Submitted to: Journal of Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2006
Publication Date: 2/28/2007
Citation: Yoon, S., Barrangou-Poueys, R., Breidt, F., Fleming, H.P. 2007. Detection and characterization of a lytic Pediococcus bacteriophage from the fermenting cucumber brine. Journal of Microbiology and Biotechnology. 17(2):262-270. Interpretive Summary: This manuscript describes the characterization of a bacterial virus. Bacterial viruses are the most common form of life on earth, but they are probably the least well understood. It is known, however, that bacterial viruses only infect bacteria and are harmless to humans. Although isolated from cucumber brine, the virus described in this research article infects a type of bacteria that is commonly found in both meat and vegetable fermentations. Understanding more about the bacterial viruses present in vegetable fermentations may allow us to use starter cultures that are resistant to infection by viruses. New fermentation technology for low salt vegetable fermentations may require the use of starter cultures, which may be attacked by naturally present bacterial viruses. A long term goal of this research is to reduce waste salt from commercial vegetable fermentations by using controlled low salt fermentations.
Technical Abstract: Of the twelve lytic bacteriophages recovered from five different fermenting cucumber tanks that were inoculated with Pediococcus sp. LA0281, a lytic phage, 'ps05, was characterized in the present study. The plaques were mostly clear and round-shaped on the lawn of starter strain, indicating lytic phage. Overall appearance indicated that it belongs to the Siphoviridae family or Bradley’s group B1, with a small isometric head and a flexible noncontractile tail with swollen base plate. The average size was found to be 51.2 nm in head diameter and 11.6 nm wide × 129.6 nm long for the tail. The single-step growth kinetics curve showed that the eclipse and the latent period were 29 min and 34 min, respectively, and an average burst size was calculated to be 12 particles per infective center. The optimum proliferating temperature (35 degrees C) was slightly lower than that of cell growth (35 to 40 degrees C). The structural proteins revealed by SDS-PAGE consisted of one main protein of 33 kDa and three minor proteins of 85, 58, and 52 kDa. The phage genome was a linear double-stranded DNA without cohesive ends. Based on the single and double digestion patterns obtained by EcoRI, HindIII, and SalI, the physical map was constructed. The overall size of the phage genome was estimated to be 24.1 kb. The present report describes the presence of a lytic phage active against a commercial starter culture Pediococcus sp. LA0281 in cucumber fermentation, and a preliminary study characterizes the phage on bacterial successions in the process of starter-added cucumber fermentation.