Multiple fluorescence approaches to identify rapid changes in microbial indicators at karst springs

Area of Science:

• Environmental Science
• Microbiology
• Water Quality Monitoring

Background:

• Karst springs are vital drinking water sources but are highly susceptible to contamination.
• Rainfall events can cause rapid, hazardous fluctuations in microbial water quality.
• Timely detection and source identification of contamination are essential for public health and aquifer management.

Purpose of the Study:

• To evaluate fluorescence-based methods for monitoring rapid, rainfall-induced microbial changes in karst springs.
• To determine if these methods can link water quality changes to human effluent contamination sources.

Main Methods:

• Utilized a fluorescence-based multi-parameter approach for water quality analysis.
• Employed flow cytometry for total cell count (TCC) measurements.
• Measured tryptophan-like fluorescence (TLF) and fluorescent whitening compounds (FWCs).

Main Results:

• All microbial parameters showed significant responses to rainfall events.
• TCC measurements strongly correlated with traditional faecal indicator bacteria (FIB) and total coliforms (TC).
• TLF measurements also showed strong positive correlations with microbial parameters, indicating potential for rapid faecal indicator detection.

Conclusions:

• Fluorescence-based techniques, particularly TCC via flow cytometry and TLF, are effective for monitoring rapid microbial shifts in karst springs.
• These methods offer a cultivation-independent alternative for indicating changes in water quality.
• FWC signals, while not directly tracking microbial indicators, can provide insights into wastewater effluent impact.