Comparative antibacterial activity of commercial chitosan and chitosan extracted from Auricularia sp.

The threat of antimicrobial resistance continues to rise, hence the need for the discovery of new antibiotics, especially from alternative sources like plants, fungi and other organisms, also increases. In this study, chitosan is derived from Auricularia sp., and its antibacterial property, together with commercial chitosan, were evaluated against Escherichia coli and Staphylococcus aureus. Chitinous material from Auricularia sp. were deproteinized and deacetylated using different concentrations of NaOH at varying temperature for hours. Extracted and commercial chitosan were verified through FT-IR Analysis, and deacetylation degrees of the two were also determined. FT-IR Analysis showed that both chitosan have similar trends in the FT-IR spectrum but differ in deacetylation degrees. The results also showed concentration-dependent antibacterial activities of both extracted and commercial chitosan against E. coli and S. aureus wherein as the concentration increases, the activity also increases. Moreover, both chitosan exhibited greater activities against S. aureus than in E. coli, and it was revealed that they exhibit significantly higher activities against Streptomycin sulfate against S. aureus and comparable activities against E. coli. Overall, the results have showed that the chitosan extracted from Auricularia sp. exhibited greater antibacterial activities on both Gram-positive and Gram-negative bacteria compared with the commercial chitosan.