New trends in mycosynthesis of cellulose nanocrystals promoted by gamma irradiation of sugarcane bagasse

The biological synthesis of cellulose nanocrystals (CNCs) involves utilizing cellulose-degrading microorganisms or their hydrolytic enzymes as catalysts for the controlled degradation of cellulose, yielding CNCs. Chemical synthesis of CNCs involves acid hydrolysis conducted for 45 min at 45 °C using sulfuric acid (64%). Neurospora intermedia (Assiut University Mycological Center (AUMC) 14,359), Fusarium verticillioides (AUMC 14360), and Rhizopus oryzae (AUMC 14361) were employed in the preparation of CNCs. Before both chemical and biological treatments, sugarcane bagasse (SCB) was irradiated with doses of 100, 200, and 300 kGy, enhancing the yield of nanocellulose from the cellulosic feedstock. The resultant nanocellulose was initially assessed using UV–Vis spectroscopy, and the characterization was further refined through Dynamic Light Scattering analysis to delineate particle size distribution within the nanoscale and to evaluate stability. CNCs and chemically purified cellulose (CPC) displayed analogous Fourier Transform Infrared Spectroscopy but were markedly different from SCB. X-ray Diffraction patterns revealed a notably higher crystallinity of cellulose in nanocellulose, with larger crystallite dimensions compared to CPC and SCB. Transmission Electron Microscope investigations elucidated the morphology of the synthesized nanoparticles. In summary, the selection of F. verticillioides for nanocellulose production represents a promising and sustainable approach that combines effectiveness, environmental friendliness, and cost-efficiency in the synthesis of this valuable nanomaterial.

Graphical abstract