Detección de enzimas extracelulares en cepas cubanas del complejo Metarhizium anisopliae con acción entomopatogénica contra Cylas formicarius Fabricius (Coleoptera: Brentidae)

Abstract

ResumenEl presente trabajo informa la detección, por métodos bioquímicos, de enzimas extracelulares relacionadas con la actividad biológica de nueve cepas del complejo Metarhizium anisopliae (Metsch.) Sorokin. Se determinó, a diferentes concentraciones, la capacidad patogénica contra el insecto Cylas formicarius Fabricius, y se calculó el tiempo y la concentración letal. Se analizó tanto la presencia de enzimas extracelulares en las cepas fúngicas como su relación con el efecto entomopatogénico y virulencia contra C. formicarius. Todas las cepas del complejo M. anisopliae estudiadas resultaron patogénicas exhibiendo un índice de actividad enzimática superior a 1. La cepa LBM-30 fue la más eficiente al detectarse la presencia de enzimas proteasa, quitinasa, caseínasa, amilasa y lipasa. Esto corrobora la relación de la actividad enzimática con la virulencia observada.Palabras clave: actividad patogénica, actividad enzimática, control biológico, coleóptero, hongos entomopatógenos, virulencia AbstractThis study reports the detection, by biochemical methods, of extracellular enzymes related to the biological activity of nine strains of the complex Metarhizium anisopliae (Metsch.) Sorokin. We determined the pathogenic capacity against the insect Cylas formicarius Fabricius at different concentrations, calculated the lethal time and concentration, and analyzed both the presence of extracellular enzymes in the fungal strains as well as their relation to the entomopathogenic effect and virulence against C. formicarius. All strains of the M. anisopliae complex studied were pathogenic with an enzymatic activity index greater than 1. The LBM-30 strain was the most effective with presence of protease, chitinase, caseinase, amylase and lipase enzymes. This result corroborates the relationship between of the enzymatic activity with the observed virulence.

EFFECT OF TEMPERATURE AND ULTRAVIOLET RADIATION ON GROWTH AND PATHOGENICITY OF Metarhizium anisopliae

“…Strains LBM-5, LBM-10, LBMa-11, LBM-12, LBM-30, LBM-41, LBM-127, LBM-146 and LBM-267 of M. anisopliae grown on MC culture medium at temperatures of 28, 30, 32 and 34 °C showed similar behaviour to that reported by Gato-Cárdenas et al (2016) on Saboraud Dextrose Agar (SDA) medium. Rodrígues et al (2016) indicated that temperature affects entomopathogenic fungi of the genus Metarhizium by affecting their metabolism, altering the processes of enzyme production, toxins, conidia germination, germ tube emission, mechanism of action, colonization and reproduction in the ecological niche.…”

“…Growth (cm) above 30 °C is closely related to the presence of hydrophobic proteins in the cell wall of conidia that protect the fungus against heat stress. It is shown that temperature, in addition to affecting growth rate, influences cultural characteristics of M. anisopliae, such as sporulation pattern, pigmentation of the culture medium and colony morphology (Gato-Cárdenas et al, 2016). The cultural characteristics of strain LBM-127 with 10 d of incubation at different temperatures showed very evident differences (Figure 2).…”