Upcycling waste cotton textiles into bacterial cellulose: Enzymatic hydrolysis evaluation and bench scale validation in a rotating disk bioreactor

Global textile waste represents a critical environmental challenge, yet its high cellulose content offers an opportunity for sustainable resource recovery. This study presents an integrated enzymatic–microbial platform to convert mono-material waste cotton textiles (WCT) into bacterial cellulose (BC). Systematic investigation of WCT enzymatic hydrolysis achieved a maximum glucose yield of 94.4%, providing an effective nutrient base for microbial synthesis. Initial shake-flask fermentations using Komagataeibacter intermedius B1034 demonstrated that WCT-derived hydrolysates supported BC production equivalent to conventional carbon sources and biodiesel-derived glycerol (2.3–3.4 g/L) ( p > 0.05 ). Bench-scale validation in a custom-designed rotating disk bioreactor (RDB) led to 3.2 g BC/disk using WCT-supported cultures; this performance demonstrates the platform's efficiency, aligning with industrial waste benchmarks such as crude glycerol (4.1 g BC/disk). BC characterization via ATR-FTIR and powder XRD confirmed the characteristic Iα crystalline form of cellulose. TEM and SEM confirmed the characteristic nanofibrillar architecture of BC, with SEM showing larger apparent fiber diameters while reproducing the same morphological trend. Furthermore, the WCT-derived BC exhibited robust thermal stability (T max = 297°C), indicating that the use of complex waste streams successfully preserves the structural integrity required for advanced biopolymer applications. Overall, this research highlights a promising bench-scale bioreactor framework to recover value from WCT, thereby advancing the strategic goals of a circular bioeconomy.