Fabio Ribeiro Braga

An isolate of the nematophagous fungus Monacrosporium thaumasium for the control of cattle trichostrongyles in south-eastern Brazil.

A mycelial formulation in sodium alginate pellets of the nematophagous fungus Monacrosporium thaumasium (isolate NF34A) was assessed in the biological control of beef cattle trichostrongyles in tropical Brazil. Two groups of ten male Nellore calves aged 6 months, a fungus-treated group and a control group, were fed on a pasture of Brachiaria decumbens naturally infected with larvae of cattle trichostrongyles. The fungus-treated group received doses of sodium alginate mycelial pellets orally (1 g pellets (0.2 g fungus)/10 kg live weight) twice a week for 12 months. At the end of the study there was a significant reduction (P< 0.01) in the number of eggs per gram of faeces and coprocultures of the fungus-treated group--47.8% and 50.2%, respectively--in relation to the control group. There was a 47.3% reduction in herbage samples, collected up to 0-20 cm from faecal pats, between the fungus-treated and control groups, and a 58% reduction when the sampling distance was 20-40 cm from faecal pats (P< 0.01). The treatment with sodium alginate pellets containing the nematode-trapping fungus M. thaumasium reduced trichostrongyles in tropical south-eastern Brazil and could be an effective tool for the biological control of this parasitic nematode in beef cattle. However, in such a tropical climate with low rainfall the fungal viability can be reduced.

ENZYMATIC ACTION OF PROTEASES AND CHITINASES OF THE NEMATOPHAGOUS FUNGIPOCHONIA CHLAMYDOSPORIA ON DIOCTOPHYMA RENALE EGGS

The giant kidney worm, Dioctophyma renale, is the largest nematode known. Eggs of D. renale are eliminated through urine of the dog and its development occurs in the external environment. In addition, its shell thick and wrinkled confers resistance in the environment for years. However, measures such as biological control that can help decrease egg concentrations may aid in the control of this zoonosis. The present study aimed to evaluate the enzymatic action of proteases and chitinases produced by Pochonia chlamydosporia(VC4) on Dioctophymarenale eggs. Four groups were formed in sterile tubes, three treatment groups, one group treated with only VC4 proteases, one group treated with only VC4 chitinases, one group treated with both classes of enzymes (proteases and chitinases) and one control group (no enzyme). To avoid protease activity in the group treated only with chitinases, the protease inhibitor PMSF (phenylmethylsulfonyl fluoride) was used. One hundred D. renale eggs were transferred into sterile tubes containing enzyme for each treated group. The control group consisted of one hundred D. renale eggs. The sterile tubes were incubated at 28 °C in the dark for 24 hours. After 24 hours, the total number of D. renale intact eggs present in each of the treated and control tubes was calculated. At the end of the experiment, it was observed that the proteases and chitinases of P. chlamydosporia (VC4), either individually or together, have caused a significant percentage reduction (p <0.01) on the number of viable eggs Blucher Biochemistry Proceedings Janeiro de 2015, Volume 1, Numero 1 www.proceedings.blucher.com.br/evento/jaibiq