TY - JOUR

T1 - Simple high-cell density fed-batch technique for high-level recombinant protein production with Pichia pastoris

T2 - Application to intracellular production of Hepatitis B surface antigen

AU - Gurramkonda, Chandrasekhar

AU - Adnan, Ahmad

AU - Gäbel, Thomas

AU - Lünsdorf, Heinrich

AU - Ross, Anton

AU - Nemani, Satish Kumar

AU - Swaminathan, Sathyamangalam

AU - Khanna, Navin

AU - Rinas, Ursula

PY - 2009/2/10

Y1 - 2009/2/10

N2 - Background: Hepatitis B is a serious global public health concern. Though a safe and efficacious recombinant vaccine is available, its use in several resource-poor countries is limited by cost. We have investigated the production of Hepatitis B virus surface antigen (HBsAg) using the yeast Pichia pastoris GS115 by inserting the HBsAg gene into the alcohol oxidase 1 locus. Results: Large-scale production was optimized by developing a simple fed-batch process leading to enhanced product titers. Cells were first grown rapidly to high-cell density in a batch process using a simple defined medium with low salt and high glycerol concentrations. Induction of recombinant product synthesis was carried out using rather drastic conditions, namely through the addition of methanol to a final concentration of 6 g L-1. This methanol concentration was kept constant for the remainder of the cultivation through continuous methanol feeding based on the on-line signal of a flame ionization detector employed as methanol analyzer in the off-gas stream. Using this robust feeding protocol, maximum concentrations of ∼7 grams HBsAg per liter culture broth were obtained. The amount of soluble HBsAg, competent for assembly into characteristic virus-like particles (VLPs), an attribute critical to its immunogenicity and efficacy as a hepatitis B vaccine, reached 2.3 grams per liter of culture broth. Conclusion: In comparison to the highest yields reported so far, our simple cultivation process resulted in an ∼7 fold enhancement in total HBsAg production with more than 30% of soluble protein competent for assembly into VLPs. This work opens up the possibility of significantly reducing the cost of vaccine production with implications for expanding hepatitis B vaccination in resource-poor countries.

AB - Background: Hepatitis B is a serious global public health concern. Though a safe and efficacious recombinant vaccine is available, its use in several resource-poor countries is limited by cost. We have investigated the production of Hepatitis B virus surface antigen (HBsAg) using the yeast Pichia pastoris GS115 by inserting the HBsAg gene into the alcohol oxidase 1 locus. Results: Large-scale production was optimized by developing a simple fed-batch process leading to enhanced product titers. Cells were first grown rapidly to high-cell density in a batch process using a simple defined medium with low salt and high glycerol concentrations. Induction of recombinant product synthesis was carried out using rather drastic conditions, namely through the addition of methanol to a final concentration of 6 g L-1. This methanol concentration was kept constant for the remainder of the cultivation through continuous methanol feeding based on the on-line signal of a flame ionization detector employed as methanol analyzer in the off-gas stream. Using this robust feeding protocol, maximum concentrations of ∼7 grams HBsAg per liter culture broth were obtained. The amount of soluble HBsAg, competent for assembly into characteristic virus-like particles (VLPs), an attribute critical to its immunogenicity and efficacy as a hepatitis B vaccine, reached 2.3 grams per liter of culture broth. Conclusion: In comparison to the highest yields reported so far, our simple cultivation process resulted in an ∼7 fold enhancement in total HBsAg production with more than 30% of soluble protein competent for assembly into VLPs. This work opens up the possibility of significantly reducing the cost of vaccine production with implications for expanding hepatitis B vaccination in resource-poor countries.

UR - http://www.scopus.com/inward/record.url?scp=61649103787&partnerID=8YFLogxK

U2 - 10.1186/1475-2859-8-13

DO - 10.1186/1475-2859-8-13

M3 - Article

AN - SCOPUS:61649103787

VL - 8

JO - Microbial cell factories

JF - Microbial cell factories

SN - 1475-2859

M1 - 13

ER -