title: Proteolytic activity of extracellular products from Arthrobotrys musiformis and their effect in vitro against Haemonchus contortus infective larvae.
abstract: Arthrobotrys musiformis is a nematophagous fungus with potential for the biological control of Haemonchus contortus larvae. This study aimed to identify and demonstrate the proteolytic activity of extracellular products from A musiformis cultured in a liquid medium against H contortus infective larvae. A musiformis was cultured on a solid medium and further grown in a liquid medium, which was then processed through ion exchange and hydrophobic interaction chromatography. The proteolytic activity of the purified fraction was assayed with either gelatin or bovine serum albumin as substrate. Optimum proteolytic activity was observed at pH 8 and a temperature of 37°C. Results obtained with specific inhibitors suggest the enzyme belongs to the serine-dependent protease family. The purified fraction concentrate from A musiformis was tested against H contortus infective larvae. A time-dependent effect was observed with 77 per cent immobility after 48 hours incubation, with alteration of the sheath. It is concluded that A musiformis is a potential candidate for biological control because of its resistant structures and also because of its excretion of extracellular products such as proteases. The present study contributes to the identification of one of the in vitro mechanisms of action of A musiformis, namely the extracellular production of proteases against H contortus infective larvae. More investigations should be undertaken into how these products could be used to decrease the nematode population in sheep flocks under field conditions, thereby improving animal health while simultaneously diminishing the human and environmental impact of chemical-based drugs.
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia , Universidad Nacional Autónoma de México, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Perla María Del Carmen
authors.initials: PM
authors.lastname: Acevedo-Ramírez
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia , Universidad Nacional Autónoma de México, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Figueroa-Castillo
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia , Universidad Nacional Autónoma de México, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Raúl
authors.initials: R
authors.lastname: Ulloa-Arvizú
authors.affiliation: Facultad de Medicina , Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Luz Gisela
authors.initials: LG
authors.lastname: Martínez-García
authors.affiliation: Facultad de Medicina , Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Alberto
authors.initials: A
authors.lastname: Guevara-Flores
authors.affiliation: Facultad de Medicina , Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Rendón
authors.affiliation: Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias, Cenid-Pavet. Carretera Federal Cuernavaca-Cuautla , Jiutepec, Morelos , México.
authors.forename: Rosa Ofelia
authors.initials: RO
authors.lastname: Valero-Coss
authors.affiliation: Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias, Cenid-Pavet. Carretera Federal Cuernavaca-Cuautla , Jiutepec, Morelos , México.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mendoza-de Gives
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia , Universidad Nacional Autónoma de México, Col. Universidad Nacional Autónoma de México , Coyoacán, Distrito Federal , México.
authors.forename: Héctor
authors.initials: H
authors.lastname: Quiroz-Romero