A commercial amylase (amy) was immobilized by adsorption onto Luffa operculata fibers (LOFs). The derivative LOF-amy presented capacity to hydrolyze starch continuously and repeatedly for over three weeks, preserving more than 80% of the initial activity. This system hydrolyzed more than 97% of starch during 5？min, at room temperature. LOF-amy was capable to hydrolyze starch from different sources, such as maize (93.96%), wheat (85.24%), and cassava (79.03%). A semi-industrial scale reactor containing LOF-amy was prepared and showed the same yield of the laboratory-scale system. After five cycles of reuse, the LOF-amy reactor preserved over 80% of the initial amylase activity. Additionally, the LOF-amy was capable to operate as a kitchen grease trap component in a real situation during 30 days, preserving 30% of their initial amylase activity. 1. Introduction Amylases figure among the most studied enzymes for biotechnology and industrial purposes [1, 2]. They are used in many industrial fields, including food, detergent, textile, and paper industries [3–5]. A main problem of food industries, particularly bakeries, pastries, and industrial kitchens, is the starch waste produced from machines, cans, and containers washing. This waste can obstruct industrial ducts causing several damages and financial losses. An alternative to avoid these losses is the continuous use of detergents containing high concentration of amylase. Nevertheless, they are more expensive than the nonenzymatic detergents, making them not attractive and impracticable for small business. To solve these inconvenient, immobilized enzymes may play a remarkable role, once their main advantage is the repeated use, which considerably reduces the costs [6–8]. Among the several available methods of immobilization, adsorption is the cheapest one considering the reagents and time employed [9–13]. This method should be considered when the costs of the final product are a limiting factor for the process. For this purpose, the material of the support must be considered, once its destination cannot cause environmental damages. Natural organic materials are promising candidates for large-scale processes, because of their biodegradability behavior, permitting the use of these substances as clean devices in the environment . In this study, a commercial thermostable -amylase was immobilized by adsorption onto Luffa operculata fibers (LOFs). The system LOF-amy was used for continuous starch hydrolysis and wastewater treatment in kitchen grease traps. 2. Material and Methods Luffa operculata L. fruits
J. C. Soares, P. R. Moreira, A. C. Queiroga, J. Morgado, F. X. Malcata, and M. E. Pintado, “Application of immobilized enzyme technologies for the textile industry: a review,” Biocatalysis and Biotransformation, vol. 29, no. 6, pp. 223–237, 2011.
M. Soleimani, A. Khani, and K. Najafzadeh, “α-amylase immobilization on the silica nanoparticles for cleaning performance towards starch soils in laundry detergents,” Journal of Molecular Catalysis B, vol. 74, no. 1-2, pp. 1–5, 2012.
G. Bayramo？lu, M. Yilmaz, and M. Y. Arica, “Immobilization of a thermostable α-amylase onto reactive membranes: kinetics characterization and application to continuous starch hydrolysis,” Food Chemistry, vol. 84, no. 4, pp. 591–599, 2004.
E. F. Barbosa, F. J. Molina, F. M. Lopes, P. A. García-Ruíz, S. S. Caramori, and K. F. Fernandes, “Immobilization of peroxidase onto magnetite modified polyaniline,” The Scientific World Journal, vol. 2012, Article ID 716374, 5 pages, 2012.
S. S. Caramori, K. F. Fernandes, and L. B. Carvalho-Junior, “Immobilized horseradish peroxidase on discs of polyvinyl alcohol-glutaraldehyde coated with polyaniline,” The Scientific World Journal, vol. 2012, Article ID 129706, 8 pages, 2012.
A. L. Toledo, J. B. Severo Jr., R. R. Souza, E. S. Campos, J. C. C. Santana, and E. B. Tambourgi, “Purification by expanded bed adsorption and characterization of an α-amylases FORILASE NTL from A. niger,” Journal of Chromatography B, vol. 846, no. 1-2, pp. 51–56, 2007.
Y. C. Liao and M. J. Syu, “Novel immobilized metal ion affinity adsorbent based on cross-linked β-cyclodextrin matrix for repeated adsorption of α-amylase,” Biochemical Engineering Journal, vol. 23, no. 1, pp. 17–24, 2005.
M. Reiss, A. Heibges, J. Metzger, and W. Hartmeier, “Determination of BOD-values of starch-containing waste water by a BOD-biosensor,” Biosensors and Bioelectronics, vol. 13, no. 10, pp. 1083–1090, 1998.
D. Gangadharan, K. M. Nampoothiri, S. Sivaramakrishnan, and A. Pandey, “Immobilized bacterial α-amylase for effective hydrolysis of raw and soluble starch,” Food Research International, vol. 42, no. 4, pp. 436–442, 2009.
A. Kumari and A. M. Kayastha, “Immobilization of soybean (Glycine max) α-amylase onto Chitosan and Amberlite MB-150 beads: optimization and characterization,” Journal of Molecular Catalysis B: Enzymatic, vol. 69, no. 1-2, pp. 8–14, 2011.
F. Wang, Z. Gu, Z. Cui, and L. Liu, “Comparison of covalent immobilization of amylase on polystyrene pellets with pentaethylenehexamine and pentaethylene glycol spacers,” Bioresource Technology, vol. 102, no. 20, pp. 9374–9379, 2011.
M. S. Hernández, M. R. Rodríguez, N. P. Guerra, and R. P. Rosés, “Amylase production by Aspergillus niger in submerged cultivation on two wastes from food industries,” Journal of Food Engineering, vol. 73, no. 1, pp. 93–100, 2006.