Main description (English)

Introduction A current trend in sustainable agriculture is the use of beneficial microorganisms to promote plant growth and biologically control phytopathogens. Innovative biocontrol agents can accelerate the reduction of pesticide dependence, ensuring environmentally friendly and sustainable farming practices. Encapsulation of selected bioagents into precisely designed polymeric carriers represents a rational approach to developing biohybrid materials for use as biocontrol formulations. als for use as biocontrol formulations. Experimental part Poly(3-hydroxybutyrate) (PHB) was supplied by Biomer (Germany). Sodium carboxymethyl cellulose (CMC) and 2-hydroxyethyl cellulose (HEC) were obtained from Sigma-Aldrich (Germany). Bacillus subtilis strains were provided by the microbial collection of Biodinamika Ltd. (Bulgaria). crobial collection of Biodinamika Ltd. (Bulgaria). Results Novel eco-friendly hybrid materials based on electrospun PHB coated with cellulose derivatives and B. subtilis were successfully fabricated using a combination of electrospinning and dip-coating techniques [1]. The influence of the type and molecular weight of cellulose derivatives on solution viscosity, film formation, mechanical properties, and bacterial incorporation and growth was investigated. Scanning electron microscopy revealed the morphology of fibers, films, and incorporated bacterial cells. Conclusions The dip-coating process enhanced the mechanical strength of fibrous PHB materials, preserved bacterial viability, and enabled long-term storage and controlled release. The developed hybrid materials, based on electrospun PHB coated with cellulose derivatives and encapsulated Bacillus subtilis, show strong potential as sustainable biocontrol systems for plant protection and growth promotion in eco-agriculture. Keywords: electrospinning; dip-coating; poly(3-hydroxybutyrate); cellulose derivatives; Bacillus subtilis. Acknowledgments: This research was funded under the Grant BG-RRP-2.011-0005-C01 with financial support from the European Union-NextGenerationEU, Investment C2.I2 “Increasing the innovation capacity of the Bulgarian Academy of Sciences in the field of green and digital technologies”.ferences [1] P. Tsekova, N. Nachev, I. Valcheva, D. Draganova, M. Naydenov, M. Spasova, O. Stoilova, Polymers, 2024, 16, 2749.