Document Type

Article

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Disciplines

Agricultural Science | Agriculture | Animal Diseases | Animal Sciences | Bacteriology | Biochemistry, Biophysics, and Structural Biology | Dairy Science | Environmental Microbiology and Microbial Ecology | Food Microbiology | Immunology and Infectious Disease | Immunology of Infectious Disease | Medical Sciences | Medicine and Health Sciences | Microbiology | Organismal Biological Physiology | Organisms | Parasitic Diseases | Parasitology | Pathogenic Microbiology | Virology | Virus Diseases

Publication Details

Frontiers in Microbiology / Virology

Received: 31 October 2013; Accepted: 18 December 2013; Published online: 13 January 2014.

Edited by:

Jennifer Mahony, University College Cork, Ireland

Reviewed by:

Sinead C. Leahy, AgResearch Limited, New Zealand Louis-Charles Fortier, Universite de Sherbrooke, Canada

Copyright © 2014 Cavanagh, Guinane, Neve, Coffey, Ross, Fitzgerald and McAuliffe. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Olivia McAuliffe, Department of Food Biosciences, Teagasc Food Research Centre, Fermoy, Co. Cork, Ireland e-mail: olivia.mcauliffe@teagasc.ie

Abstract

Lactococci isolated from non-dairy sources have been found to possess enhanced metabolic activity when compared to dairy strains. These capabilities may be harnessed through the use of these strains as starter or adjunct cultures to produce more diverse flavor profiles in cheese and other dairy products. To understand the interactions between these organisms and the phages that infect them, a number of phages were isolated against lactococcal strains of non-dairy origin. One such phage, ΦL47, was isolated from a sewage sample using the grass isolate L. lactis ssp. cremoris DPC6860 as a host. Visualization of phage virions by transmission electron microscopy established that this phage belongs to the family Siphoviridae and possesses a long tail fiber, previously unseen in dairy lactococcal phages. Determination of the lytic spectrum revealed a broader than expected host range, with ΦL47 capable of infecting 4 industrial dairy strains, including ML8, HP and 310, and 3 additional non-dairy isolates. Whole genome sequencing of ΦL47 revealed a dsDNA genome of 128, 546 bp, making it the largest sequenced lactococcal phage to date. In total, 190 open reading frames (ORFs) were identified, and comparative analysis revealed that the predicted products of 117 of these ORFs shared greater than 50% amino acid identity with those of L. lactis phage Φ949, a phage isolated from cheese whey. Despite their different ecological niches, the genomic content and organization of ΦL47 and Φ949 are quite similar, with both containing 4 gene clusters oriented in different transcriptional directions. Other features that distinguish ΦL47 from Φ949 and other lactococcal phages, in addition to the presence of the tail fiber and the genome length, include a low GC content (32.5%) and a high number of predicted tRNA genes (8). Comparative genome analysis supports the conclusion that ΦL47 is a new member of the 949 lactococcal phage group which currently includes the dairy Φ949.

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