Comparative Study on The Basis Of 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, Shigella dysenteriae) and gram positive (Staphylococcus aureus) bacteria. An analytical grade of commercial chitosan was included for comparison. The commercial grade chitosan possesses higher antibacterial activity against both types of bacteria, while chitosan prepared in the present study possess moderate activity. For commercial grade chitosan solution, the zones of inhibition were recorded 15.21±0.707 mm for S. typhi, 16.21±0.707 mm for E. coli, 15±0 mm for S. dysenteriae, and 12.42±1.414 mm for S. aureus. On the other hand it was 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 produced chitosan. The IC50 and MICs value of produced chitosan was quite higher than the commercial grade chitosan. For IC50 value, commercial grade had shown prominent results over produced chitosan. The lowest IC50 value of 0.433 mg/ml was seen against gram negative (E. coli) bacteria for commercial grade whereas it was relatively higher, 1.12 mg/ml for chitosan produced in lab. For gram positive (S. aureus) bacteria, IC50 value is quite higher (0.73 mg/ml for commercial grade and 1.2 mg/ml for laboratory grade chitosan) than other gram negative bacteria. The MIC was 5 mg/ml and 3 mg/ml against E. coli and S. dysenteriae respectively and MBC was 5 mg/ml and 4 mg/ml against E. coli and S. dysenteriae respectively. Whereas for gram positive S. aureus the MIC was 3 mg/ml and MBC was 4 mg/ml for commercial grade and MIC 4 mg/ml and MBC 5 mg/ml for lab grade chitosan.