Hi,
A quick addition to my earlier post. I mis-understood your comment about oxygenation. Yes, you can use aeration beneficially - shop air is enough, no need for oxygen alone! We placed a pipe attached to the shop air supply with a regulated low pressure. Start at 1 to 1.5 bar and go upwards if necessary. Use 1 to 1.5 mm holes and increase as required. The effect is like putting air into a fish aquarium. Don't let the bubbles rise too quickly.
Two things happen. One is that the bubbles can break up the surface if there is an oil film present. The other is that the anaerobic bacteria will be affected by the air, and, you are correct, by the oxygen. However bear in mind that this is more effective while the coolant is stagnant. Once in motion, through pumps, nozzles, and cutting action you will find there is plenty of air getting entrained in the coolant.

Also, do not forget the bacteria once killed, by biocides or aeration or disinfectants, do NOT disappear. Those bug 'bodies' add to the biological mix that is forming, and it isn't healthy. There is no such thing as Good Bacteria and Bad Bacteria - just bacteria. There is nothing you can add that will eat up the bugs you don't want, and cause no problems themselves.

I have a link you might find helpful. It's more than twenty years old but was something I read while trying to learn what I know now - which is not enough.
https://www.ctemag.com/news/articles/coolant-care

Good luck,