Sorry, I'm not a scientist or anything so I can't tell you how old a certain bacteria is, and I certainly don't have any faith in their dating methods. I don't believe in Science too much because the results can be shown to prove just about any point of view. Usually the point of view the scientist had before the experiment, or the point of view the business wants to promote that sponsored the study. I believe Science is sbout to be turned on it's ear from the atomic level on up pretty soon also. I've just been using ozone for 7 years now and researching what it does, how it does it, what it treats and so on and trying to verify it from first hand experience.
From my understanding, evolution says we evolved from bacteria. They were one of the first living creatures on Earth. (according to evolution) They came into existance back when the Earth had little if any oxygen. Ever since oxygen started becoming abundent most of them (the bad ones at least) started trying to find low oxygen environments to hide in like you and me, plants and dirt and so on. Quite a few cities use ozone to purify water supplies because it's safer than chamicals. Cancer is one of the low oxygen, simple life forms that can't live in high oxygen environments too.
I live in the Seattle area and as everyone knows it rains a lot here, and the north side of my house started growing mold on the outside of the house before I started using ozone. Within about three months the mold died after I started using it. Notice that's about the same amount of time it took to cure my wife's cancer too. Ozone went through paint, sheetrock, insulation, and wood to the outside of the house and killed the mold. The way you treat brain cancer with ozone is through the ears. There's someone on this site (can't remember his name, but he's from Texas)that healed his brain cancer using this method along with a good diet. The ozone goes through the ear drum into the sisuses and through the membrane behind the nose and into the brain. So as you can see ozone is a strong penetrate too.
I'll shut up, cause as you can see I could go on and on about ozone, but trust me, the ozone layer is not suffering from bacteria or any other low oxygen critter. It could be easily argued that it's getting used up oxidizing all the pollutants in the air because that's one of the jobs ozone does. That's why there's always a high ozone concentration in air that's highly polluted. Just doing it's job. (The Earth is about to turn the tide on this problem too)