Bacteria communicate by producing, detecting and responding to low molecular mass molecules known as autoinducers (AI) in a process called quorum sensing. The process is well-described in Vibrio fischeri , an organism that turns bioluminescent with high cell density. The molecule responsible for bioluminescence development is N-3-oxo-hexanoyl-L-homoserine lactone (3-oxo-C6-HSL).
This application note shows how a BMG LABTECH microplate reader detects bioluminescence of V. fischeri to report on quorum sensing and how these data can be related to the cell density determined by OD600 measurements. Vibrio fischeri strains mutated in different genes required for luminescence development were exposed to 3-oxo-C6-HSL to study cell-to-cell communication.
Using the script mode to combine luminescence and absorbance measurements enabled to monitor microbial growth at the same time with bioluminescence. This means that signal and an internal control can be acquired to allow a ratiometric readout.