Abstract

 Background and Objectives

 Human serum albumin (HSA) is the major protein component of human plasma. I t plays a very important role in transporting of macro molecules and maintaining the normal osmolarity. It is used as a therapeutical protein in patients with hypoalbuminemia and acute bleeding and burning. Albumin consumption in the world is about 500 ton/year. The aim of this research is to study the production of rHSA in shake flask culture by Hansenula polymorpha.

  Materials and Methods 

 H. polymorpha was used for the production of recombinant human serum albumin (rHSA) in several of shake flask culturing expression of rHSA was investigated relating several parameters affecting the expression of HSA. To optimize the secretory expression of rHSA under the control of FMD promoter in H. polymorpha RB-11 incubation time, culture media temperature and protease inhibitors were analyzed .

 Results

 This study not only established production of rHSA in yeast but also analyzed the correlation between affecting parameters and the level of HSA expression. Comparison of the HSA levels in the culture supernatants showed that the highest HSA yield was 17.6mg/l. The research shows that among three different temperatures (25^oC,30^oC and 37^oC) 37^oC was the best temperature and amongst three different incubation times (24h,48h and 72h) 48h was the optimum time and YNB 1% glycerol with buffer was the best derepression medium in comparison with others.

 Conclusions

 Using these optimized conditions, stable production of rHSA of around 17.6mg/l was achieved. Our results suggest that affecting experssion factors improved in this study are suitable for production of recombinant albumin.

 Key words: Hansenula polymorpha, Yeast, Human serum albumin, Affecting factors