中文摘要：

鼠李糖和福乐糖胺是多杀菌素生物合成必需的2个脱氧糖结构单元,负责其合成的4种酶的基因（gtt、epi、gdh、kre）与多杀菌素生物合成基因簇并不在一起,而是分散分布在染色体的3个位点上。为克隆到完整的多杀菌素生物合成基因簇,采用构建基因组文库、PCR扩增等手段从刺糖多孢菌NRRL18395染色体分别克隆gtt、epi、gdh和kre基因,并将其克隆组装在同一整合型载体上,以便于构建用于表达多杀菌素糖单元合成基因的表达载体。

英文摘要：

Rhamnose and forosamine are two essential deoxysugars components of spinosad.Four genes involved in the biosynthesis of rhamnose and forosamine,i.e.gtt（encoding NDP-glucose synthase）,gdh（encoding NDP-glucose dehydratase）,epi（encoding epimerase） and kre（encoding 4′-ketoreductase）,are not located together with the spinosad biosynthetic gene cluster,but distributed in 3 scattered loci in the chromosome of Saccharopolyspora spinosa NRRL18395.To get an integral spinosad biosynthetic pathway,the four genes were cloned by constructing a genomic library and PCR amplifying from S.spinosa NRRL18395.The 4 genes were successively assembled into an integrative vector to construct an expression vector for biosynthesis of rhamnose and forosamine in heterologous hosts.