VOCs-mediated allelopathy by Bacillus subtilis on suppressing drainage malodor

Area of Science:

• Microbiology
• Environmental Science
• Biotechnology

Background:

• Microbial volatile organic compounds (mVOCs) are crucial mediators of microbial community interactions.
• Odorous emissions from drainage systems pose significant environmental challenges.
• Pseudomonas aeruginosa is a key contributor to malodorous volatile compounds in aquatic environments.

Purpose of the Study:

• To investigate the allelopathic potential of Bacillus subtilis-derived mVOCs against odor-producing bacteria.
• To assess the impact of B. subtilis mVOCs on microbial community volatile emissions and odor intensity in drainage systems.
• To evaluate the efficacy of B. subtilis mVOCs as a biocontrol agent for odor mitigation.

Main Methods:

• Exposure of Pseudomonas aeruginosa to B. subtilis-derived mVOCs.
• Analysis of volatile organic compound profiles in coastal drainage microbial communities.
• Quantification of odor intensity (sum of odor intensities, SOI) under aerobic and anaerobic conditions.
• Assessment of microbial viability and community structure shifts.

Main Results:

• B. subtilis mVOCs significantly reduced P. aeruginosa viability by impairing metabolic and respiratory functions.
• Key odor compounds (methylamine, acetaldehyde, nonane, dodecane) were reduced by over 95% in drainage systems.
• Odor intensity (SOI) decreased substantially, and microbial viability declined significantly under both aerobic and anaerobic conditions.
• Specific shifts in microbial community composition were observed, including changes in the abundance of Marinomonas, Thalassolituus, Psychrosphaera, and Maricurvus.

Conclusions:

• Bacillus subtilis-derived mVOCs demonstrate potent allelopathic activity against odor-causing bacteria.
• mVOCs offer a promising biocontrol strategy for reducing odor pollution in complex microbial environments like coastal drainage systems.
• This approach presents an innovative, environmentally friendly solution for odor management in aquatic ecosystems.