Angularly resolved light scattering from aerosolized spores: observations and calculations.

Area of Science:

• Microbiology
• Optical Physics
• Aerobiology

Background:

• Bacillus subtilis spores are important biological particles.
• Understanding their optical properties is crucial for detection and characterization.
• Light scattering is a key technique for analyzing particle morphology.

Purpose of the Study:

• To compare experimental light scattering data of Bacillus subtilis spores with theoretical simulations.
• To determine the best geometric model for representing Bacillus subtilis spores in optical scattering simulations.

Main Methods:

• Collected 2D angular elastic light scattering patterns from individual aerosolized Bacillus subtilis spores.
• Simulated scattering patterns using the T-matrix formalism.
• Compared experimental data with simulations using three models: finite-length cylinder with spherical caps, spheroid, and two spheres in contact.

Main Results:

• Excellent agreement was observed between experimental scattering patterns and simulations of a finite-length cylinder with spherical end caps.
• Poorer agreement was found for the spheroid model.
• The poorest agreement was achieved with the model of two spheres in contact.

Conclusions:

• The finite-length cylinder with spherical end caps is an effective model for simulating light scattering by Bacillus subtilis spores.
• Accurate modeling of spore shape is critical for interpreting light scattering data.
• This research contributes to the optical characterization of microbial aerosols.