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Luminous Bacteria

Higgins

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Apparently, when you are luminous, the whole world gets luminous with you. Or maybe, if you have a brain the size of a bacteria, you think it might.

The initial description of Vibrio fischeri quorum sensing was paralleled by a similar description in the related luminescent marine bacterium Vibrio harveyi103. Before we had any mechanistic understanding of acyl-homoserine lactone (acyl-HSL) signalling, it was shown that many other marine bacteria made something that signalled V. harveyi to induce its luminescence genes104. It seemed that V. harveyi might measure the total bacterial load in its local environment rather than simply its own population size104.


http://www.nature.com/nrm/journal/v3/n9/box/nrm907_BX4.html
 
NeuroFizz

NeuroFizz

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Vibrio harveyi is found in many animal tissues where the host cultures them in a symbiotic relationship (provides nutrients and uses the bioluminescence). It's interesting stuff, particularly for many mid-water animals, and the hosts have developed many accessory structures that allow them to take the continuous light of the bacteria and shutter is to flash or be hidden. It's a ripe story for illustrating some aspects of co-evolution.
 
Higgins

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NeuroFizz said:
Vibrio harveyi is found in many animal tissues where the host cultures them in a symbiotic relationship (provides nutrients and uses the bioluminescence). It's interesting stuff, particularly for many mid-water animals, and the hosts have developed many accessory structures that allow them to take the continuous light of the bacteria and shutter is to flash or be hidden. It's a ripe story for illustrating some aspects of co-evolution.
Click to expand...

I wonder if the hosts can signal the bacteria to do its luminous stuff since the bacteria seems to be picking up population density signals from other types of bacteria.
 
NeuroFizz

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Most work has been done on Virbrio fischeri, and the growth of bacteria in the "crypts" of the light organs of the host are most influenced by nutrient availability, which is kept extremely high. I'm not aware of any specific inducers that come from the host, but I haven't been in that literature for some time. A quick search of Google Scholar will get a long list of original papers on the topic. I'll have to check it out later, and I may end up slapping my forehead if a forgotten inducer pops up in my search.

IN EDIT: A quick scan says nitric oxide may provide a host-to-bacteria signal. The leader in this research is someone I know. Go here to her site and look at her publications:

http://www.medmicro.wisc.edu/department/faculty/mcfall-ngai.html
 
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Higgins

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NeuroFizz said:
Most work has been done on Virbrio fischeri, and the growth of bacteria in the "crypts" of the light organs of the host are most influenced by nutrient availability, which is kept extremely high. I'm not aware of any specific inducers that come from the host, but I haven't been in that literature for some time. A quick search of Google Scholar will get a long list of original papers on the topic. I'll have to check it out later, and I may end up slapping my forehead if a forgotten inducer pops up in my search.

IN EDIT: A quick scan says nitric oxide may provide a host-to-bacteria signal. The leader in this research is someone I know. Go here to her site and look at her publications:

http://www.medmicro.wisc.edu/department/faculty/mcfall-ngai.html
Click to expand...

Very interesting. So there might be two layers of "signals" at least: one genetic and one chemical.
 
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