手性醇腈化合物是一类非常重要的手性分子，是制备精细化工、医药、农用化学品的中间体，具有广泛的应用前景。手性化合物中不同立体异构体具有不同的生理活性，许多医用药品要求必须是单一性化合物，因为单一性药物不仅药效高，更为重要的是副作用小。α-醇腈酶(α-hydroxynitrilelyase，HNL)作为一种生物催化剂，能可逆地催化由氰化氢（HCN）和醛或酮类化合物反应生成手性醇腈化合物，产物可转化成羟基化合物、胺化合物、羧基化合物等多种重要的手性中间体，还可进而转化成多种手性药物，从而克服了为得到纯手性化合物而采用光学拆分所带来的生产工序复杂、成本高等一系列问题。因此，在不对称合成领域中，HNL日益成为研究的热点。本论文分别利用枯草芽孢杆菌表达系统和汉逊酵母表达系统表达了中国木薯醇腈酶基因。在枯草芽孢杆菌表达系统中，含有诱导型表达载体pSBPTQ的重组子中并没有目的基因的表达。在含有pMA5Z2载体的重组子中获得了具有生物活性的木薯醇腈酶， 但是酶活性并不高.由于木薯醇腈酶基因来自高等植物木薯中，基因表达可能存在密码子的偏爱性的问题，所以我们尝试应用真核细胞表达系统汉逊酵母来表达此基因。多形汉逊酵母是最近几年发展起来的作为细胞工程表达外源基因的一种甲醇酵母。利用甲醇氧化酶启动子（Methanol oxidase promoter，MOXp）构建的胞内表达和分泌型表达载体进行了木薯醇腈酶基因的表达，对于分泌表达采用的是来自啤酒酵母（Saccharomyces cerevisiae）中的分泌信号α-MF（Mating factor-alpha）。并且引入了汉逊酵母自动复制序列（Hansenula auto-replication sequence,HARS）和重组序列25SrDNA。在胞内和分泌表达重组子中都获得了有生物活性的目的蛋白，但分泌表达蛋白比胞内表达具有更高的生物活性，其酶活大约是胞内表达的2倍。

Chiral cyanohydrins are kinds of very important molecules and the intermediates in the production of fine chemicals, pharmaceuticals and agrochemicals. Different stereoisomer during chiral compounds have different physiological activity. A lot of pharmaceuticals desire haploid compounds, because of the strong pharmic effect and more importantly the small side-effect. As a kind of biological catalyzer, α-hydroxynitrilelyase can reversibly catalyse the condensation of hydro-cyanic acid with aldehydes or ketone into chiral cyano-hydrins compounds, which are valuable starting material for various optically active compounds, such as hydroxy compounds, amine compounds and carboxyl compounds. A series of troubles such as the complexity of working procedure and high cost using optical splitting to gain pure optical compounds are then conquered.Therefore, in asymmetry synthesis field, HNL increasingly become investigative hotspot.This paper utilized Bacillus subtilis and Hansenula polymorpha to do research on expression of Hydroxynitrile lyase from Chinese subspecies of Manihot esculenta respectically. According to the result of experiment, in Bacillus subtilis, Recombine strains containing inducing expression vector pSBPTQ did not express target gene. In recombine strains containing vector pMA5Z2, bioactive Hydroxynitrile lyase from Chinese subspecies of Manihot esculenta was gained, but the enzyme activity is not high. Coming from high plant Chinese subspecies of Manihot esculenta, Hydroxynitrile lyase gene may exist problems of the bias of codon. So we try to utilize eukaryote expression system Hansenula polymorpha to express this gene.The methylotrophic yease, Hansenula polymorpha, has been successfully exploited as a cell factory for the large-scale production of heterologous genes in recent years. Endocellular and secretive expression vectors constructed using methanol oxidase promoter(MOXp) was used to express Hydroxynitrile lyase gene in H.polymorpha. A secretion signal sequence of the mating factor-alpha from Saccharomyces cerevisiae was inserted in the secretory expression plasmids for efficient secretion. Hansenula auto-replication sequence(HARS) and recombine sequence 25SrDNA was introduced into the vectors. Bioactive target protein was gained in endocellular and secretive expression recombine strains. secretive expression proteins have higher bioactive than endocellular expression, owning two times the activity of endocellular expression.