A polyphasic approach to characterize Weissella cibaria and Weissella confusa strains

Abstract

Weissella cibaria and Weissella confusa are controversial species of lactic acid bacteria (LAB) found in food products. They are naturally present in many fermentation processes of vegetables and cereals, with a positive implication for the quality of food. On the other hand, Weissella species have been associated to possible human infections, and for this reason the strains of the species are not yet used as starter cultures and are not included in Qualified Presumption of Safety status of European Food Safety Authority (EFSA). An in-depth analysis of the physiological and genetic characteristics of Weissella species could help to select suitable strains for possible practical applications. A comparative genome analysis of 15 sequenced W. cibaria and five W. confusa genomes available to date was carried out, in parallel with a polyphasic study of twelve strains of W. cibaria and eight strains of W. confusa previously isolated from sourdough-like maize bran fermentation. The comparative genomic analysis resulted in an absence of severe pathogenicity factors. Although some putative virulence genes were found, these, for homology and function, were present in other LAB species/strains, considered safe by EFSA and commonly used as probiotics. The phenotypic tests carried out on our strains corroborated the genomic results.Moreover, interesting functional and pro-technological traits were highlighted in the tested strains, for both the species.

Complete Genome Sequence of Weissella confusa LM1 and Comparative Genomic Analysis

“…Moreover, ANI analysis were helpful in predicting and analyzing the functions of different species and strains. For instance, W. cibaria and W. confusa were found to have a high ANI value ( Figure 2 ) and possessed many similar characteristics ( Fusco et al, 2015 ; Nel et al, 2019 ; Rizzello et al, 2019 ; Quattrini et al, 2020 ).…”

“…They also exist in the guts of humans and vertebrate animals, such as giant pandas and rainbow trout ( Xiong et al, 2019 ; Mortezaei et al, 2020 ; Wang et al, 2020 ), their functions involve reducing depressive-like behavior ( Sandes et al, 2020 ), influencing gut permeability and intestinal epithelial regeneration ( Prado et al, 2020 ), killing harmful bacteria ( Dey and Kang, 2020 ; Lee et al, 2020 ; Pelyuntha et al, 2020 ), affecting host metabolism ( Elshaghabee et al, 2020 ), and preventing cancer cell proliferation ( Le et al, 2020 ). Some Weissella species may be beneficial to plants because they inhibit the infection of plant pathogenic fungi, such as Fusarium verticillioides ( Quattrini et al, 2020 ).…”

Ability of a Wild Weissella Strain to Modify Viscosity of Fermented Milk

“…suggest their ability to adapt to different environment and different sugars availability (Abriouel et al, 2015). However, to the best of the authors' knowledge, there are no specific literature data on W. minor ability to ferment milk, but at the same time, some data are available about the inability W. confusa and Weissella cibaria to use lactose and galactose (Quattrini et al, 2019). In our study, when fermentation was stopped, W4451 was able to produce HePS similarly to other LAB strains such as Ldb2214 and Ldb147, although the EPS produced were different either for the monosaccharides composition or percentage of the repeating units ( Table 1).…”

Effect of Lactic Acid Fermentation on Color, Phenolic Compounds and Antioxidant Activity in African Nightshade

“…Weissella cibaria, Weissella confusa and Leuconostoc pseudomesenteroides are used in the food sector because these LAB strains produce exopolysaccharides [7]. W. cibaria isolated from fermented vegetables produces bacteriocin and weisseillicin, the natural peptides that can control food-borne pathogens or spoilage microorganisms [8]. Furthermore, the acidification of foods by organic acids produced by LAB stains and bacteriocins during fermentation can extend the shelf life and improve the safety of the product for consumption [9].…”