Diversity of Weissella confusa in Pozol and Its Carbohydrate Metabolism

Abstract

The genus Weissella is composed of a group of Gram-positive facultative anaerobe bacteria with fermentative metabolism. Strains of this genus have been isolated from various ecological niches, including a wide variety of fermented cereal foods. The present study aimed to determine the relative abundance and fermentation capabilities of Weissella species isolated from pozol, a traditional maya product made of lime-cooked (nixtamalized) fermented maize. We sequenced the V3-V4 regions of 16S rDNA; Weissella was detected early in the fermentation process and reached its highest relative abundance (3.89%) after 3 h of culture. In addition, we evaluated five Weissella strains previously isolated from pozol but reported as non-amylolytic, to define alternative carbon sources such as xylan, xylooligosaccharides, and sucrose. While no growth was observed on birch xylan, growth did occur on xylooligosaccharides and sucrose. Strains WcL17 and WCP-3A were selected for genomic sequencing, as the former shows efficient growth on xylooligosaccharides and the latter displays high glycosyltransferase (GTF) activity. Genomes of both strains were assembled and recorded, with a total of 2.3 Mb in 30 contigs for WcL17 and 2.2 Mb in 45 contigs for WCP-3a. Both strains were taxonomically assigned to Weissella confusa and genomic analyses were performed to evaluate the gene products encoding active carbohydrate enzymes (CAZy). Both strains have the gene content needed to metabolize sucrose, hemicellulose, cellulose, and starch residues, all available in pozol. Our results suggest that the range of secondary enzymatic activity in Weissella confusa strains confer them with wide capabilities to participate in fermentative processes of natural products with heterogeneous carbon sources.

A comprehensive comparison of fecal microbiota in three ecological bird groups of raptors, waders, and waterfowl

“…C. perfringens is a rapidly growing opportunistic pathogen associated with intestinal diseases in humans and animals that secretes more than 20 virulent toxins (Kiu and Hall, 2018). In the fecal microbiota of waders and waterfowl, most genera, including Turicibacter, Romboutsia, Weissella, and Lactobacillus, were demonstrated as commensal bacteria, which were mainly driven by a diet with fiber-rich plant and grains, to maintain host health status and provide a host energy source by inhibiting inflammatory reactions, antimicrobial activity, or specific metabolic capability (Liu et al, 2014;Zhong et al, 2015;Milani et al, 2016;Ricaboni et al, 2016;Hernandez-Oaxaca et al, 2021). Besides, the usual habitat, migration paths, and host evolutionary also impact on the gut bacterial composition of birds (Loo et al, 2019;Lee et al, 2020;Skeen et al, 2021) exploration is still necessary to ensure taxonomic accuracy due to the low resolution of amplicon sequencing.…”

Analysing the dynamics of the bacterial community in pozol, a Mexican fermented corn dough

“…infantarius [16] and W. confusa [21]. Furthermore, the prevalence of the CAZy families GH1, GH8, GH5 and GH6, involved in the degradation of cellulose and cellulose derivatives, is an indication that this maize substrate could also be available for degradation by the pozol community through nixtamalization.…”

“…Two MAGs were assigned at the genus level and nine at the species level (Table S3). We can conclude that these bins correspond to the most abundant genera found in pozol (, Table S3) [21].…”

Functional Foods, Nutraceuticals and Probiotics: A Focus on Human Health

“…Among them, we can mention pozol, a drink based on cocoa and nixtamalized corn. Strains of the bacterium Weissella confusa have been isolated from pozol, demonstrating that this drink represents an interesting source for the isolation of new potentially probiotic strains and their possible use in a functional food [ 56 ].…”