Culture Media for Euglena gracilis

Abstract

This chapter reviews Euglena gracilis group II strains, which may also include var. bacillaris. All have an intense photosynthesis of the green-plant type, and in the dark, given various simple substrates, grow as colorless cells with equal or even superior vigor. They again turn green in a few hours on restoration to light. Permanently bleached strains are easily induced. This array of organisms simplifies decision as to whether a substance is localized in the chloroplast; examination of light- vs. dark-grown cultures generally settles the question. As such inquiries increasingly revolve around trace constituents and large quantities of cells are often needed, this chapter emphasizes high-yield media and how to compound media as dry mixes, which may be prepared cheaply in bulk and have a long shelf life. The use of Euglena for vitamin B12 assay enhances the desirability of high-yield media, which permit a linear response through a wide range of vitamin B12 concentrations along with rapid growth.