Upgrading Oryza sativa wastes into multifunctional antimicrobial and antibiofilm nominees; Ionic Metallo-Schiff base-supported cellulosic nanofibers

摘要

Biofilm formation acts as an important self-defense strategy used by bacteria to protect itself against external changes and antibiotics effects. Moreover, biofilms have serious environmental and health impacts. Potent and safe natural antimicrobials may offer an ideal solution to tackle this challenge. In this context, we have recycled rice wastes into amino-functionalized cellulose nanofibers (CNF-NH2), ammonium-based cellulosic nanofibers Schiff bases (CNFSBs), and their corresponding Ag(I)/Zn(II) complexes. The antibacterial study of new cellulosic specimens revealed that the grafting of CNF-NH2 with ammonium ionic liquids segments and metal ions has remarkably improved its antibacterial activity. CNFSB1-Ag was the most potent antibiotic candidate against common medically-relevant strains, methicillin-resistant S. aureus (MRSA) and E. coli (MICMRSA/E. coli = 0.19/0.65 mu g/mL). Moreover, it is more active than the clinical drug (vancomycin) (MICMRSA/E. coli = 1.02/0.85 mu g/mL). Also, CNFSB1-Ag was the most active in limiting of MRSA and E. coli biofilms formation with 97.9% and 81.0% biofilm reduction, respectively.