Genome-Assisted Characterization of Lactobacillus fermentum, Weissella cibaria, and Weissella confusa Strains Isolated from Sorghum as Starters for Sourdough Fermentation

Abstract

Sourdough fermentation of bakery products is a well-established and widespread technique to confer an added value to the resulting food. In recent decades, gluten-free raw materials have gained more attention due to the diffusion of food disorders such as coeliac disease, but, at the same time, they present difficult manipulation and scarce technological properties because of the absence of gluten. For this reason, the present work was aimed at selecting starter cultures for sourdough application that are isolated from fermentation of sorghum flour. Three isolates of Lactobacillus fermentum, Weissella cibaria, and Weissella confusa were selected for the following properties: exopolysaccharide synthesis, acidification, CO2 production, and amylase activity. The investigated phenotypic characteristics were confirmed by genomic analyses, which also highlighted other potentially beneficial features for use in bakery products employment. These strains, together with bakery yeast, were used for bread preparation using sorghum and wheat flour and after 24 h of fermentation the resulting dough was analyzed to assess the improvement of its characteristics. The presence of lactic acid bacteria (LAB) had a great impact on the final dough, and the best preparation, from a rheological point of view, resulted in one made of sorghum and wheat flour with added LAB and bakery yeast, whose resulting characteristics were similar to all wheat flour doughs. The results of this study suggest a potential application of the selected starters in sorghum composite bread and should be validated with data from large-scale pilot tests conducted in industrial bakeries.

Lactic Acid Bacteria Isolated from Fermented Doughs in Spain Produce Dextrans and Riboflavin

“…The production by the three W. cibaria strains ranged from 684 to 584 µg/L ( Table 2 ), with the BAL3C-7 strain producing the highest secretion levels. Analysis of the genomic features of W. cibaria UC4051 isolated from sorghum flour revealed the presence of the rib operon involved in riboflavin synthesis, indicating that this LAB strain could synthesize vitamin B 2 [ 67 ]. To our knowledge, this is the first report of detection of riboflavin production and secretion by a W. cibaria strain.…”

Next-Generation Sequencing for Whole-Genome Characterization of Weissella cibaria UTNGt21O Strain Originated From Wild Solanum quitoense Lam. Fruits: An Atlas of Metabolites With Biotechnological Significance

“…A putative allantoin permease belonging to a superfamily of AA permeases responsible for amino acid transport and metabolism was detected in the UTNGt21O genome. These proteins were found in several W. cibaria strains and related to probiotic potential ( Falasconi et al, 2020 ). Besides, maltose phosphorylase ( malP ) was annotated.…”

“…The length of the intact prophage varies from 18.5 to 22.9 kb. The presence of intact regions might help against the invasion of other prophages ( Falasconi et al, 2020 ). No mobile elements were found with PlasmidFinder (selected %ID threshold: 95.00%, selected minimum length: 60%), which indicates the stability of the UTNGt21O genome.…”

“…The length of the intact prophage varies from 18.5 to 22.9 kb. The presence of intact regions might help against the invasion of other prophages (Falasconi et al, 2020). No mobile elements were found with PlasmidFinder (selected %ID threshold: 95.00%, Region: the number assigned to the region; region length: the length of the sequence in that region; completeness: a prediction of whether the region contains an intact or incomplete prophage based on the criteria: intact (score > 90%); questionable (score 70-90); incomplete (score < 70%); score: the score of the region on the basis of the mentioned criteria; # of total proteins: the number of ORFs present in the region; region position: the start and end positions of the region on the bacterial chromosome; most common phage: the phages(s) with the highest number of proteins most similar to those in the region; GC %: the percentage of GC nucleotides of the region.…”

Metabolism Characteristics of Lactic Acid Bacteria and the Expanding Applications in Food Industry

“…Lactiplantibacillus plantarum can produce amylase to hydrolyze starch into dextrin, and finally into glucose ( Oguntoyinbo and Narbad, 2012 ). There is a potential gene encoding maltogenic amylase in the Weissella genome, which is used to hydrolyze starch in sourdough ( Falasconi et al, 2020 ).…”