Nikolova P, Ward O P
Department of Biology, University of Waterloo, Ontario, Canada.
J Ind Microbiol. 1993 Feb;12(2):76-86. doi: 10.1007/BF01569905.
In this paper biocatalytic reactions carried out by whole cells in nonconventional media are reviewed. Similar relationships are observed between solvent hydrophobicity and catalytic activity in reactions carried out by isolated enzymes and whole cells. In addition to the effect of organic solvent on biocatalyst stability, microbial cells are susceptible to damaging effects caused by the organic phase. In general, more hydrophobic solvents manifest lower toxicity towards the cells. Whole cell biocatalysts require more water than isolated enzymes and two-phase systems have been most widely used to study whole cell biocatalysis. Immobilization makes cell biocatalysts more resistant to organic solvents and helps achieve homogeneous biocatalyst dispersion. Cell entrapment methods have been widely used with organic solvent systems and mixtures of natural and/or synthetic polymers allow adjustment of the hydrophobicity-hydrophilicity balance of the support matrix. Some examples of stereoselective catalysis using microbial cells in organic solvent media are presented.
本文综述了全细胞在非常规介质中进行的生物催化反应。在分离酶和全细胞进行的反应中，观察到溶剂疏水性与催化活性之间存在相似的关系。除了有机溶剂对生物催化剂稳定性的影响外，微生物细胞还易受有机相造成的破坏作用影响。一般来说，疏水性更强的溶剂对细胞的毒性更低。全细胞生物催化剂比分离酶需要更多的水，两相体系已被最广泛地用于研究全细胞生物催化。固定化使细胞生物催化剂对有机溶剂更具抗性，并有助于实现生物催化剂的均匀分散。细胞包埋方法已广泛应用于有机溶剂体系，天然和/或合成聚合物的混合物可调节载体基质的疏水-亲水平衡。本文还介绍了在有机溶剂介质中使用微生物细胞进行立体选择性催化的一些实例。
