Search Results (407)

Pulque is a traditional Mexican beverage produced through the fermentation of agave sap (aguamiel). Its primary sensory properties are attributed to the fermentative activity of Saccharomyces cerevisiae, Leuconostoc mesenteroides, and Zymomonas mobilis. However, the overproliferation of these microorganisms results in an extremely short shelf life, which hinders its commercialization. Tomatillo accrescent calyx extract (TACE) shows potential as a food preservative due to its high physalin content. Therefore, this study aimed to evaluate the effect of adding microencapsulated TACE on the shelf life and organoleptic properties of pulque. The extract demonstrated effective antimicrobial activity against L. mesenteroides, Z. mobilis, and S. cerevisiae, successfully delaying further fermentation. Additionally, the addition of TACE prevented an excessive increase in acidity, maintaining values suitable for consumption for up to 15 days, in accordance with regulatory standards, while the viscosity and alcohol content were not negatively affected. These findings suggest that TACE has significant potential for preserving both the microbiological and sensory quality of pulque. Full article

Fuqu plays a crucial role in initiating fermentation and flavor compound production during sesame flavor-type baijiu fermentation. However, selecting microorganisms for Fuqu to enhance flavor compound production remains a challenge. This work designs a synthetic microbial community (SynCom) for Fuqu to improve the production of flavor compounds, with a focus on the diversity of flavor compounds and the content of a key flavor compound—sulfur compounds. Through multi-omics analysis, 13 genera (Aspergillus, Bacillus, Lactobacillus, Leuconostoc, Pediococcus, Pichia, Saccharomyces, Trichosporon, Weissella, Candida, Torulaspora, Clavispora, and Wickerhamomyces) were identified as core microbiota involved in the production of those flavor compounds, and these core microbiota were used to construct a SynCom to enhance flavor compound production in baijiu fermentation. The resulting SynCom exhibited the highest flavor compound diversity (0.64) and 3-(methylthio)-1-propanal content (618.14 μg/kg) in simulative fermentation. In large-scale production, Fuqu made with the SynCom achieved greater flavor compound diversity (0.56) and a higher concentration of 3-(methylthio)-1-propanal (590 μg/kg) compared to commercial Fuqu (0.40 and 324 μg/kg, respectively) (p < 0.05). The results demonstrated that the SynCom developed for Fuqu effectively enhances the production of flavor compounds. This work provides a strategy for constructing SynCom to improve the formation of flavor compounds in baijiu fermentation. Full article

The effect of cold smoking on the physicochemical, microbiological, and aromatic properties of Formaella-type cheese has not been previously investigated. In this study, experimental Formaella-type hard cheeses (≤38% moisture) were produced using a multistep high-temperature cooking process and subjected to weak (20 min) and intense (60 min) cold smoking, alongside an unsmoked control. Cheeses were analyzed before and after smoking and during refrigerated storage (up to 90 days). Smoking significantly influenced pH, water activity, and colour parameters, with intensively smoked cheeses exhibiting lower pH, reduced lightness (L*), and increased redness (a*) and yellowness (b*). Microbiological analyses revealed low viable counts across all samples, attributed to severe cooking steps and vacuum storage. Smoking, particularly at high intensity, significantly reduced total mesophilic counts and enterococci, while Enterobacteriaceae, staphylococci, yeasts, and moulds were not detected after manufacture. The dominant microbiota consisted mainly of lactic acid bacteria, identified by MALDI-TOF MS, including Enterococcus durans, Ent. faecium, Leuconostoc lactis, Leuconostoc mesenteroides, Streptococcus thermophilus, Lacticaseibacillus rhamnosus, and Lactobacillus curvatus. Headspace-SPME-GC-MS analysis identified 75 volatile compounds, with free fatty acids, ketones, aldehydes, and lactones as the predominant groups. Smoking introduced characteristic phenolic and furan derivatives associated with smoky aroma. Overall, smoking intensity modulated microbial dynamics and aroma development without compromising microbiological quality. Full article

Silage serves as a cornerstone for the advancement of the livestock industry and a critical method for biomass preservation and utilization. This study investigated the impact of geographical and environmental factors—including longitude, latitude, temperature, relative humidity, precipitation, altitude, and sunshine duration—on fermentation parameters and bacterial communities in natural forage silage. Fresh samples of Saccharum arundinaceum and Leucaena leucocephala were collected from Changjiang, Haikou, Wanning, Danzhou, Qiongzhong and Sanya in Hainan Province, China. After 60 days of anaerobic fermentation, fermentation parameters and bacterial communities were analyzed. Results showed that fermentation parameters of the same plant exhibited significant variations across different regions. For instance, Leucaena leucocephala silage from Haikou showed the lowest pH value (4.32), while that from Danzhou recorded the highest pH value (5.63). In Saccharum arundinaceum silages, the prevalent genera in HGH (Saccharum arundinaceum silage from Haikou) were Weissella (49.85%) and Leuconostoc (20.42%), while the bacterial community of DGH (Saccharum arundinaceum silage from Danzhou) was dominated by Klebsiella (62.69%). These results revealed significant variations in fermentation characteristics and microbial community structure of the same plant species across different geographical regions. The Mantel-test network heatmap analysis demonstrated that longitude, latitude, altitude, precipitation, and relative humidity were identified as influential factors shaping silage microbial communities, with latitude being the most important geographical factor influencing silage microbiota. In conclusion, these findings highlight the critical need for region-specific adaptation of silage production strategies, particularly in response to latitudinal variations, to accommodate local environmental conditions, even when processing identical plant species. Full article

Highland barley Baijiu is a kind of fermented liquor with national characteristics produced in the Qinghai–Tibet Plateau, and its quality largely depends on the highland barley Baijiu Daqu (HBQ). HBQ contains abundant microbial resources and embedded unknown genomes that have not yet been decoded. In order to deeply understand the key contribution of microorganisms in HBQ, this study analyzed the microbial community structure of HBQ, inferred predicted functions and recovered high-quality metagenome-assembled genomes (MAGs) based on Metagenomics. The results indicated that Pantoea agglomerans was the most abundant species in HBQ, followed by Lichtheimia ramosa, Pichia kudriavzevii, Saccharomycopsis fibuligera and Wickerhamomyces anomalus. The predictive function of the HBQ was focused on annotating carbohydrate metabolism and amino acid metabolism. Meanwhile, six high-quality MAG strains were recovered and identified as Unclassified Kroppenstedtia, Erwinia persicina, Leuconostoc citreum, Saccharopolyspora rectivirgula, Levilactobacillus brevis, and Pantoea agglomerans. Genome annotation of the recovered genomes showed eggNOG predicted function as well as primary and secondary metabolites. The metabolic network diagram of the functional microorganisms in HBQ related to flavor compounds was also predicted. The results can help to understand the formation mechanism of flavor profiles in highland barley Baijiu. Full article

Foodborne diseases represent a major public health concern, particularly those associated with dairy products contaminated with Staphylococcus aureus, a pathogen capable of producing heat-stable enterotoxins. This study evaluated the potential of native lactic acid bacteria (LAB) isolated from artisanal kefir grains as natural biocontrol agents in fermented dairy foods. Kefir grains obtained from three artisanal producers were microbiologically characterized, revealing LAB as the dominant group and the absence of Enterobacteriaceae. Strains belonging mainly to the genera Lactobacillus sensu lato, Leuconostoc, and Pediococcus were isolated and exhibited differentiated metabolic profiles. Safety assessment showed no hemolytic activity and an overall susceptibility to clinically relevant antibiotics, although genus-dependent intrinsic resistance patterns were observed. Several strains displayed enzymatic activities related to carbohydrate digestion and high tolerance to simulated gastrointestinal conditions, with survival rates exceeding 90% during both gastric and intestinal phases. Neutralized cell-free supernatant (CFS) demonstrated differential inhibitory activity, with significant antagonism of S. aureus and E. coli, comparable to those of commercial reference strains. In a yogurt model system stored at 4 °C, selected Lactobacillus and Pediococcus strains induced a progressive and significant reduction in S. aureus populations, achieving complete elimination to undetectable levels in shorter times than commercial probiotic strains. Overall, these results demonstrate that native LAB from artisanal kefir grains exhibit an adequate safety and functional profile, together with strong antagonistic activity, supporting their potential application as natural protective cultures to improve the food hygiene of fermented dairy products. Full article

This study aims to investigate the ability of sourdough fermented with Leuconostoc citreum (Lc) DSM 5577 to produce mannitol and to evaluate its impact in reduced-added-sugar muffins. Compared to a standard recipe with 100% sugar, two formulations with 50% and 0% added sugar were used. Sourdough fermented for 24 and 48 h was incorporated at different levels (30% and 50%) into muffins. The effects on the technological properties, as well as mannitol, carbohydrate, and organic acid contents, microbiological profile, and sensory characteristics, were evaluated. The optimum sourdough fermentation time was 48 h, which produced high levels of lactic acid (2.25 mg/g), acetic acid (4.61 mg/g), and mannitol (6.27 mg/g). The use of 50% sourdough fermented for 48 h in the muffin formulations produced the greatest amount of mannitol (3.57 mg/g). FTIR spectroscopy revealed compositional changes associated with fermentation in the sourdough and muffins. The baking tests demonstrated a reduction in baking losses without compromising specific volume. Muffins containing 50% added sugar and 30% sourdough fermented for 24 h were the most appreciated in terms of taste and flavor. The results suggest that sourdough fermented with Lc DSM 5577 may be an innovative approach for a natural reduction in sugar in muffins while preserving their technological quality. Full article

While the gut microbiota of pollen-carrying bees (e.g., honeybees and bumblebees) has been well studied, the gut microbiota of vespine wasps remains poorly understood. Unlike pollen-carrying bees, which primarily consume pollen and nectar, vespine wasp larvae mainly feed on insects, suggesting that their gut bacterial communities may be different. Therefore, this study aimed to reveal the differences in larval gut bacterial communities between pollen-carrying bees and vespine wasps. Using datasets obtained from our own samplings and public resources released by other researchers, we compared the diversity and composition of larval gut bacterial communities between vespine wasps and pollen-carrying bees. Alpha diversity and beta diversity of bacterial communities were measured. Results showed that vespine wasp larvae harbored distinct gut bacterial communities from those of pollen-carrying bees, dominated by Leuconostoc, Hafnia-Obesumbacterium and Lactobacillus. Significant differences in bacterial composition were observed at both the community level and the dominant taxa level between pollen-carrying bee larvae and vespine wasp larvae. Moreover, significant differences were also found among larval gut bacteria of vespine wasps. These findings provide insights into the bacterial composition of aculeate wasps with different dietary habits. Full article

Fermented foods are produced through controlled microbial activity and are valued for their extended shelf life, sensory attributes, and potential health benefits. This study examined the effects of production methods on microbial ecology by comparing microbial community structure, Shannon diversity, and pH changes in traditional and commercially produced Korean fermented foods. Cabbage and radish kimchi were fermented for four weeks to assess microbial succession and physicochemical changes, and additional fermented foods, including soy sauce, soybean paste, pepper paste, fruit vinegar, yogurt, and aged kimchi, were compared according to production method. Microbial communities were analyzed using amplicon sequencing targeting the V3–V4 regions of the bacterial 16S rRNA gene and the fungal internal transcribed spacer (ITS) region. Traditionally produced cabbage kimchi exhibited high microbial diversity at the early fermentation stage, initially dominated by Weissella and Leuconostoc, followed by a gradual shift toward lactic acid bacteria dominance at later stages. In contrast, commercially produced cabbage kimchi maintained a simplified microbial community dominated by a limited number of lactic acid bacteria throughout fermentation. Radish kimchi showed production-method-dependent patterns, with the rapid dominance of lactic acid bacteria during traditional fermentation and partial recovery of microbial diversity during commercial fermentation. Shannon diversity was consistently higher in traditionally produced kimchi during fermentation. In contrast, commercially produced kimchi exhibited more rapid acidification. Across other fermented foods, traditionally produced soy-based products exhibited complex microbial communities dominated by Bacillus spp., whereas commercially produced products were characterized by yeast-dominant profiles. Fruit vinegar and yogurt showed low microbial diversity regardless of the production method. These findings demonstrate the importance of production strategies in shaping microbial ecology, fermentation dynamics, and resulting product characteristics across various Korean fermented foods. Full article

Moroccan lben is a traditional spontaneously fermented milk widely consumed across the Maghreb. In this review, we synthesize data on spontaneously fermented milks from Morocco and the wider Maghreb–Middle Eastern region to infer the likely microbiota of Moroccan lben, with particular emphasis on dominant lactic acid bacteria such as Lactococcus lactis, Streptococcus thermophilus, Leuconostoc mesenteroides and lactobacilli sensu lato, alongside yeasts including Kluyveromyces marxianus and Saccharomyces cerevisiae. These communities drive a staged fermentation in which early mesophilic lactic acid bacteria (LAB) rapidly acidify the milk and initiate coagulation, intermediate heterofermentative LAB and yeasts generate key aroma compounds and mild effervescence, and late acid-tolerant lactobacilli contribute to flavor refinement and microbiological stability. We summarize how these bacteria and fungi collectively shape physicochemical, sensory and safety attributes through pH reduction, organic acid and bacteriocin production, proteolysis, and volatile formation, and discuss potential nutritional and health-related effects associated with bioactive peptides and putative probiotic strains. Finally, we identify major research gaps, including the need for high-resolution, culture-dependent and culture-independent studies, systematic safety assessments, and rational design of starter and adjunct cultures that reproduce traditional sensory profiles while improving process control. Full article

A number of products for maintaining intimate hygiene are available on the market. They consist of a blend of components intended to cleanse, care for and protect the area of application, and support its microbiological balance. The present study reviews the compositions of international intimate hygiene product brands currently available in Poland (within the European Union) and the frequency of their components: their surfactants, plant extracts, prebiotics, postbiotics and skin care agents. The most popular surfactants in rinse-off products for women were Cocamidopropyl Betaine, present in 72% of products, followed by Coco-Glucoside (58%) and Sodium Laureth Sulfate (24%). Similarly, in the products for girls, the most common were Cocamidopropyl Betaine (55%), Lauryl Glucoside (45%), Coco-Glucoside (40%) and Sodium Laureth Sulfate (20%). The intimate wipes contained mainly nonionic surfactants: PEG-40 Hydrogenated Castor Oil (28%), Coco-Glucoside and Polysorbate 20 (20% each). Many components with protective and caring properties were identified: plant extracts (e.g., Aloe Barbadensis Leaf Juice, Chamomilla Recutita Flower Extract), prebiotics (Inulin, Alpha-Glucan Oligosaccharide) and postbiotics (Lactobacillus Ferment, Leuconostoc/Radish Root Ferment Filtrate), as well as Lactic Acid, Glycerin, Citric Acid, Panthenol and Allantoin. Full article

This study investigated the diversity and functional potential of lactic acid bacteria isolated from traditional lamb rennet, cheese, and whey collected from seven artisanal sheep farms in southern Romania. A total of 31 samples were analyzed, yielding 118 Gram-positive, catalase-negative isolates. Following dereplication by rep-PCR and 16S rRNA gene sequencing, 63 unique strains were identified across nine genera, with Lactiplantibacillus, Lactococcus, and Leuconostoc being the most prevalent. Strain distribution varied by sample type and manufacturer, with rennet and whey showing greater species diversity than cheese. Technological characterization showed strain-dependent differences in acidification and growth in cow’s and goat’s milk. Genetic screening revealed a high prevalence of functional genes such as ribA, gad, and α-amy, while genes associated with bacteriocin (nisA, pln) and folate (folK) production were less common. Most strains carried multiple functional genes, indicating a genetic potential for diverse functional traits. Antibacterial activity assays demonstrated that nearly all strains inhibited at least three indicator pathogens, with ten strains, particularly Lactiplantibacillus plantarum and Lactococcus lactis strains, exhibiting strong inhibitory effects. Bacteriocin production was confirmed for three Lact. lactis strains. Exopolysaccharide (EPS) production was confirmed in two strains, with yields varying by growth medium and sucrose supplementation. Overall, the results underscore the rich microbial diversity and promising biotechnological potential of LAB from traditional Romanian dairy ecosystems, supporting their use in food fermentation and functional product development. Full article

In traditional vegetable fermentation, the lack of effective microbial community control often leads to excessive nitrite accumulation, a major food safety concern. To address this challenge, this study aimed to isolate and characterize a high-performance starter culture strain capable of simultaneously degrading nitrite and guiding safe, controlled fermentation. A strain of L. mesenteroides AA001 was isolated from traditionally fermented Yingcai. It exhibited strong nitrite-degrading activity, with degradation rates consistently exceeding 90% under various environmental conditions, and demonstrated robust environmental adaptability. When used as a starter culture in vegetable fermentation, L. mesenteroides AA001 significantly accelerated nitrite degradation and consistently maintained peak nitrite concentrations below the Chinese national standard limit (20 mg/kg), while also shortening the fermentation period. Moreover, inoculation with L. mesenteroides AA001 had no significant impact on most nutrients in fermented vegetables across 8 crucial nutritional indicators (comprising 22 specific parameters), and only β-carotene content shows differences. The sensory attributes of the inoculated samples are basically similar to those of the naturally fermented samples, except that they are significantly brighter in color. No harmful substances were detected among 16 tested safety indicators, and the profile of 46 major volatile flavor compounds showed no significant difference compared to the spontaneously fermented control. Microbial community profiling throughout fermentation revealed that early dominance by this strain rapidly established a lactic acid–driven anaerobic environment, effectively suppressing nitrite-accumulating microorganisms and steering the process toward a stable, safe, and flavor-consistent trajectory. Thus, L. mesenteroides AA001 is a safe starter strain that combines potent nitrite-degrading capacity with fermentation-guiding functionality, effectively ensuring safety and process controllability in traditional vegetable fermentation. Full article

Mezcal is an ancestral beverage from Oaxaca, Mexico, produced using traditional biotechnological procedures without artificial inoculation. The role of bacteria in fermentation has been studied less. Our work aimed to analyze the bacterial diversity in mezcal must and determine its relationship with ethnobiotechnological variables. Fermentation must samples were collected from four Palenques in the Valles Centrales, Cañada, and Mixteca regions of Oaxaca. Molecular and phenotypic identification and characterization, including ethanol tolerance testing, were performed. Ethnobiotechnological data were acquired through interviews and official databases. Six bacterial genera were identified in mezcal must, including Lactiplantibacillus, Enterobacter, Enterococcus, Bacillus, Leuconostoc, and Levilactobacillus. Therefore, through a factorial experiment, it was determined that the selected Lactiplantibacillus plantarum strains were able to withstand 6% and 8% ethanol. A direct relationship was observed between species diversity and the degree of population marginalization. Palenque 2, representing the most urbanized population, exhibited the lowest diversity, with only two species detected. In contrast, Palenques characterized by high marginalization harbored a substantially greater diversity, ranging from six to ten species. These differences are likely associated with variations in microbiota composition, microbial growth dynamics, and ethanol tolerance. Overall, the findings suggest that ethnobiotechnological factors play a significant role in shaping bacterial diversity. In Oaxaca, “ethnobiotechnological” implies the deep relationship between biodiversity, Indigenous culture, and territory, with a strong emphasis on living traditional knowledge and its intergenerational transmission. Full article

Lactic acid bacteria (LAB) are widely used in food systems; among them, bacteriocin-producing strains have attracted attention for their potential in the biopreservation of dairy products. This study started from the detection of bacteriocin-encoding genes in eight probiotic Leuconostoc mesenteroides subsp. mesenteroides strains, previously isolated, identified, and characterized for antimicrobial activity. Results confirmed the presence of bacteriocin genes across the strains, with Ln.F5 harboring both mesB and lcnA genes, and three other strains, including the Ln.M14 strain, exclusively carrying the lcnA gene. The two strains, Ln.F5 and Ln.M14, were used, in single and mixed cultures, for the first time, as adjunct cultures in a model cheese. Their impact against Listeria spp., Staphylococcus aureus, Escherichia coli, Micrococcus luteus, and Brochothrix thermosphacta, and on volatile organic compounds (VOCs), during ripening and storage, was evaluated. Results showed high viability (9.2 Log CFU/g) of Leuconostoc spp. in model cheese, up to 60 days of storage, and Pulsed-Field Gel Electrophoresis (PFGE) profiles of the re-isolated bacteria confirmed the survival of the added strains. Furthermore, results indicated the inhibition of E. coli and Listeria spp. started from the 15th day of ripening in samples differently inoculated with the two Leuconostoc strains. Listeria spp. was completely inhibited starting from 15 days by Ln.M14, in single culture. The complete inhibition of S. aureus, M. luteus, and B. thermosphacta was detected after 30 days of ripening in samples differently inoculated with Ln.F5 and Ln.M14. The VOC analyses revealed more complex aromatic profiles in samples inoculated with Leuconostoc strains, which, along with the development of cheese eyes, confirmed the effect of the Leuconostoc strains in enhancing quality traits of cheeses. Full article