Luminescent Bacteria

Herring as a source of luminescent bacteria, fresh and after three (!) days of incubation
Recipe for enrichment
Place a fresh herring in a bowl, covered with saltwater (3 %) by half. Put the bowl into a refrigerator at 8 - 10 C for two days (no longer, not warmer, otherwise bad smell will develop!). Then you will be able to detect light-emitting pin-points, often on the side-line organ. You have to perfectly darken the room for that, and to adapt your eyes to the darkness for at least 5 minutes.

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