Improved Biocontrol Efficacy of Bacillus velezensis FZB42 through Encapsulation in Sustainable Tunicate-based Carboxymethylcellulose Hydrogel

초록

The excessive application of pesticides and chemical fertilizers has caused a significant decline in biodiversity and increas ed environmental pollution, promoting the development of resistant phytopathogens, which are a serious threat to the agricultural industry. Among them, Fusarium graminearum (F. graminearum ) is a vital species known to generate disease in plants during cultivation and storage. An alternative approach is to offer a sustainable solution through a biological contro l a gent; however, their efficacy often exhibits limited efficacy because of poor stability under different environmental conditions, drawing the need for an improved formulation approach. Due to its degree of substitution, molecular weight, aspect ratio and crystallinity, TCMC shows enhanced thermal and mechanical performances, compared to commercial CMC A composite hydrogel made from tunicate derived carboxymethylcellulose ( and alginate was formulated in this study to serve as a pH responsive system for encapsulating spores of the biocontrol bacterium Bacillus velezensis FZB 42 The resulting TCMC hydrogel demonstrated not only enhanced mechanical strength and thermal stability but also controlled spore release under alkaline conditions Alkaline favoring fungal pathogens, F graminearum were inhibited up to 57 10 depending on the composition of TCMC and alginate in an in vitro assay In addition to its functional performance, this study provides an eco friendly solution by utilizing discarded tunicate shells, a significant marine byproduct waste In conclusion, this system enables pH dependent release of microbial biocontrol agents and long term stabilization while facilitating sustainable agricultural applications and valorizing marine biowaste