Navigation Links
Researchers from the UGR use a bacterium to obtain biopreservatives from food

The research group "Estudio de sustancias antagonistas producidas por microorganismos" (Antagonistic substances produced by microorganisms), part of the Microbiology Department of the University of Granada (Universidad de Granada []), has succeeded in isolating enterocin AS-48, which could have a medium-term use as food biopreservative. This represents a significant advance, given that biopreservation is an innovative method in food-preservation systems based on the use of microorganisms or their metabolic products to inhibit or destroy undesirable microorganisms.

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 egies to compete for nutrients in their environment. One of these strategies is to produce antimicrobial compounds such as antibiotics, certain metabolism products, lytic agents, numerous types of protein exotoxins, and bacteriocins. It has become increasingly more necessary to find new antimicrobial agents because of the stronger resistance acquired by bacteria. Researcher Sánchez Hidalgo points out that natural antimicrobial cationic peptides such as bacteriocins "represent a good alternative."

Bacteriocins are proteins that are biologically active against members of the same species or species closely related to the producing bacterium. Some noteworthy bacteriocins those produced by lactic-acid bacteria (LAB), as they have been used to prepare fermented food, improve quality, and extend the average duration of many foods for centuries.

The work presented in the doctoral thesis approaches the molecular aspects of the permeabilization that AS-48 exerts on bacterial membranes. "We designed a strategy to carry out site-directed mutagenesis on the as-48A gene, the one which generates enterocin AS-48", the researcher from Granada pointed out, "and we have studied the role of seven amino acids that could be involved in biological activity and in the hydrophobic nature and thermodynamic stability of the molecule. We made this study by changing the amino acids into others with different properties."

The results of this work made it possible to conclude that while some of the mutated amino acids are essential for biological activity, others improve AS-48 biotechnological characteristics. During the process of obtaining mutated amino acids, it was also determined that three out of the ten genes involved in the production of AS-48 express themselves together. The research also determined the way of that these genes are regulated and expressed as well.


Source:Universidad de Granada

Related biology news :

1. Researchers discover way to make cells in the eye sensitive to light
2. Researchers find how protein allows insects to detect and respond to pheromones
3. Researchers Uncover Key Step In Manufacture of Memory Protein
4. Researchers reveal the infectious impact of salmon farms on wild salmon
5. Researchers identify target for cancer drugs
6. Researchers discover molecule that causes secondary stroke
7. Researchers find missing genes of ancient organism
8. Researchers trace evolution to relatively simple genetic changes
9. Researchers add new tool to tumor-treatment arsenal
10. UF Researchers Map Bacterial Proteins That Cause Tooth Loss
11. VCU Researchers Identify Networks Of Genes Responding To Alcohol In The Brain
Post Your Comments:

(Date:10/29/2015)... --  MedNet Solutions , an innovative SaaS-based eClinical technology ... is pleased to announce that it has been selected ... of only three finalists for a 2015 Tekne ... category. The Tekne Awards honor Minnesota ... and leadership. iMedNet™ eClinical  technology ...
(Date:10/29/2015)... ARBOR, Mich. , Oct. 29, 2015 /PRNewswire/ ... Eurofins Genomics for U.S. distribution of its DNA ... DNA-seq kit and Rubicon,s new ThruPLEX Plasma-seq kit. ... to enable the preparation of NGS libraries for ... plasma for diagnostic and prognostic applications in cancer ...
(Date:10/29/2015)... YORK , Oct. 29, 2015 ... technology, announced a partnership with 2XU, a global ... to deliver a smart hat with advanced bio-sensing ... and other athletes to monitor key biometrics to ... the strategic partnership, the two companies will bring together ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 26, 2015 --> ... 2016 - 2020 report analyzes that automating biobanking ... quality in long-term samples, minimizing manual errors, improving ... minimizes manual errors such as mislabeling or inaccurate ... it plays a vital role in blood fractionation, ...
(Date:11/25/2015)... HOLLISTON, Mass. , Nov. 25, 2015 ... HART ), a biotechnology company developing bioengineered organ implants ... McGorry will present at the LD Micro "Main ... 2:30 p.m. PT. The presentation will be webcast live ... Management will also be available at the conference for ...
(Date:11/25/2015)... Orexigen® Therapeutics, Inc. (Nasdaq: OREX ) ... chat discussion at the Piper Jaffray 27th Annual Healthcare ... discussion is scheduled for Wednesday, December 2, at 8:00 ... replay will be available for 14 days after the ... NormartVP, Corporate Communications and Business Development , BrewLife(858) 875-8629 ...
(Date:11/24/2015)... , ... November 24, 2015 , ... The United States ... of the 2016 USGA Green Section Award. Presented annually since 1961, the USGA Green ... or her work with turfgrass. , Clarke, of Iselin, N.J., is an ...
Breaking Biology Technology: