The present invention relates to the
Schizochytrium genus SR21 strain and a
microorganism belonging to the same species as does said SR21 strain or having substantially the same fungological properties as does said SR21 strain, the said SR21 strain and
microorganism having the ability to produce the (n-3) series of
docosahexaenoic acid (DHA) and the (n-6) series of
docosapentaenoic acid (DPA), and the invention also relates to a process for preparing the (n-3) series of DHA and the (n-6) series of DPA utilizing said microorganisms. The microorganisms according to the present invention are superior in their proliferation character and their propensity to produce fat, and have the ability to produce the (n-3) series of DHA and the (n-6) series of DPA very well. Accordingly, it is possible to effectively produce the (n-3) series of DHA and / or the (n-6) series of DPA, which are useful in the fields of foods and pharmaceuticals, using the microorganisms according to the present invention. In addition, the present invention provides a fat obtained by culturing the present microorganisms. Since the
fat composition contains the (n-6) series of DPA in addition to the (n-3) series of DHA having various physiological activities, it is possible to stably and effectively supply the (n-6) series of DPA and / or the (n-3) series of DHA to subjects in need of these highly unsaturated fatty acids by adding the
fat composition to various feedstuffs or foods.