The immobilisation of proteases produced by SSF onto functionalized magnetic nanoparticles : application in the hydrolysis of different protein sources
Abu Yazid, Noraziah (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)
Barrena Gómez, Raquel (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)
Sanchez, Antoni (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)

Date:	2016
Abstract:	Alkaline proteases produced from protein-rich waste (hair waste and soya residues) by solid state fermentation (SSF) were immobilised onto functionalized magnetic iron oxide nanoparticles (MNPs) using glutaraldehyde as a crosslinking agent. The covalent binding method had a better immobilisation yield compared to simple adsorption, retaining 93%-96% (459 ± 106 U/mg nanoparticles, 319 ± 34 U/mg nanoparticles) of hair waste and soya residues proteases, respectively after crosslinking with 5% glutaraldehyde for 6 h. However, the adsorption immobilisation yield was 47%-54% after 8 h for both proteases. MNPs and immobilised proteases were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and electron diffraction. Our results indicated successful crosslinking between the proteases and amino-functionalized MNPs. The operational stability (pH and temperature) and storage stability of free and immobilised enzyme were also analysed. Despite the fact that the optimum pH of free and immobilised proteases was identical in the alkaline region, the immobilised proteases reached their optimum condition at higher temperatures (40 °C-60 °C). After 2 months of storage at 4 °C, the immobilised proteases showed good stability, retaining more than 85% of their initial activity. The high magnetic response of MNPs render an ease of separation and reusability, which contributes to the residual activity of both immobilised proteases on MNPs retaining more than 60% of their initial values after seven hydrolytic cycles. These results showed the enhancement of the stability of the crosslinking interactions between the proteases and nanoparticles. The immobilised proteases were capable of hydrolysing selected proteins (casein, oat bran protein isolate, and egg white albumin). However, differences in the degree of hydrolysis were observed, depending on the combination of the protease and type of substrate used.
Grants:	Ministerio de Economía y Competitividad CTM2015-69513-R
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Protease ; Protein-rich waste ; Solid state fermentation ; Hydrolysis ; Immobilisation
Published in:	Journal of molecular catalysis B: enzymatic, Vol. 133, Supplement 1 (Nov. 2016) , p. S230-S242, ISSN 1381-1177

DOI: 10.1016/j.molcatb.2017.01.009

Preprint 40 p, 2.0 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Engineering > Composting Research Group (GICOM)
Articles > Research articles
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