Selective removal of Gentamicin C1 from biosynthetic Gentamicins by facilitated pertraction for increasing antibiotic activity

The less active Gentamicin C1 have been selectively removed from the biosynthetic mixture containing Gentamicins C1, C1a, C2 and C2a by facilitated pertraction with D2EHPA dissolved in dichloromethane as the liquid membrane U-shaped pertraction cell. The pertraction has been analyzed by means of initial and final mass flows, permeability and selectivity factors. The main factors, which control the pertraction selectivity, were identified to be the pH-gradient between the feed and stripping phase, mixing intensity of the aqueous phases and carrier concentration in the membrane phase. The maximum selectivity factor has been recorded for pH 8 of feed phase, pH 3 of stripping phase, rotation speed lower than 100 rpm, and carrier concentration of 10 g/l.