High Xylanase and Low Cellulase Producing Bacteria as a Whole Cell Biocatalyst for Eco-Friendly Surface Modification of Banana Pseudostem Fibers

The study aimed to assess the efficiency of higher xylanase and lower cellulase-producing bacteria as a whole-cell biocatalyst for surface modification of banana pseudostem fibers in an eco-friendly and cost-effective manner. The ability of bacterial biocatalysts to alter fibers’ surface during fiber-biocatalyst interaction in liquid media was determined by analyzing fibers' chemical composition (cellulose, hemicellulose, and lignin), surface color, thickness, surface morphology, and spectral attributes. Results indicated that the production of xylanase by Bacillus licheniformis (1.23 IU/mg of protein) and Bacillus pumilus (1.29 IU/mg of protein) was almost 15 times more than cellulase produced by them. The content of alpha-cellulose (46.7%), hemicelluloses (21.6%), and lignin (11.7%) was slightly decreased in B. licheniformis-treated BPFs. The surface color (whiteness index) was positively improved, indicating color changes (ΔE) of 6.37 and 8.28 for B. pumilus and B. licheniformis-treated fibers, respectively. The thickness of fibers pretreated with B. lichenifiormis (160.75 ± 22.43 mm) and B. pumilus (202.655 ± 24.83) was reduced by 31.90 and 14.14%, respectively. Scanning electron micrograph studies revealed the increased roughness and grooves on the biocatalysts-treated fiber surface. Spectral analysis confirmed the stretching and deformation of inter and intra-molecular bonds of components of banana fibers. Briefly, the study highlights the effectiveness of whole-cell bacterial biocatalysts as a greener and cheaper tool for the surface modification of banana pseudostem fibers.