> Plastic in ocean gives extreme insensitive to bacteria or other life forms to come with way to consume it for energy.
That's just not very likely to happen from a basic chemistry point of view.
Plastic tends to be quite stable--that's the whole point. However, that stability means that there is almost nothing to be gained by breaking plastic down--certainly not energy. And, in the ocean, practically everything plastic could provide when broken down is far more abundant and easier to access by other means.
Consequently, there is no good reason to evolve the ability to consume plastic.
Plastics burns and releases a lot of energy during that process. In that regard its energy density is similar to wood. The problem is that compared with cellulose the life has not figured out how to harvest the energy of plastic oxidation at the room temperature. But there is no law that prevents that.
Given that amount of plastic waste that humans put into the ocean is already on the scale comparable with a mass of a lot of fish species, an organism that can consume it can have a nice evolutionary advantage.
And, yet, that bacterium isn't consuming and breaking down all the PET around it (It was isolated outside a bottling facility, after all. It should spread like wildfire.).
Why?
Because the energy expended to break down the plastic means that it is outcompeted by the bacteria who get their materials by other means unless plastic is the only thing available.
In the ocean, there is always lots of other things available.
Perhaps this will turn out like the evolution of lignin-modifying enzymes, but those took a LONG time to come about even while lignin is far less stable than most plastics.
That's just not very likely to happen from a basic chemistry point of view.
Plastic tends to be quite stable--that's the whole point. However, that stability means that there is almost nothing to be gained by breaking plastic down--certainly not energy. And, in the ocean, practically everything plastic could provide when broken down is far more abundant and easier to access by other means.
Consequently, there is no good reason to evolve the ability to consume plastic.