The effect of aeration on lignin peroxidase production by Streptomyces viridosporus T7A was studied in a bench-scale bioreactor using a previously optimized growth medium (0.65% yeast extract and 0.1% corn oil, pH 7.0) at 37degreesC and natural pH. Airflow rates of 0.3, 1.0, and 1.5 vvm and a fixed agitation, of 200 rpm were initially studied followed by 1.0 vvm. and 200, 300, 400, and 500 rpm. The use of 1.0 vvm. and 400 rpm increased enzyme concentration 1.8-fold (100-180 U/L) and process productivity 4.8-fold (1.4-6.7 U/[L.h]) in comparison with the use of 200 rpm and 0.3 vvm. The inexpensive corn oil, used as carbon source, besides its antifoam properties, proved to be nonrepressive for enzyme production.