Characterization of the bacteriophage B2 of Lactobacillus plantarum ATCC 8014 (original) (raw)
Analysis of the complete genome sequence of the lactococcal bacteriophage bIBB29
International Journal of Food Microbiology, 2009
Bacteriophage bIBB29 was isolated from a whey sample originating from an industrial biotechnological process, disturbed by a bacteriophage attack. Phage bIBB29 was determined to be active against three phageresistant strains of Lactococcus lactis. It belongs to the 936 species containing virulent phages with isometric head and short non-contractile tail. One-step growth kinetics of bIBB29 phage showed that its latent time was 23 min, and the burst size was about 130 bacteriophages. The complete nucleotide sequence of the virulent L. lactis bacteriophage bIBB29 comprises 29305 nucleotides and is the sixth phage genome of the 936 species published until now. The G + C content of the bIBB29 genome (34.7%) is similar to that of its host and also to that of other phages from the 936 species. The bIBB29 genome counts 54 open reading frames organized in three typical clusters, corresponding to the early, middle and late expressed genes. Only 20 protein products of the predicted genes were found to have their homologs among proteins with known function. The early expressed region in the genomes of 936 group members displays the highest divergence, whereas the late and middle regions share high similarities, with the exception of five genes. The genome of bIBB29 shares the highest overall nucleotide similarity with bIL170 (87%), and the lowest with phage 712 (77%). The host range analysis showed that despite the high level of similarity between the receptor binding protein (RBP) of phage bIBB29 and P475, they have a different host range. This implies that RBP is not a sufficient factor for host range.
Applied and Environmental Microbiology, 2001
The Lactococcus lactis temperate bacteriophage BK5-T is one of twelve type phages that define L. lactis phage species. This paper describes the nucleotide sequence and analysis of a 21-kbp region of the BK5-T genome and completes the nucleotide sequence of the genome of this phage. The 40,003-nucleotide linear genome encodes 63 open reading frames. Sequence runoff experiments showed that the cohesive ends of the BK5-T genome contained a 12-bp 3 single-stranded overhang with the sequence 5-CACACACATAGG-3. Two major BK5-T structural proteins, of approximately 30 and 20 kDa, were identified, and N-terminal sequence analysis determined that they were encoded by orf7 and orf12, respectively. A 169-bp fragment containing a 37-bp direct repeat and several smaller repeat sequences conferred resistance to BK5-T infection when introduced in trans to the host cell and is likely a part of the BK5-T origin of replication (ori).
Journal of Applied Microbiology, 2008
Aims: Frequency of lysogeny in Lactobacillus delbrueckii strains (from commercial and natural starters) and preliminary characterization of temperate bacteriophages isolated from them. Methods and Results: Induction of strains (a total of 16) was made using mitomycin C (MC) (0AE5 lg ml )1 ). For 37% of the MC-treated supernatants, it was possible to detect phage particles or presence of killing activity, but only two active bacteriophages were isolated. The two temperate phages isolated were prolate-headed phages which belonged to group c of Lact. delbrueckii bacteriophages classification. Different DNA restriction patterns were obtained for each phage, while the structural protein profiles and packaging sites were identical. Distinctive one-step growth curves were exhibited by each phage. An influence of calcium ions was observed for their lysis in broth but not on the adsorption levels. Conclusions: Our study showed that lysogeny is also present in Lact. delbrueckii strains, including commercial strains. Significance and Impact of the Study: Commercial strains could be lysogenic and this fact has a great practical importance since they could contribute to the dissemination of active-phage particles in industrial environments.
Identification of the Repressor-Encoding Gene of the Lactobacillus Bacteriophage A2
1998
Bacteriophages are recognized to be the main source of disruption in industrial food fermentations (5). The temperate phage A2 infects strains of Lactobacillus casei and Lactobacil- lus paracasei of industrial relevance. The virions present iso- metric heads and noncontractile tails. The phage genome is a 44.02-kb double-stranded DNA molecule with 39-protruding cohesive ends (6, 7). A2 can be recovered from
Archives of Virology, 2003
The genes that encode the morphogenetic proteins of bacteriophage A2 are clustered and expressed as a single operon which originates a late transcript of more than 20 kb. This DNA stretch is analyzed in the context of the whole phage genome, which presents the following peculiarities: a) the head presents two major proteins that share their NH 2 termini, i.e.: both are translated from a single gene (orf5), b) these two proteins suffer a proteolytic maturation process before being incorporated into the capsid, rendering a 123 NH 2 terminal putative polypeptide that is postulated to be the scaffolding protein of the phage, c) similar maturation processes occur at the portal and tail length determination proteins, having all in common a Pho-Pho-Arg↓ sequence (where Pho stands for any hydrophobic amino acid) at the processing point, d) the genes encoding the subunits of the terminase (orf61 and orf2) are separated by the cohesive ends, e) two genes that might mediate lysogenic conversion (orf19 and orf22) have been identified and f) the genome presents a dispensable region (which covers at least 10 orfs, as judged from analysis of deletion mutants) that might be involved in maintaining its size between the packaging limits of the capsid.
1989
Lactobacillus acidophilus ADH is lysogenic and harbors an inducible prophage, +adh. Bacteriophage were detected in cell lysates induced by treatment with mitomycin C or UV light. Electron microscopy of lysates revealed phage particles with a hexagonal head (62 nm) and a long, noncontractile, flexible tail (398 nm) ending in at last five short fibers. Phage 4adh was classified within Bradley's B1 phage group and the Siphoviridae family. The 4adh genome is a linear double-stranded DNA molecule of 41.7 kilobase pairs with cohesive ends: a physical map of the 4adh genome was constructed. A prophage-cured derivative of strain ADH, designated NCK102, was isolated from cells that survived UV exposure. NCK102 did not exhibit mitomycin C-induced lysis, but broth cultures lysed upon addition of phage. Phage 4adh produced clear plaques on NCK102 in media containing 10 mM CaC12 at pH values between 5.2 and 5.5. A relysogenized derivative (NCK103) of NCK102 was isolated that exhibited mitomycin C-induced lysis and superinfection immunity to phage 4adh.
Bulgarian Journal of Agricultural Science, 2013
The modular evolution of phage genomes makes their classifi cation extremely diffi cult. Still in dairy industry, the identifi cation of the phage species that disturbs the fermentation process is of crucial importance in the selection of a strategy to avoid or eliminate phage infections. Phages attacking Lactobacillus delbrueckii are currently divided into four groups assigned as "a", "b", "c" and "d" which have substantial differences in their virion morphology and DNA homology. Lactobacillus delbrueckii ssp. bulgaricus phage Gb1 was isolated in 2005 from yoghurt production. Restriction fragments of phage Gb1 DNA were cloned into pIL253 in Lactococcus lctis IL1403 and PCR amplifi ed with vector-specifi c primers. The resulting amplicons were sequenced and identities with existing sequence databases were searched. All of the obtained sequences showed homology only to regions within the genome of phages LL-Ku and c5 with levels of nucleotide identity of 80-99%. No signifi cant sequence matches were found with other L. delbrueckii phages. The sequenced fragments from the genome of phage Gb1 were homologous to key genes in phages LL-Ku and c5 encoding a major head protein, the tape-measure protein, tail proteins, the single strand binding protein and a diesterase. As phages LL-Ku and c5 are typical representatives of group "b" L. delbrueckii bacteriophages that do not share DNA homology with L. delbrueckii phages from other groups we could classify phage Gb1 into group "b" L. delbrueckii phages. This is the fi rst report of a bacteriophage from this group isolated in Bulgaria. Further studies of phage Gb1 will facilitate the work on the selection of phage resistant starters and prevention of phage infections in yoghurt production.
Virology, 2001
A complete analysis of the entire genome of the temperate lactococcal bacteriophage TP901-1 has been performed and the function of 21 of 56 TP901-1-encoded ORFs has been assigned. This knowledge has been used to propose 10 functional modules each responsible for specific functions during bacteriophage TP901-1 proliferation. Short regions of microhomology in intergenic regions present in several lactococcal bacteriophages and chromosomal fragments of Lactococcus lactis are suggested to be points of exchange of genetic material through homologous recombination. Our results indicate that TP901-1 may have evolved by homologous recombination between the host chromosome and a mother phage and support the observation that phage remnants as well as prophages located in the Lactococcus chromosome contribute significantly to bacteriophage evolution. Some proteins encoded in the early transcribed region of the TP901-1 genome were more homologous to proteins encoded by phages infecting gram-positive hosts other than L. lactis. This protein homology argues for the occurrence of horizontal genetic exchange among these bacteriophages and indicates that they have access to a common gene pool.
1991
4vML3 is a virulent prolate-headed bacteriophage that attacks a genetically well-studied strain family including Lactococcus Iactis subsp. Iactis strains 712, C2 and ML3. A restriction map was constructed for &ML3 using a wide variety of restriction endonucleases. The DNA was highly refractory to in uitro restriction; this is a common feature of lytic lactococcal phages. Genome size was estimated as 23 kb, which is similar to the sizes of other phages of the same morphological group. The presence of heat-dissociable DNA fragments was noted in gel electrophoresis of restriction enzyme digests. Cohesive ends were confirmed by pretreating the DNA with T4 ligase, which rendered the composite fragment insensitive to heat. The phage &ML3 genome thus consists of linear and non-permuted double-stranded DNA with complementary cohesive ends. The lysin gene from this phage acts as a specific lysis agent against the lactic streptococci. This gene has been cloned and sequenced previously. Further specific subcloning of EcoRV fragments of &ML3 DNA has located the lysin gene in the central region of the genome, orientated from right to left. This location was confirmed by hybridization of a lysin gene probe to @ML3 DNA. The lysin gene probe showed homology to a number of other prolate-headed phages including Pool. The lysin gene of PO01 was shown to be located in the central region of its genome. However, the isometric phage P107 did not hybridize, in spite of encoding its own lysin gene.