Production of mycelium and blastospores of <i.Hirsutella</i> sp. in submerged culture

Abstract

Hirsutella sp. was grown in four liquid media containing either casamino acids, corn steep liquor, collagen peptone or casein peptone. These media were inoculated with a 7 day-old culture of mycelia and blastospores of Hirsutella sp. and the cultures incubated with shaking at 250 rpm at 26°C. The media containing corn steep liquor, casamino acids or collagen peptone produced abundant mycelium, varying from 64 to 76.3 mg/ml at different fermentation days, whereas the medium containing casein peptone produced less biomass. Additionally, the casamino acids and collagen peptone media showed similar biomass values, as well as blastospore counts after 14 fermentation days, without significant differences between the two media. The highest number of blastospores produced was 3.8 × 10⁷ blastospores/ml using medium with casamino acids. This medium, as well as that with collagen peptone gave suitable results for the preparation of an inoculum for the production of conidia in solid medium.

Key words: Hirsutella, liquid media, fermentation, blastospores, microbial control, mass propagation.