The aim of this study was to optimize the dextranase production by fungus Pochonia chlamydosporia... more 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 trea...
The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) after pa... more The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) after passage through the gastrointestinal tract of dogs was assessed in vivo against Toxocara canis eggs. Twelve dogs previously wormed were divided into two groups of six animals and caged. The treatments consisted of a fungus-treated group (VC4) and a control group without fungus. Each dog of the fungus-treated group received a single 4 g dose of mycelial mass of P. chlamydosporia (VC4). Fecal samples from animals of both groups (treated and control) were collected at five different times (6, 12, 24, 36, and 48 h) after fungal administration, and placed in Petri dishes. Each Petri dish of both groups for each studied time interval received approximately 1000 T. canis eggs. Thirty days after the fecal samples were collected, approximately one hundred eggs were removed from each Petri dish of each studied time interval and evaluated by light microscopy (LM) and scanning electron microscopy (SEM). Microscopy examination of plates inoculated with the fungus showed that the isolate VC4 was able to destroy the T. canis eggs with destruction percentages of 28.6% (6 h), 29.1% (12 h), 32.0% (24 h), 31.7% (36 h), and 37.2% (48 h). These results suggest that P. chlamydosporia can be used as a tool for the biological control of T. canis eggs in feces of contaminated dogs.
The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates... more The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates of Pochonia chlamydosporia in a solid medium and the action of a crude extract of P. chlamydosporia against eggs of Ascaridia galli. To evaluate ovicidal activity in culture medium, 1000 A. galli eggs were plated on Petri dishes containing 2% water-agar with grown fungal isolates (VC1 or VC4) and without fungus (control group) and were examined at 1, 3 and 5 days post-inoculation (assay A). Then, to test the action of crude extracts of P. chlamydosporia (VC1 or VC4), 500 eggs of A. galli were plated on Petri dishes of 4.5 cm diameter with 5 ml of fungal filtrate from each tested isolate. The control group consisted of 500 eggs of A. galli with 10 ml of distilled water on each Petri dish (assay B). Fungal isolates were effective (P &lt; 0.01) at destroying these eggs, showing a type 3 effect at the studied intervals. On the other hand, the crude extract of isolates (VC1 or VC4) reduced the number of A. galli eggs in the treated group compared with the control group by 64.1% and 56.5%, respectively. The results of the present study show that P. chlamydosporia is effective at destroying eggs of A. galli and could therefore be used in the biological control of nematodes.
The aim of this work was to analyze the enzymatic activity and in vitro ovicidal effect of Pochon... more The aim of this work was to analyze the enzymatic activity and in vitro ovicidal effect of Pochonia chlamydosporia (VC1 and VC4) and Paecilomyces lilacinus (PL1) on Oxyuris equi eggs of horses. The growth of isolates and their enzymatic production were evaluated on agar media supplemented with gelatin (GA), casein (CA), olive oil (OOA) or starch (SSA). The ovicidal effect
ABSTRACT The present work aimed to evaluate the production and the characterisation of a chitinas... more ABSTRACT The present work aimed to evaluate the production and the characterisation of a chitinase from nematophagous fungus Duddingtonia flagrans (AC001) and observe the interaction of this fungus on engorged females of Amblyomma cajennense under laboratory conditions. In assay A, the engorged females of A. cajennense were separated and immersed for 5 seconds in a fungal suspension of 106 conidia/ml of the fungus D. flagrans and placed in Petri dishes, in the dark. In assay B, wheat bran supplemented with 1% chitin and liquid minimal medium was used [K2HPO4 (5.0 g/l), MgSO4 (0.10 g/l), ZnSO4 (0.0050 g/l), FeSO4 (0.001 g/l) e CuSO4 (0.50 mg/l)], as a substrate for chitinase production. To demonstrate the presence of chitinase in the crude extract obtained after the enzymatic extraction, a purification process was developed using a specific adsorption technique. The results from assay A demonstrated the interaction of the D. flagrans conidia produced from chitin-agar on engorged females of A. cajennense. In the assay B, D. flagrans produced a chitinase successfully, with a high value for enzyme activity. The molecular mass of semi-purified enzyme was estimated at approximately 34 kDa. It was concluded that the fungus produced a chitinase and has some entomopathogenic activity, as demonstrated here for the first time; however, it is strongly suggested that further studies are needed to elucidate the molecular mechanism of infection of target organisms by this fungus.
This study aimed to present a protease produced by Duddingtonia flagrans fungus (AC001), and to e... more This study aimed to present a protease produced by Duddingtonia flagrans fungus (AC001), and to evaluate its activity in the biological control of cyathostomin infective larvae (L3). The crude extract from D. flagrans grown in liquid medium was applied first to a DEAE-Sepharose™ and later to a CM-Sepharose™ ion exchange column. Protease activity was determined under different pHs and temperatures.
The aim of this study was to optimize the dextranase production by fungus Pochonia chlamydosporia... more 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 trea...
The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) after pa... more The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) after passage through the gastrointestinal tract of dogs was assessed in vivo against Toxocara canis eggs. Twelve dogs previously wormed were divided into two groups of six animals and caged. The treatments consisted of a fungus-treated group (VC4) and a control group without fungus. Each dog of the fungus-treated group received a single 4 g dose of mycelial mass of P. chlamydosporia (VC4). Fecal samples from animals of both groups (treated and control) were collected at five different times (6, 12, 24, 36, and 48 h) after fungal administration, and placed in Petri dishes. Each Petri dish of both groups for each studied time interval received approximately 1000 T. canis eggs. Thirty days after the fecal samples were collected, approximately one hundred eggs were removed from each Petri dish of each studied time interval and evaluated by light microscopy (LM) and scanning electron microscopy (SEM). Microscopy examination of plates inoculated with the fungus showed that the isolate VC4 was able to destroy the T. canis eggs with destruction percentages of 28.6% (6 h), 29.1% (12 h), 32.0% (24 h), 31.7% (36 h), and 37.2% (48 h). These results suggest that P. chlamydosporia can be used as a tool for the biological control of T. canis eggs in feces of contaminated dogs.
The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates... more The present study aimed to evaluate the ovicidal activity (type 3 effect) of VC1 and VC4 isolates of Pochonia chlamydosporia in a solid medium and the action of a crude extract of P. chlamydosporia against eggs of Ascaridia galli. To evaluate ovicidal activity in culture medium, 1000 A. galli eggs were plated on Petri dishes containing 2% water-agar with grown fungal isolates (VC1 or VC4) and without fungus (control group) and were examined at 1, 3 and 5 days post-inoculation (assay A). Then, to test the action of crude extracts of P. chlamydosporia (VC1 or VC4), 500 eggs of A. galli were plated on Petri dishes of 4.5 cm diameter with 5 ml of fungal filtrate from each tested isolate. The control group consisted of 500 eggs of A. galli with 10 ml of distilled water on each Petri dish (assay B). Fungal isolates were effective (P &lt; 0.01) at destroying these eggs, showing a type 3 effect at the studied intervals. On the other hand, the crude extract of isolates (VC1 or VC4) reduced the number of A. galli eggs in the treated group compared with the control group by 64.1% and 56.5%, respectively. The results of the present study show that P. chlamydosporia is effective at destroying eggs of A. galli and could therefore be used in the biological control of nematodes.
The aim of this work was to analyze the enzymatic activity and in vitro ovicidal effect of Pochon... more The aim of this work was to analyze the enzymatic activity and in vitro ovicidal effect of Pochonia chlamydosporia (VC1 and VC4) and Paecilomyces lilacinus (PL1) on Oxyuris equi eggs of horses. The growth of isolates and their enzymatic production were evaluated on agar media supplemented with gelatin (GA), casein (CA), olive oil (OOA) or starch (SSA). The ovicidal effect
ABSTRACT The present work aimed to evaluate the production and the characterisation of a chitinas... more ABSTRACT The present work aimed to evaluate the production and the characterisation of a chitinase from nematophagous fungus Duddingtonia flagrans (AC001) and observe the interaction of this fungus on engorged females of Amblyomma cajennense under laboratory conditions. In assay A, the engorged females of A. cajennense were separated and immersed for 5 seconds in a fungal suspension of 106 conidia/ml of the fungus D. flagrans and placed in Petri dishes, in the dark. In assay B, wheat bran supplemented with 1% chitin and liquid minimal medium was used [K2HPO4 (5.0 g/l), MgSO4 (0.10 g/l), ZnSO4 (0.0050 g/l), FeSO4 (0.001 g/l) e CuSO4 (0.50 mg/l)], as a substrate for chitinase production. To demonstrate the presence of chitinase in the crude extract obtained after the enzymatic extraction, a purification process was developed using a specific adsorption technique. The results from assay A demonstrated the interaction of the D. flagrans conidia produced from chitin-agar on engorged females of A. cajennense. In the assay B, D. flagrans produced a chitinase successfully, with a high value for enzyme activity. The molecular mass of semi-purified enzyme was estimated at approximately 34 kDa. It was concluded that the fungus produced a chitinase and has some entomopathogenic activity, as demonstrated here for the first time; however, it is strongly suggested that further studies are needed to elucidate the molecular mechanism of infection of target organisms by this fungus.
This study aimed to present a protease produced by Duddingtonia flagrans fungus (AC001), and to e... more This study aimed to present a protease produced by Duddingtonia flagrans fungus (AC001), and to evaluate its activity in the biological control of cyathostomin infective larvae (L3). The crude extract from D. flagrans grown in liquid medium was applied first to a DEAE-Sepharose™ and later to a CM-Sepharose™ ion exchange column. Protease activity was determined under different pHs and temperatures.
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Papers by Filippe E F Soares