Physiology:
Vibrio Fischeri are Gram negative, motile rods. One of the key features that can be found in the species Vibrio Fischeri is its bioluminescence. This bioluminescence comes from one of the products of a reaction catalysed by the enzyme luciferase (see biochemistry and metabolism).
Vibrio Fischeri are easy to grow and they display chemotaxic behaviour. It is best to grow Vibrio Fischeri at 28 degrees Celsius. (DeLoney-Marino CR, 2013)
Vibrio Fischeri is a heterotroph and has the ability to be anaerobic and aerobic which was determined through genome sequencing and chemical assays. One of the ways in which it is able to grow anaerobically is by using mixed-acid fermentation. (Ruby et al. 2005)
Vibrio Fischeri is also oxidase positive.
Location:
Vibrio Fischeri is found in shallow marine environments and has a symbiont relationship with certain squid and fish (see Figure 1). Vibrio Fischeri stops the squid from casting a shadow which acts as an antipredatory defence (Visick et al. 2000).
Figure 1 shows Vibrio Fischeri within an Euprymna scolopes squid. It shows the bioluminescence that the bacteria give. The image was taken from National Geographic …show more content…
This reaction is catalysed by the enzyme luciferase. Luciferase uses oxygen that has been taken from the environment to oxidise a reduced Flavin mononucleotide and aliphatic aldehydes. The end products of this reaction include aliphatic acids, oxidised flavin, water and an unstable intermediate. This unstable intermediate is able to emit photons of blue-green light. This in turn is what produces the bioluminescence coming from the bacteria. The regulon that is able to control the expression of the luciferase enzyme that catalyses this reaction is controlled in several ways, one of which is quorum