Hugo Leonardo André Geniêr

Ação ovicida do extrato bruto enzimático do fungo Pochonia chlamydosporia sobre ovos de Ancylostoma sp

INTRODUCTION Ancylostoma sp is a potentially zoonotic geohelminth. METHODS This study aimed to evaluate in vitro the action of crude enzyme extract of Pochonia chlamydosporia (VC4) on eggs of Ancylostoma sp in 2% water-agar and in fecal cultures. RESULTS The percentage reduction in Ancylostoma sp egg eclosion was 76.8% in Petri dishes of the treated group compared to the control group. CONCLUSIONS The crude enzyme extract of Pochonia chlamydosporia was effective at reducing Ancylostoma sp egg eclosion and can be used as biological control of this nematode.

Optimizing protease production from an isolate of the nematophagous fungus Duddingtonia flagrans using response surface methodology and its larvicidal activity on horse cyathostomins.

Protease production from Duddingtonia flagrans (isolate AC001) was optimized and the larvicidal activity of the enzymatic extract was evaluated on infective horse cyathostomin larvae (L3). Duddingtonia flagrans was grown in liquid medium with eight different variables: glucose, casein, bibasic potassium phosphate (K2HPO4), magnesium sulphate (MgSO4), zinc sulphate (ZnSO4), ferrous sulphate (FeSO4), copper sulphate (CuSO4) and temperature. The Plackett-Burman analysis showed a significant influence of MgSO4, CuSO4 and casein (P < 0.05) on protease production by D. flagrans in liquid medium. Central composite design indicated that the highest proteolytic activity was 39.56 U/ml as a function of the concentrations of casein (18.409 g/l), MgSO4 (0.10 g/l) and CuSO4 (0.50 mg/l). A significant difference (P < 0.01) was found for the larval number between the treated and control groups at the end of the experiment. A reduction of 95.46% in the number of free-living larvae was found in the treated group compared with the control. The results of this study suggest that protease production by D. flagrans (AC001) in liquid medium was optimized by MgSO4, CuSO4 and casein, showing that the optimized enzymatic extract exerted larvicidal activity on cyathostomins and therefore may contribute to large-scale industrial production.

Ovicidal action of a crude enzymatic extract of the fungus Pochonia chlamydosporia against cyathostomin eggs.

The aims of this study were to test the action of the fungal extract of Pochonia chlamydosporia (VC4) on the hatching of cyathostomin eggs plated in Petri dishes containing 2% water-agar (2% WA) and its enzymatic activity in fecal cultures, in two experimental assays (A and B). The fungus P. chlamydosporia (VC4) was cultured in Erlenmeyer flasks (250ml) containing 50ml of liquid minimal medium supplemented with 0.2% gelatin for production of the crude enzymatic extract. Approximately 1kg of fresh feces was collected directly from the rectum of crossbred horses naturally infected with cyathostomins. The fecal material was used to obtain eggs and prepare fecal cultures. For assay A, one thousand eggs were plated on 4.5cm diameter Petri dishes together with 5ml of VC4 fungal filtrate and incubated at 26 degrees C in the dark for 24h. The control group consisted of 1000 eggs in Petri dishes containing 10ml of distilled water, which were incubated under the same conditions. After 24h, the total number of cyathostomin larvae present in each plate of the treated and control groups was counted. For assay B, about 20g of feces were added with 10ml of fungal extract of P. chlamydosporia (VC4) and incubated at 26 degrees C for 8 days. Third stage larvae (L(3)) were recovered at the end of this period. Significant difference (p<0.01) was found for the number of larvae between the treated group and the control at end of assay A. A 72.8% reduction in the hatching of cyathostomin eggs was found in the plates of the treated group compared with the control group. At the end of 8 days, the fungal extract of P. chlamydosporia (VC4), in assay B, was effective in reducing the number of L(3) cyathostomins in the treated group by 67.0% compared with the control group. Significant difference (p<0.01) was found between the means of L(3) recovered from the treated group and the control group. The results of this work showed that crude enzymatic extract of P. chlamydosporia (VC4) was effective in reducing hatching of cyathostomin eggs and therefore could be used as a biological control agent of this nematode.

An extracellular serine protease of an isolate of Duddingtonia flagrans nematophagous fungus

Abstract 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. Subsequently, the effects of metal ions and phenylmethylsulfonyl fluoride (PMSF) inhibitor on activity were evaluated. Next, the protease activity in the biological control of nematodes was tested. A new 38 kDa serine protease (Df1) was purified. Optimum activity was obtained at pH 8.0 and 60°C; CuSO4, ZnSO4 and PMSF strongly inhibited the activity. Df1 (AC001) showed an L3 reduction rate of 58%. In conclusion, a serine protease produced by D. flagrans (AC001) has been isolated, which is effective in the in vitro destruction of cyathostomin L3.

Atividade larvicida do extrato bruto enzimático do fungo Duddingtonia flagras sobre larvas de primeiro estádio de Angiostrongylus vasorum

INTRODUCAO: Angiostrongylus vasorum e um nematoide que parasita caes domesticos e eventualmente o homem. METODOS: O objetivo deste trabalho foi observar a atividade predatoria in vitro do extrato bruto enzimatico do fungo Duddingtonia flagrans sobre larvas de primeiro estadio A. vasorum em condicoes laboratoriais no meio agar-agua 2%. RESULTADOS: Ao final do experimento, os percentuais de reducao das L1 de A. vasorum observados foram de: 53,5% (24h) e 71,3% (48h) CONCLUSOES: O extrato bruto enzimatico do fungo D. flagrans destruiu in vitro as L1, podendo ser utilizado como controle biologico desse nematoide.

Optimizing Ethanol Production by Thermotolerant Kluyveromyces marxianus CCT 7735 in a Mixture of Sugarcane Bagasse and Ricotta Whey

The simultaneous saccharification and fermentation (SSF) process is a promising strategy to obtain ethanol from cellulosic biomass. In this study, sugarcane bagasse was supplemented with ricotta whey to increase the sugar, vitamin, and trace metal concentrations in the fermentation medium. The optimum conditions for SSF ethanol production from a mixture of sugarcane bagasse and ricotta whey produced by Kluyveromyces marxianus CCT 7735 were evaluated considering five factors: cellulase concentration, cellulosic biomass concentration, pH, temperature, and agitation. The highest ethanol yield was 49.65 g/L with a cellulosic biomass of 80 g/L, pH value of 5.05, agitation at 65 rpm and temperature of 39.2°C. The results demonstrated that a mixture of the cellulosic residue of sugarcane bagasse and ricotta whey is promising for ethanol production because the ethanol yield in the mixture was higher than that in single substrate of sugarcane bagasse.

Biological control of Taenia saginata eggs

SummaryTaenia saginata, is a cestode with zoonotic potentially. The objective of this work was to evaluate the ovicide activity (type 3 effect) of the fungus, Paecilomyces lilacinus (PL1), on the eggs of Taenia saginata, in vitro. The eggs were inverted in Petri dishes containing PL1, or in Petri dishes without the fungus (control). After 5, 10, or 15 days, we extracted approximately 100 eggs for evaluation and for classifying the ovicide activity. At the end of the 15 days of interaction, a significant difference (p < 0.05) due to the ovicide activity of PL1, was noted in relation to the control group, with a medium percentage (type 3 effect) at 24.6 %. These results show that the fungus, P.lilacinus (PL1), destroyed the eggs of T. saginata, suggesting its biological control potential of the eggs of this cestode.

Nematicidal activity of Paecilomyces marquandii proteases on infective larvae of Ancylostoma spp

The present study aimed to evaluate the action of Paecilomyces marquandii proteases on Ancylostoma spp L3. White halos in the zymogram confirmed the proteolytic action. Difference (p <0.01) between the number of L3 in the differents groups was found, with 41.4% of reduction of Ancylostoma spp. L3 before 24 hours.