Screening for Tocopherol-producing Microorganisms and α-Tocopherol Production by<i>Euglena gracilis</i>Z

Abstract

Various kinds of eucaryotic microorganisms were screened as to their tocopherol production by means of high performance liquid chromatography. Non-photosynthetic microorganisms did not produce detectable amounts of the vitamin. In cells of photosynthetic algae grown photoheterotrophi- cally, toeopherols, mainly of the a-type, were detected. Euglena gracilis Z was employed for further study to optimize the culture conditions for a-tocopherol production. The a-tocopherol production was affected by the concentrations of the carbon and nitrogen sources, glucose and peptone. In a constructed medium, the amount of a-tocopherol in cells reached 9.9 mg per liter of culture broth or 1. 1 mg per gram of dry cells. The effects of the addition of some compounds to the culture medium on a- tocopherol production were then studied. Homogentisate and L-tyrosine were very effective as additives. Feeding of ethanol and peptone also increased the production. With the feeding of ethanol, peptone, homogentisate and L-tyrosine three-times, the amount of a-tocopherol reached 143.6 mg per liter of culture broth or 5.1 mg per gram of dry cells.