Phenotypic biomonitoring using multivariate flow cytometric analysis of multi-stained microorganisms.

Area of Science:

• Microbiology
• Environmental Science
• Analytical Chemistry

Background:

• Monitoring microbial community dynamics is crucial for understanding environmental processes.
• Existing methods for analyzing microbial communities often focus on genotypic composition, potentially missing functional shifts.

Purpose of the Study:

• To evaluate a new flow cytometry (FCM) method for monitoring phenotypic profiles of microbial populations and communities.
• To assess the method's quantitative accuracy and reproducibility in resolving microbial abundances.
• To demonstrate the feasibility of using FCM for tracking functional changes in microbial communities during biodegradation.

Main Methods:

• Microorganisms were stained with fluorescent dyes and analyzed using flow cytometry (FCM).
• Multivariate data analysis techniques, including principal component analysis (PCA) and partial least squares (PLS), were employed.
• The FCM method was quantitatively validated using pure cultures and diverse microbial communities, including those from contaminated groundwater and bio-basin water undergoing naphthalene biodegradation.
• Phenotypic profiles were compared with genotypic profiles obtained from random-amplified polymorphic DNA (RAPD) analysis.

Main Results:

• The FCM method accurately and reproducibly resolved microbial populations and communities with as little as 5% abundance in complex backgrounds.
• FCM successfully distinguished between four different microbial communities during naphthalene biodegradation.
• Phenotypic profiles provided insights into both microbial composition and functional changes, unlike genotypic profiles.
• Event analysis revealed that microbial communities could converge or diverge in composition based on their degradation capacity and initial state.

Conclusions:

• The developed FCM method offers a robust and quantitative approach for analyzing microbial community phenotypes.
• This technique provides a more comprehensive understanding of microbial community dynamics by capturing functional shifts alongside compositional changes.
• FCM is a valuable tool for monitoring complex microbial ecosystems, particularly in environmental remediation studies like naphthalene biodegradation.