Selection of enhanced antimicrobial activity posing lactic acid bacteria characterised by (GTG)5-PCR fingerprinting

Abstract

The aim of the study was a detail evaluation of genetic diversity among the lactic acid bacteria (LAB) strains having an advantage of a starter culture in order to select genotypically diverse strains with enhanced antimicrobial effect on some harmfull and pathogenic microorganisms. Antimicrobial activity of LAB was performed by the agar well diffusion method and was examined against the reference strains and foodborne isolates of Bacillus cereus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Antifungal activity was tested against the foodborne isolates of Candida parapsilosis, Debaromyces hansenii, Kluyveromyces marxianus, Pichia guilliermondii, Yarowia lipolytica, Aspergillus brasiliensis, Aspergillus versicolor, Cladosporium herbarum, Penicillium chrysogenum and Scopulariopsis brevicaulis.A total 40 LAB strains representing Lactobacillus (23 strains), Lactococcus (13 strains) and Streptococcus spp. (4 strains) were characterised by repetitive sequence based polymerase chain reaction fingerprinting which generated highly discriminatory profiles, confirmed the identity and revealed high genotypic heterogeneity among the strains. Many of tested LAB demonstrated strong antimicrobial activity specialised against one or few indicator strains. Twelve LAB strains were superior in suppressing growth of the whole complex of pathogenic bacteria and fungi. These results demonstrated that separate taxonomic units offered different possibilities of selection for novel LAB strains could be used as starter cultures enhancing food preservation.

Diversity and Functional Properties of Lactic Acid Bacteria Isolated From Wild Fruits and Flowers Present in Northern Argentina

“…The rep-PCR technique has been recognized as a simple technique, with high discriminatory power, low cost, suitable for handling large numbers of strains, and for classifying a wide range of Gram (+) and Gram (–) bacteria at species, subspecies, and/or strain level (Gevers et al, 2001). Rep-PCR has been used for typing LAB from different origins by several authors (Gevers et al, 2001; Ouadghiri et al, 2005; Vasilopoulos et al, 2008; Sengun et al, 2009; Papalexandratou et al, 2011b; Perin and Nero, 2014; Šalomskiene et al, 2015; Sáez et al, 2017). In this work, 673 isolates were grouped into 95 different clusters according to their band profiles, indicating higher species and strain diversity of LAB in the samples examined than that found in other fruits and vegetables (Bae et al, 2006; Chen et al, 2010; Di Cagno et al, 2010; Askari et al, 2012; Emerenini et al, 2013; Wu et al, 2014); (Verón et al, 2017).…”

Application of Edible Coating Based on Liquid Acid Whey Protein Concentrate with Indigenous Lactobacillus helveticus for Acid-Curd Cheese Quality Improvement

“…Indigenous L. helveticus MI-LH13 previously isolated from raw bovine milk was stored at −80 °C in MRS broth (Merck, Germany) in the presence of 30% glycerol. Antimicrobial properties of this strain and some of the technological properties relevant to the dairy industry were tested in vitro before the study [ 27 ].…”

Effects of Natural Antimicrobials on Xanthomonas Strains Growth

“…This study focuses on twelve lactic acid bacteria (LAB) strains [28] obtained from the Kaunas University of Technology (KTU) Food Institute LAB collection: Enterococcus faecium 59-30, E. faecium 41-2B 2v, Lactobacillus helveticus 14, Lb. helveticus 3, Lb.…”