New potential green, bioactive and antimicrobial nanocomposites based on cellulose and amino acid

The present study deals with novel synthesizing method of TEMPO oxidized cellulose (extracted from bagasse) (TOC) amino acids (L-phenyl alanine (Phe) and L-tryptophan (Trp)) nano-composites as potential antimicrobial biocompatible agents. The produced nanocomposites were characterized via Fourier transform Infrared (FT-IR) spectroscopy, thermal analysis (TGA and DTGA), scanning electron microscope(SEM), and transmission electron microscope (TEM) which approved that the synthesis of composites in nano-scale in spherical shape with average particle size 72 and 44.37 nm for L-phenylalanine composite (Phe-TOC) and L-tryptophan composite (Trp-TOC) respectively. The antimicrobial studies were carried out on (i) Gram-negative bacteria: Escherichia coli (NCTC-10416) and Pseudomonas aeruginosa (NCID-9016); (ii) Gram-positive bacteria: Streptococcus aurous (NCTC-7447) and Bacillus subtilis (NCID-3610); (iii) unicellular fungi: namely, Candida albicans (NCCLS 11). The results were cleared that the both composites have high effective, rapid and broad-spectrum antimicrobial activity. The Trp-TOC showed slightly higher antimicrobial activity than Phe-TOC especially in time required of killing performance. The Phe-TOC has required 20 h for killing all microbial population while Trp-TOC required only 12 h. The MIC values were close in both nanocomposites with high clear zone measurements in the same concentration in the case of Trp-TOC. (C) 2019 Elsevier B.V. All rights reserved.