Genomics of tailless bacteriophages in a complex lactic acid bacteria starter culture

Alexeeva, Svetlana; Liu, Y.; Zhu, Jingjie; Kaczorowska, Joanna; Kouwen, Thijs R. H. M.; Abee, Tjakko; Smid, Eddy J.

doi:10.1016/j.idairyj.2020.104900

Cited by 6 publications

(11 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2F ). This conclusion is also supported by the previous study where the tailless phage particles were isolated with the same method and subjected to DNA sequencing, and full phage genomes were recovered with more than 100-fold higher coverage than the background ( 6 ).…”

Section: Resultssupporting

confidence: 76%

“…In cells actively replicating the phage particles, green fluorescence intensity was expected to increase. As mentioned, we used L. lactis TIFN1 as the model strain, which harbors the genome of prophage proPhi1 ( 6 ). The insertion site was selected within the prophage sequence between stop codons of open reading frames (ORFs) 48 and 49 located on opposite DNA strands ( Fig.…”

Section: Resultsmentioning

confidence: 99%

“…They can be icosahedral, spherical, pleomorphic, filamentous, and droplet, bottle, and spindle shaped; some have a long or short tail, and some are tailless, engulfed in a lipid bilayer or containing lipids beneath the protein capsid; the genetic material can be double-stranded or single-stranded DNA or RNA ( 1 , 2 ). The broad accessibility of high-throughput sequencing technologies also revealed a high degree of genetic diversity in bacteriophages; mosaic genomes and numerous novel sequences of unknown function have been reported ( 3 – 6 ). Over 90% of reported phages are tailed double-stranded DNA phages belonging to the order Caudovirales ( 7 ).…”

Section: Introductionmentioning

confidence: 99%

“…Practicing back-slopping creates the boundaries for natural selection, which drives adaptive evolution of the culture and its constituent microbial strains. Although (pro)phages are not desired in industrial fermentations with defined starter compositions, the common presence of prophages in the naturally evolved, stable, and robust starter cultures like Ur suggests an evolutionary success ( 6 , 23 ). Investigating the behavior of phages and bacteria in such a model system contributes to the understanding of bacterium-phage interactions as well as its ecological and evolutional significance.…”

Section: Introductionmentioning

confidence: 99%

“…However, (pro)phages in this starter culture possess some peculiar features: phage particles are abundantly released spontaneously and further stimulated by mitomycin C induction ( 23 ). The phage particles appear to be tailless due to disruptions in tail-protein-encoding genes ( 6 ). Moreover, the release of the (pro)phages from the host cells was not accompanied by detectable cell lysis, a phenomenon that is typical for release of Siphoviridae bacteriophages ( 24 – 27 ).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Chronic Release of Tailless Phage Particles from Lactococcus lactis

Liu

Alexeeva

Bachmann

et al. 2022

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Lactococcus lactis strains residing in the microbial community of a complex dairy starter culture named “Ur” are hosts to prophages belonging to the family Siphoviridae . L. lactis strains (TIFN1 to TIFN7) showed detectable spontaneous phage production and release (10 9 -10 10 phage particles/mL) and up to 10-fold increases upon prophage induction, while in both cases we observed no obvious cell lysis, typically described for the lytic life cycle of Siphoviridae phages. Intrigued by this phenomenon, we investigated the host-phage interaction using strain TIFN1 (harboring prophage proPhi1) as a representative. We confirmed that during the massive phage release, all bacterial cells remain viable. Further, by monitoring phage replication in vivo , using a green fluorescence protein reporter combined with flow cytometry, we demonstrated that the majority of the bacterial population (over 80%) is actively producing phage particles when induced with mitomycin C. The released tailless phage particles were found to be engulfed in lipid membranes, as evidenced by electron microscopy and lipid staining combined with chemical lipid analysis. Based on the collective observations, we propose a model of phage-host interaction in L. lactis TIFN1, where the phage particles are engulfed in membranes upon release, thereby leaving the producing host intact. Moreover, we discuss possible mechanisms of chronic, or non-lytic release of LAB Siphoviridae phages and its impact on the bacterial host. Importance: In complex microbial consortia such as fermentation starters, bacteriophages can alter the dynamics and diversity of microbial communities. Bacteriophages infecting Lactococcus lactis are mostly studied for their detrimental impact on industrial dairy fermentation processes. In the submitted article, we describe a novel way of phage-bacteria interaction in a L. lactis strain isolated from a complex dairy starter culture: when the prophages harbored in the L. lactis genome are activated, the phage particles are engulfed in lipid membranes upon release, leaving the producing host intact. Findings from this study provide additional insights into the diverse manners of phage-bacteria interactions and co-evolution, which is essential for understanding the population dynamics in complex microbial communities like fermentation starters.

show abstract

Section: Resultssupporting

confidence: 76%

Section: Resultsmentioning

confidence: 99%