Valorization of Glycerol through the Enzymatic Synthesis of Acylglycerides with High Nutritional Value

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.

Different strategies for the lipase immobilization on the chitosan based supports and their applications

Immobilized enzymes have received incredible interests in industry, pharmaceuticals, chemistry and biochemistry sectors due to their various advantages such as ease of separation, multiple reusability, non-toxicity, biocompatibility, high activity and resistant to environmental changes. This review in between various immobilized enzymes focuses on lipase as one of the most practical enzyme and chitosan as a preferred biosupport for lipase immobilization and provides a broad range of studies of recent decade. We highlight several aspects of lipase immobilization on the surface of chitosan support containing various types of lipase and immobilization techniques from physical adsorption to covalent bonding and cross-linking with their benefits and drawbacks. The recent advances and future perspectives that can improve the present problems with lipase and chitosan such as high-price of lipase and low mechanical resistance of chitosan are also discussed. According to the literature, optimization of immobilization methods, combination of these methods with other techniques, physical and chemical modifications of chitosan, co-immobilization and protein engineering can be useful as a solution to overcome the mentioned limitations.

New Glycerol Upgrading Processes

Energy policies in the US and in the EU during the last decades have been focused on enhanced oil and gas recovery, including the so-called tertiary extraction or enhanced oil recovery (EOR), on one hand, and the development and implementation of renewable energy vectors, on the other, including biofuels as bioethanol (mainly in US and Brazil) and biodiesel (mainly in the EU) [...]

Chemoenzymatic Synthesis of the New 3-((2,3-Diacetoxypropanoyl)oxy)propane-1,2-diyl Diacetate Using Immobilized Lipase B from Candida antarctica and Pyridinium Chlorochromate as an Oxidizing Agent

To exploit the hydrolytic activity and high selectivity of immobilized lipase B from Candida antarctica on octyl agarose (CALB-OC) in the hydrolysis of triacetin and also to produce new value-added compounds from glycerol, this work describes a chemoenzymatic methodology for the synthesis of the new dimeric glycerol ester 3-((2,3-diacetoxypropanoyl)oxy)propane-1,2-diyl diacetate. According to this approach, triacetin was regioselectively hydrolyzed to 1,2-diacetin with CALB-OC. The diglyceride product was subsequently oxidized with pyridinium chlorochromate (PCC) and a dimeric ester was isolated as the only product. It was found that the medium acidity during the PCC treatment and a high 1,2-diacetin concentration favored the formation of the ester. The synthesized compounds were characterized using IR, MS, HR-MS, and NMR techniques. The obtained dimeric ester was evaluated at 100 ppm against seven bacterial strains and two Candida species to identify its antimicrobial activity. The compound has no inhibitory activity against the bacterial strains used but decreased C. albicans and C. parapsilosis growth by 49% and 68%, respectively. Hemolytic activity was evaluated, and the results obtained support the use of the dimeric ester to control C. albicans and C. parapsilosis growth in non-intravenous applications because the compound shows hemolytic activity.