Key Lab of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Microbiol Res. 2013 Jun 12;168(5):305-10. doi: 10.1016/j.micres.2012.11.008. Epub 2012 Dec 28.
Homologues of plnB gene have been shown to participate in regulation of bacteriocin production through quorum sensing system in other organisms, to investigate the possible role of plnB gene in Lactobacillus paraplantarum L-XM1, we cloned and insertionally inactivated the plnB gene. The plnB knockout mutant ΔplnB21 showed loss of bacteriocin production, its Bac⁺ phenotype could not be restored even after the addition of PlnA. Furthermore, reverse transcription-PCR analysis from total RNA preparations showed that the bacteriocin structural genes of the plnEF and plnJK were not transcribed in the plnB knockout mutant compared with the wild-type strain. It was therefore concluded that plnB is invovled in a quorum sensing based bacteriocin production. This is the first demonstration of a role for plnB by gene knockout in L. paraplantarum.
plnB 基因的同源物已被证明通过其他生物体中的群体感应系统参与细菌素产生的调节，为了研究 plnB 基因在植物乳杆菌 L-XM1 中的可能作用，我们克隆并插入失活了 plnB 基因。plnB 敲除突变体 ΔplnB21 表现出细菌素产生的丧失，即使添加 PlnA，其 Bac⁺表型也无法恢复。此外，从总 RNA 制备物的反转录-PCR 分析表明，plnB 敲除突变体中细菌素结构基因 plnEF 和 plnJK 没有转录，而与野生型菌株相比。因此，可以得出结论，plnB 参与了基于群体感应的细菌素产生。这是首次通过基因敲除在植物乳杆菌中证明 plnB 的作用。
