Microbial community and physicochemical dynamics during the production of ‘Chicha’, a traditional beverage of Indigenous people of Brazil

Fungal community and physicochemical profiles of ripened cheeses from the Canastra of Minas Gerais, Brazil

Canastra's Minas artisanal cheese [QMA (Minas artisanal cheese)] is a protected geographical indication traditional food. The influence of fungi on the cheese ripening process is of great importance. This study aimed to apply culture-dependent and -independent methods to determine the mycobiota of QMA produced in the Canastra region, as well as to determine its physicochemical characteristics. Illumina-based amplicon sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were the culture-independent methods used. The physicochemical analysis results showed that the QMA has a moisture content ranging 18.4-28.2%, fat content ranging 20.5-40%, sodium chloride percentage of approximately 0.9%, and pH ranging 5.2-5.5. The population of fungi ranged between 6.3 and 8 log colony-forming unit/g. Fusarium spp., Geotrichum candidum, Paecilomyces spp., Trichosporon coremiiforme, Candida catenulata, Aspergillus spp., Trichosporon japonicum, Aspergillus oryzae, Kluyveromyces spp., Torulaspora spp., and Debaryomyces spp. were the most prevalent fungi. The methods used to evaluate the mycobiota provide a better understanding of which species are present in the final product and eventually contribute to the characteristics of QMA. Geotrichum candidum and C. catenulata were identified as promising species for future studies on product quality.

Identification of yeasts in fermented foods and beverages using MALDI-TOF MS

Yeasts are an important group of microorganisms and contribute to the fermentation of a broad range of foods and beverages spontaneously or as a starter culture. Rapid and reliable microbial species identification is essential to evaluate biodiversity in fermented foods and beverages. Nowadays, high-throughput omics technologies and bioinformatics tools produce large-scale molecular-level data in many fields. These omics technologies generate data at different expression levels and are used to identify microorganisms. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a powerful analytical technique in proteomic technology. It is a tool used to analyze the peptides or proteins of microorganisms for identification. MALDI-TOF MS has been used for the taxonomic identification of microorganisms as a fast, high-throughput, and cost-effective method. This review briefly discussed the application of MALDI-TOF MS in identifying yeasts in fermented foods and beverages.

Microorganisms present in artisanal fermented food from South America

Artisanal fermented products (foods and beverages) are produced in an artisanal way in many countries around the world. The main purpose of fermentation is to preserve the food, improve its safety, increase the nutritional and health-promoting value and add specific flavours. In South America, there is a great variety of fermented food produced in an artisanal way. Different raw materials are used such as potatoes, sweet potato, cassava, maize, rice, milk (cow, ewe, goat) and meat (beef, goat, lamb, llama and guanaco). Some of these fermented foods are typical of the region and are part of the culture of native communities, e.g. tocosh, masa agria, puba flour, charqui, chicha, champu and cauim among others (indigenous foods). However, other fermented foods produced in South America introduced by mainly European immigration, such as cheeses and dry sausages, and they are also produced in many different parts of the world. In this work, the microbial composition of the different artisanal fermented products produced in South America is reviewed, taking into consideration the associated raw materials, fermentation conditions and methodologies used for their production.

Traditional Fermented Foods from Ecuador: A Review with a Focus on Microbial Diversity

The development of early civilizations was greatly associated with populations’ ability to exploit natural resources. The development of methods for food preservation was one of the pillars for the economy of early societies. In Ecuador, food fermentation significantly contributed to social advances and fermented foods were considered exclusive to the elite or for religious ceremonies. With the advancement of the scientific research on bioprocesses, together with the implementation of novel sequencing tools for the accurate identification of microorganisms, potential health benefits and the formation of flavor and aroma compounds in fermented foods are progressively being described. This review focuses on describing traditional fermented foods from Ecuador, including cacao and coffee as well as less popular fermented foods. It is important to provide new knowledge associated with nutritional and health benefits of the traditional fermented foods.

Characterization of Dadih: Traditional Fermented Buffalo Milk of Minangkabau

Dadih or dadiah is traditional fermented buffalo milk of Minangkabau, which occurs spontaneously. Dadih is commonly served as ampiang dadih, or other dishes. The microbiota found in dadih are dominated by lactic acid bacteria, and yeasts are also found. The lactic acid bacteria provide functional value, such as antimicrobial, hypocholesterolemic, antimutagenic, antioxidant, and immunomodulatory properties, as well as being the source of γ-aminobutyric acid (GABA) as an anti-stress agent and folate. Nevertheless, many challenges were observed in dadih production, including the limitation of buffalo milk production due to decreasing populations of buffalo in the last two decades, unstandardized dadih production due to the spontaneous fermentation in natural bamboo tubes, and safety problems as no heat treatment is applied in the production of dadih. These problems impede the development of dadih production, thus is it important to improve buffalo cultivation through artificial insemination programs, using different types of milk and pasteurization processes in dadih production, and incubator development to accelerate the fermentation period.

Microbiota assembly, structure, and dynamics among Tsimane horticulturalists of the Bolivian Amazon

Selective and neutral forces shape human microbiota assembly in early life. The Tsimane are an indigenous Bolivian population with infant care-associated behaviors predicted to increase mother-infant microbial dispersal. Here, we characterize microbial community assembly in 47 infant-mother pairs from six Tsimane villages, using 16S rRNA gene amplicon sequencing of longitudinal stool and tongue swab samples. We find that infant consumption of dairy products, vegetables, and chicha (a fermented drink inoculated with oral microbes) is associated with stool microbiota composition. In stool and tongue samples, microbes shared between mothers and infants are more abundant than non-shared microbes. Using a neutral model of community assembly, we find that neutral processes alone explain the prevalence of 79% of infant-colonizing microbes, but explain microbial prevalence less well in adults from river villages with more regular access to markets. Our results underscore the importance of neutral forces during microbiota assembly. Changing lifestyle factors may alter traditional modes of microbiota assembly by decreasing the role of neutral processes.

Selective and neutral forces shape human microbiota assembly in early life. Here, Sprockett et al. study microbial community assembly in 47 infant-mother pairs from the Tsimane, an indigenous Bolivian population, highlighting the importance of neutral forces during microbiota assembly.

Changes Occurring in Spontaneous Maize Fermentation: An Overview

Maize and its derived fermented products, as with other cereals, are fundamental for human nutrition in many countries of the world. Mixed cultures, principally constituted by lactic acid bacteria (LAB) and yeasts, are responsible for maize fermentation, thus increasing its nutritional value and extending the products’ shelf-life. Other microorganisms involved, such as molds, acetic acid bacteria, and Bacillus spp. can contribute to the final product characteristics. This review gives an overview of the impact of the activities of this complex microbiota on maize product development and attributes. In particular, starting from amylolytic activity, which is able to increase sugar availability and influence the microbial succession and production of exopolysaccharides, vitamins, and antimicrobial compounds, which improve the nutritional value. Further activities are also considered with positive effects on the safety profile, such as phytates detoxification and mycotoxins reduction.

Peruvian chicha: A Focus on the Microbial Populations of This Ancient Maize-Based Fermented Beverage

Peruvian chicha de jora is one of the most ancient traditional beverages produced through maize fermentation, still popular to modern consumers, but less studied in terms of microbial compositions. In this work, the bacterial biodiversity of 27 chicha samples collected from 14 different "chicherias" in seven provinces of Peru was investigated by Next-Generation Sequencing (NGS). A large dissimilarity in chicha microbial composition was a direct consequence of ingredients, manufacturing processes and geographical influences. The core microbiome was represented by six main genera, belonging to Lactic Acid Bacteria (LAB) and Acetic Acid Bacteria (AAB). Lactobacillus prevailed (more than 50% of sequences belong to this genus) followed by Weissella, Leuconostoc, Lactococcus and Streptococcus. Acetobacter was the only AAB genus identified in chicha. The occurrence of sequences associated to spoiling and pathogenic bacteria, such as Bacillus, Clostridium, and Enterobacteriaceae, was observed only in a few samples, validating the safety of this beverage. Predictive functional annotation of metagenomic sequences revealed that carbohydrate and amino acid metabolisms and coenzyme transport are the main KEGG categories associated to chicha fermentation pathways. The old recipes and traditional processing of each chicherias helps maintain native microorganisms as a resource of biodiversity with potential technological and health-beneficial properties.

Yeast Species, Strains, and Growth Media Mediate Attraction of Drosophila suzukii (Diptera: Drosophilidae)

Specific ecological interactions between insects and microbes have potential in the development of targeted pest monitoring or control techniques for the spotted wing drosophilid, Drosophila suzukii (Matsumura), an exotic invasive pest of soft fruit. To evaluate D. suzukii attraction to yeast species from preferred types of fruit, three yeasts were isolated from blackberry fruit and two yeasts from raspberry fruit and used to bait simple plastic bottle traps. Saccharomyces cerevisiae and Hanseniaspora uvarum were identified from blackberries, whereas a different H. uvarum strain was identified from raspberry. Yeast identification was based on sequence analysis of the D1/D2 domain of the large subunit 26S rRNA gene. Commercial baker’s yeast (S. cerevisiae) was similar or more effective for the capture of D. suzukii males and females than yeasts isolated from blackberry or raspberry when grown in sucrose. However, when grown in corn syrup, a strain of S. cerevisiae from blackberry captured the highest number of females and a strain of H. uvarum isolated from raspberry captured high numbers of males and females. Species of Candida, Hanseniaspora, and Pichia from a laboratory yeast collection did not outperform baker’s yeast in pairwise tests when grown in sucrose solution or yeast-peptone-dextrose medium. The raspberry strain of H. uvarum grown in corn syrup outperformed S. cerevisiae grown in sucrose, in terms of captures in baited traps under laboratory conditions. We conclude that yeast species, strain, and growth medium can have a marked influence on D. suzukii attraction to baited traps, a finding that could assist in the development of yeast-related monitoring or control techniques targeted at this pest.

Microbial Ecology of Fermented Vegetables and Non-Alcoholic Drinks and Current Knowledge on Their Impact on Human Health

Fermented foods are currently experiencing a re-discovery, largely driven by numerous health benefits claims. While fermented dairy, beer, and wine (and other alcoholic fermented beverages) have been the subject of intensive research, other plant-based fermented foods that are in some case widely consumed (kimchi/sauerkraut, pickles, kombucha) have received less scientific attention. In this chapter, the current knowledge on the microbiology and potential health benefits of such plant-based fermented foods are presented. Kimchi is the most studied, characterized by primarily acidic fermentation by lactic acid bacteria. Anti-obesity and anti-hypertension properties have been reported for kimchi and other pickled vegetables. Kombucha is the most popular non-alcoholic fermented drink. Kombucha's microbiology is remarkable as it involves all fermenters described in known fermented foods: lactic acid bacteria, acetic acid bacteria, fungi, and yeasts. While kombucha is often hyped as a "super-food," only antioxidant and antimicrobial properties toward foodborne pathogens are well established; and it is unknown if these properties incur beneficial impact, even in vitro or in animal models. The mode of action that has been studied and demonstrated the most is the probiotic one. However, it can be expected that fermentation metabolites may be prebiotic, or influence host health directly. To conclude, plant-based fermented foods and drinks are usually safe products; few negative reports can be found, but more research, especially human dietary intervention studies, are warranted to substantiate any health claim.