Ehrmann Matthias A, Angelov Angel, Picozzi Claudia, Foschino Roberto, Vogel Rudi F
Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Gregor-Mendel-Str, 4, Freising 85354, Germany.
BMC Res Notes. 2013 Dec 5;6:514. doi: 10.1186/1756-0500-6-514.
Bacteriophages infection modulates microbial consortia and transduction is one of the most important mechanism involved in the bacterial evolution. However, phage contamination brings food fermentations to a halt causing economic setbacks. The number of phage genome sequences of lactic acid bacteria especially of lactobacilli is still limited. We analysed the genome of a temperate phage active on Lactobacillus sanfranciscensis, the predominant strain in type I sourdough fermentations.
Sequencing of the DNA of EV3 phage revealed a genome of 34,834 bp and a G + C content of 36.45%. Of the 43 open reading frames (ORFs) identified, all but eight shared homology with other phages of lactobacilli. A similar genomic organization and mosaic pattern of identities align EV3 with the closely related Lactobacillus vaginalis ATCC 49540 prophage. Four unknown ORFs that had no homologies in the databases or predicted functions were identified. Notably, EV3 encodes a putative dextranase.
EV3 is the first L. sanfranciscensis phage that has been completely sequenced so far.
噬菌体感染可调节微生物群落，转导是细菌进化过程中最重要的机制之一。然而，噬菌体污染会导致食品发酵停滞，造成经济损失。乳酸菌尤其是乳酸杆菌的噬菌体基因组序列数量仍然有限。我们分析了一种对旧金山乳杆菌（I型酸面团发酵中的优势菌株）具有活性的温和噬菌体的基因组。
EV3噬菌体DNA测序显示其基因组为34,834 bp，G + C含量为36.45%。在鉴定出的43个开放阅读框（ORF）中，除8个外，其余均与其他乳酸杆菌噬菌体具有同源性。相似的基因组组织和同一性镶嵌模式使EV3与密切相关的阴道乳杆菌ATCC 49540前噬菌体相似。鉴定出四个在数据库中无同源性或预测功能的未知ORF。值得注意的是，EV3编码一种假定的葡聚糖酶。
EV3是迄今为止首个已完成全序列测定的旧金山乳杆菌噬菌体。
