OK Coug I am going to give it a shot, hopefully its understandable. We as hobbist think that the nitrogen cycle is a simple thing, ammonia-nitrite-nitrate-nitrogen gas, all this is done by bacterial action. Well of course
its not quite like that. Thier are basically two types of processes that can occur Both with simular results but with some big differences. The two processes are called assimilative and dissimilative. Ok now before we go thier you have to understand this. In the reduction process (as in ammonia to nitrite and so on) is a process done by selective baceria in each step, now each bacteria uses a distinct enzyme to catalyze a reduction (so no enzyne no reduction). Ok here we go, the process we are all used to is the Dissimilative dentrification. In this process nitrate replaces oxygen as the electron acceptor in the biochemistry of the cell. Basically the bacteria uses nitrate in place of oxygen to respire. the result of this is the conversion of nitrate to nitrogen gas. now the bacteria that does this are fuclative and can live in either oxygenated or suboxygenated water. Ok now for assimilative denitrification. what happens in this process is that with the presence of ammonia, the ammonia represses assimilative nitrate reductase (which is the first enzyme in this nitrate reduction pathway ) the result of assimilative dentrification means that ntriate does not turn into notrogen gas but instead to ammonium, the ammonium then would perk through the bed and enter the cycle once more at the ammonia to nitrite reduction part of the cycle.
Ok now looking at the results of Charles study he is saying that ammonia was present through out the bed and in the plenum. So if you take these results and apply them to how the cycles work it would mean that only assimilative dentrification is occuring and not the off gassing we are looking for.
Did I make a muckery of trying to explain that??????????
Mike