Sustainable exploitation of agro-industrial by-products has attracted great interest in cereal bran valorization. In this research, a polyphasic approach has been carried out to characterize maize bran at microbiological and chemical level during a sourdough like fermentation process, in order to enhance its technological and nutritional properties. Autochthonous microbiota was isolated at different refreshment steps and subjected to identification and molecular characterization. Fermentation was characterized by a rapid increase in lactic acid bacteria and yeasts, with a co-dominance, at the initial stage, of Weissella spp., Pediococcus spp. and Wickerhamomyces anomalus. At the end of the fermentation, a natural selection was produced, with the prevalence of Lactobacillus plantarum, Lactobacillus brevis and Kazachstania unispora. This is the first time that a specific association between LAB and yeasts is reported, during the maize bran fermentation process. Enzymatic activities related to this microbial consortium promoted a “destructuration” of the fiber fraction, an increase in soluble dietary fiber and a reduction of phytic acid content. Our data also evidenced a noticeable increment in ferulic acid. The results obtained indicate that fermentation processes represent an efficient biotechnological approach to increase nutritional and functional potential of maize bran. Moreover, the characterization of microbiota involved in natural fermentation process will allow the selection of specific biotypes, with appropriate metabolic and enzymatic activities, to conduct “tailored” fermentation processes and improve brans or whole-meal flours from both nutritional and technological points of view.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.