Evaluation of the viability of microencapsulated Trichoderma longibrachiatum conidia as a strategy to prolong the shelf life of the fungus as a biological control agent
Luis Diego Arias-Chavarría, Diego Batista-Menezes, Steffany Orozco-Cayasso, Alejandro Vargas-Martínez, José Roberto Vega‐Baudrit, Gabriela Montes de Oca-Vásquez
Abstract
Trichoderma is an antagonistic fungus used commercially; however, the viability of these formulations is affected by biotic and abiotic factors. In this research, microcapsules of sodium alginate reinforced with nanocellulose and/or chitosan were developed to encapsulate T. longibrachiatum conidia and characterized by SEM, FTIR, and TGA. The viability of the microencapsulated conidia was evaluated through different temperatures (room temperature, 5°C and 37°C), as well as their in vitro antagonistic potential against Fusarium oxysporum . The formulations evaluated had encapsulation efficiencies above 92% and the microcapsules with alginate, chitosan, and nanocellulose maintained 100% viability at 37°C for 2 months. In addition, all formulations evaluated retained antagonistic ability against F. oxysporum . These findings support the use of alginate, nanocellulose and chitosan for the formulation of microcapsules to maintain the viability of T. longibrachiatum conidia over time and at different temperature conditions.