Re: nano bioroids
We are very good at crippling bacteria. E. coli in particular. For eg the sort used in bio labs cannot make the amino acid tryptophan which is very rare in the environment. So to grow them you have to supply in the growth media/plate. It gets used up, growth stops.
So that can be done here with these bugs and almost certainly has been done. So in essence we can switch the bugs on or off, on or off, on or off. Biotech has had this sorted for Decades. Google the Asilomar Conference for the start of it.