Low cost production of bacterial cellulose through statistical optimization and developing its composites for multipurpose applications

Abstract

The current investigation reports the enhanced bacterial cellulose (BC) productivity from previously isolated bacteria, Enterobacter hormaechei subsp. steigerwaltii strain ZKE7 using different raw sources. Optimization by Plackett–Burman and central composite designs revealed improved BC production of 31.7 g/L BC (In-situ) with 7.54-fold enhancement. Different BC composites were synthesized using optimized In-situ BC that showed excellent water retention capability, moisture content, water release rate, porosity, thickness and protein adsorption. In vitro drug (methylene blue dye and ceftriaxone) release profile of the composites (BC-Cu and BC-CMC) suggested a sustained drug delivery and indicated a non-Fickian diffusion behavior based on Peppas model. The quick catalytic activity of BC-Cu in fast reduction of 4-nitrophenol was demonstrated spectrophotometrically with decline in the characteristic absorbance peak of 4-nitrophenol. In-situ BC and composites exhibited antimicrobial properties with differential activity against different pathogens. Significant antibacterial and inhibitory effect was evidenced against Bacillus cereus. Only In-situ BC showed a pronounced antifungal activity against Candida albicans. In-situ BC and composites were characterized by various analytical techniques including FTIR, SEM-EDS, TGA and DSC. The current study reveals enhanced BC yield with the reduction of 4-nitrophenol by BC-Cu composite and antimicrobial property suggests its employability in drug delivery systems and environmental applications.