Cultivation and Lyophilization of Mastigina sp.

SYNOPSIS Mastigina sp. is an amoeboid flagellate isolated from pine frass collected in the Guadarrama Mountains in Spain. It feeds on bacteria and yeasts. It prefers yeasts that produce extracellular polysaccharides, and the 2 species that have been used predominantly for cultivation of the flagellate are Pachysolen tannophilus and Hansenula holstii. Mastigina sp. is easily isolated in axenic culture and grows abundantly therein. Its locomotive form, averaging 27 μ in length, resembles that of a limax amoeba, with a vesiculate nucleus at the anterior end. Cells are capable of simultaneous movement by pseudopodia and flagella. It develops rapidly on dead or living yeast cells in shaken cultures and the trophozoites may convert quantitatively to cysts. The cysts remain viable for long periods of time in refrigerated suspensions and in the lyophilized state. They are spherical or ovoid and smooth-walled cysts; the trophozoite emerges from them by breaking the wall.