Bacteriocin ‐phage interaction (BaPI): Phage predation of Lactococcus in the presence of bacteriocins

In this study, we have studied how bacteriocins may influence the progress of phage infection in dairy starter bacteria. Our results show that phage predation is indeed facilitated by particular bacteriocins depending on their mode of action, anticipating detrimental consequences for milk fermentations. AbstractBacteriophages infecting dairy starter bacteria are a leading cause of milk fermentation failure and strategies to reduce the risk of phage infection in dairy settings are demanded. Along with dairy starters, bacteriocin producers (protective cultures) or the direct addition of bacteriocins as biopreservatives may be applied in food to extend shelf-life. In this work, we have studied the progress of infection ofLactococcus cremoris MG1363 by the phage sk1, in the presence of three bacteriocins with different modes of action: nisin, lactococcin A (LcnA), and lactococcin 972 (Lcn972). We aimed to reveal putative bacteriocin-phage interactions (BaPI) that could be detrimental and increase the risk of fermentation failure due to phages. Based on infections in broth and solid media, a synergistic effect was observed with Lcn972. This positive sk1-Lcn972 interaction could be correlated with an increased burst size. sk1-Lcn972 BaPI occurred independently of a functional SOS and cell envelope stress response but was lost in the absence of the major autolysin AcmA. Furthermore, BaPI was not exclusive to the sk1-Lcn972 pairing and could be observed with other phages and lactococ...

Source: MicrobiologyOpen - August 16, 2022 Category: Microbiology Authors: Claudia Rendueles, Susana Escobedo, Ana Rodr íguez, Beatriz Martínez Tags: ORIGINAL ARTICLE Source Type: research