Microbial metabolic exchange in 3D.

Area of Science:

• Microbiology
• Analytical Chemistry
• Biophysics

Background:

• Microbial populations dynamically alter their chemical environment, impacting community behavior and interactions.
• Understanding these chemical exchanges is crucial for deciphering microbial ecology and pathogenesis.

Purpose of the Study:

• To develop a novel methodology for creating three-dimensional (3D) models of microbial chemotypes.
• To correlate these 3D models with colony phenotypes using multimodal imaging analysis.
• To visualize metabolic exchange and chemical interactions in microbial communities.

Main Methods:

• Serial cross-sections of microbial colonies grown on deep agar were analyzed using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) imaging mass spectrometry (IMS).
• Data sets from serial sections were registered in MATLAB to construct 3D models, which were then superimposed with colony photographs.
• The 3D models were applied to study interactions between Bacillus subtilis and Streptomyces coelicolor, and Candida albicans and Pseudomonas aeruginosa.

Main Results:

• The 3D models successfully visualized the depth profile of secreted metabolites within the agar medium.
• Novel chemical signals and distributions within sub-surface hyphae of Candida albicans were observed.
• The presence of Candida albicans induced increased rhamnolipid production by Pseudomonas aeruginosa, inhibiting hyphal growth.

Conclusions:

• The developed 3D MALDI-TOF IMS methodology provides unprecedented insights into microbial chemical ecology.
• This technique reveals complex metabolic interactions and chemical alterations driven by interspecies microbial encounters.
• The findings highlight the role of Pseudomonas aeruginosa's rhamnolipid production in modulating Candida albicans growth dynamics.