Estudo das enzimas de Metarhizium anisopliae e da papaína como biopesticidas

Abstract

The control of insect vectors, nematodes, and plant and animal parasites often relies on the massive use of chemical pesticides. In light of these issues, a sustainable alternative emerges: biological and biochemical control, which uses living organisms and natural chemical products to suppress the population density or impact of a particular pest or parasite. Among entomopathogenic fungi, Metarhizium anisopliae stands out. This fungus produces hydrolytic enzymes, such as proteases and chitinases, which are essential in the host infection process. Additionally, papaya latex (Carica papaya) is known as a rich source of papain. Therefore, the present study aimed to investigate the enzymes of M. anisopliae and papain as biopesticides. The work was structured into a book chapter on the biochemistry of entomopathogens and mycoparasites, focusing on Metarhizium, and two research articles. The first article described the production of enzymes by M. anisopliae in different culture media and their efficacy in the in vitro control of parasitic nematodes of animals and plants (Haemonchus spp. and Meloidogyne incognita). The second article investigated the compatibility between the use of papain and conidia of M. anisopliae IP119 for the control of third-instar larvae (L3) of Aedes aegypti. The results showed that the rice medium with whey was the most effective for the production of protease and chitinase by M. anisopliae IBCB 424, with activities of 52 U/mg and 0.60 U/mg, respectively. The crude extract tested showed a 100% reduction in animal parasites and a 71% reduction in plant parasites. Regarding Aedes aegypti (L3), 100% mortality was observed with 10% (w/v) papain, and 97% mortality was observed with 4% (w/v) papain supplemented with M. anisopliae IP119 (10^7 conidia/mL). The results are promising, indicating the efficacy of the enzyme produced by M. anisopliae against the tested nematodes and demonstrating the potential of the papain and conidia combination for the control of A. aegypti. This pioneering study opens new research perspectives in the field of enzymes, with potential future applications.