Staka is a traditional Greek sour cream made mostly from spontaneously fermented sheep milk or a mixture of sheep and goat milk. At the industrial scale, cream separators and starter cultures may also be used. Staka is sometimes cooked with flour to absorb most of the fat. In this study, we employed culture-based techniques, amplicon sequencing, and shotgun metagenomics to analyze the Staka microbiome for the first time. The samples were dominated by Lactococcus or Leuconostoc spp. Most other bacteria were lactic acid bacteria (LAB) from the Streptococcus and Enterococcus genera or Gram-negative bacteria from the Buttiauxella, Pseudomonas, Enterobacter, Escherichia-Shigella, and Hafnia genera. Debaryomyces, Kluyveromyces, or Alternaria were the most prevalent genera in the samples, followed by other yeasts and molds like Saccharomyces, Penicillium, Aspergillus, Stemphylium, Coniospotium, or Cladosporium spp. Shotgun metagenomics allowed the species-level identification of Lactococcus lactis, Lactococcus raffinolactis, Streptococcus thermophilus, Streptococcus gallolyticus, Escherichia coli, Hafnia alvei, Streptococcus parauberis, and Enterococcus durans. Binning of assembled shotgun reads followed by recruitment plot analysis of single reads could determine near-complete metagenome assembled genomes (MAGs). Culture-dependent and culture-independent analyses were in overall agreement with some distinct differences. For example, lactococci could not be isolated, presumably because they had entered a viable but not culturable (VBNC) state or because they were dead. Finally, several LAB, Hafnia paralvei, and Pseudomonas spp. isolates exhibited antimicrobial activities against oral or other pathogenic streptococci, and certain spoilage and pathogenic bacteria establishing their potential role in food bio-protection or new biomedical applications. Our study may pave the way for additional studies concerning artisanal sour creams to better understand the factors affecting their production and the quality.

Environmental pollution is a growing concern, particularly the impact of sewage treatment gas on the atmosphere\'s greenhouse effect. Efficient sewage resource recycling is crucial to achieving carbon neutrality. The bacteria-algae symbiotic sewage treatment system combines wastewater treatment, carbon dioxide fixation, and biomass energy recovery to achieve the goal of carbon neutrality, environmental protection, and the transformation of high-value added products. This paper presents the construction of a sequencing batch photobiological reaction system that utilizes a microbial-algae symbiotic relationship. The system was used to analyze the degradation effects of sCOD, TN, AN, and TP in anaerobic digestion wastewater by varying the microbial-algae ratios. Additionally, changes in the microbial community were analyzed to explore the system\'s potential for reducing carbon emissions. The study\'s findings indicate that: 1)When the ratio of bacteria to algae was 2:3, the removal rates of TN, AN, sCOD, and TP were 81.38%, 94.28%, 75.33%, and 96.56%. 2)Changing the ratio of bacteria to algae would affect the bacterial concentration in the mixed system, but not the bacterial community structure. The results indicate that a ratio of 2:3 enhances the removal of pollutants by bacteria and algae symbionts.3) Under the context of carbon neutralization, this paper investigates the reduction of carbon emissions in ADE treated by bacteria-algae symbiosis at the optimal bacteria to algae ratio. The experimental process can reduce 177.03 mg CO2 compared to complete nutrient consumption treatment, which is equivalent to a reduction of 355.08 g CO2 per 1 m3 of ADE. For full anaerobic treatment, this experimental process can reduce 228.35 mg of CO2 equivalent CH4, which translates to a reduction of 456.71 g of CO2 equivalent CH4 per 1 m3 of ADE.

Background Dental caries is the most common bacterial disease of calcified tissues of teeth. Cariogenic biofilms formed on the tooth surface secrete organic acids and thus result in demineralization. Delving into the depth of biofilms is crucial to understand the pathogenic mechanisms and design improved therapeutic approaches. The aim of the study is to analyze the spatial and biochemical characteristics of cariogenic biofilms. Materials and methods Pulp tissue samples sourced from freshly extracted third molars were incubated with oral cariogenic bacteria namely Streptococcus mutans, Staphylococcus aureus, Escherichia coli, Entamoeba faecalis, and Candida albicans to form the biofilm. Spatial assessment of biofilms was done under FESEM (field emission scanning electron microscope, JSM-IT800, JEOL, Tokyo, Japan). FTIR (Fourier transform infrared spectroscopy, Alpha II, Bruker, Germany) spectra were assessed for chemical molecular interactions in 24- and 48-hour time periods.  Results Morphological assessment with FESEM revealed rapid growth and aggregation within a short time period. FTIR spectra to analyze chemical constituents of biofilm presented with varied peaks of water, amide A, amide I, water, lipids, and phospholipids. Conclusion Further validation with more advanced imaging for an extended time period is vital to derive better conclusive evidence.

The gut microbiota, a complex and dynamic microbial ecosystem, plays a crucial role in regulating the intestinal barrier. Polysaccharide foraging is specifically dedicated to establishing and maintaining microbial communities, contributing to the shaping of the intestinal ecosystem and ultimately enhancing the integrity of the intestinal barrier. The utilization and regulation of individual polysaccharides often rely on distinct gut-colonizing bacteria. The products of their metabolism not only benefit the formation of the ecosystem but also facilitate cross-feeding partnerships. In this review, we elucidate the mechanisms by which specific bacteria degrade polysaccharides, and how polysaccharide metabolism shapes the microbial ecosystem through cross-feeding. Furthermore, we explore how selectively promoting microbial ecosystems and their metabolites contributes to improvements in the integrity of the intestinal barrier.

The microbial fuel cell (MFC) is a promising bio-electrochemical technology that enables simultaneous electricity generation and effluent purification. Harnessing solar energy to provide sustainable power for MFC operation holds great potential. In this study, a semiartificial photosynthetic self-circulating MFC ecosystem is successfully established through the collaboration of electrogenic microorganisms and photosynthetic algae. The ecosystem can operate continuously without carbon sources and produces a voltage of 150 mV under irradiation. The irradiation doubles the maximum power density of the ecosystem, reaching 8.07 W/m2 compared to dark conditions. The results of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) suggest a higher diffusion capacity or faster electron replenishment ability within the ecosystem. Furthermore, the capacity of ecosystem for removing chromium (Cr(VI)) has been investigated comprehensively. Under irradiation, the ecosystem demonstrates a 2.25-fold increase in Cr(VI) removal rate compared to dark conditions. Finally, the results of 16S rRNA amplicon sequencing indicates an increase in the relative abundance of strict and facultative aerobic electroactive bacteria in the ecosystem, including Citrobacter (21 %), Bacillus (15 %) and Enterococcus (6 %). The ecosystem offers a novel, self-sustaining approach to address the challenges of energy recovery and environmental pollution.

OBJECTIVE: Primary choledocholithiasis is a common digestive disease with high morbidity and relapse. However, the compositions and functions of the bile microbial ecosystem and the pathogenesis of microfloral regulation of host metabolism resulting in stone formation are poorly understood.
METHODS: Biliary samples collected from patients with acute cholangitis induced by benign biliary stricture (nonlithiasis group, n = 17) and primary choledocholithiasis (lithiasis group, n = 33) were subjected to multiomics analyses. Furthermore, clinicopathological features collected over a 24-month follow-up period were examined to evaluate the predictive value of candidate microbes.
RESULTS: Five alpha diversity indices of the bile microbiome were significantly decreased in the lithiasis group. Furthermore, we identified 49 differential bile flora between the two groups, and the relative abundances of 6 bacteria, Actinobacteria, Actinobacteriota, Staphylococcales, Micrococcales, Altererythrobacter and Carnobacteriaceae, were associated with primary choledocholithiasis relapse conditions. Multiomics analyses showed that specific changes in disease-related bacterial taxa were closely related to metabolite variation (low-molecular weight carboxylic acids, sterol liquid and acylcarnitine), which might reflect disease prognosis. According to microbiomic and metabolomic pathway analyses, we revealed that bacterial infections, microbiota-derived amino acid metabolites and secondary bile acid-related pathways were significantly enriched in the stone-formation group, suggesting a novel host-microbial metabolic mechanism of primary choledocholithiasis.
CONCLUSIONS: Our study first indicates bile host-microbial dysbiosis modulates the abnormal accumulation of metabolites might further disrupt calcium homeostasis and generate insoluble saponification. Additionally, we determined the predictive value of Actinomycetes phylum reduction for recurrence in primary common bile duct stone patients.

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Under natural conditions, a complex and dynamic microbial ecosystem exists on the grape epidermis, which plays an important role in safeguarding grape health and facilitating the conversion of grapes into wine. However, current viticulture and vinification are flooded with excessive chemical additives and commercial ferments, leading to a reduction in microbial diversity, affecting the ecological balance of the natural microbiota and masking the wine terroir. This experiment comprehensively explored the continuous changes in the natural microbiota from the Ecolly (Vitis vinifera L.) grape epidermis to spontaneous fermentation over two years. The results suggested that microbial community structure and composition were significantly influenced by vintage and growing stage, with fungal genera being more stable than bacterial genera during the growing season. The fungal genera Alternaria, Ascochyta, Gibberella and Dissoconium and the bacterial genera Pantoea, Sediminibacterium, Ralstonia and Sphingomonas were mainly present on the grape epidermis in both years. The natural microbial diversity decreased from grape growth to spontaneous fermentation, and the fermentation environment reshapes the community structure, composition and diversity of the wine microbial consortium. These findings provide insights to promote cultivation and fermentation management strategies, advocate natural terroir attributes for grapes and wines, and promote sustainable development of the wine industry.

The structural and functional diversities of the microbial ecosystem on the grape surface affect the health of berries and the flavor of wines, which are also changed by many factors such as climate, weather conditions, agronomic practices, and physiological development. To understand and explore the natural characteristics of the grape surface microbial ecosystem during ripening, the species composition and dynamics of fungal and bacterial communities on the skin of Ecolly grape were determined by Illumina Novaseq platform sequencing. The results showed that 2146 fungal OTUs and 4175 bacterial OTUs were obtained, belonging to four fungal phyla and 20 bacterial phyla. The Shannon index indicated that the fungal community had the highest species diversity at the véraison stage and the bacterial community at the harvest stage. The four dominant fungal genera during grape ripening were Alternaria, Naganishia, Filobasidium, and Aureobasidium, which accounted for 82.8% of the total fungal community, and the dominant bacterial genera included Sphingomonas, Brevundimonas, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, and Massilia, which accounted for 77.9% of the total bacterial community. The species richness and diversity in the grape microbial ecosystem changed constantly during the maturation stages, and there were strong correlations between certain core microbial genera, which may have an important impact on the function and ecological role of the community. This study provides a basis for understanding the natural characteristics of the microbial ecosystem on the grape surface during grape ripening, as well as the sustainable production concept of the microecology driving the viticulture management system.

A sulfate-reducing population of thermophiles grew in porous, permeable niches within glass-bearing impact breccias of the Chicxulub impact crater. The microbial community grew in an impact-generated hydrothermal system that vented on the seafloor several hundred meters beneath the sea surface. Potential electron donors for that metabolism are hydrocarbons, although a strong C-isotope signature of that source does not exist. Model calculations explored here suggest that alteration of glass within the impact breccias may have produced H2 in sufficient quantities for population growth as the hydrothermal system cooled through thermophilic temperatures, although it is sensitive to the oxidation state of iron in the melt rock prior to hydrothermal alteration and the secondary mineral assemblage. At high water-to-rock ratios and temperatures below 45°C, H2 yields are insufficient to maintain a population of hydrogenotrophic sulfate-reducing bacteria, but yields double with a higher proportion of ferrous iron between 45 and 65°C. The most reduced rocks (i.e., highest proportion of ferrous iron) that are allowed to form andradite, which is observed in core samples, produce copious amounts of H2 in the temperature window for thermophiles and hyperthermophiles. Mixtures of melt rock and carbonate, which is observed in breccia matrices, produce somewhat less H2, and the onset of massive H2 production is shifted to higher temperatures (i.e., lower W/R).