Growth, tolerance, and enzyme activities of Trichoderma strains in culture media added with a pyrethroids-based insecticide.

The application of pyrethroids and carbamates represents an environmental risk and may exert adverse effects on beneficial microorganisms such as Trichoderma, which contribute to the biocontrol of several fungal phytopathogens. This research evaluated the tolerance of several strains of Trichoderma to a selected culture medium contaminated with a commercial insecticide (H24®) composed of pyrethroids, permethrin and prallethrin, and carbamate propoxur, and determined the influence of this insecticide on the release of enzymes such as chitinases, peroxidases, and endoglucanases by a consortium of selected Trichoderma strains grown in liquid culture medium. Four out of 10 Trichoderma strains showed tolerance to 200ppm (∼48.3% of growth) of the commercial insecticide after 96h of exposure to a contaminated solid medium. After eight days of growth in liquid culture, the insecticide enhanced extracellular protein content and peroxidase activities in the Trichoderma consortium but decreased both chitinase and glucanase activities. These fungal responses should be considered when implementing strategies that combine alternative pesticides and fungal biocontrollers for managing fungal phytopathogens.

Preparación de un conjugado peroxidasa-anti IgG humana (cadena ) en conejo / Preparation of a peroxidase-anti human IgG conjugate (chain g) in rabbit

Se preparó un conjugado con peroxidasa a partir de los anticuerpos específicos aislados de un suero de conejo anti cadenas g de la IgG humana. Los anticuerpos específicos se aislaron por cromatografía de afinidad, y el conjugado se preparó por el método de oxidación con peryodato. El conjugado obtenido presentó una relación molar IgG/peroxidasa de 1,07, un valor de RZ de 0,33 y resultó evaluado satisfactoriamente en cuanto a su especificidad y reactividad en los ensayos inmunoenzimáticos realizados.

A peroxidase conjugate was prepared starting from the specific antibodies isolated from an anti-chain rabbit serum and from human IgG. The specific antibodies were isolated by affinity chromatography and the conjugate was prepared by the method of oxidation with periodate. The conjugate obtained presented a molar IgG/peroxidase relation of 1.07, a RZ value of 0.33 and it was satisfactorily evaluated as regards its specificity and reactivity in the immunoenzimatic assays carried out.