Interaction between Sophorolipids and β-glucan in Aqueous Solutions

Area of Science:

• Biochemistry
• Microbiology
• Cosmetic Science

Background:

• Skin disorders like acne, atopic dermatitis, and rosacea involve microbial biofilms.
• Polysaccharides are crucial for biofilm mechanical stability.
• Sophorolipids are biosurfactants with potential anti-biofilm properties, offering alternatives to petrochemical surfactants.

Purpose of the Study:

• To investigate the effect of sophorolipids on beta-glucan, a model biofilm polysaccharide.
• To understand the interaction mechanism and structural changes between sophorolipids and beta-glucan in aqueous solutions.

Main Methods:

• Dynamic light scattering (DLS) to assess beta-glucan aggregation.
• Surface tension measurements to study interfacial interactions.
• Isothermal titration calorimetry (ITC) to determine binding thermodynamics.
• Optical rotation to evaluate structural changes in beta-glucan.

Main Results:

• Sophorolipids dispersed beta-glucan, inhibiting aggregation, unlike sodium dodecyl sulfate (SDS).
• Interactions occurred in solution, driven by hydrophobic forces, not at the air-liquid interface.
• Sophorolipids did not disrupt the triple helical structure of beta-glucan.
• Dispersion is attributed to steric hindrance and electrostatic repulsion from sophorolipids' unique structure.

Conclusions:

• Sophorolipids exhibit unique dispersion properties on beta-glucan.
• Their interaction mechanism involves hydrophobic forces and steric/electrostatic effects.
• These findings support sophorolipids' efficacy as anti-biofilm agents in cosmetic applications.