Is the rebalancing of the naturally occurring microbial groups so each group can undertake their function of enzyme production that leaves you with a healthy water system. Bacteria feed off each other so you end up with a chain of different bacterial species all relying on each other for their own survival.
All bacteria are required in this nutrient cycling process that leads to healthy water systems. Even the bad ones such as E coli are important. E coli enzymes are critical in phosphate cycling but in large numbers these same enzymes are toxic, causing disease and death. So whilst its importance in water is critical, to maintain E coli in the correct numbers you must have a balanced microbial system. To balance any microbial system you must start from the very beginning, then each bacterial group will align itself into it's required position in nature. Disease-causing bacteria explode in numbers whenever a link within the microbial grouping is broken. This is also why very good bacterial technologies dealing with different water issues, also end up causing a problem known as a biotoxin. This occurs because the problem they are fixing is generally towards the end of the chain in the microbial system and the link backwards in the process has now been broken.
Bioremediation with TWC works successfully because it concentrates on fixing the first link in the microbial chain, this then re-establishes all the links into their required places recreating a balanced healthy ecosystem.