Isolation of Luminescent Bacteria from Natural Sources

I tried to isolate luminescent bacteria from the surface of the squid, in the first week of my internship.  Bioluminescent bacteria are able to emit a glowing light due to the process of converting chemical energy into that light. There are fish and squid that have specialized organs that provide bioluminescent bacteria with both a safe place to live and a source of food. Reciprocally, the animals is able to use the light that is produced by the microbes either as a means of camouflage, as an aid in hunting, or even as a way of attracting mates. The marine luminescent bacteria are found in the genera Vibrio, Photobacterium, Photorhabdus, and Shewanella. The bioluminescence system is combined of a group of proteins, such as luciferase the main enzyme which produces light. I will be trying to isolate a bioluminescent strain of gram negative cocci from the squid.

First, I placed my squid in a dish and flood the dish with 3% NaCl solution that I made it before until the squid partially covered with solution. Then, I put my dish in the incubator at 16 ºC for 24 hours.

After 24 hours I examined my sample several times in a dark room to check for luminescent patches in the dish. Unfortunately, I didn’t observe luminescent patches in 2 days. I discarded my sample and started to find another way to do it.