Enhanced esterification activity through interfacial activation and cross‐linked immobilization mechanism of Rhizopus oryzae lipase in a nonaqueous medium

Abstract

Interfacial activation via surfactant (Tween 80, Triton X-100) treatment was conducted to improve the esterification activity of Rhizopus oryzae lipase that had undergone immobilization through cross-linked enzyme aggregates (CLEA®) technique. Surfactant pretreated immobilized enzymes exhibited better esterification activity compared to free and non-pretreated immobilized enzyme (Control CLEAs) since higher conversion rates were obtained within shorter times. The superiority of surfactant pretreated CLEAs, especially Tween 80 pretreated CLEAs (T 80 PT CLEAs), were clearly pronounced when longer alcohols were used as substrates. Conversion values exceeded 90% for octyl octanoate, oleyl octanoate and oleyl oleate synthesis with T 80 PT CLEAs whereas Control CLEAs and free enzyme showed no activity. Maximum conversions were achieved in the case equal molars of the substrates or in the case excess of the alcohol to acid in cyclohexane. In solvent free medium containing equal molars of substrates the conversion rates were 85% and 87% with T 80 PT CLEAs respectively for octyl octanoate and oleyl oleate within 2 hours. T 80 PT CLEAs showed 59% of its original activity after 7 consecutive usage for oleyl oleate synthesis. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:899-904, 2016.

Enhancement of activity and reusability of lipase immobilized on magnetic mesoporous silica for the resolution of racemic secondary alcohols

“…From Table , all BCL/MMS‐ x exhibited far higher activity than the non‐immobilized BCL in terms of the conversion of 1‐phenylethanol (C%), and the enantiomeric excess of ( S )‐1‐phenylethanol (ee S ), meanwhile, achieved the same enantiomeric excess of ( R )‐1‐phenylethyl acetate (ee P ), indicating a faster reaction rate. The result can be explained by the following reasons: (a) non‐immobilized BCL got aggregated in the organic solvent, leading to low dispersion and diffusion limitation; (b) during the process of immobilization, hydrophobic isooctane promotes the interfacial activation of the BCL, thus improving its catalytic activity; (c) the large number of mesopores of the MMS‐ x facilitated the mass transfer . These favorable factors make MMS‐ x a very suitable carrier for lipase immobilization.…”

“…Immobilization of BCL was conducted according to a procedure described previously, in which BCL was completely immobilized onto magnetic mesoporous silica (MMS‐ x ) via physical adsorption and interfacial activation . First, 0.1 g MMS‐ x was dispersed in 10 mL isooctane in a vessel, and then 0.1 mL 0.1 M pH 6.5 phosphate buffer solution (PBS), which provided “essential water” and pH, was added to the above suspension.…”

Enhanced Performance of Immobilized Rhizopus oryzae Lipase on Coated Porous Polypropylene Support with Additives

“…Such an observation on ester yields indicates the effect of organic solvent towards enzyme aggregation. To avoid lipase aggregation, immobilized RoL was utilized as the lipase was configured to be more accessible to substrate [16].…”

Novel and Efficient Synthesis of Phenethyl Formate via Enzymatic Esterification of Formic Acid

“…Nine different solvents were chosen for the optimization of the Novozym 435-catalyzed esterification reaction. Almost all lipases have a hydrophobic lid attached to their active sites; i.e., they are activated, when the lid is opened in an organic solvent or oil-water surface, but not in an aqueous environment [48,49]. Therefore, only commonly used organic solvents were selected for the reaction [18,20].…”