SCI和EI收录∣中国化工学会会刊

›› 2009, Vol. 17 ›› Issue (5): 822-828.

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Deactivation Kinetics of Nitrile Hydratase in Free Resting Cells

孙旭东, 于慧敏, 沈忠耀   

  1. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • 收稿日期:2008-12-05 修回日期:2009-04-07 出版日期:2009-10-28 发布日期:2009-10-28
  • 通讯作者: YU Huimin,E-mail:yuhm@tsinghua.edu.cn
  • 基金资助:
    Supported by the Foundation for the Authors of National Excellent Doctoral Dissertation of China (200345);the National High Technology Research and Development Program of China (2007AA02Z201);the National Basic Research Program of China (2007CB714304)

Deactivation Kinetics of Nitrile Hydratase in Free Resting Cells

SUN Xudong, YU Huimin, SHEN Zhongyao   

  1. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2008-12-05 Revised:2009-04-07 Online:2009-10-28 Published:2009-10-28
  • Supported by:
    Supported by the Foundation for the Authors of National Excellent Doctoral Dissertation of China (200345);the National High Technology Research and Development Program of China (2007AA02Z201);the National Basic Research Program of China (2007CB714304)

摘要: Nitrile hydratase (NHase) is an important industrial enzyme used for acrylamide production from acrylonitrile.The deactivation kinetics of NHases in free resting cells of Rhodococcus sp.was presented based on a bi-steady state assumption.Effects of hydration temperature,product concentration and substrate concentration on NHase deactivation were investigated experimentally and correlated with a first order deactivation kinetics.The results showed that the hydration temperature and product concentration were major factors governing the deactivation of NHases under substrate-feeding conditions.When acrylamide concentration was higher than 250 g·L-1,the deactivation of NHases became serious and the bi-steady state assumption was not applicable.When the hydration temperature was controlled at a relatively higher level such as 28℃,the total deactivation rate constant was about 2.8-fold of that at 20℃.

关键词: nitrile hydratase, deactivation kinetics, free resting cell, bi-steady state assumption, total deactivation rate constant

Abstract: Nitrile hydratase (NHase) is an important industrial enzyme used for acrylamide production from acrylonitrile.The deactivation kinetics of NHases in free resting cells of Rhodococcus sp.was presented based on a bi-steady state assumption.Effects of hydration temperature,product concentration and substrate concentration on NHase deactivation were investigated experimentally and correlated with a first order deactivation kinetics.The results showed that the hydration temperature and product concentration were major factors governing the deactivation of NHases under substrate-feeding conditions.When acrylamide concentration was higher than 250 g·L-1,the deactivation of NHases became serious and the bi-steady state assumption was not applicable.When the hydration temperature was controlled at a relatively higher level such as 28℃,the total deactivation rate constant was about 2.8-fold of that at 20℃.

Key words: nitrile hydratase, deactivation kinetics, free resting cell, bi-steady state assumption, total deactivation rate constant