Process for Extraction of Acarbose from Fermentation Broth by Ultrafiltration and Nanofiltration Membranes

Ultrafiltration and nanofiltration membrane were used for the separation and extraction of acarbose from fermentation broth.The impurities were removed from the fermentation broth through the ultrafiltration membrane and then the ultrafiltration solution was desalted and concentrated through the nanofiltration membrane.The ultrafiltration and nanofiltration membranes with different molecular weight cutoff were screened and the operation conditions were optimized.Ultrafiltration was performed with ULT-1 membrane and fermentation broth containing and 3 g/ml of acarbose at 25 ℃ and 0.26-0.28 MPa.Nanofiltration was carried out with STM-2 membrane at 25 ℃ and 0.6-0.8 MPa.The final concentration of acarbose was six times higher than the initial one and the extraction yield was 62.2%,a 20% increase compared with the original process.The content of acarbose in the concentrated solution was over 98.8%.