Biotechnology and Bioengineering, Vol.53, No.2, 185-190, 1997
Production of Antioxidant Vitamins, Beta-Carotene, Vitamin-C, and Vitamin-E, by 2-Step Culture of Euglena-Gracilis Z
Euglena gracilis Z is one of the few microorganisms which simultaneously produces antioxidant vitamins such as p-carotene and vitamins C and E. Photoheterotrophically cultured E. gracilis Z produced larger levels of biomass but with a lower content of antioxidant vitamins than photoautotrophically grown cultures. For efficient production of these vitamins, a two-step culture was performed. Cells were grown photoheterotrophically and then transferred to photoautotrophic conditions. When E. gracilis Z cells were grown in fed-batch culture under photoheterotrophic conditions, their density reached 19 g/L after 145 h. Subsequent transfer of these cells to photoautotrophic conditions increased vitamin content, enhancing the total vitamin yields, which were 71.0 mg/L of beta-carotene, 30.1 mg/L of vitamin E, and 86.5 mg/L of vitamin C.