Bioactivity of Chitosan Extracted from the Red Palm Weevil, Rhynchophorus Ferrugineus Olivier (Coleoptera: Dryophthoridae)

Document Type : Original Article


Department of Zoology, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.


Abstract: the present study aimed at investigating the antibacterial and antioxidant activities of chitosan extracted from Rhynchophorus ferrugineus adults. The Fourier transform infrared (FT-IR) analysis exhibited an absorption peak of amide I band at 1635 cm−1, respectively. The degree of deacetylations (DDA) recorded 74.25%, respectively. The X-ray diffraction (XRD) analysis showed two sharp peaks at 14.76 and 19.98º and two faints at 10.02º and 26.48º diffraction peaks. Also, scanning electron microscope (SEM) studies for the extracted chitosan surface morphology exhibited a regular surface, soft structure with nanopores and consisted of long and tidy nanofibers that adhered to each other and randomly scattered big nanopores. On the other hand, results of antibacterial activity indicated that tested Gram-positive bacterial strains were more sensitive to R. ferrugineus extracted chitosan than those of Gram-negative ones. The highest antibacterial activity (24.6±0.5 and 21.3±0.5 mm inhibition zones) recorded against Escherichia coli and Enterobacter hormaechei at 750 µg/ml, respectively. In addition, 2,2-Diphenyl-1-picryl Hydrazine, or hydrazyl-hydrate free radical (DPPH) screening test showed the good antioxidant effects of the R. ferrugineus extracted chitosan) and their scavenging activity depending on the concentration used. At 1000 and 1.95 µg/ml, R. ferrugineus extracted chitosan was found to be active radical scavenger (61.14 and 21.92%), respectively. Based on these results, chitosan extracted from R. ferrugineus adults can play an important role as potential antibacterial and antioxidant agent.