1993 Volume 26 Issue 5 Pages 470-474
Factors affecting α-tocopherol production using safflower (Carthamus tinctorius) cells were studied from the engineering aspects for plant cell culture. The specific production rate was evaluated as a function of rate-limiting factors. The conditioning factor released from cells, dissolved oxygen (DO) and medium components were considered as the limiting factors responsible for the specific production rate. Increasing the conditioning factor enhanced α-tocopherol production. Increasing DO concentration up to 9 mg-O2/l also caused a linear increase in specific production rate. The specific production rate in batch cultivation decreased, however, at a constant DO concentration with a sufficient amount of the conditioning factor. In repeated batch cultivation, the specific production rate was recovered by the addition of fresh medium. These results showed that an essential component in the medium was exhausted at an early stage of the batch cultivation and that the medium-feeding operation with sufficient CF and DO concentrations was required to maintain high productivity. By repeated batch cultivation, the content of α-tocopherol in the cell was increased to 9 mg/100 g-dry cell, which was considerably higher than that in natural safflower seeds.
