Exopolysaccharide-Forming Weissella Strains as Starter Cultures for Sorghum and Wheat Sourdoughs

Abstract

The addition of sourdough fermented with lactic acid bacteria synthesizing organic acids and oligo- and exopolysaccharides (EPS) from sucrose enhances texture, nutritional value, shelf life, and machinability of wheat, rye, and gluten-free bread. This study compared acetate, mannitol, and oligosaccharide formation of EPS-producing strains of Weissella and Leuconostoc spp. to the traditional sourdough starter Lactobacillus sanfranciscensis. In broth, Leuconostoc strains generally formed acetate and mannitol, whereas Weissella produced only small amounts of acetate and no mannitol in the presence of sucrose. In the presence of sucrose and maltose, Weissella and Leuconostoc strains synthesized glucooligosaccharides and EPS. Strains of Weissella were employed as starter cultures for wheat and sorghum sourdough and formed 0.8-8 g kg(-1) EPS and gluco-oligosaccharides but only low amounts of acetate and mannitol. In contrast, the formation of EPS from sucrose led to the production of high amounts of acetate and mannitol by L. sanfranciscensis LTH 2950 in wheat sourdough. This study indicates that Weissella strains are suitable starter cultures for wheat and sorghum sourdoughs and efficiently produce gluco-oligosaccharides and EPS.

Genomics of Weissella cibaria with an examination of its metabolic traits

“…cibaria MG1 is of particular interest in our group due to its ability to produce a dextran HoPS in large quantities (~36 g l 21 ). This strain and its associated EPSs have been studied in connection with potential bakery, brewing and dairy applications (Galle et al, 2010;Lynch et al, 2014;Wolter et al, 2014;Zannini et al, 2013). Genomic analysis confirmed the EPS-producing phenotype with the identification of a 1447 aa protein (MG1_1773) with 75 % identity to a dextransucrase in W. confusa.…”

“…W. cibaria and W. confusa are known for their slime-producing properties, i.e. production of the homoexopolysaccharide (HoPS), dextran, in significant quantities (Ahmed et al, 2012;Bounaix et al, 2010;Galle et al, 2010;Huys et al, 2012). HoPS production is also reported for some members of the genera Leuconostoc, Lactobacillus and Streptococcus (Korakli & Vogel, 2006;Monsan et al, 2001;Tieking et al, 2005).…”

“…The sources of isolation of weissellas suggest an environmental origin. Strains have been isolated from a variety of niches including meat products (Diez et al, 2009), dairy products ( Van der Meulen et al, 2007), fermented foods of vegetable origin (Björkroth et al, 2002), sourdoughs (Galle et al, 2010) and soil (Magnusson et al, 2002). The species Weissella confusa and Weissella cibaria have also been found in clinical samples of human and animal origin (Björkroth et al, 2002;Huys et al, 2012).…”

“…Our aim was to provide a genomic overview of this lesserknown genus of lactic acid bacteria LAB, with particular emphasis on W. cibaria due to high levels of dextran production by this species, which has been increasingly studied and applied in a number of food-related applications in recent years (Amari et al, 2013;Galle et al, 2010;Katina et al, 2009;Lynch et al, 2014;Zannini et al, 2013).…”

Development of a method for the direct fermentation of semolina by selected sourdough lactic acid bacteria

“…Data within a column followed by the same letter are not significantly different according to Tukey's test. P value: ***, P b 0.001. , are commonly present in the sourdough ecosystems produced in different countries (Choi et al, 2012;Coppola et al, 1996;De Vuyst et al, 2002;Iacumin et al, 2009;Robert et al, 2006Robert et al, , 2009Valmorri et al, 2006) and might also contribute to the structure of the final dough by exopolysaccharides (Choi et al, 2012;Di Cagno et al, 2006;Galle et al, 2010;Maina et al, 2008). Specifically, the strains Lb.…”