Rice husk ash as a potential carrier for the immobilization of lipases applied in the enzymatic production of biodiesel

Abstract

The potential application of rice husk ash (RH26) as support for the immobilization of a recombinant Rhizopus oryzae (rROL) lipase as biocatalyst in the enzymatic biodiesel production using alperujo oil and the comparison with commercial hydrophobic support OD403 (RelOD) has been made. Although the specific activity (UA mg support À1 ) was around one-half lower in RH26 than in RelOD when they were used as biocatalyst in biodiesel reaction, the normalized initial rate was similar, between 1.6 and 2.4 lmol FAME mL À1 mL À1 UA À1 . Thus in terms of biocatalysis performance, rice husk as is an alternative to commercial supports. However, the main problem is the more complex recovery of RH26 for the reutilization compared with commercial ones. ARTICLE HISTORY

Enzymatic Production of Biodiesel Using Immobilized Lipase on Core-Shell Structured Fe3O4@MIL-100(Fe) Composites

“…In this case, the enzymatic activity recovery was shown to increase from 34.1% to 63.5% by enhancing the lipase concentration from 1.0 mg/mL to 2.0 mg/mL; however, further increment in the lipase concentration beyond 2.0 mg/mL led to decreased activity recovery. A similar phenomenon has also been observed in several previous studies [12,[33][34][35]. At a low lipase concentration, the low activity recovery was attained owing to less amounts of bound lipase.…”

“…In this regard, various methods for lipase immobilization, including physical adsorption, covalent binding, as well as hydrophobic ion affinity ligation, have been extensively explored so far. In particular, covalent binding approach is deemed to be a viable and appealing method for the immobilization of a lipase by the tight fixation of the enzyme against its leaching from the support [11][12][13].Over the past decades, a growing attention has been paid to porous nanomaterials that can be employed as an important support for enzyme immobilization because of their large surface area and low mass transfer resistance [14]. The reduction in the size of the immobilized lipase can permit better exposure to and access of the active sites.…”

“…In most cases, the recycling of immobilized lipases with small sizes is difficult, making these conventional separation methods time-consuming and inefficient. Moreover, the inevitable loss of the biocatalysts in the separation processes can also preclude their wide practical application [12,14]. From a sustainability point of view, it is still of great demand to fabricate a novel enzyme support with the aim of improving the separation performance of the immobilized lipase.…”

“…In this regard, various methods for lipase immobilization, including physical adsorption, covalent binding, as well as hydrophobic ion affinity ligation, have been extensively explored so far. In particular, covalent binding approach is deemed to be a viable and appealing method for the immobilization of a lipase by the tight fixation of the enzyme against its leaching from the support [11][12][13].…”

Progress in Enzymatic Biodiesel Production and Commercialization

“…For immobilized lipase, a smaller-sized carrier can permit better exposure to the active sites but also causes problems in separating the lipase from the reaction mixture [35,36]. Using magnetic materials as lipase support helps to quickly separate the lipase by introducing external magnets with minimal mass loss.…”