Microbial Cellulases Immobilized in/on Porous Supports
Keywords:
cellobiase, cellulase, entrapment, physical adsorbtion, sol-gel, TrichodermaAbstract
Biodegradation of cellulose by enzymatic hydrolysis using cellulases has an important value in biotechnology and the immobilization of enzyme on inorganic materials is very useful in practical applications. Enzymatic preparations with cellulase and cellobiase activities from Trichoderma viride were liophylized from the culture medium and immobilized in/on porous matrices. The methods used for immobilization were physical adsorption on ceramics and entrapment in glass sol-gel matrices using as alkoxysilane precursors tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS). The immobilization efficiency of the solid enzymatic preparations was about 60%. The immobilized enzymatic preparations were used for hydrolysis of carboxymethyl cellulose (CMC) and cellobiose at different temperature and pH values. The resulted immobilized enzymes had the same optimum pH of 4.0 in the case of cellobiase substrate and a shifted optimum pH towards the less acid side (pH 5.0) in the hydrolysis of CMC. The optimum temperature of entrapped enzyme against CMC was shifted to a lower temperature (40°C) in comparison with the native one (60°C).
References
Adsul, M.G., Bastawde, K.B., Varma, A.J., Gokhale, D.V., Strain improvement of Penicillium janthinellum NCIM 1171 for increased cellulase production, Bioresource Technology, 2007, 98, 1467-1473
Zhang Y.-H. P., Himmel M.E., Mielenz J.R., Outlook for cellulose improvement: Screening and selection strategies, Biotechnology Advances, 2006, 24, 452-481
Paljevac, M., Primožič, M., Habulin, M., Novak, Z., Knez, Z., Hydrolysis of carboxymethyl cellulose catalyzed by cellulose immobilized on silica gels at low and high pressures, Journal of Supercritical Fluids, 2007, 43, 74-80
Takimoto, A., Shiomi, T., Ino, K., Tsunoda, T., Kawai, A., Mizukami, F., Sakaguchi, K., Encapsulation of cellulose with mesoporous silica (SBA-15), Microporous and Mesoporous Materials, 2008, 116, 601-606
Reetz, M.T., Zonta, A., Simpelkamp, J., Efficient immobilization of lipases by entrapment in hydrofobic sol – gel materials, Biotechnology and Bioengineering, 1996, 49 (5), 527-534
Lowry, O.H., Rozbrough, N.J., Pan, L.A., Randall, R.J., Journal of Biological Chemistry, 1951, 193; Chem Abstr. 42, 75843 (1959)
Iordachescu, D., Dumitru, I. F., Biochimie practică, Tipografia Universităţii din Bucureşti, București, 1980, pp. 138-141
Vintilǎ, T., Dragomirescu, M., Jurcoane, S., Vintila, D., Caprita, R., Maniu, M., Production of cellulase by submerged and solid-state cultures and yeasts selection for conversion of lignocellulose to ethanol, Rom.
Diguta, C., Jurcoane, S., Israel-Roming, F., Brule, M., Mukengele, M., Lemmer, A., Oechsner, H., Studies concerning enzymatic hydrolysis of energy crops, Rom. Biotechnol. Lett., 2007, 12(2), 3203-3207
