Anti-Spoilage Activity and Exopolysaccharides Production by Selected Lactic Acid Bacteria

Abstract

In this study, eight lactic acid bacteria (LAB) strains, previously isolated from traditional and gluten-free sourdoughs, and selected for their potential in improving the sensory and rheological quality of bakery products, were screened against some common spoilage agents. The anti-mould activity was tested using strains of the species Fusarium graminearum, Aspergillus flavus, Penicillium paneum and Aspergillus niger. Regarding the antibacterial activity, it was assessed against four strains of the species Escherichia coli, Campylobacter jejuni, Salmonella typhimurium and Listeria monocytogenes. Furthermore, LAB strains were evaluated for their ability to produce exopolysaccharides, which are gaining considerable attention for their functional properties and applicability in different food industrial applications. A strain-specific behaviour against the moulds was observed. In particular, F. graminearum ITEM 5356 was completely inhibited by all the LAB strains. Regarding the antibacterial activity, the strains Leuconostoc citreum UMCC 3011, Lactiplantibacillus plantarum UMCC 2996, and Pediococcus pentosaceus UMCC 3010 showed wide activity against the tested pathogens. Moreover, all the LAB strains were able to produce exopolysaccharides, which were preliminarily characterized. The assessed features of the LAB strains allow us to consider them as promising candidates for single or multiple starter cultures for food fermentation processes.

Kinetic modeling the survival of Escherichia coli in pickled radish fermentation with different salt concentrations

“…The comparatively lower negative correlation coefficient between the numbers of E. coli and LAB, on the other hand, suggested that the inhibition effect on E. coli by LAB growth during the pickle fermentation was indirect. Similar results were reported previously (Iosca et al, 2022;Yang et al, 2014).…”

Exploring the Inhibitory Activity of Selected Lactic Acid Bacteria against Bread Rope Spoilage Agents

“…Five strains were provided by the Unimore Microbial Culture Collection (UMCC), University of Modena and Reggio Emilia (Italy), and the remaining strains were provided by the National Food Institute Culture Collection (NFICC), Technical University of Denmark (Table 1). UMCC strains were identified and characterized by 16 s RNA gene sequencing in previous works and selected for their antispoilage activity [14,15]. Regarding NFICC strains, they were identified by using the MALDI Biotyper ® sirius IVD System (BRUKER, Roskilde, Denmark) or through whole-genome sequencing, and selected for their suitability to ferment plantbased substrates [23].…”

“…Ideally, the need for alternative preservatives should be obtained from naturally occurring sources that can be achievable using microorganisms or/and their metabolites [13]. In this context, selected lactic acid bacteria (LAB) can be exploited to prevent spoilage of bread and contribute both to the production of sensory properties and microbial safety of bakery products [14,15]. The use of LAB as a starter culture has a long history in a variety of fermented foods.…”

Isolation and screening of lactic acid bacteria and yeast starters from ersho (traditional Ethiopian sourdoughs) and evaluation of their role in bread production

“…During bread storage, the microbial load of breads varied. The reasons might be variation in antimicrobial metabolite production (Iosca et al, 2023), acidification rate, and organic acid type and amount production (Sarac & Ahmet, 2022). The bread production process (Jasper et al, 2022), bread processing environment (air), and bread ingredients contributed to the microbial contamination of breads (Juliana et al, 2016).…”