Anon wrote:

Isn't that contrary to the laws of entropy?

well, it would be if it were not a biological process...

Going from a lower state to
a higher state?

If that happenned spontaneously, yes. But that is not what is going on.

I will need to research this, since energy would be
required to un-oxidize nitrite.

Indeed energy IS required. I don't understand why you think that would
be an issue? the bacteria doing the reaction obviously provide it. MOST
biolgical processes use energy...

Any references?