Bron P A, Meijer M, Bongers R S, de Vos W M, Kleerebezem M
Wageningen Centre for Food Sciences, Microbial Functionality and Safety Programme, Wageningen, The Netherlands.
J Appl Microbiol. 2007 Nov;103(5):1424-34. doi: 10.1111/j.1365-2672.2007.03376.x.
This study aims to evaluate the impact of mutation of previously identified in vivo-induced (ivi) genes on the persistence and survival of Lactobacillus plantarum WCFS1 in the gastrointestinal (GI) tract of mice.
Nine Lact. plantarum ivi gene replacement mutants were constructed, focussing on ivi genes that encode proteins with a predicted role in cell envelope functionality, stress response and regulation. The in vitro growth characteristics of the mutants appeared identical to those observed for the wild-type strain, which agrees with the recombination-based in vivo expression technology suggestion that these genes are not transcribed in the laboratory. Quantitative PCR experiments demonstrated differences in the relative population dynamics of the Lact. plantarum ivi mutants in faecal samples after passage through the GI tract of mice.
The in situ competition experiments revealed a 100- to 1000-fold reduction of the relative abundance of three of the ivi gene mutants, harbouring deletions of genes predicted to encode a copper transporter, an orphan IIC cellobiose PTS and a cell wall anchored extracellular protein.
These experiments clearly establish that the proteins encoded by these three genes play a key role in Lact. plantarum performance during passage of the GI tract.
本研究旨在评估先前鉴定的体内诱导（ivi）基因的突变对植物乳杆菌WCFS1在小鼠胃肠道（GI）中的持久性和存活的影响。
构建了9个植物乳杆菌ivi基因替换突变体，重点关注那些编码预测在细胞壁功能、应激反应和调控中起作用的蛋白质的ivi基因。突变体的体外生长特性与野生型菌株观察到的特性相同，这与基于重组的体内表达技术的推测一致，即这些基因在实验室中不转录。定量PCR实验证明了植物乳杆菌ivi突变体在通过小鼠胃肠道后粪便样本中相对种群动态的差异。
原位竞争实验表明，三个ivi基因突变体的相对丰度降低了100至1000倍，这些突变体分别缺失了预测编码铜转运蛋白、孤儿IIC纤维二糖磷酸转移酶和细胞壁锚定细胞外蛋白的基因。
这些实验清楚地表明，这三个基因编码的蛋白质在植物乳杆菌通过胃肠道的过程中起关键作用。
