Abstract: To improve the acrylamide-tolerance of Nocardia sp., acrylonitrile was fed periodically into the shaking flasks containing Nocardia sp.RS cells and the culture medium.Acrylamide was accumulated gradually along with the hydration of acrylonitrile and the RS cells were acclimated to the increasing acrylamide.The growth of cells, enzymatic hydration of acrylonitrile and the screening of acrylamide-tolerance cells were coupled in the same process.The survival rate and nitrile hydratase activity of cells in the process were investigated.The acrylamide-tolerance of the RS-1 strain achieved in that process was improved significantly compared with the RS strain.The accumulation of acrylamide catalyzed by RS-1 could reach 587 g•L^-1, which is 30.6% higher than that of RS strain in shaking flasks.And a high acrylamide concentration of 535 g•L^-1 was also achieved in a bioreactor catalyzed by the strain RS-1.The concentration of acrylamide in the bioreactor was high enough to crystallize directly in 2℃.Based on the high accumulation of acrylamide, an improved process of hydration and crystallization was designed.By applying the improved process, the energy consumption in concentration can be reduced by 32.8% compared with the present process.

Key words: 腈水合酶, 丙烯酰胺耐受性, 水合, 结晶, Nocardia sp.

摘要： 在极端条件下改造了现有的丙烯酰胺生产菌株Nocardia sp.RS，通过向发酵液中间歇加入丙烯腈催化生成丙烯酰胺而形成极端环境，将菌体生长、酶催化和菌种筛选这3个过程耦合在一起.研究了极端条件下菌体存活率、腈水合酶活性随丙烯酰胺浓度的变化.驯化得到的RS-1菌株有很好的丙烯酰胺耐受性，摇瓶水合的丙烯酰胺终浓度达到了587 g•L^-1，比RS菌株提高30.6％.利用RS-1菌株在小型反应器规模上实现了高浓度丙烯酰胺的制备，累积浓度达到了535 g•L^-1，不需浓缩即可满足市场对丙烯酰胺水溶液产品的浓度要求.在此基础上，设计了水合结晶改进工艺，预计可比现有工艺降低浓缩能耗32.8％.

关键词: 腈水合酶, 丙烯酰胺耐受性, 水合, 结晶, Nocardia sp.