A method for sampling microbial aerosols using high altitude balloons

Area of Science:

• Atmospheric Science
• Microbiology
• Aerosol Science

Background:

• Microbial aerosols in the Earth's atmosphere are poorly understood due to sampling challenges at high altitudes.
• Existing methods struggle to effectively collect viable microorganisms from diverse atmospheric layers.

Purpose of the Study:

• To design, construct, and validate a novel system for passive microbial aerosol sampling during atmospheric ascent.
• To address the knowledge gap regarding the abundance, diversity, and distribution of microbial taxa in the troposphere and stratosphere.

Main Methods:

• A lightweight (~2.7 kg) payload system utilizing a helium-filled balloon for atmospheric ascent.
• Passive aerosol sampling via Rotorod® collectors within sealed chambers, opened at specific altitudes.
• Real-time GPS tracking and safe payload recovery using a parachute and cut mechanism.

Main Results:

• The system successfully samples aerosols using the Rotorod® method, collecting 0.035 m3 per km of altitude per rod.
• Quality control indicates a detection limit of approximately 100 cells rod(-1) with a 3-sigma confidence level.
• The payload is adaptable to various balloon platforms for versatile atmospheric research.

Conclusions:

• The developed system provides a reliable tool for characterizing the vertical distribution of microorganisms in the atmosphere.
• This technology facilitates direct investigation into the composition and extent of the atmospheric microbiome.
• Enables crucial data collection for understanding microbial life in the upper troposphere and stratosphere.