State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; International Joint Research Center for Probiotics & Gut Health, Jiangnan University, Wuxi, Jiangsu, China.
Virus Res. 2020 Sep;286:198003. doi: 10.1016/j.virusres.2020.198003. Epub 2020 May 22.
Lysogenic bacterial strains abound in the Lactobacillus genus and contain dormant prophages inserted within their genomes. To evaluate the prophage-induction potential of the Lactobacillus strains of six species, 142 randomly selected strains from these species were induced with Mitomycin C. Eight newly-induced phages were identified and found to be diverse in morphology. Among the six species assessed, Lactobacillus plantarum and Lactobacillus rhamnosus strains were generally insensitive to induction. The genomic characterizations of eight phages were performed via whole genome sequencing and protein prediction. Meanwhile, genome comparison of the induced phages and predicted prophages demonstrated that the prediction software PHASTER can accurately locate major prophage regions in Lactobacillus. A phylogenetic tree of the Lactobacillus phage population was constructed to obtain further insights into the clustering of individuals, two major groups were found, one of which consisted mostly of L. plantarum virulent phages, the other was represented by Lactobacillus casei/paracasei temperate phages. Finally, it was confirmed via genomic collinear analysis, which seven of the eight Lactobacillus temperate phages were newly discovered, and two Lactobacillus brevis temperate phages belonged to a novel lineage.
溶原性细菌菌株在乳杆菌属中大量存在，其基因组内插入有休眠的原噬菌体。为了评估 6 个种属的乳杆菌菌株的原噬菌体诱导潜力，从这些种属中随机挑选了 142 株乳杆菌进行丝裂霉素 C 诱导。鉴定出了 8 种新诱导的噬菌体，它们在形态上存在多样性。在所评估的 6 个种属中，植物乳杆菌和鼠李糖乳杆菌菌株通常对诱导不敏感。通过全基因组测序和蛋白预测对 8 种噬菌体的基因组特征进行了分析。同时，诱导噬菌体和预测原噬菌体的基因组比较表明，预测软件 PHASTER 可以准确地定位乳杆菌中的主要原噬菌体区域。构建了乳杆菌噬菌体群体的系统发育树，以进一步深入了解个体的聚类情况，发现了两个主要的群体，其中一个主要由植物乳杆菌毒力噬菌体组成，另一个则由干酪乳杆菌/副干酪乳杆菌温和噬菌体组成。最后，通过基因组共线性分析确认，8 种乳杆菌温和噬菌体中有 7 种是新发现的，而 2 种短乳杆菌温和噬菌体属于一个新的谱系。
