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Frontiers in Microbiology 2024Kefir beverage has beneficial microorganisms that have health-giving properties; therefore, they have a good potential to be probiotic. This study evaluated the...
INTRODUCTION
Kefir beverage has beneficial microorganisms that have health-giving properties; therefore, they have a good potential to be probiotic. This study evaluated the probiotic potential, technological, and safety characteristics of , , and isolated from traditional kefir beverages.
METHOD
First, isolates were evaluated in terms of resistance to acid, alkali, bile salts, trypsin, and pepsin of the gastrointestinal tract. The auto-aggregation and co-aggregation ability of isolates were measured using spectrophotometry. Antimicrobial activities were assayed against important food-borne pathogens using the agar well diffusion method. Moreover, gamma-aminobutyric acid (GABA) production was investigated by thin-layer chromatography (TLC).
RESULT
Among the isolates, had an 85% total survival rate, but its amount reached below 6 log CFU/ml which is considered non-resistant, and it showed the highest auto-aggregation (74.67%). Moreover, only showed antimicrobial activity and had the highest co-aggregation with PTCC 1338 (54.33%) and ATCC 7644 (78%). Finally, an evaluation of the technological and safety characteristics of the strains showed that the strains produced GABA and were safe.
DISCUSSION
Although the isolates were not resistant to the gastrointestinal tract, their supernatant contained valuable natural compounds, including antioxidants, GABA, and antimicrobials, which can be used to produce functional foods and medicines. In addition, other approaches, such as increasing the initial number of strains, using foods as carriers of isolates, and encapsulating the isolates, can effectively increase the survivability of isolates in the gastrointestinal tract.
PubMed: 38903778
DOI: 10.3389/fmicb.2024.1385301 -
Journal of Agricultural and Food... Jun 2024This study extensively characterized yeast polysaccharides (YPs) from (PF) and (PK), with a specific focus on their structural attributes and their interaction with...
This study extensively characterized yeast polysaccharides (YPs) from (PF) and (PK), with a specific focus on their structural attributes and their interaction with wine fruity esters in a model wine system. By finely tuning enzymatic reactions based on temperature, pH, and enzyme dosage, an optimal YP yield of 77.37% was achieved, with a specific mass ratio of cellulase, pectinase, and protease set at 3:5:2. There were four YP fractions (YPPF-W, YPPF-N, YPPK-W, and YPPK-N) isolated from the two yeasts. YPPF-N and YPPK-N were identified as glucans based on monosaccharide analysis and Fourier-transform infrared spectroscopy analysis. "Specific degradation-methylation-nuclear magnetic" elucidated YPPF-W's backbone structure as 1,3-linked α-l-Man and 1,6-linked α-d-Glc residues, while YPPK-W displayed a backbone structure of 1,3-linked α-Man residues, indicative of a mannoprotein nature. Isothermal titration calorimetry revealed spontaneous interactions between YPPK-W/YPPF-W and fruity esters across temperatures (25-45 °C), with the strongest interaction observed at 30 °C. However, distinct esters exhibited varying interactions with YPPK-W and YPPF-W, attributed to differences in molecular weights and hydrophobic characteristics. While shedding light on these intricate interactions, further experimental data is essential for a comprehensive understanding of yeast polysaccharides' or mannoproteins' impact on fruity esters. This research significantly contributes to advancing our knowledge of yeast polysaccharides' role in shaping the nuanced sensory attributes of wine.
Topics: Wine; Esters; Pichia; Polysaccharides; Vitis; Fermentation; Spectroscopy, Fourier Transform Infrared
PubMed: 38757388
DOI: 10.1021/acs.jafc.4c02073 -
Waste Management (New York, N.Y.) Apr 2024As an important source of malodor, the odor gases emitted from public toilet significantly interfered the air quality of living surroundings, resulting in environmental...
As an important source of malodor, the odor gases emitted from public toilet significantly interfered the air quality of living surroundings, resulting in environmental problem which received little attention before. Thus, this paper explored the odor release pattern of latrine feces and deodorization effect with composited microbial agent in Chengdu, China. The odor release rules were investigated in sealed installations with a working volume of 9 L for 20 days. The odor units (OU), ammonia (NH), hydrogen sulfide (HS) and total volatile organic compounds (TVOC) were selected to assess the release of malodorous gases under different temperature and humidity, while the highest malodor release was observed under 45℃, with OU and TVOC concentration was 643.91 ± 2.49 and 7767.33 ± 33.50 mg/m, respectively. Microbes with deodorization ability were screened and mixed into an agent, which composited of Bacillus amyloliquefaciens, Lactobacillus plantarum, Enterococcus faecalis and Pichia fermentans. The addition of microbial deodorant could significantly suppress the release of malodor gas during a 20-day trial, and the removal efficiency of NH, HS, TVOC and OU was 81.50 %, 38.31 %, 64.38 %, and 76.86 %, respectively. The analysis of microbial community structure showed that temperature was the main environmental factor driving the microbial variations in latrine feces, while Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes were the main bacteria phyla involved in the formation and emission of malodorous gases. However, after adding the deodorant, the abundance of Bacteroidetes, Proteobacteria and Actinobacteria were decreased, while the abundance of Firmicutes was increased. Furthermore, P. fermentans successfully colonized in fecal substrates and became the dominant fungus after deodorization. These results expanded the understanding of the odor release from latrine feces, and the composited microbial deodorant provided a valuable basis to the management of odor pollution.
Topics: Deodorants; Gases; Hydrogen Sulfide; Odorants; Toilet Facilities; China
PubMed: 38432182
DOI: 10.1016/j.wasman.2024.02.044 -
Journal of Trace Elements in Medicine... May 2024Yeasts have the remarkable capability to transform and integrate inorganic selenium into their cellular structures, thereby enhancing its bioavailability and reducing...
BACKGROUND AND OBJECTIVE
Yeasts have the remarkable capability to transform and integrate inorganic selenium into their cellular structures, thereby enhancing its bioavailability and reducing its toxicity. In recent years, yeasts have attracted attention as potential alternative sources of protein.
METHODS
This study explores the selenium accumulation potential of two less explored yeast strains, namely the probiotic Saccharomyces boulardii CCDM 2020 and Pichia fermentas CCDM 2012, in comparison to the extensively studied Saccharomyces cerevisiae CCDM 272. Our investigation encompassed diverse stress conditions. Subsequently, the selenized yeasts were subjected to an INFOGEST gastrointestinal model. The adherence and hydrophobicity were determined with undigested cells RESULTS: Stress conditions had an important role in influencing the quantity and size of selenium nanoparticles (SeNPs) generated by the tested yeasts. Remarkably, SeMet synthesis was limited to Pichia fermentas CCDM 2012 and S. boulardii CCDM 2020, with S. cerevisiae CCDM 272 not displaying SeMet production at all. Throughout the simulated gastrointestinal digestion, the most substantial release of SeCys2, SeMet, and SeNPs from the selenized yeasts occurred during the intestinal phase. Notably, exception was found in strain CCDM 272, where the majority of particles were released during the oral phase.
CONCLUSION
The utilization of both traditional and non-traditional selenized yeast types, harnessed for their noted functional attributes, holds potential for expanding the range of products available while enhancing their nutritional value and health benefits.
Topics: Saccharomyces cerevisiae; Saccharomyces boulardii; Pichia; Selenium; Probiotics; Digestion
PubMed: 38310829
DOI: 10.1016/j.jtemb.2024.127402 -
Frontiers in Bioengineering and... 2024Xylitol is a pentose-polyol widely applied in the food and pharmaceutical industry. It can be produced from lignocellulosic biomass, valorizing second-generation...
Xylitol is a pentose-polyol widely applied in the food and pharmaceutical industry. It can be produced from lignocellulosic biomass, valorizing second-generation feedstocks. Biotechnological production of xylitol requires scalable solutions suitable for industrial scale processes. Immobilized-cells systems offer numerous advantages. Although fungal pellet carriers have gained attention, their application in xylitol production remains unexplored. In this study, the yeast strain WC 1507 was employed for xylitol production. The optimal conditions were observed with free-cell cultures at pH above 3.5, low oxygenation, and medium containing (NH)SO and yeast extract as nitrogen sources (xylitol titer 79.4 g/L, Y 66.3%, and volumetric productivity 1.3 g/L/h). Yeast cells were immobilized using inactive pellet mycelial carrier (MC) and alginate beads (AB) and were tested in flasks over three consecutive production runs. Additionally, the effect of a 0.2% w/v alginate layer, coating the outer surface of the carriers (cMC and cAB, respectively), was examined. While Y values observed with both immobilized and free cells were similar, the immobilized cells exhibited lower final xylitol titer and volumetric productivity, likely due to mass transfer limitations. AB and cAB outperformed MC and cMC. The uncoated AB carriers were tested in a laboratory-scale airlift bioreactor, which demonstrated a progressive increase in xylitol production in a repeated batch process: in the third run, a xylitol titer of 63.0 g/L, Y of 61.5%, and volumetric productivity of 0.52 g/L/h were achieved. This study confirmed WC 1507 as a promising strain for xylitol production in both free- and entrapped-cells systems. Considering the performance of the wild strain, a metabolic engineering intervention aiming at further improving the efficiency of xylitol production could be justified. MC and AB proved to be viable supports for cell immobilization, but additional process development is necessary to identify the optimal bioreactor configuration and fermentation conditions.
PubMed: 38303913
DOI: 10.3389/fbioe.2024.1339093 -
Scientific Reports Jan 2024Extracellular vesicles (EVs) are lipid-bilayered particles, containing various biomolecules, including nucleic acids, lipids, and proteins, released by cells from all...
Extracellular vesicles (EVs) are lipid-bilayered particles, containing various biomolecules, including nucleic acids, lipids, and proteins, released by cells from all the domains of life and performing multiple communication functions. Evidence suggests that the interaction between host immune cells and fungal EVs induces modulation of the immune system. Most of the studies on fungal EVs have been conducted in the context of fungal infections; therefore, there is a knowledge gap in what concerns the production of EVs by yeasts in other contexts rather than infection and that may affect human health. In this work, we characterized EVs obtained by Saccharomyces cerevisiae and Pichia fermentans strains isolated from a fermented milk product with probiotic properties. The immunomodulation abilities of EVs produced by these strains have been studied in vitro through immune assays after internalization from human monocyte-derived dendritic cells. Results showed a significant reduction in antigen presentation activity of dendritic cells treated with the fermented milk EVs. The small RNA fraction of EVs contained mainly yeast mRNA sequences, with a few molecular functions enriched in strains of two different species isolated from the fermented milk. Our results suggest that one of the mechanisms behind the anti-inflammatory properties of probiotic foods could be mediated by the interactions of human immune cells with yeast EVs.
Topics: Humans; Saccharomyces cerevisiae; Yeast, Dried; Extracellular Vesicles; Fermented Beverages; Cultured Milk Products
PubMed: 38184708
DOI: 10.1038/s41598-024-51370-7 -
Food Research International (Ottawa,... Nov 2023Consumption of high FODMAP (Fermentable Oligo-, Di-, and Monosaccharides and Polyols) diet is the leading cause of alteration in the human gut microbiome, thereby,... (Review)
Review
Consumption of high FODMAP (Fermentable Oligo-, Di-, and Monosaccharides and Polyols) diet is the leading cause of alteration in the human gut microbiome, thereby, causing irritable bowel syndrome (IBS). Therefore, sourdough technology can be exploited for reduction of FODMAPs in various foods to alleviate the symptoms of IBS. Several microorganisms viz. Pichia fermentans, Lactobacillus fetmentum, Saccharomyces cerevisiae, Torulaspora delbrueckii, Kluyveromyces marxianus etc. have been identified for the production of low FODMAP type II sourdough fermented products. However, more research on regulation of end-product and volatilome profile is required for maximal exploitation of FODMAP-reducing microorganisms. Therefore, the present review is focused on utilisation of lactic acid bacteria and yeasts, alone and in synergy, for the production of low FODMAP sourdough foods. Moreover, the microbial bioprocessing of cereal and non-cereal based low FODMAP fermented sourdough products along with their nutritional and therapeutic benefits have been elaborated. The challenges and future prospects for the production of sourdough fermented low FODMAP foods, thereby, bringing out positive alterations in gut microbiome, have also been discussed.
Topics: Humans; Irritable Bowel Syndrome; Fermentation; Diet; Monosaccharides; Food; Saccharomyces cerevisiae
PubMed: 37803764
DOI: 10.1016/j.foodres.2023.113425 -
Food Science & Nutrition Jun 2023Mongolian butter and Tude are traditional high-fat dairy products produced in Xilin Gol, China, which have unique chemical and microbiological characteristics. Mongolian...
Mongolian butter and Tude are traditional high-fat dairy products produced in Xilin Gol, China, which have unique chemical and microbiological characteristics. Mongolian Tude is made from Mongolian butter, dreg, and flour. In this study, the traditional manufacturing process of Mongolian butter and Tude was investigated for the first time. Mongolian butter was characterized by high-fat content (99.38 ± 0.63%) and high acidity (77.09 ± 52.91°T), whereas Mongolian Tude was considered a high-fat (21.45 ± 1.23%) and high-protein (8.28 ± 0.65%) dairy product obtained by butter, dreg, and flour. Mongolian butter and Tude were proven to be safe for human consumption in terms of benzopyrene content. In addition, , , , coliforms, and aflatoxin M1 were not detected in the samples. Bacteria and molds were not isolated from Mongolian butter; in contrast, the total count of bacteria and molds in Mongolian Tude was within the range of 4.5 × 10 to 9.5 × 10 and 0 to 2.2 × 10, respectively. Moreover, (41.55%), (11.05%), (40.20%), and (12.90%) were the predominant bacterial and fungal genera, and (15.6%), (9.6%), (8.5%), (6.1%), (4.2%), (3.5%), (3.5%), (46.2%), (14.7%), and (11.7%) were the predominant species in the microbiota of Mongolian Tude. Thus, it can be stated that the microbiota of food products produced by different small families varied significantly. Collectively, the findings presented herein are the first report of chemical and microbiological characterization of products of geographical origin and highlight the need for standardization of manufacturing procedures of Mongolian butter and Tude in the future.
PubMed: 37324868
DOI: 10.1002/fsn3.3283 -
Food Microbiology Aug 2023Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize...
Contamination of white-brined cheeses (WBCs) with yeasts is of major concern in the dairy industry. This study aimed to identify yeast contaminants and characterize their succession in white-brined cheese during a shelf-life of 52 weeks. White-brined cheeses added herbs (WBC1) or sundried tomatoes (WBC2) were produced at a Danish dairy and incubated at 5 °C and 10 °C. An increase in yeast counts was observed for both products within the first 12-14 weeks of incubation and stabilized afterwards varying in a range of 4.19-7.08 log CFU/g. Interestingly, higher incubation temperature, especially in WBC2, led to lower yeast counts, concurrently with higher diversity of yeast species. Observed decrease in yeast counts was, most likely, due to negative interactions between yeast species leading to growth inhibition. In total, 469 yeast isolates from WBC1 and WBC2 were genotypically classified using the (GTG)-rep-PCR technique. Out of them, 132 representative isolates were further identified by sequencing the D1/D2 domain of the 26 S rRNA gene. Predominant yeast species in WBCs were Candida zeylanoides and Debaryomyces hansenii, while Candida parapsilosis, Kazachstania bulderi, Kluyveromyces lactis, Pichia fermentans, Pichia kudriavzevii, Rhodotorula mucilaginosa, Torulaspora delbrueckii, and Wickerhamomyces anomalus were found in lower frequency. Heterogeneity of yeast species in WBC2 was generally larger compared to WBC1. This study indicated that, along with contamination levels, taxonomic heterogeneity of yeasts is an important factor influencing yeast cell counts, as well as product quality during storage.
Topics: Cheese; Yeasts; Polymerase Chain Reaction
PubMed: 37098422
DOI: 10.1016/j.fm.2023.104266 -
Letters in Applied Microbiology Feb 2023Nowadays, isoamyl acetate production is carried out by chemical synthesis with a recent interest in developing biological producing processes, mainly based on...
Nowadays, isoamyl acetate production is carried out by chemical synthesis with a recent interest in developing biological producing processes, mainly based on microorganisms in submerged fermentation. This work assayed producing isoamyl acetate through solid-state fermentation (SSF), feeding the precursor in the gas phase. Polyurethane foam functioned as the inert support to contain 20 ml of a solution of molasses (10% w/v, pH 5.0). The yeast Pichia fermentans was inoculated at 3 × 107 cells per gram of initial dry weight. The airstream to supply oxygen also served to supply the precursor. Slow supply was obtained using an isoamyl alcohol solution of 5 g l-1 in the bubbling columns and an air stream of 50 ml min-1. For fast supply, fermentations were aerated using 10 g l-1 and 100 ml min-1 for isoamyl alcohol solution and air stream, respectively. It demonstrated the feasibility of isoamyl acetate production in SSF. Moreover, the slow supply of the precursor increased isoamyl acetate production up to 390 mg l-1, which is 12.5 times higher than that obtained without precursor (32 mg l-1). On the other hand, fast supply caused an evident inhibition of the growth and production capacity of the yeast.
Topics: Fermentation; Saccharomyces cerevisiae; Pentanols
PubMed: 36794886
DOI: 10.1093/lambio/ovac061