Synthesis of structured triacylglycerols enriched in n-3 fatty acids by immobilized microbial lipase

Abstract The search for new biocatalysts has aroused great interest due to the variety of micro-organisms and their role as enzyme producers. Native lipases from Aspergillus niger and Rhizopus javanicus were used to enrich the n-3 long-chain polyunsaturated fatty acids content in the triacylglycerols of soybean oil by acidolysis with free fatty acids from sardine oil in solvent-free media. For the immobilization process, the best lipase/support ratios were 1:3 (w/w) for Aspergillus niger lipase and 1:5 (w/w) for Rhizopus javanicus lipase using Amberlite MB-1. Both lipases maintained constant activity for 6 months at 4 °C. Reaction time, sardine-free fatty acids:soybean oil mole ratio and initial water content of the lipase were investigated to determine their effects on n-3 long-chain polyunsaturated fatty acids incorporation into soybean oil. Structured triacylglycerols with 11.7 and 7.2% of eicosapentaenoic acid + docosahexaenoic acid were obtained using Aspergillus niger lipase and Rhizopus javanicus lipase, decreasing the n-6/n-3 fatty acids ratio of soybean oil (11:1 to 3.5:1 and 4.7:1, respectively). The best reaction conditions were: initial water content of lipase of 0.86% (w/w), sardine-free faty acids:soybean oil mole ratio of 3:1 and reaction time of 36 h, at 40 °C. The significant factors for the acidolysis reaction were the sardine-free fatty acids:soybean oil mole ratio and reaction time. The characterization of structured triacylglycerols was obtained using easy ambient sonic-spray ionization mass spectrometry. The enzymatic reaction led to the formation of many structured triacylglycerols containing eicosapentaenoic acid, docosahexaenoic acid or both polyunsaturated fatty acids.

Isolamento e seleção de microorganismos produtores de lipase como biocatalisadores na hidrólise parcial de óleo de sardinha / Isolation and selection of lipase producing microorganisms as biocatalysts in the partial hydrolysis of sardine oil

O trabalho descreve o isolamento e a seleção de microorganismos produtores de enzimas lipolíticas e a utilização do extrato enzimático bruto como biocatalisador na hidrólise do óleo de sardinha brasileiro. A biocatálise tem por objetivo enriquecer o óleo em ácidos graxos pliinsaturados, os quais possuem efeitos benéficos em doenças cardiovasculares, processos inflamatórios e alérgicos. Os produtos resultantes da hidrólise foram analisados por cromatografia gás-liquido. Dentre as quatrocentos e vinte e cinco amostras de fungos isoladas e testadas, uma delas (nº 122) foi capaz de produzir modificações favoráveis na composição em ácidos graxos de sardinha, mostrando-se promissora no enriquecimento de ácidos graxos poliinsaturados.