Rl. Evangelista et al., PROCESS AND ECONOMIC-EVALUATION OF THE EXTRACTION AND PURIFICATION OFRECOMBINANT BETA-GLUCURONIDASE FROM TRANSGENIC CORN, Biotechnology progress, 14(4), 1998, pp. 607-614
A process model for the recovery and purification of recombinant beta-
glucuronidase (rGUS) from transgenic corn was developed, and the proce
ss economics were estimated. The base-case bioprocessing plant operate
s 7500 h/year processing 1.74 million (MM) kg of transgenic corn conta
ining 0.015% (db) rGUS. The process consists of milling the corn into
flour, extraction of protein by using 50 mM sodium phosphate buffer, a
nd rGUS purification by ion exchange and hydrophobic interaction chrom
atography. About 137 kg of rGUS of 83% (db) purity can be produced ann
ually. The production cost amounted to $43000/kg of rGUS. The cost of
milling, protein extraction, and rGUS purification accounted for 6, 40
, and 48% of annual operating cost, respectively. The cost of transgen
ic corn was 31% of the raw material costs or 6% of the annual operatin
g cost. About 78% of the cost of buffer and water were incurred in the
protein extraction section, while 88% of other consumables were from
the purification section. The sensitivity analysis indicated that rGUS
can be produced profitably from corn even at the 0.015% (db) expressi
on lever, assuming a selling price of $100000/kg GUS. An increase in r
GUS expression levels up to 0.08% significantly improves the process e
conomics.