Method for growing edible Euglena gracilis in an inexpensive medium with tomato juice to a high cell density equivalent to the density in KH medium

Abstract

This paper proposes a low-cost technology for growing Euglena gracilis using beverages that people consume on a daily basis as a nutrient source. Among the 13 beverages tested, the most suitable one for growing E. gracilis was tomato juice. In four different brands of tomato juice, E. gracilis was grown to a cell density (10⁷ cells per mL) comparable to that in KH medium, a conventional heterotrophic medium. The cost is only 1/6 of KH medium. In addition, growth of 100 times the initial cell density was observed in a medium containing tomato juice even without essential vitamins. Since this method does not use genetic modification or genome editing techniques and animal products, it expands the potential for the use of E. gracilis as a food.