چکیده (انگلیسی):

The simultaneous production of amylase (AA) and protease (PA) activity by Bacillus subtilisUO-01 in brewery wastes was studied by combining the response surface methodology withthe kinetic study of the process. The optimum conditions (T = 36.0◦C and pH = 6.8) for highbiomass production (0.92 g/L) were similar to the conditions (T = 36.8◦C and pH = 6.6) forhigh AA synthesis (9.26 EU/mL). However, the maximum PA level (9.77 EU/mL) was obtainedat pH 7.1 and 37.8◦C. Under these conditions, a considerably high reduction (between 69.9and 77.8%) of the initial chemical oxygen demand of the waste was achieved. In verificationexperiments under the optimized conditions for production of each enzyme, the AA andPA obtained after 15 h of incubation were, respectively, 9.35 and 9.87 EU/mL. By using theLuedeking and Piret model, both enzymes were classified as growth-associated metabolites.Protease production delay seemed to be related to the consumption of non-protein andprotein nitrogen. These results indicate that the brewery waste could be successfully usedfor a high scale production of amylases and proteases at a low cost.© 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. This isan open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).