Serum-free media for cultivation of spiroplasmas

Abstract

Serum-free media that contained bovine serum albumin and lipids (fatty acids, cholesterol, phosphatidic acid, and phospholipids) to replace serum were formulated for the culture of some fastidious strains of corn stunt spiroplasma, Spiroplasma kunkelii. These media also supported good growth of other spiroplasmas, including epiphytic, entomopathogenic, and phytopathogenic strains. The growth rates attained in these serum-free media were comparable to those in media which contained serum. The serum-free broth and agar media were of major importance for culture of several fastidious strains of corn stunt spiroplasma because the serum-containing media supported little, if any, of their growth. Colonies of these fastidious strains were readily formed on serum-free agar media in aerobic, candle jar, and anaerobic environments, but were not readily formed on the serum-containing media. The serum-free media were less subject to deterioration during storage or incubation, and the growth-supporting capacity of serum-free media diminished more slowly than that of serum-containing media.Key words: Spiroplasma kunkelii, Spiroplasma citri, Mollicutes, Mycoplasma spp. culture, entomopathogens.