Inhibitory Effects of Streptomycin and Colistin on the Anaerobic Digestion of Cattle Manure

Anaerobic digestion is a waste treatment technology used to break down organic matter and further convert it to useful products for energy and soil amendment applications. This biological process is highly sensitive to environmental conditions and impurities that can have inhibitory effects on methane production. This study investigates the effects of colistin and streptomycin, two antibiotics commonly administered to livestock, on the digestion of cattle manure. Volumes and compositions of biogas were monitored for a one month period. Experimental data indicated that colistin is not inhibitory at concentrations up to 1 mg/L, and that streptomycin becomes inhibitory between 8 and 80 mg/L. Future work is required to determine more precisely the levels of inhibition for both antibiotics