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.

Abstract: An immobilized lipase is prepared for transesterification of oils, fats or phospholipids in a reaction system containing a very small amount of water such as 50 to 2,000 ppm. The lipase may be a phospholipase such as 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. A solution of lipase is contacted with the polymer carrier for 10 minutes to 40 hours to covalently bond the lipase to the carrier. The immobilized lipase is dried under reduced pressure to a water content of 0.5 to 30 wt %. 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 a functional group capable of binding lipase in a aqueous solution and an anion-exchange group on the surface.

Abstract: A process for producing a glycolipid having a high eicosapentaenoic acid (EPA) content is provided, which process comprises fractionating the whole lipids of marine chlorella by means of a combination of solvent-fractionation with column chromatography, which glycolipid has platelet agglutination-inhibiting effect, serum cholesterol-increase-inhibiting effect, etc. of EPA and also having a higher absorption rate in intestinal canal than EPA triglyceride or ethyl ester.

Abstract: Enzymes or microorganisms are immobilized by bringing a first aqueous solution into contact with a second aqueous solution containing metal ions having a valence of 3 or more. The first solution contains enzymes or microorganisms, and at least one immobilizing agent selected from the group consisting of Xanthan gum and derivatives thereof. The immobilizing agent is thereby hardened in a state to enclose the enzymes or microorganisms. Preferably, the metal ions are iron, tin, manganese or titanium ions.

Abstract: An immunopotentiator having an anti-tumor activity such as an effect for inhibiting the growth of tumor cells, an effect for prolonging the death by tumor, etc. is provided, which agent contains as its active ingredient, the lipid fraction or the glycolipid fraction of a marine chlorella such as Chlorella minutissima or Chlorella vulgaris, the lipid fraction being obtained e.g. by extracting a marine chlorella with an organic solvent, and the glycolipid fraction, e.g. by separating it from the lipid fraction with a mixed solvent according to silica gel chromatography.