Baker's yeast (Saccharomyces cerevisiae) was shaken with a 53.7% soln. of (Me)(2)CHOH in phosphate buffer (pH 7) at 15.6 degrees C for 40 min. After centrifugation and washing with the buffer, the cell were mixed with the 1.5-2.5% Na alginate soln. and the suspension was added dropwise to the 1% CaCl2 soln. The obtained biocatalyst showed high activity in the H2O2 decompn. It was easy to sep. from the reaction medium and could be reused. The biocatalyst was most effective at 20 degrees C and lost 50% of its initial activity only after a 15 cycle of use.