Question

Why E.coli is used much more time as a host cell and why not any other bacteria?

Answer 1

Growth Rate
Bacteria typically grow much faster than more complex organisms. E. coli grows rapidly at a rate of one generation per twenty minutes under typical growth conditions. This allows for preparation of log-phase (mid-way to maximum density) cultures overnight and genetic experimental results in mere hours instead of several days, months, or years. Faster growth also means better production rates when cultures are used in scaled-up fermentation processes.