radioactivity analyses on the gases produced were conducted using liquid scintillation techniques. The degradation of propionic, succinic and lactic acids appear to be closely related with common intermediates. Propionic acids can be degraded through lactic or succinic acids and the reverse is true for each of the other two compounds. Propionic acid may also be metabolized by alpha or beta-oxidation giving rise to an intact methyl group in the methane formed, from either the number two or three carbon. A pathway for glutamic acid utilization was postulated involving the formation of two moles of acetic acid for each mole of substrate used. Oleic acid was primarily degraded by beta-oxidation. In the fermentation of benzoic acid, three moles of acetic acid were produced per mole degraded. (Author)

"PB198 655." Federal Water Pollution Control Administration research grant 17070/DFK. Microfiche.