Attempts to Improve Antimicrobial Efficiency by Mixed-Lactobacillus Extracts as Crude or Nano-formulated Against Pathogenic and Food Spoilage Bacteria, Molds and Yeasts

Abstract

Over the world, there are millions of disease cases, in addition to thousands of deaths due to food-based outbreaks every year. In order to diminish the risk of foodborne infection and intoxications and control microbial food spoilage, there is a great need to improve modes of food preservation. As well-known, nature-dependent preservation enables consumers to keep their safety while eating highly qualified food. This work aims to enhance the safety and quality of common popular food products by introducing new preservative applications suggestions. The idea is to use different lactobacilli-based fermentations; in single or mixed-status and study the obtained extracts to evaluate their influence to manage microbial contamination of food. A set of five Lactobacillus strains was utilized by this study, methanol extract of cold acetone precipitate, Diethyl ether extract, and both were tested as crude or Nano-formulated against common microbial pathogens and food spoilers. Methanol extract of all lactobacillus strains shows antibacterial-specific activity with inhibition zone ranging from 7 mm in the case of Lactobacillus rhamnosus against Salmonella enterica, to 24 mm in the case of Lactobacillus helveticus against Escherichia coli. Diethyl ether extracts based on Lactobacillus helveticus and Lactobacillus plantarum show a considerable inhibition to all utilized microbial concerns, including Saccharomyces cerviceae. Upon estimating three forms of mixed-Lactobacillus that are based on Lactobacillus helveticus (h), Lactobacillus plantarum (p), and Lactobacillus rhamnosus GG (G), the ph-dependant combination showed uprising inhibition that reached maximally 58% over that of single Lactobacilli. Nano formulation of mixed-based total extracts maximally upraised the inhibition to 39%, 32%, and 100% against gram-positive, gram-negative, and the fungus; Penicillium chrysogenum, respectively.