In article ,
says...

NASA got a bad day some weeks ago.

A microbiologist discovered that Acetinobacter can eat the desinfectant
that NASA sprays in their clean rooms...

A soil bacteria.

Now, NASA is selecting the hardest microbes to send to space... All
other normal microbes are dead, and Actetinobacter has no competition.

Arrived to destination (say Mars) Acetinobacter could be devasting for a
local biota. Since it is extremely resistant, it could spread unchecked.

There is zero proof that Mars has actual living "local biota".
Furthermore, I am unaware of any earth microbes which would "thrive" in
the extremely thin atmosphere and radiation environment of Mars.

Is it a good idea to desinfect spaceships?

If you want the crew on the inside to stay healthy, yes. Otherwise it's
like locking them inside a dank basement for the duration of the trip
and hoping they don't get sick.

Or it would be better to have as much as possible of weak, normal
bacteria that are surely dead if confronted to space?

Or coat the spaceships with very fragile bacteria that would prevent
Acetinobacter to thrive and would be immediately dead in space?

What is important is that in space no earth bacteria survive unchecked.

Inside ISS, where they try to combat microbes for the health of the
crew, is not the same as outside ISS in vacuum. Inside the spacecraft
is also not the same as outside in the very thin atmosphere of Mars.

Jeff
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