Towards a Novel Biocontrol Strategy: High Performance of Optimised Cell Wall‐Degrading Enzymes Secreted by Escovopsis primorosea LBM 277

Abstract

Fungi of the genus Escovopsis are specialised mycoparasites of the mutualistic fungus Leucoagaricus gongylophorus, cultivated by leaf-cutter ants. Harnessing this natural antagonism represents a promising and environmentally friendly strategy for the indirect biological control of these agroforestry pests. This study optimised and characterised the production of cell wall-degrading enzymes (CWDEs), key effectors in the degradation of the host, by the Escovopsis primorosea LBM 277 strain. Using submergedfermentation and Box–Behnken response surface methodology (RSM-BBD), we identified optimal culture conditions, including the concentrations of carbon and nitrogen sources, initial pH and inoculum size. Under optimised conditions, protease, β-1,3- glucanase and chitinase activities increased by 3.5-, 6.7- and 6.8-fold, respectively. The enzymes remained active for at least 30 days at room temperature and in the pH range 4–6, resembling the microenvironment of ant fungal gardens. Zymographic analysis revealed one isoform of protease, one of β-1,3-glucanase and two chitinase isoenzymes. This is the first report combining RSM-based optimization with biochemical profiling of CWDEs in Escovopsis. These findings highlight the need for further functional assays to validate the role of these enzymes in the ant–symbiont fungus–mycoparasite interaction.