Sustainable fungal production of pectinase in orange peel-based medium: Taguchi optimization, juice clarification and green synthesis of selenium nanoparticles for biomedical applications

Pectinase is a commercially important enzyme that is extensively utilized in the food, textile, and paper industries; yet, its large-scale production poses a hurdle due to high cost of pectin for its production. This research utilized Taguchi optimization to improve pectinase production from a non-aflatoxigenic local strain of Aspergillus flavus, using orange peel as an economical substrate. The improved pectinase was studied for juice clarification and eco-friendly synthesis of selenium nanoparticles (AFP-SeNPs), showcasing its enhanced biotechnological capabilities. The Taguchi L9 orthogonal optimization of pH, inoculum size, substrate concentration, and incubation time yielded a 397.7 % enhancement in pectinase production with maximum enzyme activity of 921.3 U/ml, which clarified orange juice by 76.6 %. Herein, we report the first study to synthesize SeNPs using pectinase which were spherical, crystalline, having sizes of 50.97–98.43 nm and absorbed maximally at 268 nm. The nanoparticles inhibited growth of multidrug-resistant bacterial pathogens (Klebsiella oxytoca, Enterobacter cloacae, and Salmonella enterica) up to 25.3 mm and total suppression of fungal growth (Aspergillus flavus, Aspergillus niger, and Penicillium sp.), while displaying 35.9–59.3 % DPPH radical scavenging activities. Additionally, AFP-SeNPs successfully prevented blood clot formation in vitro. This research which uniquely combines pectinase-assisted green production of SeNPs has broadened the applications of pectinase. The multifunctional bioactivities of AFP-SeNPs—antimicrobial, antioxidant, and anticoagulant—underscore their significance in biomedicine, pharmaceuticals, and industrial biotechnology. These findings would enhance sustainable enzyme manufacturing and environmentally friendly nanotechnology, providing a cost-efficient and scalable approach for future developments.