Only E coli are currently in use for this purpose around the world, and so in our operation.
There is no other way to prodeuce GH but taking the engineered bacteria, which we keep frozen at -80C, then induce it to growth rapidely under optimal conditions. There is no use in a reactor in this process(this is not engineered chemisry, but biotechnology) but a fermentor is used for this process.
Regarding purification etc' - there are 2 critical pillars in this process which are
1. Getting the engineered bacteria
2. using an effective optimal process to extract and purify the protein we're interested in (GH in this case) without harming it.
so I guess that I won't give u the engineered bacteria, nor specify much on the purification process which is the million dollars technology issue here.
BTW - if you google on this subject you'll see published info on purification process of recombinant GH, we use similiar but upgraded method, if I specify more u may indirectly recognize from official published medical info from which institute we got the technology