Production and Characterization of Komagataeibacter xylinus SGP8 Nanocellulose for Its Application in the Removal of Cd Ions

In the present study, fermentative production of bacterial nanocellulose (BNC) by using Komagataeibacter xylinus SGP8 and characterization of nanocellulose is presented. The bacterium was able to produce 1.82 gL⁻¹ of BNC in the form of pellicle under standard Hestrin-Schramm (HS) medium. The morpho-structural characterization of the BNC using scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies, respectively, revealed nanofibrillar structure and high crystallinity Index (~80%) of nanocellulose. The thermogravimetric analysis (TGA) showed stability of BNC up to 280 °C, a further rise in temperature to 350 °C results in the depolymerization of the sample. In order to show the applicability of produced BNC, it was first modified separately using CaCO₃ and carboxymethyl cellulose (CMC) followed by usage in removal of heavy metal Cd from an aqueous solution. The BNC-CaCO₃ composite resulted in >99% removal of initial 10 mg L⁻¹ of Cd (II) at pH 5, 7, and 9, respectively, after 12 h of treatment. On the other hand, CMC-modified BNC showed 30, 86, and 88% removal of the same level of Cd at pH 5, 7, and 9, respectively. Overall, the above results suggest that cellulose produced by K. xylinus SGP8 showed good material properties, and modified BNC could effectively be used for remediation of toxic levels of Cd from the contaminated system.