The actinomycete Streptomyces sp. QM-B814 is able to use polymeric glucaris as sole carbon source by the induction of specific extracellular enzymatic systems. Carboxymethylcellulose and barley beta-glucan were the most effective inducers of endoglucanase activities towards beta-(1,4) and mixed beta-(1,3)-(1,4) linkages. Avicelase activity was induced by Avicel and carboxymethylcellulose. The higher activity towards filter paper (cellulase) was measured in cultures growing in Avicel, carboxymethylcellulose, and barley beta-glucan. Laminarinase activity was induced only by laminarin and lichenan failed to induce significant activity levels against any of the substrates tested.