title: Nematocidal activity of extracellular enzymes produced by the nematophagous fungus Duddingtonia flagrans on cyathostomin infective larvae.
abstract: Duddingtonia flagrans produces chitinases, however, optimization of the production of these enzymes still needs to be explored, and its nematocidal activity should still be the subject of studies. The objective of the present study was to optimize chitinase production, and evaluate the nematocidal activity of extracellular enzymes produced by the nematophagous fungus D. flagrans on cyathostomin infective larvae. An isolate from D. flagrans (AC001) was used in this study. For the production of enzymes (protease and chitinase), two different culture media were inoculated with AC001 conidia. Both enzymes were purified. The statistical Plackett-Burman factorial design was used to investigate some variables and their effect on the production of chitinases by D. flagrans. After that, the design central composite (CCD) was used in order to determine the optimum levels and investigate the interactions of these variables previously observed. Only two variables (moisture and incubation time), in the evaluated levels, had a significant effect (p<0.05) on chitinase production. The conditions of maximum chitinase activity were calculated, with the following values: incubation time 2 days, and moisture 511%. The protease and chitinase derived from D. flagrans, individually or together (after 24h), led to a significant reduction (p<0.01) in the number of intact cyathostomin L3, when compared to the control, with following reduction percentage values: 19.4% (protease), 15.5% (chitinase), and 20.5% (protease+chitinase). Significant differences were observed (p<0.05) between the group treated with proteases in relation to the group treated with proteases+chitinases. In this study, the assay with the cyathostomins showed that chitinase had a nematocidal effect, suggesting that this enzyme acts on the "fungus versus nematodes" infection process. It is known that nematode eggs are rich in chitin, and in this case, we could think of a greater employability for this chitinase.
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Fabio Ribeiro
authors: FR
authors: Braga
authors: Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil. Electronic address: filippeufv@yahoo.com.br.
authors: Filippe Elias Freitas
authors: FE
authors: Soares
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Thais Zanotti
authors: TZ
authors: Giuberti
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Aline Del Carmen Garcias
authors: Adel C
authors: Lopes
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Tracy
authors: T
authors: Lacerda
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Tiago de Hollanda
authors: Tde H
authors: Ayupe
authors: Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil.
authors: Paula Viana
authors: PV
authors: Queiroz
authors: Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil.
authors: Angélica de Souza
authors: Ade S
authors: Gouveia
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Larissa
authors: L
authors: Pinheiro
authors: Department of Parasitology, University of VilaVelha-ES, VilaVelha, ES CEP: 29102206, Brazil.
authors: Andreia Luíza
authors: AL
authors: Araújo
authors: Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, MG 36570-000, Brazil.
authors: José Humberto
authors: JH
authors: Queiroz
authors: Department of Veterinary Medicine, Federal University of Viçosa, Viçosa, MG CEP: 3657000, Brazil.
authors: Jackson Victor
authors: JV
authors: Araújo
mesh_terms: D000818:Animals; D002688:Chitinases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D059586:Duddingtonia / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D007814:Larva / Q000382:microbiology; D009348:Nematoda / Q000187:drug effects*; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D010572:Pest Control, Biological
chemical_list: D002688:Chitinases; D010447:Peptide Hydrolases
keywords: Biological control; Chitinase; Horses; Protease; Small strongyles