Targeted RNAi screen identifies transcriptional mechanisms that prevent premature degeneration of adult photoreceptors.

Aging is associated with a decline in visual function and increased prevalence of ocular disease, correlating with changes in the transcriptome and epigenome of cells in the eye. Here, we sought to identify the transcriptional mechanisms that are necessary to maintain photoreceptor viability and function during aging. To do this, we performed a targeted photoreceptor-specific RNAi screen in to identify transcriptional regulators whose knockdown results in premature, age-dependent retinal degeneration.

Resistance to the Bacteriocin Lcn972 Deciphered by Genome Sequencing.

In view of the current threat of antibiotic resistance, new antimicrobials with low risk of resistance development are demanded. Lcn972 is a lactococcal bacteriocin that inhibits septum formation by binding to the cell wall precursor lipid II in . It has a species-specific spectrum of activity, making Lcn972 an attractive template to develop or improve existing antibiotics.

Cell wall modifications that alter the exolytic activity of lactococcal phage endolysins have little impact on phage growth.

Bacteriophages are a nuisance in the production of fermented dairy products driven by starter bacteria and strategies to reduce the risk of phage infection are permanently sought. Bearing in mind that the bacterial cell wall plays a pivotal role in host recognition and lysis, our goal was to elucidate to which extent modifications in the cell wall may alter endolysin activity and influence the outcome of phage infection in . Three lactococcal endolysins with distinct catalytic domains (CHAP, amidase and lysozyme) from phages 1,358, p2 and c2 respectively, were purified and their exolytic activity was tested against lactococcal mutants either overexpressing or lacking genes involved in the cell envelope stress (CES) response or in modifying peptidoglycan (PG) composition.

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

Bacteriophages 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 of Lactococcus 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).

Combined use of bacteriocins and bacteriophages as food biopreservatives. A review.

Throughout history, humans have consistently developed strategies to prevent food-associated illnesses. However, despite our multiple technological advances, food safety is still an issue of concern. Moreover, there is a demand for gaining access to less processed and naturally preserved food.