Immobilization of Trypsin in Lignocellulosic Waste Material to Produce Peptides with Bioactive Potential from Whey Protein

In this study, trypsin (Enzyme Comission 3.4.21.4) was immobilized in a low cost, lignocellulosic support (corn cob powder-CCP) with the goal of obtaining peptides with bioactive potential from cheese whey. The pretreated support was activated with glyoxyl groups, glutaraldehyde and IDA-glyoxyl. The immobilization yields of the derivatives were higher than 83\%, and the retention of catalytic activity was higher than 74\%. The trypsin-glyoxyl-CCP derivative was thermally stable at 65 degrees C, a value that was 1090-fold higher than that obtained with the free enzyme. The trypsin-IDA-glyoxyl-CCP and trypsin-glutaraldehyde-CCP derivatives had thermal stabilities that were 883-and five-fold higher, respectively, then those obtained with the free enzyme. In the batch experiments, trypsin-IDA-glyoxyl-CCP retained 91\% of its activity and had a degree of hydrolysis of 12.49\%, while the values for trypsin-glyoxyl-CCP were 87\% and 15.46\%, respectively. The stabilized derivative trypsin-glyoxyl-CCP was also tested in an upflow packed-bed reactor. The hydrodynamic characterization of this reactor was a plug flow pattern, and the kinetics of this system provided a relative activity of 3.04 +/- 0.01 U . g(-1) and an average degree of hydrolysis of 23\%, which were suitable for the production of potentially bioactive peptides.Juliana Cristina Bassan thanks Brazilian Agency FAPESP (Process 2012/07680-4 and 2014/12563-2) for financial support. The authors also thank Rafael Rodrigues Hatanaka from CEMPEQC and LME-IQ (Chemistry Institute-UNESP) for infrared analysis and Scanning Electronic Microscopy facilities. Andre Ferraz (Engineering School of Lorena/EEL-USP) for the porosity analysis. Marco Filice thanks Spanish Ministry of Economy and Competitiveness (MINECO) for the research grant SAF2014-59118-JIN (Programa Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad 2014: ``Proyectos de I+D+i para jovenes investigadores´´), and co-funding by Fondo Europeo de Desarrollo Regional (FEDER).S