The answer is quite simple: we do not know! There are so many microorganisms (trillions of trillions) that we cannot even fathom such a number. Microorganisms are everywhere, from ocean abysses to volcanic craters, from the most arid deserts to the tops of the highest mountains. They all produce molecules: one microorganism may produce just a few, another hundreds of them. With so many microorganisms out there, we know just some of those that are good at producing molecules.
In the environment, it can be difficult to see molecules, because they are produced in very small amounts. But even if we could, detecting molecules in all the different possible environments would be a never-ending task, as there are so many places to look. And their microbial composition – and hence the molecules produced – change with the seasons and as a result of floods, wildfires, earthquakes and other natural processes.
In the laboratory, we have been able to domesticate only a tiny fraction of the microorganisms present in the environment. And for those that we can, we know that under artificial laboratory conditions they produce only some of the molecules they are potentially capable of making.
Existing databases list over 30,000 molecules produced by microorganisms (e.g., www.npatlas.org) discovered in over 70 years of research. These molecules are derived from a tiny fraction of the microorganisms that are out there. In comparison with a few decades ago, today’s technologies allow us to see minute amounts of molecules, so discovering new molecules has become more effective and databases will keep growing.
At NAICONS, we keep finding new molecules from just a few of our 45,000 microorganisms. This is why we started the micro4all project. In a couple of years, when our Catalogue of Molecules will be ready, it will list over 30,000 molecules from a portion of our microorganisms. That may seem like a lot, but I am convinced it is just the tip of the iceberg and the Catalogue will keep expanding as more microorganisms are analyzed. So, it may take a long time before we run out of molecules to list. That sounds like a fun!