Until last week I could come up with 4:
I came across this flavor, when I got interested in Old Roman Cooking. Back in the days, the Romans stored fish in salt, to prevent them from roting. After 4 months the fermenting bacteria would eat all the sugar and break down most of the proteins in fish, leaving them with a delicious sauce they called the Garum. Unfortunately this sauce disappeared suddenly in the 11th century. This tradion continues still, in East Asian cusine, where they ferment fish for longer periods. So I grabbed a Vietnamese sauce, and "softened" it with grape juice. The fish sauce smelled unbelievably like the Gran Padano cheese in my refrigerator. It added a whole new dimension to the nut-cakeI made from an Roman recipe.
Here is a very good link about umami, and this one's for Fish Sauces.
I'll write more on fermentation, and how much we must be thankful to the microorganisms doing it for us in my coming posts...