ABSTRACT The aim of this study was to optimize the dextranase production by fungus Pochonia chlamydosporia (VC4) and evaluate its activity in dextran reduction in sugarcane juice. The effects, over the P. chlamydosporia dextranase production, of different components from the culture medium were analyzed by Plackett-Burman design and central composite design. The response surface was utilized to determine the levels that, among the variables that influence dextranase production, provide higher production of these enzymes. The enzymatic effect on the removal of dextran present in sugarcane juice was also evaluated. It was observed that only NaNO3 and pH showed significant effect (p<0.05) over dextranase production and was determined that the levels which provided higher enzyme production were, respectively, 5 g/L and 5.5. The dextranases produced by fungus P. chlamydosporia reduced by 75% the dextran content of the sugarcane juice once treated for 12 hours, when compared to the control treatment.

A capacidade predatória de um isolado de fungo predador de nematoides Duddingtonia flagrans (AC001) sobre larvas infectantes de ciatostomíneos foi avaliada em condições laboratoriais em ensaio experimental em meio ágar-água 2% (AA 2%). Houve redução significativa (p < 0,01) de 93,64% na média de larvas infectantes de ciatostomíneos recuperadas do meio AA2%, ao final de sete dias. Os resultados desse ensaio evidenciam que o isolado fúngico AC001 poderia ser utilizado no controle biológico de ciatostomíneos de equinos.

The predatory capacity of one isolate of nematode-trapping fungus Duddingtonia flagrans (AC001) on infective larvae of cyathostomes was evaluated in laboratorial conditions in medium water-agar 2% (WA 2%). There was significant reduction (p < 0. 01) of 93.64% in the average of infective larvae of cyathostomes recovered of medium WA 2% at seven day. These results show that the isolated AC001 could be used in the biological control of cyathostomes of horses.

Observou-se a ação in vitro dos fungos nematófagos Duddingtonia flagrans, Monacrosporium thaumasium e Verticillium chlamydosporium sobre ovos de Ascaris lumbricoides. Após sete, dez e quatorze dias de interação, o fungo promissor a ser utilizado no controle biológico de Asaris lumbricoides foi o Verticillium chlamydosporium (26-30%). Os outros fungos não foram satisfatórios.

The in vitro action of the nematophagous fungi Duddingtonia flagrans, Monacrosporium thaumasium and Verticillium chlamydosporium on eggs of Ascaris lumbricoides was observed. After 7, 10 and 14 days of interaction, the fungus showing most promise for use in biologically control over Ascaris lumbricoides was Verticillium chlamydosporium (26-30%). The other fungi did not present satisfactory results.