Question

In a microbiology lab assignment involving Vibrio fischeri and bioluminescence:

Would shaking your flask of bioluminescent bacteria increase or decrease the intensity of the light? Why does this occur?

I know that oxygen exposure causes an increase in intensity, but I'm unsure of how shaking would affect this.

Answer 1

Yes, shaking the flask containing bioluminescent bacteria would result in increase in light density. The chemical reaction which is responsible for bioluminescense in Vibrio fischeri is catalyzed by the enzyme luciferase. The biochemical reaction involves the oxidation of an aliphatic aldehyde by reduced flavin mononucleotide. The products of this oxidation reaction are oxidized flavin mononucleotide, a fatty acid chain and energy in the form of blue-green visible light. In bioluminescent bacteria growing in shake flasks, the enzyme luciferase is synthesized in a relatively short burst during the period of exponential growth. The lux operon produces an autoinducer protein homoserine lactone which is involved in sensing the concentration of bacterium in a space. When the bacteria is in restricted space this autoinducer protein reacts with regulatory protein and eventually producing bioluminescence.