Production of Recombinant Humanized Anti-HBsAg Fab Fragment from Pichia pastoris by Fermentation

Received 23 September 2004, Accepted 16 November 2004In this report, we describe the high-yield secretoryexpression of the recombinant human anti-HBsAg Fabfragment from Pichia pastoris that was achieved by co-integration of the genes encoding the heavy and lightchains (both under the control of alcohol oxidasepromoter) into the genome of the yeast cells. The fed-batchfermentations were carried out in a 5 L scale. Both chainsof the Fab were successfully expressed upon methanolinduction. The absorbance (OD