Dry Yeast Research Articles

Improvement of bread kadayıf formulation with wheat germ and different fermentation methods

In this study, it was aimed to improve the functional properties of bread kadayıf. For this purpose, 30% of the wheat flour was replaced with wheat germ, and the samples were fermented in 3 different methods including active dry yeast, sourdough and chickpea yeast. Selected physical, chemical and sensorial properties were examined in the final samples. The use of chickpea yeast increased ash content, antioxidant activity, and total phenolic content. The amount of phytic acid reached higher values in the samples with wheat germ, but sourdough and chickpea yeast addition decreased phytic acid content both in the samples with and without germ. On the other hand, the mineral amounts of the samples (Ca, K, Fe, Zn) increased with wheat germ. When the sensory analysis results were examined, it was seen that the use of wheat germ did not have any negative effects on the bread kadayıf samples and active dry yeast added samples had higher overall acceptability scores compared to sourdough and chickpea yeast.

Effect of additives on the fermentative ability of commercial dry yeast in the production of mead

Effect of additives on the fermentative ability of commercial dry yeast in the production of mead

Effects of Active Dry Yeast Supplementation in In Vitro and In Vivo Nutrient Digestibility, Rumen Fermentation, and Bacterial Community.

This study assessed the impact of active dry yeast (ADY) on nutrient digestibility and rumen fermentation, using both in vitro and in vivo experiments with lambs. In vitro, ADYs were incubated with rumen fluid and a substrate mixture to assess gas production, pH, volatile fatty acid (VFA) profiles, and lactate concentration. In vivo, Hu lambs were randomly assigned to five dietary treatments: a control group and four groups receiving one of two dosages of either Vistacell or Procreatin7. Growth performance, nutrient digestibility, rumen fermentation parameters, and bacterial community composition were measured. Pro enhanced the propionate molar proportion while it decreased the n-butyrate molar proportion. Vis reduced the lactate concentration in vitro. In the in vivo experiment, Vis increased the propionate molar proportion and the Succinivibrionaceae_UCG-001 abundance while it decreased the n-butyrate molar proportion and the Lachnospiraceae_ND3007 abundance. Additionally, Vis showed a greater impact on improving the NDF digestibility and total VFA concentration in vivo compared to Pro. Overall, the effects of ADYs on rumen fermentation were found to vary depending on the specific ADY used, with Vis being the most suitable for lamb growth. It was observed that Vis promoted propionate fermentation and Succinivibrionaceae_UCG-001 abundance at the expense of reduced n-butyrate fermentation and Lachnospiraceae_ND3007 abundance. Importantly, differences were noted between the outcomes of the in vitro and in vivo experiments concerning the effects of ADYs on rumen fermentation, highlighting the need for caution when generalizing batch culture results to the in vivo effects of ADYs.

Qingfei Zhisou oral liquid alleviates fever-induced inflammation by regulating arachidonic acid and lysophospholipids metabolism and inhibiting hypothalamus transient receptor potential ion channels expression.

To explore how Qingfei Zhisou oral liquid (, QFZS) adjusts body temperature bias and the interaction of inflammatory factors levels and metabolomic differences. Dry yeast was subcutaneously injected at 10 mL/kg to establish the pyrexia model. We randomly divided 60 Sprague-Dawley rats into five groups: control, model, positive, low dose of QFZS and high dose of QFZS. Inflammatory proteins were evaluated by Western blotting and immunohistochemistry. For the examination of the endogenous metabolites, enzyme linked immunosorbent assay and ultra-high-performance liquid chromatography high-resolution mass spectrometry were employed. QFZS significantly reduced rats' body temperature within 6 h after dry yeast injection and reduced the secretion of the arginine vasopressin, cyclic adenosine monophosphate, prostaglandin E-2, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β in serum. Meanwhile, we identified 41 metabolites between the model and QFZS groups, including arachidonic acid and lysophospholipids. QFZS restored normal arachidonic acid levels. Based on the differential metabolite enrichment analysis, QFZS's anti-inflammatory and anti-pyrexia effects might be related to the inflammatory pathway regulated by transient receptor potential. Additionally, QFZS treatment reduced transient receptor potential melastatin 2 ion channel expression and affected TNF-α, heat shock protein 70, and cyclooxygenase-2 expression in the hypothalamus. QFZS exerts its regulatory effects on fever by regulating the metabolism of lysophospholipids and arachidonic acid and the regulation of inflammation via transient receptor potential ion channels channels.

Evaluation of SO2, glutathione, and glutathione-rich inactive dry yeast as antioxidants on the fermentation properties of Roxburgh rose wine

Cili (Roxburgh rose) wine, which is rich in ascorbic acid, flavones, and polyphenols, presents unique challenges in wine production, including oxidation, aroma loss, and SO2 residues. This study investigated the effects of three antioxidants (SO2, glutathione (GSH), and GSH-rich inactive dry yeast (g-IDY)) on the fermentation properties of cili wine and evaluated the potential of g-IDY for addressing the aforementioned issues. g-IDY significantly enhanced the fermentation rate, as evidenced by increased CO2 production within 48 h, and maintained high levels of GSH, total phenolics, total flavones, and ascorbic acid, contributing to the antioxidant capacity and overall stability of the wine. g-IDY also improved the retention and concentration of key aromatic compounds, including higher alcohols, esters, and terpenes, thereby enhancing the sensory profile of the wine. Principal component analysis confirmed that different antioxidants significantly altered the volatile profile, with g-IDY demonstrating distinct improvements. The optimal concentration was 400 mg/L g-IDY. Compared with traditional antioxidants like SO2 and pure GSH, g-IDY offers a safer and more effective solution for preserving the quality of cili wine. This study provides experimental evidence for refining the fermentation process and promotes the use of g-IDY for enhancing the antioxidant capacity and sensory attributes of cili wine.

The bacterial and yeast microbiota in livestock forages in Hungary

BackgroundAlong bacteria, yeasts are common in forages and forage fermentations as spoilage microbes or as additives, yet few studies exist with species-level data on these fungi’s occurrence in feedstuff. Active dry yeast and other yeast-based products are also common feed additives in animal husbandry. Here, we aimed to characterize both fermented and non-fermented milking cow feedstuff samples from Hungary to assess their microbial diversity in the first such study from Central Europe.ResultsWe applied long-read bacterial metabarcoding to 10 fermented and 25 non-fermented types of samples to assess bacterial communities and their characteristics, surveyed culturable mold and yeast abundance, and identified culturable yeast species. Fermented forages showed the abundance of Aerococcaceae, Bacillaceae, Brucellaceae, Lactobacillaceae, Staphylococcaceae, and Thermoactinomycetaceae, non-fermented ones had Cyanothecaceae, Enterobacteriaceae, Erwiniaceae, Gomontiellaceae, Oxalobacteraceae, Rhodobiaceae, Rickettsiaceae, and Staphylococcaceae. Abundances of bacterial families showed mostly weak correlation with yeast CFU numbers, only Microcoleaceae (positive) and Enterococcaceae and Alcaligenaceae (negative correlation) showed moderate correlation. We identified 14 yeast species, most commonly Diutina rugosa, Pichia fermentans, P. kudriavzevii, and Wickerhahomyces anomalus. We recorded S. cerevisiae isolates only from animal feed mixes with added active dry yeast, while the species was completely absent from fermented forages. The S. cerevisiae isolates showed high genetic uniformity.ConclusionOur results show that both fermented and non-fermented forages harbor diverse bacterial microbiota, with higher alpha diversity in the latter. The bacterial microbiome had an overall weak correlation with yeast abundance, but yeasts were present in the majority of the samples, including four new records for forages as a habitat for yeasts. Yeasts in forages mostly represented common species including opportunistic pathogens, along with a single strain of Saccharomyces used as a feed mix additive.

Encapsulation of Saccharomyces spp. for Use as Probiotic in Food and Feed: Systematic Review and Meta-analysis.

Probiotics, particularly yeasts from the genus Saccharomyces, are valuable for their health benefits and potential as antibiotic alternatives. To be effective, these microorganisms must withstand harsh environmental conditions, necessitating advanced protective technologies such as encapsulation to maintain probiotic viability during processing, storage, and passage through the digestive system. This review and meta-analysis aims to describe and compare methods and agents used for encapsulating Saccharomyces spp., examining operating conditions, yeast origins, and species. It provides an overview of the literature on the health benefits of nutritional yeast consumption. A bibliographic survey was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The meta-analysis compared encapsulation methods regarding their viability after encapsulation and exposure to the gastrointestinal tract. Nineteen studies were selected after applying inclusion/exclusion criteria. Freeze drying was found to be the most efficient for cell survival, while ionic gelation was best for maintaining viability after exposure to the gastrointestinal tract. Consequently, the combination of freeze drying and ionic gelation proved most effective in maintaining high cell viability during encapsulation, storage, and consumption. Research on probiotics for human food and animal feed indicates that combining freeze drying and ionic gelation effectively protects Saccharomyces spp.; however, industrial scalability must be considered. Reports on yeast encapsulation using agro-industrial residues as encapsulants offer promising strategies for preserving potential probiotic yeasts, contributing to the environmental sustainability of industrial processes.

Evaluation of different hydration techniques on the viability of commercial dry brewing yeast

The utilization of dry yeast is increasingly becoming established in the brewing context, owing to the ease of storage and handling, the long shelf life and the convenience of dispensing a delicate and costly propagation process for fresh liquid cultures, which would need specialized labor and equipment. Dried yeasts undergo a procedure that removes nearly all liquid contents from the cell, and rehydration is then recommended prior to inoculation into the wort. Hydration is a nuanced procedure that allows yeasts to regain their vitality and viability, however, if carried out improperly, it can adversely affect fermentation. This study aimed to evaluate the impact of four hydration techniques on the viability and vitality of dry commercial yeast cells, preliminarily evaluating the influence of hydration using distilled and filtered water. Two different methodologies were employed, including the assessment of viability, by counting live and dead cells in the Neubauer chamber and the evaluation of vitality, by measuring the CO₂ released after inoculation. The hydration techniques tested included hydration in water without stirring, hydration in water with stirring, and these two techniques replicated in dry malt extract (DME) wort with Specific Gravity (SG) 1040. Firstly, it was found that rehydrating the yeast in distilled water has a negative impact on cell viability. Also, the results indicated that initial agitation has a negative effect on yeast viability and vitality, while hydration in water without agitation produced the best results. Correct hydration of dry yeast is crucial for avoiding off-flavors due to accelerated or delayed fermentation.

Different Nitrogen Consumption Patterns in Low Temperature Fermentations in the Wine Yeast Saccharomyces cerevisiae.

Nowadays, the wine industry carries out fermentations at low temperatures because this oenological practice clearly improves the aromatic complexity of the final wines. In addition, nitrogen content of the must also influences the quality of the wine. In this study, we carried out a phenotypic and fermentative analysis of two industrial wine Saccharomyces cerevisiae strains (P5 and P24) at 15 and 28 °C and three nitrogen concentrations (60, 140 and 300 mg N/L) in synthetic must. Our results show that both parameters, temperature and nitrogen, are interrelated and clearly determine the competitiveness of the wine strains and their ability to adapt at low temperatures. The best adapted strain at low temperatures decreased its competitiveness at lower nitrogen concentrations. In addition, our results show that it is not only the quantity of nitrogen transported that is important but also the quality of the nitrogen source used for wine yeast adaptation at low temperatures. The presence of some amino acids, such as arginine, branched chain amino acids, and some aromatic amino acids can improve the growth and fermentation activity of wine yeasts at low temperatures. These results allow us to better understand the basis of wine yeast adaptation to fermentation conditions, providing important information for winemakers to help them select the most appropriate yeast strain, thus reducing the economic costs associated with long and sluggish fermentations. The correlation between some amino acids and better yeast fermentation performance could be used in the future to design inactive dry yeast enriched in some of these amino acids, which could be added as a nutritional supplement during low temperature fermentations.

Bioprocess Optimization by Taguchi Design and Response Surface Analysis for Obtaining Active Yeast Used in Vinification

This study presents the behavior of the identified yeast strain S. cerevisiae, isolated from Busuioacă de Bohotin grapes from the Pietroasa winery, during the process of fermentation to obtain dry active yeast biomass for the winemaking process. In this respect, we promoted an optimization strategy for obtaining active dry yeast biomass. The cultivation conditions for micropilot fermentation (temperature, pH, carbon source, and nitrogen source) were selected and designed according to a Taguchi design with four factors and three levels. Reproducibility testing was conducted under specific fermentation parameters: temperature (32 °C), pH (4.5), carbon source (12%), and nitrogen source (0.7%). Following the optimization process, two combinations of cultivation parameters were selected, and one of them, based on the results, was selected for further analysis. Quantitative data were obtained, showing dry yeast biomass (DCW) at 1.39 g/100 mL and protein content at 45.57%. The active yeast was then used in the winemaking process for Tămâioasă Românească and Busuioacă de Bohotin varieties at Pietroasa winery for validation. This optimization aims to facilitate easy and rapid production of fresh wine yeast tailored to the local winemaking practices of Pietroasa winery, with real application potential in other viticultural areas, aligning with the terroir concept.

Combinations of bacterial probiotics and yeast postbiotics influence fat deposition and growth in the nematode C. elegans

BackgroundProbiotics are live microorganisms with intended benefits on human health including obesity. As a small and fast-growing whole organism model, Caenorhabditis elegans has been used to assess the health effects of probiotics where mechanisms can be assessed through available genetic tools. Results from C. elegans can provide data on the effect of specific probiotic strains and combinations with prebiotics and postbiotics on health-related physiology to inform selections of interventions for further study. We hypothesized that specific combinations with prebiotics and postbiotics could both speed up worm development and reduce fat deposition, suggesting they allow for more effective nutrient utilization. MethodsHere we expose C. elegans to the ABB S20 strain of Lactiplantibacillus plantarum in combination with different prebiotics and postbiotics. We then measure how these affect growth and development speed as well as fat deposition by measuring the time until the appearance of progeny and measuring Oil Red O staining respectively. ResultsOur results show that the combination of probiotic L. plantarum ABB S20 plus the postbiotic inactive yeasts K. marxianus ABB S8 and S. boulardii ABB S3 resulted in fast growth and reduced fat deposition compared to L. plantarum ABB S20 alone. ConclusionThese results demonstrate the usefulness of C. elegans as a model to efficiently screen though combinations of probiotics, prebiotics and postbiotics to find those that are candidates to help with effective nutrition use and therefore weight management.

Use of spent yeasts from bioethanol production plant as low-cost nitrogen sources for ethanol fermentation from sweet sorghum stem juice in low-cost bioreactors

Two spent yeasts from an ethanol production plant, spent yeast after distillation (SY-AD) and spent yeast after fermentation (SY-AF), were used as low-cost nitrogen sources for ethanol fermentation from sweet sorghum stem juice (SSJ) by a commercial dry yeast (Saccharomyces cerevisiae) in air-locked flasks. SY-AF was the more effective nitrogen source for ethanol fermentation, giving ethanol concentration (PE) and ethanol productivity (QE) values of 95.22 g/L and 1.98 g/L·h, respectively. When SY-AF was disrupted by autolysis, and the spent yeast hydrolysate (SYH) obtained was used as a nitrogen supplement. It was found that ethanol production in terms of PE and QE values increased to 102.20 g/L and 2.83 g/L·h, respectively. When three bioreactors, a stirred-tank bioreactor (STR, a typical bioreactor), a column bioreactor with stirrer (CS-R, a tower bioreactor) and an external loop bioreactor (ELR, a low-cost bioreactor with no agitation), were used for ethanol production from the SSJ supplemented with SYH, the fermentation efficiencies of all bioreactors were not different. Appropriate aeration during fermentation (0.31 vvm for 12 h) in the three bioreactors could enhance the QE value, reaching 3.36 g/L·h. Both the CR-S and ELR could be successfully used for ethanol production from SSJ supplemented with SYH.

Influence of reducing sugars and protein‐to‐sugar ratios on volatile profile, pH, and browning intensity of Maillard‐reacted nutritional yeast hydrolysate

SummaryThis study investigated the effects of reducing sugars and protein‐to‐sugar ratios on generating volatile compounds from nutritional yeast hydrolysates after Maillard reaction. Nutritional yeast extract (NYE) was cleaved using Flavourzyme® at an enzyme‐to‐substrate ratio of 0.5% w/w, followed by heat treatment with varying concentrations of reducing sugars (i.e., hexoses: glucose and fructose and pentoses: xylose and ribose). The results showed that pentoses generate higher numbers and concentrations of volatiles than hexoses, especially furans, Strecker aldehydes, and sulphur‐containing compounds such as dimethyl disulphide. However, hexoses produced higher concentrations of pyrazines. Strecker aldehydes and pyrazines served as key aroma‐active compounds in meat aroma. Likewise, sulphur‐containing compounds played an important role in meat aroma due to their low detection threshold. The results showed that reducing sugars significantly impacts the volatile profile of NYE, potentially influencing the formation of meaty aroma compounds. These findings demonstrate the potential of MRPs to enhance meaty flavours due to the presence of volatile compounds with characteristics of cooked meat.

Antipyretic and Anti-inflammatory Effects of Sanchen Pediatric Antipyretic Paste

Objective:: This study aimed to investigate the antipyretic and anti-inflammatory effects and mechanisms of Sanchen Pediatric antipyretic Paste (SPAP). Methods:: Rats were randomly divided into 7 groups: negative control group, positive control group, positive treatment group, SPAP high-dose, medium-dose and low-dose groups, and blank substrate group. Except normal control group, rats in other groups were subcutaneously injected with 10% dry yeast suspension (10mL/kg) on the back to establish a fever model, and the normal group was given the same volume of saline. At the 4 h and 7 h after modeling, each treatment group was subjected to corresponding SPAP intervention. Anal temperature was measured every one hour after modeling for 10 consecutive times. The average temperature-rise curve, maximum temperature and body temperature response index (TRI) were calculated to evaluate the efficacy of SPAP. After the last temperature measurement, abdominal aortic blood was collected, and serum was separated from blood. The levels of IL-6, TNF-α and CRP in serum were determined by enzyme-linked immunosorbent assay. Results:: The body temperature of the positive control group was significantly increased (p < 0.01) 4 hours after model establishment, and that of the SPAP groups significantly decreased (p < 0.01) after 5 hours of the model establishment. The levels of Serum IL-6, TNF-α and CRP were significantly decreased (p < 0.01) in a dose-dependent manner. Conclusion:: SPAP has an obvious antipyretic effect on fever caused by dry yeast in rats. One of its antipyretic mechanisms may be associated with inhibiting inflammatory reactions by reducing the production or accelerating the degradation of endogenous thermogenic cytokines, such as IL-6, TNF- α, and CRP.

Study on the Kinetic Model of Mixed Fermentation by Adding Glutathione-Enriched Inactive Dry Yeast

In order to investigate the impact of glutathione-enriched inactive dry yeast (g-IDY) on the co-fermentation process of Torulaspora delbrueckii and Saccharomyces cerevisiae, different contents of g-IDY (0, 20, 40, and 100 mg/L) were added to the simulated liquid for fermentation. The yeast quantity, reducing sugar content, and ethanol volume fraction in the fermentation system were determined every 24 h. Nonlinear fitting of the measured values was carried out using classical Logistic, SGompertz, Boltzmann, and DoseResp models. Additionally, the aroma components of the wine were analyzed by GC-MS. The results indicate that the Logistic model performs best in terms of yeast growth kinetics, whereas the DoseResp and Boltzmann models exhibit the same fitting performance for reducing sugar consumption, both superior to the Logistic model, and the Boltzmann model shows the best-fitting performance for ethanol production. All optimal models have fitting coefficients (R2 values) above 0.99, demonstrating that different contents of g-IDY can effectively complete fermentation. Furthermore, all three fitting models can effectively describe the fermentation process using g-IDY. The use of g-IDY can increase the content of ethyl phenylacetate and phenylethanol, which can be employed to enhance the aroma of wine.

Ameliorative action of "daitongxiao" against hyperuricemia includes the "uric acid transporter group".

This study aimed to investigate the potential mechanisms involved in the therapeutic effects of daitongxiao (DTX) on hyperuricemia (HUA). DTX was administered to two animal models of HUA via gavage feeding: HUA quail model (a uricotelic animal with urate oxidase deficiency), treated continuously for 35 days post-HUA induction, and HUA rats (an animal with active urate oxidase), treated continuously for 28days post-HUA induction. HUA was induced in quail by administering a solution of sterile dry yeast powder via gavage feeding, while in rats, it was induced by intragastric gavage feeding of a solution of adenine and ethambutol hydrochloride. DTX improved overall health; increased bodyweight; reduced renal index, serum urate levels, serum xanthine oxidase activity, blood urea nitrogen, and creatinine; and enhanced urinary and fecal uric acid (UA) excretion in these two animal models. The results of hematoxylin and eosin and hexamine silver staining of kidney sections revealed that DTX significantly mitigated HUA-induced renal structural damage and inflammatory response. The results of quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence analyses revealed that DTX downregulated the renal expression levels of glucose transporter 9 (GLUT9) and upregulated the renal expression levels of organic anion transporters (OAT1 and OAT3) in both HUA models. Thus, the findings of this study suggest that DTX suppresses the progression of HUA by modulating the expression of the UA transporter group members.

Educational activity of enzyme kinetics in an undergraduate biochemistry course: invertase enzyme as a model.

This article aims to simplify and facilitate the process of practical teaching of enzyme kinetics by utilizing minimal teaching laboratory requirements. Simultaneously, it ensures that students comprehend the enzyme kinetics experiment effectively. The focus is on teaching students how to estimate the maximum velocity (Vmax) and Michaelis constant (Km) of β-fructofuranosidase enzyme (also known as invertase) isolated from dry yeast. The invertase enzyme catalyzes the hydrolysis of sucrose substrate into glucose and fructose, employing the Michaelis-Menten approach of evaluating invertase enzyme kinetics as well as Lineweaver-Burk linear graphic approach of evaluating the Michaelis-Menten enzyme kinetics. The practical experiment seeks to reinforce the concepts of initial velocity dependence on substrate concentration. The data presented in the work were generated from a genuine practical biochemistry course enrolled by second-year undergraduate students in the Department of Pharmacy and the Department of Medical Laboratory Science. While there were minor variations in the invertase enzyme kinetic parameters among students, they successfully carried out the experiment. The students accurately estimated the Vmax and Km of the invertase enzyme in the sucrose hydrolysis chemical reaction. Moreover, they demonstrated an understanding of the meanings of the kinetic parameters (Km and Vmax) and the utility of the Lineweaver-Burk plot.

Addition of S-servicia Dry Yeast at Different Densities and its Effect in Some Productive Traits of Quail

Background: Dry yeast is considered a food additive that is used as a probiotic. In this study, it was added to the diet of quails that were raised at different densities to enhance growth and raise production performance, especially with the high density of birds per unit area. Methods: This research was conducted in the field of poultry production, College of Agriculture and Forestry/University of Mosul, (50 days) to study the effect of adding yeast in concentrations of (0, 2, 4, 6) gram/liter of drinking water with three densities of breeding (56, 72, 88) birds/m2 for the purpose of identifying the productive performance and some characteristics that are related to egg production for quail birds. Result: Statistical analysis showed that: - Average body weight, weight gain and feed consumption increased significantly with increasing the density, while the feed conversion factor decreased with the increase of egg mass at a density of 72 birds/m2. From the other hand, the egg weight increased significantly at the density of 88 birds/m2. - Body weight and weight gain increased significantly with increasing the amount of the yeast added and the consumed feed decreased with the improvement in the feed conversion factor. Moreover, there was a significant increase in egg mass, both of the weight of egg, yolk, albumin, shell, egg length, height of yolk and albumin. - The combination 72 bird/m2 +4 gm yeast gave the best body weight, weight gain, egg mass, while the conversion factor decreased with the addition of yeast for all densities in addition to a significant increase in the weight of each of egg, yolk, albumin and the shell. The feed consumption increased significantly in the density 88 bird /m2 with different concentrations of yeast addition.

Characteristic aroma compounds during the fermentation of Chinese steamed bread fermented with different starters

The characteristic aroma compounds of Chinese steamed bread (CSB) fermented with different starters were studied using HS-SPME-GC/MS, aroma recombination and omission experiments. The dynamic changes of the microbiota and their function and metabolites during fermentation were analyzed using metagenomics and non-targeted metabolomics. Forty-nine volatile flavor compounds were identified, while 5 characteristic aroma-active compounds were investigated in CSB fermented with commercial dry yeast (AQ-CSB), and 10 were investigated in CSB fermented with traditional starter (NY-CSB). Microbial structure and function analysis showed that Saccharomyces cerevisiae dominated during AQ-CSB fermentation and contributed >95% to its KEGG pathways, while Pediococcus pentosaceus, unclassified Pediococcus, Lactobacillus plantarum, Lactobacillus brevis and unclassified Lactobacillus were predominant in NY-CSB and together had an ~96% contribution to these pathways. NY-CSB showed higher metabolic activity during fermentation, and the characteristic metabolites were mainly involved in carbohydrate, amino acid and lipid metabolism. The characteristic aroma compounds were identified and increased the understanding of the contributions of the microbiota. This may be useful for designing starter cultures that produce CSB with desirable aroma properties.

Exploring the “gene–metabolite” network of ischemic stroke with blood stasis and toxin syndrome by integrated transcriptomics and metabolomics strategy

A research model combining a disease and syndrome can provide new ideas for the treatment of ischemic stroke. In the field of traditional Chinese medicine, blood stasis and toxin (BST) syndrome is considered an important syndrome seen in patients with ischemic stroke (IS). However, the biological basis of IS-BST syndrome is currently not well understood. Therefore, this study aimed to explore the biological mechanism of IS-BST syndrome. This study is divided into two parts: (1) establishment of an animal model of ischemic stroke disease and an animal model of BST syndrome in ischemic stroke; (2) use of omics methods to identify differentially expressed genes and metabolites in the models. We used middle cerebral artery occlusion (MCAO) surgery to establish the disease model, and utilized carrageenan combined with active dry yeast and MCAO surgery to construct the IS-BST syndrome model. Next, we used transcriptomics and metabolomics methods to explore the differential genes and metabolites in the disease model and IS-BST syndrome model. It is found that the IS-BST syndrome model exhibited more prominent characteristics of IS disease and syndrome features. Both the disease model and the IS-BST syndrome model share some common biological processes, such as thrombus formation, inflammatory response, purine metabolism, sphingolipid metabolism, and so on. Results of the “gene–metabolite” network revealed that the IS-BST syndrome model exhibited more pronounced features of complement-coagulation cascade reactions and amino acid metabolism disorders. Additionally, the “F2 (thrombin)–NMDAR/glutamate” pathway was coupled with the formation process of the blood stasis and toxin syndrome. This study reveals the intricate mechanism of IS-BST syndrome, offering a successful model for investigating the combination of disease and syndrome.