LIPASE-CATALYZED MODIFICATION OF PHOSPHOLIPIDS - INCORPORATION OF N-3 FATTY-ACIDS INTO BIOSURFACTANTS

Phospholipids were successfully modified by lipase-catalyzed transesterification to incorporate n-3 polyunsaturated fatty acids such as eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6). The phospholipid modification was carried out in organic media with lipase from Mucor miehei (lipozyme) as biocatalyst. The parameters studied were the effect of different solvents, enzymes, acyl donor type, phospholipid class, water, enzyme and substrate concentrations. Hydrolysis of phosphatidylcholine to yield lysophosphatidylcholine and the synthesis of phosphatidylcholine from lysophosphatidylcholine was also carried out. The optimal conditions for the modification of phospholipids by transesterification were obtained with phosphatidylcholine and free eicosapentaenoic acid EPA 45 as acyl donor in the presence of 15% w/w nonimmobilized Mucor miehei lipase (lipozyme) in hexane with no added water. The maximum incorporation of EPA 45 was 17.7 mol%. Hydrolysis was easily achieved with phospholipase A2 in benzene and Tris-HCI buffer. The synthesis of phosphatidylcholine was difficult, and when it was achieved, not enough phosphatidylcholine was obtained for quantitation.