In a search for new molecules toxic to plant parasitic nematodes, procedures were set up to purify nematode toxic molecules produced by Cunninghamella elegans, Fusarium sp., Paecilomyces lilacinus and P. variotii. Those fungi were grown in Czapek-Dox liquid medium during 15 days, at 25 ºC, in an orbital shaker. After fungus mycelium removal by filtration, the solutions were concentrated under vacuum and submitted to purification, guided by in vitro assays with Meloidogyne incognita juveniles. As a result, it was observed that P. lilacinus and P.variotii filtrates lost their activity after vacuum concentration, which suggests that the nematocides produced by those fungi are considerably volatile. In the case of Fusarium sp. filtrate, the active substance seems to be unstable, as the activity against M. incognita juveniles completely disappeared after chromatography in a silica gel column. The C. elegans filtrate rendered one isolated substance that immobilized 94% of the M. incognita juveniles exposed during 48 h to an aqueous solution of the substance at 250 ppm.
