农杆菌介导的出芽短梗霉遗传转化及高效筛选聚苹果酸高产菌株

Agrobacterium tumefaciens-mediated transformation of Aureobasidium pullulans and high-efficient screening for polymalic acid producing strain

摘要:

建立根癌农杆菌介导的出芽短梗霉遗传转化方法及T-DNA突变库，高效筛选聚苹果酸高产菌株及功能基因。通过含潮霉素和草铵磷抗性基因的农杆菌转化出芽短梗霉，抗性压力筛选及PCR验证建立根癌农杆菌介导的出芽短梗霉遗传转化方法，结合发酵液pH与聚苹果酸含量响应变化，微孔板高效筛选高产聚苹果酸的T-DNA插入突变株，基因组步移确定T-DNA插入位点及功能基因。结果获得遗传稳定的抗性基因菌株，每107个细胞可获得80?120个转化子，出芽短梗霉H27 号T-DNA突变株聚苹果酸摇瓶发酵产量提高24.5%，基因组步移证实糖酵解途径磷酸甘油酸变位酶基因被破坏。成功建立了根癌农杆菌介导的出芽短梗霉遗传转化方法和T-DNA插入突变库，结合高效筛选方法为聚苹果酸合成功能基因挖掘及高产机制解析奠定基础。

Abstract:

To develop a genetic transformation method of Aureobasidium pullulans and T-DNA insertion for high-efficient screening of polymalic acid (PMA) producing strain. Agrobacterium tumefaciens-AGL1, containing the selection genes encoding hygromycin B phosphotase or phosphinothricin acetyltranferase, was used to transform Aureobasidium pullulans CCTCC M2012223 and transformants were confirmed by colony PCR method. Transferred DNA (T-DNA) insertional mutants were cultured in microwell plate, and screened for high-titer PMA producing strain according to the pH response model. DNA walking was used to detect the insertion sites in the mutant. Results show that the selection markers could stably generated in the transformants, and 80 to 120 transformants could be found per 107 single cells. A high-titer PMA mutant H27 was obtained, giving a good PMA production caused by the disruption of phosphoglycerate mutase, that increased by 24.5% compared with the control. Agrobacterium tumefaciens-mediated transformation and high-efficient screening method were successfully developed, which will be helpful for genetic transformation of Aureobasidium pullulans and its functional genes discovery.