Synthesis, characterization, and antimicrobial activities of sulfonated chitosan

Area of Science:

• Biochemistry
• Materials Science
• Microbiology

Background:

• Chitosan is a biopolymer with antimicrobial potential.
• Modifications can enhance chitosan's properties.
• Sulfonation is a common modification strategy.

Purpose of the Study:

• To synthesize and characterize sulfonated chitosan (SCS).
• To evaluate the antibacterial and antifungal activities of SCS.
• To compare SCS with water-soluble chitosan (WCS).

Main Methods:

• Sulfonation of chitosan using 1,3-propane sultone.
• Characterization using FTIR, NMR, GPC, elemental analysis, and TGA.
• Antibacterial and antifungal assays to determine Minimum Inhibitory Concentrations (MIC).
• Scanning electron microscopy (SEM) to visualize effects on fungal hyphae.

Main Results:

• SCS demonstrated superior antibacterial activity against Escherichia coli and Staphylococcus aureus compared to WCS.
• SCS exhibited varying antifungal activities against Arthrinium sacchari and Botrytis cinerea.
• SEM analysis showed distinct modes of action by WCS and SCS on fungal hyphae.
• SCS displayed selective antifungal activity.

Conclusions:

• Sulfonated chitosan (SCS) possesses enhanced antibacterial efficacy.
• SCS shows selective antifungal properties, indicating potential for targeted applications.
• The modification of chitosan via sulfonation is a viable strategy to improve its antimicrobial performance.