Vibrio fischeri is a toxin-producing bacterium that is often found in residing in the light-emitting organ of marine animals such as squid and fishes. It is used as a model system for studying the symbiotic relationships between bacteria and animal. For example, V. fischeri colonizes the light-producing organ on certain squid and fishes and helps it develop, serving as a source of light in return. One well-documented relationship is between V. fischeri and the Hawaiian bob-tailed squid. The squid stay buried in the sand during the day but at night they swim through the water looking for food with the help of a light sensing organ on its underside that is composed of the bioluminescent V. fischeri and reflector plates.
V. fischeri (right) is a bioluminescent symbiont found in the
light-sensing organ of the Hawaiian bobtailed squid (left).
Photo by Eric Stabb, University of Georgia
The V. fischeri genome has already been sequenced and is being studied to understand the bacterium’s bioluminescent properties. Researchers have found that some bacterial mutants can produce as much as 500 times more luminescence compared to the wild type V. fischeri. Inn sequencing these mutants and resequencing the V. fischeri genome using new sequencing technologies, researchers hope to gain a better understanding of how respiring bacteria such as V. fischeri can generate energy. They also intend to use the information to find out more about the bacterium’s role in the global carbon cycle.
Principal Investigators: Eric Stabb, University of Georgia
Program: CSP 2010