Improved method for Duddingtonia flagrans chlamydospores production for livestock use.

ABSTRACT

Duddingtonia flagrans is a nematode-trapping fungus responsible for attacking larval stages of helminthes in pasture. D. flagrans chlamydospores were produced using a two-step liquid/solid culture system. The inoculum grown in liquid medium was transferred to a rice substrate and kept at room temperature for 30 days. Grains were washed, filtered and centrifuged. The pellet was lyophilized and the obtained yield averaged 1 x 10(5) chlamydospores per gram of dried material. The lyophilized chlamydospores showed a trapping rate of 69% of infective larvae in vitro and were excreted entirely in ovine faeces. The results showed that most of the chlamydospores remained intact and viable after the lyophilization process.