Transesterification with lipase immobilized on a polymer containing

Abstract

Transesterification involving a fat, or a fat and fatty acid, or a phospholipid is carried out with a lipase or phospholipase immobilized on a polymer carrier. The transesterification is preferably carried out in a system containing a very small amount of water such as 50 to 2,000 ppm. The phospholipase can be phospholipase A.sub.2. In a first embodiment, lipase from a microorganism of the genus Rhizopus, Mucor, Alcaligenes or Candida is immobilized on the surface of a hydrophobic, insoluble organic polymer carrier having pores of an average diameter of 10 nm or larger and having on the surface epoxy groups capable of covalently binding lipase. The immobilized lipase is dried under reduced pressure. In a second embodiment, lipase is immobilized on the surface of a polymer carrier such as a hydrophobic, insoluble organic polymer carrier having a pore diameter of 5 to 1,000 nm and having on the surface a functional group capable of binding lipase and an anion-exchange group. Preferably, the functional group is an epoxy group and the anion-exchange group is a tertiary amino group. The lipase may be obtained from the same microorganism as in the first embodiment or from another lipase-producing microorganism. Iramobilization can be carried out as in the first embodiment. It is preferred to contact a solution of lipase with the polymer carrier in the presence of a fatty acid or derivative thereof for 10 minutes to 10 hours to covalently bond the lipase to the polymer carrier.