Figure 3.

Concentration dependence of chitosan hydrolysates on bacterial growth. MRSA was cultured in LB liquid medium at 37 °C overnight in the presence or absence of chitosan hydrolysates ranging from 0 to 800 µg/mL. Chitosan hydrolysates included: (a) CTSN-P2, (b) CTSN-B2, (c) CTSN-S2. (d) The growth inhibitory effect of chitosan hydrolysates was monitored at the same concentration (100 µg/mL) to define the effective molecular weight of chitosan. Acetic acid (0.1%, v/v) was used as a control for the base solvent of chitosan, and 1,2-Hexandiol (0.1%, v/v) was used as a commercialized agent for antimicrobial chemicals. Growth of microorganisms collected on the surface of the mask was monitored by optical density at 595 nm in a time-dependent manner up to 24 h.