Table of Contents
ISRN Microbiology
Volume 2013, Article ID 369082, 8 pages
http://dx.doi.org/10.1155/2013/369082
Research Article

Canola Cake as a Potential Substrate for Proteolytic Enzymes Production by a Selected Strain of Aspergillus oryzae: Selection of Process Conditions and Product Characterization

1Department of Food Engineering, Federal University of Maranhão, Rua Urbano Santos S/N, 65900-410 Imperatriz, MA, Brazil
2Department of Chemical Engineering, Federal University of Ceará, Avenida da Universidade 2853, 60020-181 Fortaleza, CE, Brazil
3Embrapa Tropical Agroindustry, Rua Doutora Sara Mesquita 2270, 60511-110 Fortaleza, CE, Brazil
4Embrapa Goats and Sheep, Estrada Sobral/Groaíras km 04, 62010-970 Sobral, CE, Brazil
5Embrapa Instrumentation, Rua XV de Novembro 1452, 13560-970 São Carlos, SP, Brazil

Received 17 November 2013; Accepted 4 December 2013

Academic Editors: T. Alatossava, I. Mannazzu, J. Ruiz-Herrera, and T. P. West

Copyright © 2013 Adriana C. Freitas et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Oil cakes have excellent nutritional value and offer considerable potential for use in biotechnological processes that employ solid-state fermentation (SSF) for the production of high value products. This work evaluates the feasibility of using canola cake as a substrate for protease production by a selected strain of Aspergillus oryzae cultivated under SSF. The influences of the following process parameters were considered: initial substrate moisture content, incubation temperature, inoculum size, and pH of the buffer used for protease extraction and activity analysis. Maximum protease activity was obtained after cultivating Aspergillus oryzae CCBP 001 at 20°C, using an inoculum size of 107 spores/g in canola cake medium moistened with 40 mL of water to 100 g of cake. Cultivation and extraction under selected conditions increased protease activity 5.8-fold, compared to the initial conditions. Zymogram analysis of the enzymatic extract showed that the protease molecular weights varied between 31 and 200 kDa. The concentrated protease extract induced clotting of casein in 5 min. The results demonstrate the potential application of canola cake for protease production under SSF and contribute to the technological advances needed to increase the efficiency of processes designed to add value to agroindustrial wastes.