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PhoR/PhoP双因子调控系统是枯草芽胞杆菌中一个重要的全局性调控系统,在低磷环境下,感应激酶PhoR自磷酸化,并且将获得的磷酸基团转移到调控因子PhoP上,从而激活PhoP的调控活性。为了明确调控因子PhoP对枯草芽胞杆菌NCD-2菌株中主要抑菌活性物质-fengycin合成能力的调控作用,本研究通过同源重组技术缺失突变NCD-2菌株中的phoP基因,拮抗活性测定结果表明,phoP基因缺失菌株显著降低了对立枯丝核菌的抑菌活性。通过快速蛋白质液相色谱(FPLC)技术比较了NCD-2菌株野生型及其phoP基因突变子fengycin的合成能力,结果证明,phoP基因突变菌株降低了fengycin的合成能力。对突变子进行phoP基因互补发现,互补phoP基因可使突变子的相关性状恢复到野生型菌株水平。以上结果证明,phoP基因对枯草芽胞杆菌NCD-2菌株中fengycin的合成具有正调控功能。
The PhoR / PhoP two-factor regulation system is an important global regulation system in B. subtilis. Under low phosphorus environment, PhoR induces autophosphorylation of Phokinase and transfers the obtained phosphate group to PhoP, a regulatory factor, to activate PhoP Regulatory activity. In order to clarify the regulatory role of PhoP on the synthesis of -fengycin, a major antibacterial substance in B. subtilis NCD-2, the phoP gene was deleted from the mutant strain NCD-2 by homologous recombination. The results of the antagonistic activity assay The deletion of phoP gene significantly reduced the antibacterial activity of Rhizoctonia solani. The ability to synthesize fengycin, a wild-type strain of phsPNP-2, and its phoP gene, was compared by rapid protein-liquid chromatography (FPLC). The results demonstrated that phoP mutant strains reduced fengycin biosynthesis. Mutant phoP gene complementation found that complementary phoP gene can make mutant-related traits restored to the level of wild-type strain. The above results demonstrate that the phoP gene has a positive regulatory function on the synthesis of fengycin in B. subtilis NCD-2 strain.