Application of the immobilized bacterial recombinant lipase from Geobacillus stearothermophilus G3 for the production of fatty acid methyl esters

Abstract

The heterogeneous BCL biocatalyst based on the recombinant extracellular lipase from the thermophilic bacteria Geobacillus stearothermophilus G3 with an activity of 23.6 U.A./g was prepared by covalent immobilization on aminated silica gel. The effect of the solvent, temperature (30–60°C), methanol : oil molar ratio (1 : 1 to 9 : 1), and the amounts of water (1–10%) and catalyst (0.25–25%) on the yield of fatty acid methyl esters (FAME) during the methanolysis of sunflower oil with BCL was studied. The maximum yield of FAME was 43%. The biocatalyst exhibits high operational stability: after 480 h of operation (20 cycles), it retains more than 50% of its original activity, making BCL a promising catalyst for application in manufacturing of FAME as feedstock for biodiesel production.