摘要
研究目的:提高胞外多糖索拉胶的产量。创新要点:透明颤菌血红蛋白基因在质粒上表达,不加抗生素发酵生产索拉胶。研究方法:将透明颤菌血红蛋白基因构建到广谱质粒pCM158上得到重组质粒pCM158-vgb,重组质粒转入土壤杆菌ZX09中,使透明颤菌血红蛋白在土壤杆菌ZX09中表达。重要结论:在土壤杆菌ZX09中颤菌血红蛋白的表达解决了发酵过程中氧受限的问题,提高了宿主菌的呼吸速率、蔗糖酶活性和黏度,将发酵产物索拉胶的产量提高了30%。
Salecan is a novel exopolysaccharide produced by the strain Agrobacterium sp. 7__X09, and it is composed of only glucose monomers. The unique chemical composition and excellent physicochemical properties make Salecan a promising material for applications in coagulation, lubrication, protection against acute liver injury, and alleviating constipation. In this study, we cloned the Vitreosci/la hemoglobin gene into a broad-host-range plasmid pCM158. Without antibiotic selection, there was negligible loss of the plasmid in the host Agrobacterium sp. ZX09 after one passage of cultivation. The expression of Vitreoscilla hemoglobin was demonstrated by carbon monoxide （CO） dif- ference spectrum. The engineered strain Agrobacterium sp. ZX09 increased Salecan yield by 30%. The other physi- ological changes included its elevated respiration rate and cellular invertase activity.
基金
supported by the Fundamental Research Funds for the Central Universities of China(No.30920130121013)
the National Natural Science Foundation of China(No.31300111)
