Question

separation processes for bioproducts from

E. coli

.

Recombinant protein production from

E. coli

resulted in the first

products from biotechnology. (a) List the primary structures and

components of

E. coli

that must be removed from a fermentation

broth to purify a heterologous protein product (one that differs from

any protein normally found in the organism in question) expressed

for pharmaceutical use. (b) Identify a sequence of steps to purify a

conjugate heterologous protein (a compound comprised of a protein

molecule and an attached non-protein prosthetic group such as a car-

bohydrate) that remained soluble in cell paste. (c) Identify a separa-

tion operation for each step in the process and list one alternative for

each step. (d) Summarize important considerations in establishing

operating procedures to preserve the activity of the protein. (e) Sup-

pose net yield in each step in your process was 80%. Determine the

overall yield of the process and the scale of operation required to

produce 100 kg per year of the protein at a titer of 1 g/L.

Answer 1

During fermentation process, as a biproduct mainly secondary metabolites are produced. They include antibiotics and other products which can be bioproducts or recombinant products such as insulin. The insulin is produced by inserting Gene of insulin in E.coli. It is a recombination product. Other than that cell debris needs to be removed ( dead E.coli cells). These can be easily separated by filtering the broth. Again the bioproducts can be separated through chromatography techniques and solvent extraction processes. The broth is separated using 0.2μm microfiltration polyethersulfone membranes. The Cells of E.coli gets retained in microfiltration membrane, and broken in high pressure homogenization. The cells debris and protein are separated using polyethersulfone 0.2μm PES Microfiltration membranes. In microfiltration, cells of E.coli are rejected and proteins collected in permeate sides. The thing to keep in consideration is that the filterate should not be brought under high pressure or high heat otherwise proteins will get denatured.