Produção de celulose bacteriana a partir do hidrolisado da casca de maracujá

Abstract

The valorization of agro-industrial residues has the potential to represent a sustainablealternative for the production of biopolymers, among other bioproducts. Passion fruit peel(PFP), which is rich in cellulose (48.03%) and hemicellulose (20.8%), can be hydrolyzed torelease fermentable sugars such as glucose and xylose, making its hydrolysate (PFPH) apromising substrate for biotechnological processes. Among the potential bioproducts obtained,bacterial cellulose (BC) stands out due to its high biocompatibility, whose production depends,among other factors, on carbon availability and suitable nitrogen sources for microbialmetabolism. In this context, this study aimed to evaluate the potential of PFPH as a carbonsource for BC production. For this purpose, PFP was subjected to dilute sulfuric acid hydrolysis(0.71 M H₂SO₄, 121 °C, 22 min), followed by detoxification through pH adjustment withCa(OH)₂ and treatment with activated carbon, resulting in a hydrolysate containing high levelsof fermentable sugars. Fermentation was carried out using a symbiotic culture of bacteria andyeasts (SCOBY) under static conditions at 28 °C for 14 days, and the effect of different nitrogensources (peptone, yeast extract, sodium nitrate, and ammonium sulfate) on biopolymer yieldwas evaluated. After synthesis, the celluloses were purified with 0.5 M sodium hydroxide(NaOH), and a second combined treatment with 3% hydrogen peroxide (H₂O₂) was alsoassessed. The highest BC yield (0.081 g/mL of medium) was obtained using ammonium sulfate,while sodium nitrate promoted the greatest removal of impurities (77.51% mass reduction).Structural and morphological analyses (FTIR, XPS, XRD, and SEM) indicated highcrystallinity, efficient lignin removal, and the formation of a porous nanofibrillar network.Thermal analyses (TGA) demonstrated thermal stability up to 300 °C, and biodegradation testsindicated a mass loss of 26% after 42 days in natural soil, confirming environmentalcompatibility. The results indicate that PFPH is an efficient and low-cost substrate for BCsynthesis, in accordance with waste valorization principles. The obtained BC shows highpotential as a sustainable biomaterial for applications in food packaging, biomedical scaffolds,and other high value-added technological uses.