Antifungal activity of Trichoderma virens and Trichoderma asperellum: Integrating Enzymatic Activity and GC-MS Analysis of Polar and Non-Polar Culture Filtrates

Abstract

Trichoderma virens and T. asperellum are widely known for their potential as biocontrol agents. In this study, single isolates and consortia of these two species were evaluated for their antagonistic activity against two soilborne pathogens; Sclerotium rolfsii and Macrophomina phaseolina under in vitro conditions. In addition, hydrolytic enzyme production was assessed, and metabolite profiles in polar and non-polar fractions were identified using GC–MS. Antifungal activity against S. rolfsii and M. phaseolina varied among the tested treatments. Both single isolates and consortia showed different levels of inhibition, even some combinations show very low antagonistic activity against M. phaseolina. Among the single isolates, strains Tv1 and Ta2 produced the highest cellulase, while chitinase production was generally higher in T. asperellum than in T. virens*. Correlation analysis revealed a positive relationship between chitinase production and inhibition of S.rolfsii in consortium treatment, while negative correlation was observed in single-isolate assay. GC–MS profiling revealed clear differences between solvent fractions. The non-polar extract was dominated by lipophilic alcohols, aldehydes, and aromatic compounds often associated with direct antifungal activity. Meanwhile, the polar fraction showed greater chemical diversity, with a higher proportion of ketones and other oxygenated compounds, suggesting a complementary role in the indirect antagonistic mechanism. The main metabolites found included hexadecanoic acid, octadecanoic acid, 2,4-di-tert-butylphenol, and phytol, which are known to disrupt cell membranes, inhibit spore germination, and suppress mycelial growth