Microstructure and molecular vibration of mannosylerythritol lipids from Pseudozyma yeast strains

Area of Science:

• Microbiology
• Biochemistry
• Materials Science

Background:

• Mannosylerythritol lipids (MELs) are biosurfactants with potential applications.
• Investigating MELs from Pseudozyma aphidis B1 and Pseudozyma hubeiensis TS18 provides insights into their microbial production and properties.

Purpose of the Study:

• To characterize the microstructure and molecular vibrations of MELs produced by specific yeast strains.
• To identify reliable indicators for detecting different MEL types using spectroscopic methods.

Main Methods:

• Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) for microstructure analysis.
• Anthrone test and thin layer chromatography for MEL confirmation.
• Surface-enhanced Raman scattering (SERS) for molecular vibration analysis.

Main Results:

• SEM revealed elongated yeast cells with polar budding. HRTEM identified lipid bodies containing MELs and unknown inclusions.
• SERS analysis indicated higher saturation in MEL-B fatty acid chains from both yeast strains.
• Specific CH bond bending vibrations (840-940 cm⁻¹) were identified as efficient indicators for MEL-A, -B, and -C detection.

Conclusions:

• The study successfully characterized MELs from Pseudozyma strains using advanced microscopy and spectroscopy.
• The identified Raman scattering peaks offer a novel, efficient method for distinguishing between MEL-A, -B, and -C.
• This research contributes to understanding MELs and developing spectroscopic detection techniques.