Chitinolytic, proteolytic and lipolytic enzymes could be important in the biological control of soil borne plant-pathogenic microorganisms by antagonistic microbes and in this way besides antibiotic production, the secretion of certain extracellular enzymes also could have great importance in the effectiveness of biocontrol bacilli. Some of these enzymes could directly promote the inhibition processes, while others could help the competition of the bacilli against other rhizosphere microbes. In case of five Bacillus strains, which showed excellent antagonistic effects against phytopathogenic fungi and bacteria, the secretion of some components of the protease, chitinase, cellulase, lipase and β-1,3-glucanase enzyme systems were investigated under inductive and non-inductive circumstances. Enzyme activities were measured both with classical methods and with other experimental approaches based on chromogenic enzyme substrates. The best biocontrol strains constitutively secreted chymotrypsin-like proteases and/or trypsin-like proteases, and lipases. On the contrary, the chitinase components were only secreted in chitin containing media. Cellulases and β-1,3- glucanases were produced only at very low level either in inductive media
