Bioconversion of acrylnitrile to acrylamide using hollow-fiber membrane bioreactor system

Abstract A poly-sulfone hollow-fiber membrane bioreactor system was designed and used in the bioconversion process of acrylonitrile to acrylamide, in which a new strategy of membrane separation coupled with bioconversion was presented. The characteristics of filtration of the membrane was evaluated and the bioconversion of arcylamide from acrylnitrile in the membrane bioreactor was carried out using the free resting cells as a biocatalyst to replace the immobilized cells in the original reacting system. The results showed that the bioconversion process continued over 5 h without renewing the cells in the system containing 10% (v/v) fermentation broth at 20 °C. The conversion rate of acrylnitrile to acrylamide and the productivity of acrylamide were 99.9% and 20.67 g/gcell h, respectively, which were much higher than those of the original bioconversion system in which the immobilized cells were used as a biocatalyst. Therefore, this membrane bioreactor has a favorable foundation for industrial application due to its high efficiency and ability to continuously produce acylamide using free resting cells.