Literatura académica sobre el tema "Fermented foods. Lactobacillaceae"

PurposeThe purpose of this paper is to estimate physico‐chemical, biochemical and microbiological changes during the three‐month ripening of the Polish traditional raw smoked fermented meat product Kumpia wieprzowa, produced from pork shoulder without fore‐shank.Design/methodology/approachAfter one, two and three months, the pH, aw, chemical composition, the content of nitrogen – total and soluble – as well as the profile of aromatic compounds and microflora, were evaluated.FindingsDuring ripening, the water content decreased from 62.7 percent to 47.5 percent, while the protein and fat amount increased from 20.8 percent to 25.0 percent and from 9.7 percent to 16.3 percent, respectively; the aw decreased from 0.95 to 0.88 and pH from 5.80 to 5.35. The proteolytic changes, measured by free amine groups and Nsoluble content, as well as the quantity of free fatty acids and percentage of most of the volatile compounds increased, particularly during the first two months of ripening. The total number of aerobic microorganisms, and Lactobacillaceae decreased during ripening from 7.9 to 6.2 and 5.6 to 4.7 log cfu/g, respectively. The count of coagulase‐negative cocci changed from 5.3 to 5.2 log cfu/g.Originality/valueKumpia wieprzowa is a unique pork product, entered on the List of Polish Traditional Products in 2005. Up to the present, the properties of Kumpia wieprzowa were not recognized and published in the scientific literature, in spite of its very interesting raw material (shoulder spontaneously fermented as a whole large primal cut).

The microbiome of animals, both in the digestive tract and in the skin, plays an important role in protecting the host. The skin is one of the largest surface organs for animals; therefore, the destabilization of the microbiota on its surface can increase the risk of diseases that may adversely affect animals’ health and production rates, including poultry. The aim of this study was to evaluate the effect of nutritional supplementation in the form of fermented rapeseed meal and housing conditions on the level of selected bacteria phyla (Firmicutes, Actinobacteria, and family Lactobacillaceae). The study was performed on 30 specimens of broiler chickens (Ross 308), individually kept in metabolic cages for 36 days. They were divided into 5 groups depending on the feed received. On day 36, skin swabs were individually collected. Temperature and humidity were measured in the room. The temperature was measured every 2 days (18 measurements × 6 points). The results of Real-Time PCR analysis have shown a significant effect of the feed additive on the level of Firmicutes phylum on the skin. On the other hand, a variable level of the tested bacteria was shown depending on the location of the cages. The Firmicutes phylum and Lactobacillaceae family achieved the highest level in the top-window zone. However, in the case of the Actinobacteria phylum, the highest level was found at the top-door and middle-door zones. The obtained results suggest that the conditions in which animals live may affect the microbiota of their skin.

The application of a mathematical model capable of providing expressions suitable for analysis of the population changes of Enterobacteriaceae and clostridia during the curing process of dry fermented sausage is proposed to facilitate better control of the safety of the product. The mathematical model provides curing times that are crucial for control of the safety of the product: the beginning of the exponential phase of inhibition, the time during which the rate of inhibition is at a maximum, and the phase in which the rate of decline of the population of microorganisms decreases until they virtually disappear from the sausage. For Enterobacteriaceae, growth inhibition and eventual disappearance are dependent on conditions during sausage drying; for clostridia the means of drying is not significant. Under programmed controlled drying conditions, the maximum speed of inhibition and the disappearance of undesirable microorganisms are reached sooner than under natural climatic drying conditions. A regression equation has been established that relates the cell number of Enterobacteriaceae to pH and aw, values, and the cell number of Lactobacillaceae, whose metabolic activities give rise to lactic and acetic acids. The significance of the drying conditions may verify the values reached by all these parameters during curing.

The microbiota involved in Korean soy paste (doenjang) fermentation are the key factors determining its quality aspects. In this study, doenjang was prepared by adding three different herbs (Peppermint, Korean mint, and Coriander), and their effect on the microbiota composition was evaluated by 16S rRNA metagenomic analyses. The β-diversity statistics indicated clear distinctions in the doenjang microbiota after the addition of herbs. A microbial composition analysis revealed that Tetragenococcus was among the dominant genera in the four doenjang groups, with a relatively higher abundance in the Korean mint group. In the Peppermint and Korean mint doenjang groups, the levels of undesirable microbes, such as opportunistic pathogens belonging to the genera Sphingobacterium and Pantoea, were significantly reduced. Additionally, other desirable microbes that are known to exhibit beneficial properties and produce bioactive compounds, such as Saccharopolyspora and Buttiauxella, were present at significantly higher levels. Significant negative correlations between members of the Bacillaceae and Halomonadaceae, Lactobacillaceae and Tissierellaceae, and the Lacobacillaceae and Erwiniaceae families were observed, indicating possible antagonistic relationships. Taken together, our results demonstrated that the incorporation of herbs, particularly Peppermint and Korean mint, during doenjang fermentation resulted in significant shifts in the microbial composition and could be utilized for beneficial effect on its fermentation.

Species belonging to the family Lactobacillaceae are found in highly diverse environments and play an important role in fermented foods and probiotic products. Many of these species have been individually reported to harbour plasmids that encode important genes. In this study, we performed comparative genomic analysis of publicly available data for 512 plasmids from 282 strains represented by 51 species of this family and correlated the genomic features of plasmids with the ecological niches in which these species are found. Two-thirds of the species had at least one plasmid-harbouring strain. Plasmid abundance and GC content were significantly lower in vertebrate-adapted species as compared to nomadic and free-living species. Hierarchical clustering highlighted the distinct nature of plasmids from the nomadic and free-living species than those from the vertebrate-adapted species. EggNOG-assisted functional annotation revealed that genes associated with transposition, conjugation, DNA repair and recombination, exopolysaccharide production, metal ion transport, toxin–antitoxin system, and stress tolerance were significantly enriched on the plasmids of the nomadic and in some cases nomadic and free-living species. On the other hand, genes related to anaerobic metabolism, ABC transporters and the major facilitator superfamily were overrepresented on the plasmids of the vertebrate-adapted species. These genomic signatures correlate with the comparatively nutrient-depleted, stressful and dynamic environments of nomadic and free-living species and nutrient-rich and anaerobic environments of vertebrate-adapted species. Thus, these results indicate the contribution of the plasmids in the adaptation of lactobacilli to their respective habitats. This study also underlines the potential application of these plasmids in improving the technological and probiotic properties of lactic acid bacteria.

Abstract In prokaryotes, a major contributor to genomic evolution is the exchange of genes via horizontal gene transfer (HGT). Areas with a high density of HGT networks are defined as genetic exchange communities (GECs). Although some phenotypes associated with specific ecological niches are linked to GECs, little is known about the phenotypic influences on HGT in bacterial groups within a taxonomic family. Thanks to the published genome sequences and phenotype data of lactic acid bacteria (LAB), it is now possible to obtain more detailed information about the phenotypes that affect GECs. Here, we have investigated the relationship between HGT and internal and external environmental factors for 178 strains from 24 genera in the Lactobacillaceae family. We found a significant correlation between strains with high utilization of sugars and HGT bias. The result suggests that the phenotype of the utilization of a variety of sugars is key to the construction of GECs in this family. This feature is consistent with the fact that the Lactobacillaceae family contributes to the production of a wide variety of fermented foods by sharing niches such as those in vegetables, dairy products and brewing-related environments. This result provides the first evidence that phenotypes associated with ecological niches contribute to form GECs in the LAB family.

Abstract The importance of the human-microbiome relationship for positive health outcomes has become more apparent over the last decade. Influencing the gut microbiome via modification of diet represents a possibility of maintaining a healthy gut flora. Fermented food and lactic acid bacteria (LAB) display a preventive way to inhibit microbial dysbioses and diseases, but their ecology on plants is poorly understood. We characterized the microbiome of medicinal plants (Matricaria chamomilla L. and Calendula officinalis L.) using 16S rRNA gene profiling from leaves that were fermented over a six-week time course. The unfermented samples were characterized by a distinct phyllosphere microbiome, while the endosphere revealed a high similarity. During fermentation, significant microbial shifts were observed, whereby LAB were enhanced in all approaches but never numerically dominated. Among the LAB, Enterococcaceae were identified as the most dominant family in both plants. M. chamomilla community had higher relative abundances of Lactobacillaceae and Carnobacteriaceae, while C. officinalis showed a higher presence of Leuconostocaceae and Streptococcaceae. The natural leaf microbiome and the indigenous LAB communities of field-grown Asteraceae medicinal plants are plant-specific and habitat-specific and are subjected to significant shifts during fermentation. Leaf surfaces as well as leaf endospheres were identified as sources for biopreservative LAB.

Les folates sont des vitamines indispensables à tous les âges, particulièrement pendant la grossesse et l’enfance, étant donné leur fonction dans la division cellulaire. Le régime alimentaire en Afrique est essentiellement basé sur les céréales, consommées toujours après transformation. La fermentation est l’un des moyens de transformation des céréales pouvant augmenter les folates dans les aliments. L’objectif de ce travail était d’utiliser la fermentation pour augmenter les ingérés en folates des populations africaines via la consommation d’aliments céréaliers fermentés. Sept aliments céréaliers fermentés couramment consommés en Afrique de l’Ouest ont été investigués. La plupart des aliments avaient des teneurs en folates (1,8–31,3 µg/100g matière fraîche) inférieures à celles des céréales de départ (13,8-73,4 µg/100g matière fraîche). Des pertes en folates ont lieu au cours de certaines étapes de procédés dont le décorticage, le séchage, le trempage, le broyage et la filtration. Toutefois, la fermentation a permis une augmentation de la teneur en folates dans certains aliments. La bioaccessibilité des folates, évaluée à l'aide d'un modèle de digestion statique in vitro, variait de 23% à 81%. Elle était influencée par la matrice alimentaire et la stabilité des folates au cours de la digestion. Il a été calculé qu’au maximum 8% des besoins journaliers en folates des jeunes enfants consommant l’un des aliments étudiés pourraient être couverts. Des essais d’inoculation de bouillies fermentés à base de mil avec des souches de bactéries lactiques sélectionnées pour leurs propriétés nutritionnelles (synthèse de folates, hydrolyse de l’amidon) permettaient d’augmenter significativement les teneurs en folates (jusqu’à 8,7 µg/100 g matière fraîche) par rapport à leur équivalent préparées de manière traditionnelle (2,5-5,4 µg/100 g matière fraîche). L’inoculation par un pied-de-cuve provenant d’une fermentation spontanée permettait aussi une augmentation significative des teneurs folates (jusqu’à 7,4 µg/100 g matière fraîche). La caractérisation de la diversité bactérienne de 7 aliments céréaliers fermentés du Burkina Faso, d’Ethiopie et de la Finlande montrait que les bactéries lactiques du genre Lactobacillus, Enterococcus, Weissella, Pediococcus, Lactococcus et Streptococcus étaient les principaux acteurs de la fermentation de ces aliments. Toutefois, une présence non négligeable d’autres microorganismes potentiellement pathogènes des genres Bacillus, Pseudomonas, Staphylococcus, Erwinia, Klebsiella, Escherichia et Acinetobacter a été identifiée. Cette contamination était liée à certaines étapes du procédé de transformation des céréales dont le stockage et broyage dans les moulins publics. Ces microorganismes pathogènes étaient réduits par fermentation et finalement éliminés après l'étape de cuisson
Folates represent an essential vitamin in the human diet at all ages, particularly during pregnancy and infancy, as it is required for the production of new cells. In many African countries, the main staple foods are based on cereals, which are always consumed after processing. Fermentation is one of the processing, which could increase folate contents in foods. The objective of this work was to increase folates intake of African people through the consumption of cereal-based fermented foods using fermentation. Seven types of cereal-based fermented foods (CBFF), commonly consumed in West Africa, were investigated in this study. Total folate content of cereal-based fermented ranged between 1.8 and 31.3 µg/100g fresh weight, and was almost always lower than in the raw material (13.8-73.4 µg/100g fresh weight). Folate losses occurred during some processing steps like debranning, soaking and drying steps. However, fermentation was able to increase the folate content in some CBFF. Folate bioaccessibility was assessed using a static in vitro digestion model, and ranged from 23% to 81%. The bioaccessible folate content was influenced by total folate content, the structure of food matrices that modulated folate release, and folate stability during digestion process. Calculations of the contributions of CBFF to the reference nutrient intake for folate showed that folate intakes from these foods would cover a maximum of 8% of the folate requirements for young children. Porridges prepared with starter cultures of lactic acid bacteria selected for the nutritional properties (folate synthesis, starch hydrolysis) had significantly higher folate contents (up to 8.7 µg/100 g fresh matter) than the porridge prepared using the traditional process (2.5-5.4 µg/100 g fresh matter). Back slopping using an inoculum from a spontaneous fermentation also enabled an interesting increase in folate contents (up to 7.4 µg/100 g fresh matter). The bacterial diversity of seven cereal-based fermented foods from Burkina Faso, Ethiopia and Finland were assessed using 16S rRNA amplicon sequencing. Lactic acid bacteria genus, including Lactobacillus, Enterococcus, Weissella, Pediococcus, Lactococcus and Streptococcus were the main bacteria present in cereal-based fermented foods. Several potentially pathogenic bacteria, namely, Bacillus, Pseudomonas, Staphylococcus, Erwinia, Escherichia, Klebsiella and Acinetobacter were also found in some intermediary products resulting from storage and wet milling. These microorganisms were reduced by fermentation and finally removed after the cooking step

Traditional fermented food, especially fermented maize and sorghum represents an important part of the diet of peri-urban and rural communities in South Africa. In this study a survey was conducted to determine the popularity and utilization of “Ting” in the Limpopo Province of South Africa. The following areas were selected for the study: Venda, Giyani, Bolobedu and Polokwane. Ting samples were collected from different areas and from different local families. Gram positive, catalase-negative, oxidase negative, non-motile cells were presumptively identified as lactobacilli. Isolates were assigned to a genus on the basis of key characteristics. Growth at 10, 15 and 45oC in MRS broth wase evaluated visually after 72h of incubation. Tests for the catalase reaction, production of gas from glucose and growth at 7 and 10% NaCl concentrations were performed. API 50CHL medium and API 50CH strips were used to identify all the isolates to species level. Microorganisms from “Ting” fermented from both sorghum and maize were bacteria, which belong to the genus Lactobacillus, Leuconostoc and Pediococcus. Lactobacillus pentosaceus, and Lactobacillus plantarum, Lactobacillus pentosaceus were dominant in the fermentation of maize, while Lactobacillus cellobisus, Leuconostoc mesenteroides, Lactobacillus collinoides, Lactobacillus brevis, Lactobacillus fermentum and Lactobacillus curvatus were identified as bacteria from fermented “Ting” sorghum. The use of polyacrylamide gel electrophoresis (PAGE) of total soluble proteins, together with computer analysis was used to analyse the resultant protein profiles. L. plantarum, L. pentosus and P. pediococcus were the most dominant isolates.
Dissertation (MSc (Microbiology))--University of Pretoria, 2007.
Microbiology and Plant Pathology
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