I've heard that idea before. I may be oversimplifying, but my common sense tells me that it's not likely. Here's why:
1. Tanks go without the problem. Sometimes never, sometimes recurring and getting out of control, sometimes recurring but never a big problem. I've seen beautiful, large and established tanks with one little spot of slime that never goes away
2. The bacteria that creates cyano is always present in the water. That's why established tanks that have never had it may get it even if nothing new has been introduced to the tank
3. If there is an organism that can create more sustenance as it feeds than it consumes, we'd be in big trouble. That's like saying we can create an energy plant that runs on electricity, but creates more power than it needs. ( I realize that may be possible in the future, but play along)
What does this all tell me? It's very unlikely, because if it did do that every tank everywhere would be covered by it.
I'm no biologist, and again I may be oversimplifying, but I don't see how that's possible.