透明颤菌血红蛋白在肉桂地链霉菌中的表达对基因细胞生长及抗生素合成的影响

肉桂地链霉菌（S.cinnamonensis)是莫能菌素（Monensin)的产生菌，大肠杆菌－链霉菌穿梭表达载体pHZ1252中的透明颤菌血红蛋白基因（vhb)位于硫链丝菌素诱导启动子ＰtipA之下，它在肉桂地链霉菌中的结构不稳定，，发生了重组缺失，缺失的片段包括大肠杆菌质粒部分vhb基因。但来自阿维链霉菌(S.avermitilis)中缺失了大肠杆菌质粒部分却保留了完整的vhb基因及tipA启动子的pHZ1252，可在肉桂地链霉菌中稳定复制，不再发生缺失，经硫链丝菌素诱导表达出了有生物活性的ＶＨb蛋白，摇瓶发酵实验证明，ＶＨb蛋白在氧限条件下可明显促进肉桂地链霉菌的菌体生长和抗生素合成。

The Effects of Vitreoscilla Hemoglobin Expression on Growth and Antibiotic Production in Streptomyces cinnamonensis

Streptomyces cinnamonensis A 10 is a monensin|producing strain. pHZ1252 is an E.coli|Streptomyces shuttle vector for expressing VHb,in which vhb structural gene is controlled by thiostrepton|inducible promoter P tipA . pHZ1252 was unstable in S.cinnamonensis ,occurring deletion recombination. The deletion DNA fragment of pHZ1252 included not only part of E.coli plasmid but also vhb gene. However,plasmid pHZ1252 isolated from S.avermitilis transformants,which lost part of E.coli plasmid but still contained vhb gene and P tipA was stable in S.cinnamonensis and expressed VHb with biological activity after thiostrepton induction. Shake flask fermentation experiments showed that the presence of VHb in S.cinnamonensis efficiently enhanced cell growth and improved antibiotic production under aeration|poor conditions.