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 photoheterotrophically, tocopherols, mainly of the α-type, were detected. Euglena gracilis Z was employed for further study to optimize the culture conditions for α-tocopherol production. The α-tocopherol production was affected by the concentrations of the carbon and nitrogen sources, glucose and peptone. In a constructed medium, the amount of α-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 α-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 α-tocopherol reached 143.6 mg per liter of culture broth or 5.1 mg per gram of dry cells.
