Integrated L-phenylalanine separation in an E. coli fed-batch process: from laboratory to pilot scale |
| |
Authors: | D Maass M Gerigk A Kreutzer D Weuster-Botz M Wubbolts R Takors |
| |
Institution: | Institute of Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. |
| |
Abstract: | Pilot-scale reactive-extraction technology for fully integrated L-phenylalanine (L-Phe) separation in Escherichia coli fed-batch fermentations was investigated in order to prevent an inhibition of microbial L-Phe production by-product accumulation. An optimal reactive-extraction system, consisting of an organic kerosene phase with the cation-selective carrier DEHPA (di-2-ethylhexyl phosphonic acid) and an aqueous stripping phase including sulphuric acid, was found particularly efficient. Using this system with two membrane contactors, mass-transfer coefficients of up to 288 x 10(-7) cm s(-1) for the aqueous/organic and 77 x 10(-7) cm s(-1) for the organic/stripping phase were derived from experimental data using a simple modelling approach. Concentration factors higher than 4 were achieved in the stripping phase as compared to the aqueous donor phase. Reactive extraction enabled a 98% cation portion of L-Phe in the stripping phase, leading to final product purity higher than 99% after L-Phe precipitation. A doubling of L-Phe/glucose yield was observed when kerosene/DEHPA was added to the fermentation solution in the bioreactor to experimentally simulate a fully integrated L-Phe separation process. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|