Comparative Study of Antibacterial Activity of Chitin and Chemically Treated Chitosan Prepared from Shrimp (Macrobrachium Rosenbergii) Shell Waste

Abstract

The antibacterial activity of chemically deacetylated chitin i.e. chitosan produced from shrimp shell. The antibacterial activity was tested against gram negative (Escherichia coli) bacteria, and gram positive (staphylococcus aureus) bacteria. To test the antibacterial activity institute of clinical laboratory standards (ICLS) approved dilution methods was used. The study was carried out by broth dilution method and used turbidity estimations to determine the growth characteristics of a bacterial culture with or without chitin or chitosan. Chitosan possess higher antibacterial activity against both types of bacteria, while chitin possess very lower activity. For staphylococcus aureus the average absorbance in every O.D value measured, staphylococcus aureus with chitin showed far higher absorbance than chitosan, indicates lower level of activity of chitin. After 32 hours of incubation s.aureus with medium absorbance was 1.15, while chitosan with s.aureus absorbance recorded 0.32, chitin with s.aureus recorded 0.733. Lower absorbance for chitosan containing E.Coli medium. At the peak point Medium and E.coli absorbance was 1.07, while chitosan with E.coli recorded 0.282 and chitin with E.coli absorbance was found 0.831. The ratio between medium E.coli and chitosan: medium and E.coli=0.26:1, and the ratio of medium S.aureus and chitosan : medium and S.aureus = 0.28:1, indicates G (+Ve) bacteria gives 0.02 times higher absorbance than G (-Ve) bacteria. The between chitin and chitosan, chitosan was found 2.2 times more active than chitin against S.aureus and 3.0 times more active than chitin against E.coli.