The biosorption of invertase onto three wood sawdust species Meranti wood sawdust (MWS), Keruing wood sawdust (KRWS) and Kempas wood sawdust (KPWS) in immobilization system was studied and equilibrium isotherm was determined. The experimental data have been analyzing by using the Langmuir and Freundlich linear and nonlinear regression form. The maximum loading calculation study revealed MWS (16.2614 ɥgg-1) as the most potential biosorbent and KPWS showed as least significant with only (10.2978 ɥgg-1). In order to determine the best fit isotherm, three error analysis methods were used to evaluate the data. The error values demonstrated that both equation demonstrated that the models for the three sets of experimental data is adequate with no significance difference value (>5%).
Invertase or also called β-D-Fructofuranoside, Fructohydrolase, β-Fructofuranosidase, sucrase, Invertin, saccharase; EC 220.127.116.11 catalyses the hydrolysis of sucrose and related to the simplest commercial carbohydrates which is Fructooligosaccharides (FOS) (Kotwal & Shankar, 2009). Invertase was immobilized on organic and inorganic materials such as cellulose, Sephadex, Sepharose and polystyrene resins (Danisman, Tan, Kacar, & Ergene, 2004),(D’Souza & Godbole, 2002),(David, Sun, Yang, & Yang, 2006)&(Cadena et al., 2010). Major drawback by using chemical polymers and synthetic for enzyme immobilization in food industry is they are highly toxic to recycle numerous times, expensive and will be a list of industrial schedule waste. According to Mahmood (2007), lignocellulosic materials especially sawdust has hydrophilic character and the great number of hydroxyl groups on the surface. It is capable of chemical reaction and gave the highest immobilization yield 80, 84 % respectively (Mahmoud, 2007). Biosorbents like wood sawdust which is biomass and naturally abundant intended for bioremediation environmental applications. It is capable to retain the enzyme activity without affecting the location of active sites, high superficial micro porous area and degradable materials that did not harms the environment for disposal purpose (Tisnadjaja, Gutierrez, & Maddox, 1996). The invertase immobilization on wood sawdust requires the mechanism of biosorption applicability of sorption processes as a unit operation (Wahab, Jellali, & Jedidi, 2010).
Numerous study on enzyme immobilization via adsorption reported such as catalase on microbeads (Bayramoglu, Karagoz, Yilmaz, Bicak, & Arica, 2011), β-glucosidase on different soil colloids (Yan et al., 2010), catalase on chitosan beads (Ran et al., 2010) and lipase on silica aerogels (Kharrat, Ali, Marzouk, Gargouri, & Karra-Châabouni, 2011) but none of them examined each of the adsorption parameters equation in describing the profound adhesion and diffusion mechanism. The elucidation of the mechanism of biosorption is necessary to enable the food technology to be developed (Bai & Abraham, 2003). Such mechanisms are complicated...