Non-selective hydrolysis of tuna fish oil for producing free fatty acids containing docosahexaenoic acid

Immobilization and bioimprinting strategies to enhance the performance in organic medium of the metagenomic lipase LipC12

The present work evaluates the immobilization of LipC12 on different supports in tandem with bioimprinting technique, in order to improve its activity and stability in organic medium. Oleic acid was selected as the bioimprinting molecule. The immobilized LipC12 was applied in the synthesis of pentyl oleate by esterification reaction and in the production of fatty acids, mono, and diglycerides via hydrolysis of triacylglycerols, in n-heptane reaction media. For all immobilized lipase preparations, an increase in the conversion of oleic acid to pentyl oleate was observed when immobilization in tandem with bioimprinting treatment was carried out versus immobilization without bioimprinting. The highest conversions were achieved using LipC12 immobilized on hydrophobic supports. The reuse potential of the immobilized preparations was evaluated. The preparations were used in eight successive cycles of esterification reactions and the best results were obtained for LipC12 immobilized on Immobead 150 and chitosan. The activity for the hydrolysis of soybean oil was improved by bioimprinting treatment only for LipC12 immobilized on commercial polypropylene and Accurel MP-1000. LipC12 immobilized on hydrophilic supports or on Immobead150 could be used to hydrolyze tricaprylin to obtain diglycerides with a high proportion of 1,2-diglycerides in reaction times as short as 30 min.

Ultrasound-assisted lipase catalyzed hydrolysis of aspirin methyl ester

The ultrasound-assisted hydrolysis of aspirin methyl ester (AME) was investigated using immobilized Candida antarctica lipase B (CALB) (1%) in the presence of solvents like triolein, chloroform (CHCl₃) and dichloromethane (DCM). The effect of ultrasound and the role of water on the conversion rates have also been investigated. Proton nuclear magnetic resonance spectroscopic (¹H NMR) was chosen to calculate hydrolysis convertion rates. We observed that lipase-ultrasound assisted hydrolysis of AME in the presence of triolein and water showed the highest hydrolysis conversion rate (65.3%). Herein low water amount played an important role as a nucleophile being crucial for the hydrolysis yields obtained. Lipase activity was affected by the conjugated action of ultrasound and solvents (35.75% of decrease), however not disturbing its hydrolytic efficiency. It was demonstrated that lipase is able to hydrolyse AME to methyl 2-hydroxy benzoate (methyl salicylate), which applications include fragrance agents in food, beverages and cosmetics, or analgesic agent in liniments.