توليد و تخليص نسبي STREPTAVIDIN از محيط كشت باكتري توسط كروماتوگرافي تعويض يوني به وسيله DEAE سلولز

Production and partial purification of Streptavidin(SA) from bacterial supernatant by DEAE-cellulose ionexchange chromatography

Streptavidin (SA) is a protein secreted by Streptomyces avidini. It has four subunits and each subunit has high affinity for biotin. In the present research ,we have analysed the effect of the defined (A&B) and undefined (LB&LB+Asn) culture media on the growth of S.avidini and the amount of protein secreted.SA in bacterial supernatant was concentrated with ammonium sulfate and then partially purified using a DEAE-cellulose column. The purity of SA was evaluated by SDS-PAGE and immunoblotting. Our results showed that the best culture conditions was in LB medium at 32C for ten days where the yield of SA was about 13mg/l and the purified SA could be used directly.