Do Lactic Acid Bacteria produce antifungal bacteriocins?

Abstract

Bacteriocins are small antimicrobial peptides that are produced by bacteria and are known to inhibit the growth of closely related or non‐related bacterial strains without causing harm to the producer strain. Bacteriocins are categorized into several classes and lactic acid bacteria (LAB) are known to produce class IIa bacteriocins which are described as small, heat‐stable peptides. LAB produced bacteriocins could create a wide range of applications in food preservation, which may present a safer alternative than currently used chemical preservatives. The mold Fusarium graminearum frequently contaminates barley malt, which along with water, yeast, and hops form the ingredients of beer. Hydrophobic compounds produced by F. graminearum causes beer to retain high levels of carbon dioxide, which results in gushing, or excessive foaming when bottled. Gushing can damage the reputation of a brewery. Thus, malt producers are searching for a way to control this grain contaminant. Recently, several studies demonstrating potential antifungal properties of bacteriocins were reported. Using a sourdough starter, we were able to isolate environmental strains of LAB by growing them anaerobically on MRS agar medium. We will then test their potential antifungal properties against F. graminearum using traditional microbiological methods. If we can determine that bacteriocins produced by LAB are in fact antifungal, we will then use PCR to rapidly detect bacteriocin genes that might be present in these strains. Potential bacteriocins will be exposed to a variety of experimental conditions such as protease treatment, pH, and detergents for further classification and characterization.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.