Quantification of nisin concentration from fluorescence-based antimicrobial activity assay using Bayesian calibration

Area of Science:

• Microbiology
• Biochemistry
• Food Science

Background:

• Bacteriocins are antimicrobial peptides with significant potential in food safety and pharmaceuticals.
• Current methods for measuring bacteriocin antimicrobial activity lack sufficient quantification and throughput.
• Nisin, a well-characterized bacteriocin, is crucial for combating pathogens like Listeria monocytogenes.

Purpose of the Study:

• To develop and validate a high-throughput, quantitative assay for bacteriocin antimicrobial activity.
• To utilize a non-linear calibration model for accurate inference of nisin concentration.
• To apply this method to Lactococcus lactis cultivation supernatants.

Main Methods:

• Development of a pHluorin2 fluorescence-based assay to monitor antimicrobial activity.
• Implementation of a non-linear calibration model for data analysis.
• Application of the assay to quantify nisin produced by Lactococcus lactis ssp. lactis B1629.

Main Results:

• The pHluorin2 fluorescence assay provides a quantitative readout of antimicrobial activity.
• The non-linear calibration model accurately infers nisin concentrations from fluorescence data.
• The method demonstrates applicability in analyzing bacteriocin production in bacterial supernatants.

Conclusions:

• The developed fluorescence-based assay offers an improved approach for bacteriocin quantification.
• This method enhances screening, identification, and process development workflows for bacteriocins.
• Accurate antimicrobial activity measurement is vital for leveraging bacteriocins in food safety and medicine.