CIESC Journal

• BIOTECHNOLOGY & BIOENGINEERING • 上一篇    下一篇

Rhodococcus sp. SHZ-1腈水合酶的诱导表达和稳定性研究

王超a; 张根林a; 徐小琳a; 李春b   

  1. a Department of Environmental and Biochemical Engineering, School of Chemistry and Chemical
    Engineering, Shihezi University, Shihezi 832003, China
    b School of Life Science and Technology, Beijing Institute of Technology, Beijing 100081,
    China
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2007-08-28 发布日期:2007-08-28
  • 通讯作者: 王超

Inducing expression and reaction characteristic of nitrile hydratase from Rhodococcus sp.
SHZ-1

WANG Chaoa; ZHANG Genlina; XU Xiaolina; LI Chunb   

  1. a Department of Environmental and Biochemical Engineering, School of Chemistry and Chemical
    Engineering, Shihezi University, Shihezi 832003, China
    b School of Life Science and Technology, Beijing Institute of Technology, Beijing 100081,
    China
  • Received:1900-01-01 Revised:1900-01-01 Online:2007-08-28 Published:2007-08-28
  • Contact: WANG Chao

摘要: Inducing expression and the reaction characteristic of nitrile hydratase (NHase) from
Rhodococcus sp. SHZ-1 were investigated. The results showed that the expression of NHase
was greatly enhanced with the coopera-tion of acrylonitrile and ammonium chloride as
inducer in the medium and the specific activity of NHase was in-creased of 44%. Then the
temperature, pH, concentration of acrylonitrile and acrylamide were evaluated, which af-
fected the activity and reaction characteristic of NHase. It was found that the temperature
and concentration of acrylamide were the most important factors for the catalyzation of
NHase. The optimal catalysis temperature of NHase from Rhodococcus sp. SHZ-1 was 30℃, and
the activation energy of the hydration of NHase was 90.2kJ∙mol-1 in the temperature range
from 5℃ to 30℃. Km of NHase was 0.095mol∙L-1 using acrylonitrile (AN) as substrate, and
NHase activity was inhibited seriously when acrylonitrile concentration was up to 40g∙L-1,
the substrate inhibition constant Ki is 0.283mol∙L-1. Moreover, the NHase from Rhodococcus
sp. SHZ-1 had very strong tolerance to acrylamide, in which the final concentration of
acrylamide reached to 642g∙L-1 and the residual activity of NHase still maintained 8.6% of
the initial enzyme activity.

关键词: nitrile hydratase;biocatalysis;acrylamide;characteristic;Rhodococcus sp. SHZ-1

Abstract: Inducing expression and the reaction characteristic of nitrile hydratase (NHase) from
Rhodococcus sp. SHZ-1 were investigated. The results showed that the expression of NHase
was greatly enhanced with the coopera-tion of acrylonitrile and ammonium chloride as
inducer in the medium and the specific activity of NHase was in-creased of 44%. Then the
temperature, pH, concentration of acrylonitrile and acrylamide were evaluated, which af-
fected the activity and reaction characteristic of NHase. It was found that the temperature
and concentration of acrylamide were the most important factors for the catalyzation of
NHase. The optimal catalysis temperature of NHase from Rhodococcus sp. SHZ-1 was 30℃, and
the activation energy of the hydration of NHase was 90.2kJ∙mol-1 in the temperature range
from 5℃ to 30℃. Km of NHase was 0.095mol∙L-1 using acrylonitrile (AN) as substrate, and
NHase activity was inhibited seriously when acrylonitrile concentration was up to 40g∙L-1,
the substrate inhibition constant Ki is 0.283mol∙L-1. Moreover, the NHase from Rhodococcus
sp. SHZ-1 had very strong tolerance to acrylamide, in which the final concentration of
acrylamide reached to 642g∙L-1 and the residual activity of NHase still maintained 8.6% of
the initial enzyme activity.

Key words: nitrile hydratase, biocatalysis, acrylamide, characteristic, Rhodococcus sp. SHZ-1