The abstraction of L-leucine from fermentation broth by ion exchange

The abstraction of L-leucine from fermentation broth by ion exchange was studied. WA-2 was the optimal resin for L-leucine abstraction by comparison of the adsorption capacity and adsorption kinetics among the different kinds of resins. The adsorption isotherm of WA-2 was further described by Freundlich equation. And the operation of fixed-bed adsorption was finally studied and the optimal conditions of extracting L-leucine were as follows: the fermentation broth was pretreated firstly and then flow through the fixed bed at the rate of 1 BV/h until the volume reached 2BV. And the elution of L-leucine was carried out at the rate of 1 BV/h using 0.3 mol/L ammonia water as the eluant. Under the optimal conditions, the recovery of L-leucine was 95.7%. The service life of resin WA-2 can not be affected because no irreversible pollution and mechanical damage to WA-2 take place during the process of abstraction.