Design of Carboxymethylcellulose/Poloxamer-Based Bioformulation Embedding Trichoderma afroharzianum for Agricultural Applications

Microbial biological control agents are believed to be a potential alternative to classical fertilizers to increase the sustainability of agriculture. In this work, the formulation of Trichoderma afroharzianum T22 (T22) spores with carboxymethyl cellulose (CMC) and Pluronic F-127 (PF-127) solutions was investigated. Rheological and microscopical analysis were performed on T22-based systems at three different CMC/PF-127 concentrations, showing that polymer aggregates tend to surround T22 spores, without viscosity, and the viscoelastic properties of the formulations were affected. Contact angle measurements showed the ability of PF-127 to increase the wettability of the systems, and the effect of the formulations on the viability of the spores was evaluated. The viability of the spores was higher over 21 days in all the formulations, compared to the control in water, at 4 and 25 °C. Finally, the effectiveness of the formulations on sweet basil was estimated by greenhouse tests. The results revealed a beneficial effect of the CMC/PF-127 mixture, but none on the formulation with T22. The data show the potential of CMC/PF-127 mixtures for the future design of microorganism-based formulations.