Marina Sánchez Hidalgo, member of the research group and author of the doctoral thesis entitled 'Caracterización de variantes de la enterocina AS-48 obtenidas mediante mutagénesis dirigida' (Characterization of enterocin AS-48 variants via site-directed mutagenesis), explains that AS-48 is a bacteriocin (protein substance with antimicrobial activity) produced by Enterococcus faecalis S-48. "The bacteriocin is characterized by its circular structure —that is, because of the joining of its ends?contrary to most of proteins, which have a beginning and an end." AS-48 is very stable with respect to pH and temperature and has a broad action spectrum against numerous bacteria, including pathogenic bacteria transmitted by food, "which makes it a suitable molecule to use as a biopreservative."
The research carried out at the UGR will complete the information concerning the way that bacteriocins act on bacterial membranes and will also help in designing antimicrobial molecules with new characteristics. "Our work," states Marina Sánchez, "has determined which AS-48 amino acids are essential for membranestability and biological activity, and it has also helped us understand how this molecule permeabilizes bacterial membranes."
Competition for nutrients
Over the course of evolution, microorganisms have developed several strat
Source:Universidad de Granada