为探索基因rpfG在产酶溶杆菌中的功能,以产酶溶杆菌OH11为研究对象,在基因组测序的基础上,通过同源比对,存OH11基因组中鉴定出rpfG的同源基因,并命名为rpfGlys。利用同源重组技术,对rpfG基因进行了定向敲除,获得了rpfG的缺失突变株。与野生型相比,rpfG基因的突变降低了产酶溶杆菌重要抗菌物质——热稳定抗菌因子HSAF的产量和对腐霉的拈抗活性。荧光定量PCR显示,在rpfG突变株中负责生物合成HSAF的关键基因Lysegl002651的表达显著下调,与HSAF活性检测结果相吻合。然而,rpfG的突变不改变产酶溶杆菌4种胞外抗菌水解酶的活性。另外,rpfG突变导致产酶溶杆菌菌落表面干燥,但滑行能力提高。
To analyse the function of rpfG in Lysobacter enzymogenes OH11, a paralogous gene of rpfG was identified through sequence homology analysis and named as rpfGlys. With homologous recombination technology, a deletion mutant of rpfG was generated. Compared with the wild type, the mutant had a low secretion of heat stable antibacterial factor ( HSAF ) which is an important antibacterial substance of Lysobacter enzymogenes and a lower antipathogenic activity toward Pythium aphanidermatum. Fluorogenic quantitative PCR showed that expression of the key gene( Lysegl002651 ) which is in charge of biosynthesis of HSAF was significantly lower,which coincided with activity detection of HSAF. Further researches found that the mutant did not change the activities of four- type lyric enzymenes of Lysobacter enzymogenes. Moreover, it was of interest that although mutation of rpfG led to acrid surface of colonies, its sliding ability was strengthened.