Microbial fortification of rotary drum compost and vermicompost with Trichoderma viride via solid-state fermentation and GC-MS profiling of bioactive compounds

Compost-based soil inputs are rich in nutrients but often lack consistent biopesticidal properties, limiting their effectiveness in integrated disease management. Microbial fortification using beneficial microorganism such as Trichoderma viride offers a sustainable approach to enhance compost functionality. This study aimed to produce Trichoderma viride-fortified rotary drum compost (RDC) and vermicompost (VC) through solid-state fermentation (SSF), and to identify associated bioactive compounds with potential biopesticidal properties using GC-MS profiling. T. viride, a well-known biocontrol agent, was selected for its antifungal activity and adaptability to compost matrices. RDC and VC inoculated with T. viride at two dosages (2.8 × 10⁷ and 2.8 × 10⁶ spores/ml) were monitored for 12 weeks. At the high dosage, the peak spore yield was recorded at weeks 3–4, with 4.5 × 10⁷ spores/g in RDC and 4.6 × 10⁷ spores/g in VC. Nitrogen content increased by 13.9% in fortified RDC and 30.1% in fortified VC, while potassium increased by 10.4% and 49.3%, respectively. In contrast, total organic carbon decreased by 16.9% and 13.1%, respectively. FE-SEM analysis confirmed spore colonization in compost. GC-MS profiling identified key bioactive compounds such as 4-Methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene, Hydroxylamine O-(3-methylbutyl), and oxirane derivatives, which are associated with antimicrobial activity. This study demonstrated the potential of microbial fortification using T. viride to enhance compost functionality with biopesticidal compounds. The identification of these compounds provides a basis for future studies focused on evaluating their efficacy in suppressing plant diseases and sustainable crop production.