Comparative Study on The Basis of I Antibacterial Activity of Commercial Grade and Locally Produced Chitosan from Shrimp (Penaeus Monodon) Shell Waste

Abstract

The antibacterial activity of chemically deacetylated chitosan, produced from shrimp (Penaeus monodon) shell, was tested against Gram-negative (Salmonella typhi, Escherichia coli, and Shigella dysenteriae) and Gram-positive (Staphylococcus aureus) bacteria. Analytical-grade commercial chitosan was included for comparison. The commercial-grade chitosan possessed higher antibacterial activity against both types of bacteria, whereas the chitosan prepared in the present study showed moderate activity. For commercial-grade chitosan solution, the zones of inhibition were recorded as 15.21±0.707 mm for S. typhi, 16.21±0.707 mm for E. coli, 15±0 mm for S. dysenteriae, and 14.22±1.414 mm for S. aureus. On the other hand, the zones of inhibition were 13.01±0.71, 13.06±0.35, 14.21±0.71, and 10.10±0.35 mm for S. typhi, E. coli, S. dysenteriae, and S. aureus, respectively, for the chitosan produced in the laboratory. The IC₅₀ and MIC values of the produced chitosan were considerably higher than those of commercial-grade chitosan. For IC₅₀ values, commercial-grade chitosan showed more prominent results than the produced chitosan. The lowest IC₅₀ value of 0.433 mg/ml was observed against the Gram-negative bacterium E. coli for commercial-grade chitosan, whereas it was relatively higher (1.12 mg/ml) for the chitosan produced in the laboratory. For the Gram-positive bacterium S. aureus, the IC₅₀ value was also higher for laboratory-produced chitosan (1.2 mg/ml) than for commercial-grade chitosan (0.73 mg/ml). The MIC was 5 mg/ml and 3 mg/ml against E. coli and S. dysenteriae, respectively, while the MBC was 5 mg/ml and 4 mg/ml against E. coli and S. dysenteriae, respectively. For Gram-positive S. aureus, the MIC was 3 mg/ml and the MBC was 4 mg/ml for commercial-grade chitosan, whereas the MIC was 4 mg/ml and the MBC was 5 mg/ml for laboratory-produced chitosan.