Yeast Culture Research Articles

Effect of composite yeast culture on the jejunal barrier function, inflammatory response, and microbial community structure of laying hens during the late stage of egg production

During the late laying period, the intestinal barrier of laying hens is susceptible to damage, resulting in enteric infections and even systemic inflammatory responses, posing a major challenge for the poultry industry. Therefore, it is crucial to investigate methods for addressing intestinal inflammation in late laying hens. In order to maximize the production potential of egg laying chickens, farmers usually use various feed additives to prevent damage to the intestinal barrier. Composite yeast cultures have shown advantages in broiler applications. This study aims to assess the impact of composite yeast culture (CYC) on the intestinal barrier function, inflammatory cytokines, and microbial community structure of Hy-Line Brown laying hens. A total of 160 healthy Hy-Line Brown hens, aged 58 weeks and of similar weight, were randomly assigned to two groups, with four replicates per group and 20 hens in each replicate. The control group was fed a basal diet (Con), while the experimental group was provided with a diet supplemented with 40 g/kg of composite yeast culture (CYC). The test period was 25 days. The results indicated that: compared to the control group, CYC significantly improved the egg production rates of hens during days 11–15, 16–20, and 21–25 (p < 0.05). CYC significantly enhanced the relative mRNA expression levels of occludin, claudin-1, zonula occludens-1 (ZO-1), and mucin 2 (Muc2) in the intestinal tract (p < 0.05), while reducing the relative expression levels of pro-inflammatory factors TNF-α and IFN-γ (p < 0.05), and increasing the levels of anti-inflammatory factors IL-4, IL-10, and TGF-β1 (p < 0.05). CYC significantly increased the abundance of Bifidobacterium pseudocatenulatum and Faecalibacterium prausnitzii in the intestine. These findings suggest that the composite yeast culture (CYC) can improve the structure of the intestinal microbial community. In conclusion, CYC may enhance egg production rates, reduce inflammatory responses, and strengthen intestinal barrier function by modulating the composition of the intestinal microbiota in late laying hens.

A Comprehensive Review on Fouling of Heat Transfer Units in Sugar Factory Ethanol Plant: Mechanisms and Mitigation Methods

ABSTRACTFouling in heat transfer units has a negative economic impact. Many scale‐forming impurities are present in cane molasses generated by sugar cane production technology, including cations of aluminum (Al), calcium (Ca), iron (Fe), magnesium (Mg), potassium (K), sodium (Na), as well as anions of carbonates, sulfites, phosphates, sulfate, silicates, and chlorides. Ca cations, in particular, form insoluble complexes with many other chemical constituents, making them a scale‐forming impurity. The accumulation of Ca ion on the heat exchanger's surface could increase heat transfer resistance and reduce its overall efficiency. This article reviews many types of heat‐transmitting unit fouling and their successive fouling occurrences. Identifying the chemicals found in scale deposits helps to determine which cleaning products will effectively clean heat transfer units and which scale inhibitors will drastically lower scale formation rates. Furthermore, numerous unit operations and unit processes, such as molasses pre‐treatment and pre‐fermentation practice (inoculation of yeast), followed by fermentation practice, and product purification practice distillation, are used to limit deposit formation and boost ethanol production efficiency. Molasses pre‐treatment and treatment such as chemical treatment, heat treatment, acid centrifugation, and mechanical treatment are critical in decreasing scale development during heat exchange operations.

Gellan-amino acid hydrogel-based bioreactor for optimizing the production of yeast metabolites

Hydrogels mimic natural environments due to their hydrated, polymeric networks which are beneficial for microorganism growth. The substantial water content maintains a consistently moist environment, and porous structure of hydrogel promotes efficient nutrient transfer and cell distribution, offering advantages over traditional liquid bioreactors. While their application in cell immobilization for bioconversion is well-known, their use as a solid-state fermentation matrix remains unexplored. This study is the first attempt to integrate gellan and amino acids to develop an innovative hydrogel bioreactor. The performance of this system was determined by cultivating Rhodosporidium sp. (MTCC 9733) as a model organism and evaluating its metabolite production. Further, gellan and amino acids concentration was optimized using one-factor-at-a-time and D-optimal response surface methodologies to produce β-carotene, lipid, and protein. Additionally, a comparison of productivity, yield, and process economics suggested that novel solid-state hydrogel fermentation approach outperformed classical submerged fermentation in YMB liquid media. Moreover, rheological properties of optimized hydrogel, conducted before and after yeast cultivation, revealed that this system possesses significant mechanical strength and structural integrity. Such attributes render the hydrogel suitable for utilization across multiple fermentation cycles. Hence, this study illustrates the potential of gellan-amino acid hydrogels as sustainable, efficient alternatives to conventional fermentation methods.

Simultaneous processing of both handheld biomixing and biowriting of kombucha cultured pre-crosslinked nanocellulose bioink for regeneration of irregular and multi-layered tissue defects

The nanocellulosic pellicle derived from the symbiotic culture of bacteria and yeast (Kombucha SCOBY) is an important biomaterial for 3D bioprinting in tissue engineering. However, this nanocellulosic hydrogel has a highly entangled gel network. This needs to be partially modified to improve its processability and extrusion ability for its applications in the 3D bioprinting area. To control its mechanical and biological properties for direct 3D bioprinting applications, uniform reinforcement of nanocellulose-interacting polymers and nanoparticles in such a prefabricated gel network is essential. In this study, the hydrogel network is partially hydrolyzed with organic acid and subsequently transformed into a 3D bioprintable polyelectrolyte complex with chitosan and kaolin nanoparticles without any chemical crosslinker using a handheld 3D bioprinter. This handheld bioprinter ensures homogeneity in both biomixing and bioprinting of chitosan and kaolin within the modified nanocellulose network for multi-layered bioprinted scaffolds through an extensional shear mechanism. The biomixing simulation, mechanical (static, dynamic, and cyclic), 3D bioprinting, and cellular studies confirm the homogeneous biomixing of kaolin nanoparticles and live cells in this nanocellulose-chitosan polyelectrolyte hydrogel. The combination of SCOBY-derived nanocellulose-chitosan bioink with kaolin nanoparticles and a screw-driven handheld extrusion bioprinter demonstrates a promising platform for layer-by-layer regeneration of complex tissues with homogeneous cell/particle distribution with high cell viability.

Ultra-high irradiance (UHI) blue light treatment: A promising method for inactivation of the wine spoilage yeast Brettanomyces bruxellensis

Ultra-high irradiance (UHI) blue light treatment: A promising method for inactivation of the wine spoilage yeast Brettanomyces bruxellensis

Quality improvement of Tofu waste as the raw material of duck feed with fermentation of yeast culture

The use of fermented products from probiotic microbes as supplement feed is expected to stimulate the growth and biocontrol of pathogenic bacteria in ducks with high feed efficiency. Feed biotechnology products based on tofu waste fermented with yeast culture (TWF) contain high levels of protein and the amino acid lysine, and contain probiotic microbes (107cfu/g). This research aims to examine the effect of fermenting tofu waste with yeast culture on the quality of tofu waste as a feed ingredient and the performance of ducks. The fermented product was tested on 240 male Bali ducks aged 2 weeks in a completely randomized design with four treatments and six replications. Each replication used 60 male Balinese ducks with homogeneous body weight. The four treatments were ducks given rations without TWF supplements as control (TWF0); diet supplemented with 2% TWF (TWF1); diet fed 4% TWF (TWF2); and rations given 6% TWF (TWF3). The results showed that supplementation of 4-6 TWF in feed significantly (P<0.05) increased body weight gain and feed efficiency.It can be concluded that the growth performance and feed efficiency of ducks increased significantly with the supplement of tofu waste fermented by yeast culture.

Antifungal activity of thiadiazole derivative in experimental candidiasis in mice

Antifungal activity of thiadiazole derivative in experimental candidiasis in mice

Review of the benefits of kombucha tea: chemical components and pharmacological activities

Kombucha tea is a type of tea that undergoes fermentation through the inclusion of tea leaves, sugar, and a symbiotic culture of bacteria and yeast (SCOBY). The fermentation process typically spans a period of around 10 to 15 days. The utilization of this substance dates back to ancient times, mostly for medicinal purposes. The review has demonstrated that kombucha tea has distinctive characteristics, including anticancer, antioxidant, antimicrobial, and antifungal activities. The chemical component of kombucha plays an important role in kombucha tea which enhances the pharmacological activities such as acetic acid, lactic acid, phenolics and flavonoids. This paper presents an analysis of recent findings pertaining to the potential health advantages of kombucha, along with an examination of the chemical constituents and metabolites generated during the fermentation process. Additionally, further recommendations are provided for future investigations in this field.

Clinical laboratory evaluation of the Hologic Panther Aptima BV and CV/TV assays for the diagnosis of vaginitis in Dunedin, Aotearoa New Zealand.

Vaginitis presentations are common, but traditional diagnostic methods are imperfect. Molecular methods for bacterial vaginosis (BV) and vulvovaginal candidiasis (CV) are increasingly available but not commonly utilized in Aotearoa New Zealand. We evaluated the Hologic Aptima BV and CV/Trichomonas vaginalis (TV) assays against our current methods (Gram stain, yeast culture, and Hologic Aptima TV assay) and performed a retrospective BV clinical audit. The BV Aptima assay performed well with high sensitivity (97.5%) and specificity (96.3%) when the indeterminate BV category was excluded. BV indeterminate samples were almost evenly split between positive and negative results when tested on the Aptima BV assay. BV Gram stain interpretation was error prone, with 20% of samples discordant on duplicate examination. Although the Aptima CV assay was highly sensitive, it lacked specificity compared with Gram stain (83.5%) but was similar to culture (91.2%). Our BV clinical audit showed that patients with a BV indeterminate result were less likely to be treated for BV than those with a positive result, meaning more women may be treated for BV if this assay were implemented. Overall, implementation may improve laboratory workflow and consistency of reporting, but cost may be a barrier. The clinical impact of changing methods needs to be considered.IMPORTANCEIn this paper, we evaluate the performance of the Aptima molecular assays against current Gram stain and culture methods, as well as a clinical audit to determine the potential clinical impact of implementation. Although molecular methods are increasingly used in other countries, New Zealand has not yet adopted this approach. Importantly, we found Gram stain for bacterial vaginosis (BV) to be error prone, with 20% of Gram stain results discordant on repeat examination. We show the potential for molecular methods to increase BV diagnoses and improve reproducibility and consistency of reporting which, according to our clinical audit results, would lead to more women being treated for this dysbiosis condition overall.

Self-induced anaerobiosis fermentation in coffees inoculated with yeast: Effect on key enzymes of the germination process and its relationship with the decrease in seed germination

Our objective was to monitor the main enzymes of coffee germinal metabolism and chemical composition during Self-Induced Anaerobiosis Fermentation (SIAF) with yeasts (Saccharomyces cerevisiae (CCMA0543), Candida parapsilosis (CCMA0544) and Torulospora delbrueckii (CCMA0684)) evaluating their relationship with seed germination. The starter cultures were assessed by qPCR. The organic acids were analyzed by liquid chromatography. Catalase (CAT), Esterase (EST), Alcohol dehydrogenase (ADH), and Isocitrate Lyase (ICL) enzyme activity was confirmed by the presence of sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-Page) gel bands. The formation of a white halo confirmed the activity of the enzyme endo-β-mannanase, and its quantification was performed using the diameter of the halo of both the samples and the standard curve. At the end of the fermentation process, S. cerevisiae and T. delbrueckii presented the highest populations (>7 log10 cells/g). Succinic acids (average −1.11 g/kg) were consumed during SIAF. Lactic acid increased after 180 h in coffees fermented by the SIAF method (average 3.57 g/kg). CAT and EST showed high activity in the conventional process. ADH activity was detected in both processes after 180 h of the SIAF method. Yeast inoculation during the SIAF method increased the activity of ICL andshowed more intense activity in the first 96 h of fermentation, especially the pulped coffee. Endo-β-mannanase activity was intense during conventional coffee processing (9.89–10.99 pmol/min/g). Natural processing tends to preserve a higher percentage of viable seeds. Therefore, the processing and fermentation methods impact seed quality differently.

Ecological conditions of vineyards and the polymorphism of Saccharomyces cerevisiae strains as a prerequisite of terroir identification

Aim. The aim of the study was to assess whether the ecological conditions for vineyards and the phylogenetic analysis of Saccharomyces cerevisiae wine yeast strains isolated from several locations in the Odesa and Mykolayiv regions could be used for terroir identification. Methods. The study employed microbiological, analytical, expedition, cartographic, and comparative assessment methods. Phylogenetic analysis was conducted using the MEGA software program, and VIN-CAD-UKR software was used for the vineyard cadastre and the ampelecological characteristics data management. Results. The study highlighted differences in the ecological conditions of vineyards in the Odesa and Mykolayiv regions and within the Tairovo and Izmail territorial communities in the Odesa region, focusing on soil and microclimatic characteristics. Saccharomyces cerevisiae strains isolated in 2012 and 2013, years with varying weather conditions in temperature and precipitation, were primarily clustered by the year of isolation. Two notable exceptions included a strain isolated from the Isabela variety belonging to a hybrid group (direct producer, contrary to other varieties, which mainly represent Vitis vinifera or its hybrids with Vitis riparia, Vitis amurensis, Vitis berlandieri) and a strain isolated from the Odesa Black variety inoculated at the beginning of fermentation with a commercial strain of wine yeast. The 2013 isolates, collected under conditions of higher precipitation and lower temperature in the first half of the growing season, showed a more differentiated clustering pattern, with two strains isolated from the Sukholymansky White variety forming a distinct cluster, while the rest grouped together, irrespective of the region, formed of isolation. Conclusions. Phylogenetic analysis of 64 strains of Saccharomyces cerevisiae isolated from 36 technical grape varieties based on the ITS1_5.8S_ITS2 nucleotide sequence demonstrated that the year of isolation (reflecting agroclimatic factors) was the primary influence on sample clustering. These factors, as components of the ecological conditions of terroir, form the foundation for terroir identification.

Dietary yeast culture can protect against chronic heat stress by improving the survival, antioxidant capacity, immune response, and gut health of juvenile Chinese mitten crab (Eriocheir sinensis)

As global warming intensifies, aquatic species are increasingly threatened by heat stress, urging the aquaculture industry to explore innovative strategies to mitigate the adverse impact of thermal stress on animals. Supplementing diets with yeast culture (YC) has shown promising results in coping with heat stress. This study evaluated the effects of YC on the survival, biochemical responses, transcriptome, and intestinal microbiota of the Chinese mitten crab (Eriocheir sinensis) under chronic heat stress. Juvenile crabs were subjected to four conditions over 42 days: a control temperature of 24 °C and a high temperature of 30 °C supplemented with three YC doses: 0, 3.2, and 6.4 g/kg. Each group had six replicates of 30 crabs each. Chronic heat stress substantially reduced survival rates and increased molting frequency. However, YC supplementation significantly improved survival and antioxidant enzyme activities (SOD and GSH-Px) while reducing MDA levels, indicating a reduction in oxidative stress. The immune response metrics (PO and AKP activities) were comparable to those of the control group when YC was included in the diet. A significant correlation existed between the crab survival rate, antioxidant performance and gut health. Histological assessment revealed that YC maintained the integrity of the intestinal lining under heat stress. 16S rRNA sequencing revealed that YC ameliorated disruptions in the diversity and structure of the intestinal microbiota caused by high temperature. Transcriptomic analysis identified DEGs linked to serine-type peptidases and ascorbate and aldarate metabolism pathways. Significant correlations were detected between Candidatus_Hepatoplasma, Rhodobacter, Aeromonas, and genes related to antioxidant and immune responses. In conclusion, dietary YC at 3.2 g/kg effectively enhanced the resilience of E. sinensis to chronic heat stress by increasing survival rates and antioxidant capacity, restoring immune function, and maintaining gut health.

Role of Oral Yeast in Replenishing Gastric Mucosa with Yeast and Helicobacter pylori.

The relationship between oral and gastric yeasts and their role in the colonization of Helicobacter pylori in the stomach was studied. Four groups of 221, 7, 44, and 10 patients were used for the isolation of H. pylori and oral and gastric yeasts. In Group 1, gastric biopsies were used for the isolation of H. pylori and yeast, rapid urease test (RUT), staining with Gram's and hematoxylin & eosin (H&E), and immunohistochemistry (IHC) methods. In the other three groups, DNAs extracted from H. pylori and yeasts were used for the amplification of H. pylori-specific genes. Wet mounts of yeasts in Group 2 were examined to observe intracellular bacteria and released EVs. Among 221 patients, 65 (29.3%) had oral yeast, 35 (15.8%) H. pylori, and 31 (14%) gastric yeast. Culture of oral yeasts showed a significant correlation with the detection of H. pylori by IHC (10.3%), Gram stain (9%), RUT (6.3%), H&E (4.9%), and culture (4%) (p < 0.05). Gram-stained biopsies showed the occurrence of yeast and H. pylori, and the release of EVs from yeast. Detection of similar H. pylori genes in oral and gastric yeasts from patients in Group 2 showed their common source. Oral yeasts in Groups 3 and 4 also carried H. pylori genes. Wet mount preparations of yeasts showed intracellular bacteria inside the yeast vacuole and the release of EVs that could carry H. pylori. Oral yeast protects its intracellular H. pylori and releases it inside EVs to safely reach gastric mucosa. Yeast, as the environmental reservoir of H. pylori, plays a crucial role in bacterial reinfection after successful eradication.

Measurement of rRNA Synthesis and Degradation Rates by 3H-Uracil Labeling in Yeast.

In order to measure the actual synthesis and degradation rates (SR, DR) for rRNA in yeast, we developed a method based on the pulse labeling and quantification of newly synthesized large rRNA molecules by a known mass of cells. The SR is calculated as the ratio of new rRNA molecules (synthesized after a short [5,6-3H]-uracil pulse) to total rRNA (a proxy of cell mass), calculated by northern blotting after hybridization with a 32P-labeled rRNA probe. Then to measure the DR we perform a chase of the existing 3H-labeled rRNA for several hours during yeast culture growth. We have used this method in control experiments where the yeast cell volume varies as a way to check if the SR and DR are constant with the cell volume.

Impact of Water Ionic Chemistry on Kombucha Fermentation

Kombucha is made by using a symbiotic culture of bacteria and yeast (SCOBY) to ferment sweetened tea. This fermentation produces a beverage with a unique aroma and acidic flavor. Kombucha has recently gained popularity in the United States and has been reported to have numerous health benefits. While there is a wide variation in kombucha composition, little is known about the impact water’s chemistry has on the fermentation and the resulting kombucha. Brewing water for kombucha was altered using the following ions: bicarbonate, chloride, calcium, magnesium, and sulfate at different concentrations. Pre-(tea) and post-(kombucha) fermentation (kombucha) products were analyzed for total acidity, pH, free amino nitrogen (FAN), total phenols, antioxidants, and biological components. A one-way ANOVA was run to determine statistical (p &lt; 0.05) differences between the characteristics analyzed. Statistical differences were observed between the different water chemistry ions for all of the characteristics analyzed. Further investigation into the impact water chemistry has on flavor analysis is required. The information obtained from this research can be used to help producers to make kombuchas with an optimized chemical profile and improved antioxidant potentials.

Effect of dietary supplementation of yeast culture Saccharomyces cerevisiae in lactating female goats.

This study was designed to investigate the effects of adding a novel yeast culture, Saccharomyces cerevisiae refermented sorghum distiller's dried grains with solubles (SSDDGS), to the diets of lactating female goats on lactation performance and lamb growth performance. We divided 10 lactating Dazu black goats of similar age, weight, and offspring into two groups: one fed a pelleted diet with 50 g/day SSDDGS (ET), and the other without SSDDGS as a control (EC) for 7 weeks. We monitor the weight changes of each goat and collect blood and milk samples from experimental ewes at specific times for hormone and milk composition determination. We use ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to detect metabolites in the serum of lactating ewes. Our results showed that SSDDGS supplementation significantly reduced female goats' average daily weight loss during weeks 2-4 of lactation and increased serum IGF-1 and prolactin levels at week 4 (p < 0.05). SSDDGS supplementation in early lactation significantly increased milk protein, lactose, and ash content (p < 0.05). UPLC-MS/MS analysis showed that SSDDGS changed the levels of 58 metabolites in the serum of lactating goats. These metabolites were mainly involved in the sohingolipid signaling pathway, and cysteine, methionine, and sphingolipid metabolism. In summary, Yeast culture SSDDGS reduced weight loss, enhanced milk quality, and modified metabolic profiles in early lactation goats, providing insight into the potential regulatory role and mechanism of yeast culture in lactation female goats.

In Vitro Cholesterol Uptake by the Microflora of Selected Kefir Starter Cultures.

Kefir, a fermented milk beverage, is recognized for its potential health benefits, including its cholesterol-lowering properties. This study demonstrated that selected kefir starter cultures, including Lactococcus strains and yeasts, significantly reduce cholesterol-binding capacity under simulated gastrointestinal conditions, underscoring the challenges of probiotic delivery. We compared the performance of these cultures under laboratory conditions (growth broths) and simulated digestive juice models. Lactococcus strains showed significant differences in cholesterol binding between the two environments, highlighting the limitations of relying solely on laboratory testing. Yeast cultures also exhibited greater cholesterol binding in their native broths, but their survival was limited in digestive models. Our findings suggest that effective probiotic formulations should prioritize strains with high cholesterol-binding capacity and robust survival rates throughout the digestive tract. This study provides valuable insights for future research on the mechanisms behind these functionalities and the potential of kefir yeast strains for use in human digestive models. Our results can be used to inform the development of improved probiotic formulations for cholesterol management.

Assessing Drug Sensitivity in Fission Yeast Using Half-Maximal Inhibitory Concentration (IC50) Assays.

Fission yeast is an excellent model organism in which to study mammalian drug sensitivities. In addition to building a mechanistic picture of drug effect, fission yeast screens may be valuable in determining compounds that show synthetic lethality effects. While compounds might be screened for a variety of phenotypes, an effective method is to detect the proliferative effects of a new compound on a yeast culture. This is traditionally performed in acute viability assays or spot tests; both methods require some knowledge of concentration to observe an effect. Mammalian cell culture experiments that assess proliferation to indicate drug dose and effect are well described. However, differences between S. pombe growth characteristics and mammalian cells mean that importing a mammalian viability assay requires consideration of potential effects on fission yeast biology. We describe the half-maximum inhibitory (IC50) dose as a method of rapid proliferation effect screening. IC50 determination is performed on liquid cultures in 96-well plates and may be developed for initial compound library uses or in synthetic lethality screening of drug effects.

Identification of ERAD-dependent degrons for the endoplasmic reticulum lumen

Degrons are minimal protein features that are sufficient to target proteins for degradation. In most cases, degrons allow recognition by components of the cytosolic ubiquitin proteasome system. Currently, all of the identified degrons only function within the cytosol. Using Saccharomyces cerevisiae, we identified the first short linear sequences that function as degrons from the endoplasmic reticulum (ER) lumen. We show that when these degrons are transferred to proteins, they facilitate proteasomal degradation through the endoplasmic reticulum associated degradation (ERAD) system. These degrons enable degradation of both luminal and integral membrane ER proteins, expanding the types of proteins that can be targeted for degradation in budding yeast and mammalian tissue culture. This discovery provides a framework to target proteins for degradation from the previously unreachable ER lumen and builds toward therapeutic approaches that exploit the highly conserved ERAD system.

Identification of ERAD-dependent degrons for the endoplasmic reticulum lumen.

Degrons are minimal protein features that are sufficient to target proteins for degradation. In most cases, degrons allow recognition by components of the cytosolic ubiquitin proteasome system. Currently, all of the identified degrons only function within the cytosol. Using Saccharomyces cerevisiae, we identified the first short linear sequences that function as degrons from the endoplasmic reticulum (ER) lumen. We show that when these degrons are transferred to proteins, they facilitate proteasomal degradation through the endoplasmic reticulum associated degradation (ERAD) system. These degrons enable degradation of both luminal and integral membrane ER proteins, expanding the types of proteins that can be targeted for degradation in budding yeast and mammalian tissue culture. This discovery provides a framework to target proteins for degradation from the previously unreachable ER lumen and builds toward therapeutic approaches that exploit the highly conserved ERAD system.