초록
<P>The simultaneous production of amylase (<I>AA</I>) and protease (<I>PA</I>) activity by <I>Bacillus subtilis</I> UO-01 in brewery wastes was studied by combining the response surface methodology with the kinetic study of the process. The optimum conditions (<I>T</I> = 36.0 °C and pH = 6.8) for high biomass production (0.92 g/L) were similar to the conditions (<I>T</I> = 36.8 °C and pH = 6.6) for high <I>AA</I> synthesis (9.26 EU/mL). However, the maximum <I>PA</I> level (9.77 EU/mL) was obtained at pH 7.1 and 37.8 °C. Under these conditions, a considerably high reduction (between 69.9 and 77.8%) of the initial chemical oxygen demand of the waste was achieved. In verification experiments under the optimized conditions for production of each enzyme, the <I>AA</I> and <I>PA</I> obtained after 15 h of incubation were, respectively, 9.35 and 9.87 EU/mL. By using the Luedeking and Piret model, both enzymes were classified as growth-associated metabolites. Protease production delay seemed to be related to the consumption of non-protein and protein nitrogen. These results indicate that the brewery waste could be successfully used for a high scale production of amylases and proteases at a low cost.</P>