PERFORMANCE OF LOOFA-IMMOBILIZED Rhizopus oryzae IN THE ENZYMATIC PRODUCTION OF BIODIESEL WITH USE OF OLEIC ACID IN n-HEXANE MEDIUM

Abstract

-The performance of loofa-immobilized Rhizopus oryzae (as a whole-cell biocatalyst) in the synthesis of methyl oleate was evaluated using oleic acid as a model substrate. The activities of the cell-bound lipase in terms of the esterification and hydrolysis reactions were found to be higher for the immobilized cells as compared with those of the free cells. The time to reach equilibrium for methyl oleate synthesis was 12 h in the presence of n-hexane (hexane:oleic acid ratio 9:1(v/v)), and the yield was 80%. In the absence of solvent, equilibrium was reached after 48 h and the yield was only 30%. The moisture repellency and the hydrophilic properties of loofa sponge make this natural fiber a good candidate for cell-enzyme immobilization, especially for lipases as the interfacial enzyme.

Ultrasound-assisted lipase catalyzed hydrolysis of aspirin methyl ester

“…The solvents were selected considering different parameters such as polarity, solubility of substrate and hydrophobicity [36]. Solvents may directly affect the activity, stability and specificity of enzymes [37]. Mostly in lipase catalyzed reactions, high enzymatic activity and reaction rates are observed using solvents with low polarity [38].…”

Response Surface Optimization of Rhizopus sp. Immobilization onto Loofah Sponge Using Potato Dextrose

“…This spore suspension was filtered to remove fungal hyphae [15]. Then, the number of spores was determined by a hemocytometer [4]. Finally, a 1 ml spore suspension containing 10 6 spores was used to deliver a constant spore quantity in each experiment…”

“…Many fermentation reactions have shown enhanced productivity when processed using immobilized cell systems [2]. The system offers many benefits over usual suspended-cell fermentations including higher cell densities, and enhancement of the tolerance and efficiency of microorganisms, increases cell productivities, lowers the production cost, simplifies the process, and provides preferable cell separation from the reaction system, making continuous and semi-continuous processes applicable in various types of reactors [3][4][5].…”

“…Fungal cells can be immobilized by adsorption on a support matrix, entrapment, or by embedding with natural polymers like alginate gels and synthetic polymers like polyurethane foam or sponges [6]. The main requirements for the immobilization matrix to be employed are that the cell-carrying material is non-reactive, non-toxic, highly porous, mechanically strong enough to withstand long-term usage, and easy to use during the immobilization procedure [4,7].…”

Potencial catalítico de lipases ligadas ao micélio de fungos filamentosos em processos de biotransformação

“…Estes suportes são constituídos de material inerte com boas propriedades mecânicas e baixo custo comercial, além de possuírem elevada porosidade e ampla superfície de adsorção. 108 Entretanto, a literatura aponta outros tipos de suportes, como por exemplo, esferas de criogel obtidas a partir do álcool polivinílico (PVA) e esferas de quitosana adicionados de polivinilpirrolidona e polisfosfatos, 114-116 esferas de polihidroxibutirato -PHB e terra diatomácea -Celite, 55 partículas de bucha vegetal, [117][118] esferas de alginato de cálcio, 119 membranas de politetrafluoretileno -PTFE, 120 conforme apresentado na Tabela 1.…”