Enhancing Stability and Efficacy of Trichoderma Bio-Control Agents Through Layer-by-Layer Encapsulation for Sustainable Plant Protection

Agricultural fungicide pollution poses a significant environmental challenge and causes adverse effects on human health. Therefore, strategies to limit fungicide usage are of paramount importance. Trichoderma fungi, due to their antagonistic activity against various pathogenic fungi, have shown potential as a sustainable alternative to chemical fungicides. However, bio-control agents like Trichoderma are vulnerable to physical stimuli and show diminished efficacy during prolonged storage. To address these challenges, a mild and scalable encapsulation method for Trichoderma spores is introduced, employing a layer-by-layer (LbL) approach using biobased lignin derivatives. It is demonstrated that the LbL encapsulation technique significantly improved spore stability relative to naked spores, even under adverse conditions including extreme temperatures and prolonged exposure to Ultraviolet (UV) irradiation. Notably, encapsulated Trichoderma spores showed enhanced efficacy in cultivating tomato plants compared to naked spores. Additionally, the findings revealed that the in planta efficacy of encapsulated spores is dependent on the specific Trichoderma strain used. This study suggests that Trichoderma spores encapsulated with lignin through the LbL approach, are a promising and sustainable alternative to chemical fungicides with potential for commercialization.