Assessing microbial growth in drinking water using nucleic acid content and flow cytometry fingerprinting

Area of Science:

• Environmental Microbiology
• Water Quality Monitoring
• Bacterial Physiology

Background:

• Bacterial populations in drinking water systems exhibit heterogeneity.
• Understanding bacterial dynamics is crucial for ensuring water safety and treatment efficacy.
• Traditional monitoring methods may not fully capture the complexity of microbial communities.

Purpose of the Study:

• To evaluate the use of flow cytometry (FCM) for differentiating bacterial populations based on nucleic acid content.
• To assess the impact of water treatment processes (chlorine, nutrients) on bacterial dynamics.
• To explore FCM fingerprinting with cluster analysis for enhanced water quality assessment.

Main Methods:

• Utilized flow cytometry (FCM) to analyze intact bacterial cells.
• Differentiated populations into high nucleic acid (HNA) and low nucleic acid (LNA) content.
• Applied cluster analysis to FCM data for comprehensive microbial profiling.

Main Results:

• Chlorine and nutrient levels differentially affect HNA and LNA bacterial populations.
• HNA bacteria indicate rapid growth in response to nutrient changes.
• LNA bacteria reflect adaptation to stable, low-organic environments.
• Water treatment conditions significantly alter the HNA/LNA ratio.

Conclusions:

• FCM is a valuable tool for monitoring bacterial dynamics in drinking water.
• HNA/LNA bacteria serve as indicators of specific physiological states and responses to treatment.
• FCM fingerprinting combined with cluster analysis offers superior sensitivity for water quality evaluation.
• Multi-parameter data analysis is recommended for advanced water treatment and supply monitoring.