Utilization of Hydrolyzed Agro-Industrial Waste from Arti-Chokes to Obtain Structurally Functional Bacterial Cellulose by Komagataeibacter rhaeticus QK23

Abstract

Bacterial cellulose (BC) is a pure, crystalline biopolymer with broad applications, though large-scale production remains limited by the high cost of culture media. This study evaluated the use of artichoke bract waste as an alternative substrate for BC production by Komagataeibacter rhaeticus QK23, focusing on culture optimization and physicochemical characterization of the resulting biopolymer. Infrared spectroscopy revealed functional groups characteristic of cellulose, hemicellulose, lignin, and inulin, along with structural sugars (glucose 24%, xylose 5.07%, arabinose 4.96%, galactose 8.81%, and mannose 1.75%). After hydrolysis with H2SO4, up to 11.81 g/L of reducing sugars were released and incorporated into Hestrin–Schramm medium lacking glucose. Using a central composite design, inoculum dose (10–20%) and incubation time (7–14 days) were optimized under static conditions at 30 °C. The highest yield (1.57 g/L) was obtained with 20% inoculum after 14 days. The product corresponded to type I cellulose with a crystallinity index of 81.87%, and AFM analysis revealed a surface roughness of 32.96 nm. The results demonstrate that artichoke hydrolysates are a viable and sustainable source for BC production, promoting agricultural waste valorization and cost reduction in industrial biotechnology.