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 cooperation of acrylonitrile and ammonium chloride as inducer in the medium and the specific activity of NHase was increased of 44%. Then the temperature, pH, concentration of acrylonitrile and acrylamide were evaluated, which affected the activity and reaction characteristic of NHase. It was found that the temperature and concentration of acrylarnide 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℃. Kmof 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.
The adsorption of protein from model wine was investigated under different temperatures, pH values, contact times, and concentrations of ethanol, by certain bentonites. The results showed that ethanol molecules could broaden the protein molecules＇ channel to the interlayer of bentonite, and the maximum protein adsorption amount occurred under an ethanol concentration of 12% （by volume） and a pH value of 3.56. The increased single point Brunauer-Emmitt-Teller （BET） surface area （SBET） and adsorption pore volume （VAds） suggested a larger amount of active adsorption sites of the bentonite surface and a wider protein channel from the surface to the inner adsorption sites of bentonite, respectively. At the same time, higher methylene blue test （MBT） and swelling index （Sw） indicated that it was easy for the entrance of water and the absorbance of protein. Higher temperature was found favorable to eliminate more proteins and it took about 20 to 40min to arrive at the maximum adsorption.
