Culture Saccharomyces Cerevisiae Research Articles

Persistent Luminescence Nanosensors: A Generalized Optode-Based Platform for Autofluorescence-Free Sensing in Biological Systems.

Fluorescent nanosensors have revolutionized diagnostics and our ability to monitor cellular dynamics. Yet, distinguishing sensor signals from autofluorescence remains a challenge. Here, we merged optode-based sensing with near-infrared-emitting ZnGa2O4:Cr3+ persistent luminescence nanoparticles (PLNPs) to create nanocomposites for autofluorescence-free "glow-in-the-dark" sensing. Hydrophobic modification and incorporation of the persistent luminescence nanoparticles into an optode-based nanoparticle core yielded persistent luminescence nanosensors (PLNs) for five analytes (K+, Na+, Ca2+, pH, and O2) via two distinct mechanisms. We demonstrated the viability of the PLNs by quantifying K+ in fetal bovine serum, calibrating the pH PLNs in the same, and ratiometrically monitoring O2 metabolism in cultures of Saccharomyces cerevisiae, all the while overcoming their respective autofluorescence signatures. This highly modular platform allows for facile tuning of the sensing functionality, optical properties, and surface chemistry and promises high signal-to-noise ratios in complex optical environments.

Biological autoluminescence enables effective monitoring of yeast cell electroporation.

The application of pulsed electric fields (PEFs) is becoming a promising tool for application in biotechnology, and the food industry. However, real-time monitoring of the efficiency of PEF treatment conditions is challenging, especially at the industrial scale and in continuous production conditions. To overcome this challenge, we have developed a straightforward setup capable of real-time detection of yeast biological autoluminescence (BAL) during pulsing. Saccharomyces cerevisiae culture was exposed to 8 pulses of 100 µs width with electric field strength magnitude 2-7kV cm-1. To assess the sensitivity of our method in detecting yeast electroporation, we conducted a comparison with established methods including impedance measurements, propidium iodide uptake, cell growth assay, and fluorescence microscopy. Our results demonstrate that yeast electroporation can be instantaneously monitored during pulsing, making it highly suitable for industrial applications. Furthermore, the simplicity of our setup facilitates its integration into continuous liquid flow systems. Additionally, we have established quantitative indicators based on a thorough statistical analysis of the data that can be implemented through a dedicated machine interface, providing efficiency indicators for analysis.

Development, characterization and application of 3D printed adsorbents for in situ recovery of taxadiene from microbial cultivations

Microbial cell factories are an attractive alternative to produce high-value natural products using sustainable processes. However, product recovery is one of the main challenges to reduce production cost and make these technologies economically interesting. In this work, new resins were formulated to 3D print hydrophobic adsorbents for the recovery of biologics from microbial cultivations. Benzyl methacrylate (BEMA) and butyl methacrylate (BUMA) were selected as functional monomers suitable for the adsorption of hydrophobic compounds. Pore morphology was tailored through the inclusion of pore forming agents (porogens) in the resin. Different porogens and porogen concentrations were evaluated resulting in materials with different porous networks. Sudan 1 and the anticancer drug paclitaxel were employed as model compounds to test the adsorption performance of hydrophobic and terpene molecules onto the developed 3D printed materials. The material with greatest adsorption capacity was obtained using BEMA monomer with 40 % (v/v) porogen (BEMA40). The performance of BEMA40 to recover taxadiene from small-scale (5 mL) Saccharomyces cerevisiae cultivations was tested and compared with commercial Diaion HP-20 beads. Taxadiene titres on BEMA40 (46 ± 2 mg/L) and Diaion HP-20 (54 ± 4 mg/L) were comparable, with no taxadiene detected in the cells and cell-free media, suggesting near 100 % taxadiene partition on the adsorbents. Compared to commercial beads, 3D printed adsorbents can be customized with adjustments in the resin formulation, are well adaptable to diverse bioreactor types, do not clog sampling ports and columns and are easier to handle during post processing. The results of this work demonstrate the potential of 3D printing to fabricate hydrophobic interaction adsorbent materials and their application in the recovery of biological products.

Modeling and simulation of an integrated bioethanol-hydrogen production process

Hydrogen (H2) production from renewable feedstocks such as bioethanol represents one of the sustainable and environmentally benign methods of making the proposed utilization of H2 as energy carrier of the future a reality. However, successful implementation of this technology depends on several factors which include understanding of the technicality, as well as process design and modelling. Generally, this area of research has not received adequate attentions. In this article, an integrated process for producing H2 through starch hydrolysis, fermentation, and ethanol steam reforming (ESTR) process has been proposed. Enzymatic hydrolysis of starch was performed to obtain the fermentable sugar (hydrolysate). In addition, batch fermentation experiments were carried out using a laboratory scale fermenter with yeast (Saccharomyces cerevisiae) culture adapted for anaerobic conversion of the hydrolysate to bioethanol. Subsequently, kinetic data obtained from these experiments was employed to guide thermodynamic modeling of fermentation process which was coupled with the ESTR model and was implemented in the Aspen HYSYS simulator. The results ultimately revealed pertinent information which could find applications in the implementation of the proposed integrated process for bioethanol and H2 production.

Physicochemical attributes and acceptability of marula wine fermented with natural Lactiplantibacillus plantarum and Saccharomyces cerevisiae

The aim of the study was to test the acceptability and physico-chemical characteristics of marula wine fermented with known cultures of natural Lactiplantibacillus plantarum and Saccharomyces cerevisiae. The LAB Lactobacillus and Saccharomyces dominate the fermentation of marula wine throughout the fermentation period. These were isolated and identified from the spontaneously fermented marula wine and re-inoculated as single cultures and as mixed cultures to ferment marula juice into wine. The Saccharomyces cerevisiae combined with Lactiplantibacillus plantarum (PYL) and Saccharomyces cerevisiae (PY) fermented wines were not significantly different (p ≥ 0.05) in all the physico-chemical characteristics and acceptability. The single culture of Lactiplantibacillus plantarum had the lowest pH of 2.8. The alcohol content of marula wine fermented with Saccharomyces cerevisiae was 6.10 ± 0.17, while the alcohol content of the spontaneously fermented wine was 3.33 ± 2.49. The oBrix of wine fermented with Saccharomyces cerevisiae only and as mixed culture was 2.07 ± 0.21 and 2.00 ± 0.00, respectively, while the control and Lactiplantibacillus plantarum had an oBrix of 6.23 ± 2.77 and 8.67 ± 0.06, respectively. The Lactiplantibacillus plantarum fermented sample and the control had significantly higher overall acceptability scores of 7.60 and 6.98, respectively. Saccharomyces cerevisiae is capable of producing ethanol as a single culture and co-cultured with Lactobacillus plantarum. The most preferred wine was that fermented by Lactiplantibacillus plantarum only because of its sweetness.

Comparative Evaluation of Unpeeled Cassava (Manihot esculenta) and Tacca (Tacca involucrata) Tuber Flours as Substrates for Bioethanol Production

The ever-increasing demand for alternatives to fossil fuel due to its negative impacts on the environment and high prices have resulted in the search for feedstock for bioethanol production. Cassava is one of the major staple foods that is processed into various preservative forms in Nigeria, while tacca is a plant growing in the wild and is eaten by a few people during scarcity of food. Unpeeled cassava and tacca tubers were processed into flour. The flour was hydrolyzed using Aspergillus niger and Saccharomyces cerevisiae, separately. The bioethanol potentials of tuber flours were evaluated using a single-step process. Hydrolysis of 10g of cassava tuber flour separately by Aspergillus niger and Saccharomyces cerevisiae produced (g/100mL) 0.720 and 0.765 of sugar, respectively, while hydrolysis of 10g of tacca tuber flour separately by Aspergillus niger and Saccharomyces cerevisiae produced (g/100mL) 0.392 and 0.367 of sugar respectively. Evaluation of the effect of time during hydrolysis of cassava tuber flour for 24h by Aspergillus niger and Saccharomyces cerevisiae separately produced (g/100mL) 1.44 and 0.737 of sugar, while hydrolysis of tacca tuber flour for 24h produced (g/100mL) 0.768 and 0.493 of sugar. Evaluation of the effect of varying pH values during hydrolysis of the tuber flours revealed that pH 5.6 produced the highest concentration of sugar (0.240g/100mL) and (0.803g/100mL) when Aspergillus niger and Saccharomyces cerevisiae were separately used to hydrolyze cassava tuber flour. When Aspergillus niger and Saccharomyces cerevisiae were separately used to hydrolyze tacca tuber flour at pH 5.6, 0.626g and 0.436g of sugar was produced. Fermentation of cassava tuber flour by mixed culture of Aspergillus niger and Saccharomyces cerevisiae for 48h produced 3.851%(w/v) bioethanol at 24h of fermentation, while fermentation of tacca tuber flour by mixed culture of Aspergillus niger and Saccharomyces cerevisiae produced 3.236% (w/v) bioethanol at 48h. Cassava tuber flour produced a higher concentration of bioethanol than tacca tuber flour. These results have shown that tacca tuber is a potential feedstock for bioethanol production, hence exploitation of nonfood materials such as tacca tuber for bioprocesses can reduce the over _dependence on cassava tuber.

Effects of Saccharomyces cerevisiae live cells and culture on growth and productive performance in lactating Nili-Ravi buffaloes.

An experimental work was conducted to evaluate the effects of Saccharomyces cerevisiae live cells and its culture on dry matter intake (DMI), milk yield, milk composition, body condition score, selected blood metabolites, feed conversion efficiency (FCE), nutrient digestibility, body weight gain, and economics of milk production in lactating multiparous Nili-Ravi buffaloes. In total, 20 buffaloes of age 5 years ± 6 months and weighing 550 ± 20 kg were selected and assigned to four dietary treatments (n=5 buffalo/treatment) under completely randomized design. The dietary treatments include treatment 1 (T1) control, treatment 2 (T2) 5g/head live yeast, treatment 3 (T3) 5g/head yeast culture, and treatment 4 (T4) 10 g/head yeast culture per day for 60 days excluding 14 days as an adjustment period. The results indicated that T4 showed significant (p<0.05) improvement in DMI, milk yield and components, blood glucose level, digestibility of nutrients, and body weight gain while significant decrease in blood urea nitrogen as compared to other treatment groups. Body condition score was not affected among treatments. In conclusion, yeast culture supplementation significantly improved (p <0.05) milk yield, milk composition, DMI, body weight gain, blood glucose level, and digestibility while significantly decreased blood urea level as compare to control. Economic return was also improved. BCS was not improved. Comparatively, yeast culture showed significant improvement in growth and productive performance as compare to live yeast. Meanwhile, 10-g yeast culture showed better results as compare to 5-g yeast culture.

Municipal green waste as substrate for the microbial production of platform chemicals

In Germany alone, more than 5·106 tons of municipal green waste is produced each year. So far, this material is not used in an economically worthwhile way. In this work, grass clippings and tree pruning as examples of municipal green waste were utilized as feedstock for the microbial production of platform chemicals. A pretreatment procedure depending on the moisture and lignin content of the biomass was developed. The suitability of grass press juice and enzymatic hydrolysate of lignocellulosic biomass pretreated with an organosolv process as fermentation medium or medium supplement for the cultivation of Saccharomyces cerevisiae, Lactobacillus delbrueckii subsp. lactis, Ustilago maydis, and Clostridium acetobutylicum was demonstrated. Product concentrations of 9.4 gethanol L−1, 16.9 glactic acid L−1, 20.0 gitaconic acid L−1, and 15.5 gsolvents L−1 were achieved in the different processes. Yields were in the same range as or higher than those of reference processes grown in established standard media. By reducing the waste arising in cities and using municipal green waste as feedstock to produce platform chemicals, this work contributes to the UN sustainability goals and supports the transition toward a circular bioeconomy.Graphical

Enhancement of superoxide dismutase activity using mixed Lactobacillus casei and Saccharomyces cerevisiae cultures in simulated gastrointestinal conditions with encapsulation

Superoxide dismutase (SOD)-producing microorganisms have attracted increasing attention given their scavenge superoxide anions capabilities, but further strengthening methods are still urgently needed. Herein, Lactobacillus casei F18 and Saccharomyces cerevisiae J14 were isolated for their high SOD activity. Co-culturing these two strains emerged effective nutritional cooperation, which increased SOD activity by 198.22% and 66.35% compared to F18 and J14, respectively. SOD activity of co-culture “F18 +J14” was further enhanced by response surface methodology and metal ion stress. High-performance liquid chromatographic and RT-qPCR analyses of “F18 +J14” revealed that SOD production pathways were active and contents of metabolites acetate and ethanol were dramatically increased. Metabolite complementarity experiment also verified the addition of acetate and ethanol in vitro enhanced SOD activity and gene expression of “F18 +J14”. These findings highlighted co-culture and metal ion stress enhanced SOD activity by cross-stimulating cells with metabolites, affecting cell growth, and up-regulating SOD genes. Furthermore, “F18 +J14” based immobilized bio-beads were successfully synthesized with sodium alginate combined CaCO3, which exhibited the highest cell vitality and SOD activity in the simulated gastrointestinal conditions. Together, this study revealed the synergistic promotion mechanism of SOD biosynthesis by co-cultivation lactic acid bacteria and yeast, and shows great promise for management of oxidation stress related diseases.

Efficiency of a food supplement containing Saccharomyces cerevisiae culture in the diet of broiler chickens

Currently, high productivity parameters in poultry farming are achievable only by maximum fulfillment of the poultry’s biological needs, because only healthy and highly productive birds can be the basis of the sphere’s profitability. All this is closely associated with the usage of feed additives of natural origin and effective methods of poultry farming, which provide high productivity and natural resistance of a bird’s body. In the experiment, we examined the effects of a probiotic feed additive on the productivity and slaughter parameters of the broiler chickens. Intake of the feed supplement by the experimental-group broiler chickens increased their live weight by 5% at the age of 28 days, 12% at the age of 35 days, and by 14% at the age of 42 days, compared with the control group. Using the tested probiotic feed supplement in the diet increased the mean daily (by 15.9%) and absolute increments (by 14.4% compared with the control group). Intake of the probiotic feed supplement by broiler chickens of the experimental group increased their pre-slaughter live weight by 14.2%, weight of non-processed carcasses by 15.5%, semi-processed carcass by 15.7% and processed carcass by 15.3%, compared with the parameters of the control group. In broilers of the experimental group, there were increases in the general weight of muscles (10.3%), namely the breast muscles (11.8%), muscles of thighs and lower legs (9.8%), and weight of the gizzard (by 6.5%), compared with the control group. Intake of the probiotic supplement by the experimental-group broiler chickens resulted in increases in width of the proventriculus (28.5%), length of the gizzard (16.3%) and width of the gizzard (29.7%), compared with the control group of animals. The probiotic feed supplement increased the length of the duodenum (by 7.6%) and the jejunum (by 4.5%) in the experimental-group broiler chickens, against the control. Therefore, feed supplements based on cheap culture Saccharomyces cerevisiae are promising, because they are able to enhance the effectiveness of poultry farming at relatively small costs.

High-throughput Saccharomyces cerevisiae cultivation method for credentialing-based untargeted metabolomics

Identifying metabolites in model organisms is critical for many areas of biology, including unravelling disease aetiology or elucidating functions of putative enzymes. Even now, hundreds of predicted metabolic genes in Saccharomyces cerevisiae remain uncharacterized, indicating that our understanding of metabolism is far from complete even in well-characterized organisms. While untargeted high-resolution mass spectrometry (HRMS) enables the detection of thousands of features per analysis, many of these have a non-biological origin. Stable isotope labelling (SIL) approaches can serve as credentialing strategies to distinguish biologically relevant features from background signals, but implementing these experiments at large scale remains challenging. Here, we developed a SIL-based approach for high-throughput untargeted metabolomics in S. cerevisiae, including deep-48 well format-based cultivation and metabolite extraction, building on the peak annotation and verification engine (PAVE) tool. Aqueous and nonpolar extracts were analysed using HILIC and RP liquid chromatography, respectively, coupled to Orbitrap Q Exactive HF mass spectrometry. Of the approximately 37,000 total detected features, only 3–7% of the features were credentialed and used for data analysis with open-source software such as MS-DIAL, MetFrag, Shinyscreen, SIRIUS CSI:FingerID, and MetaboAnalyst, leading to the successful annotation of 198 metabolites using MS2 database matching. Comparable metabolic profiles were observed for wild-type and sdh1Δ yeast strains grown in deep-48 well plates versus the classical shake flask format, including the expected increase in intracellular succinate concentration in the sdh1Δ strain. The described approach enables high-throughput yeast cultivation and credentialing-based untargeted metabolomics, providing a means to efficiently perform molecular phenotypic screens and help complete metabolic networks.Graphical abstract

Effect of dry extract from Saccharomyces cerevisiae culture with selenium-containing amino acids on the productivity and chemical composition of meat of broiler chickens

Introduction of biologically active supplements to the diet of poultry results in maximal use of nutrients and positively influences the live weight and slaughter parameters. This promotes rational and economical use of fodders and boosts the poultry productivity. We studied a mineral feed supplement – an organic selenium compound, which has a much greater bioavailability than inorganic sources of selenium. Selenomethionine is easily digested in the organism and effectively used for synthesis of proteins. Broiler chickens of the experimental group that had been consuming the selenoamino-acid feed additive had greater live weight at the age of 14–42 days, compared with the control. Intake of the mineral supplement by the broiler chickens in the experimental group increased their mean daily increment by 8.5% and the absolute increment by 8.6%, compared with the control peers. In the experimental group of broilers, the mineral supplement increased the pre-slaughter live weight by 8.4%, weight of intact carcass by 10.1%. Also, the weight of the semi-processed carcasses (i.e. those with removed intestines and cloaca, filled crop, oviduct and ovary (in female specimens) increased by 4.3%, and the weight of the processed carcasses (the internal organs and abdominal-cavity fat and esophagus of which were removed, without head, legs and wing metacarpals) increased by 8.0%, compared with the control group of broilers. In the experimental group, the feed supplement gave 13.7% rise in the weight of the breast muscles and 14.5% increase in the weight of the thigh muscles, compared with the control group. Intake of this supplement in the experimental group promoted 7.5% increase in the weight of the gizzard by and 9.2% increase in the weight of the duodenum, as compared with the control. Usage of the selenoamino-acid feed supplement increased the protein concentration in the breast muscles of the broiler chickens by 1.9%, compared with the control. Intake of the mineral supplement increased the amounts of dry matter and fat in the thigh muscles of the experimental group, compared with the control group. Therefore, adding dry yeast extract to diet of broilers together with selenium-containing amino acids is a promising method of increasing the effectiveness of poultry farming.

Quantification and mitigation of byproduct formation by low-glycerol-producing Saccharomyces cerevisiae strains containing Calvin-cycle enzymes

BackgroundAnaerobic Saccharomyces cerevisiae cultures require glycerol formation to re-oxidize NADH formed in biosynthetic processes. Introduction of the Calvin-cycle enzymes phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) has been shown to couple re-oxidation of biosynthetic NADH to ethanol production and improve ethanol yield on sugar in fast-growing batch cultures. Since growth rates in industrial ethanol production processes are not constant, performance of engineered strains was studied in slow-growing cultures.ResultsIn slow-growing anaerobic chemostat cultures (D = 0.05 h−1), an engineered PRK/RuBisCO strain produced 80-fold more acetaldehyde and 30-fold more acetate than a reference strain. This observation suggested an imbalance between in vivo activities of PRK/RuBisCO and formation of NADH in biosynthesis. Lowering the copy number of the RuBisCO-encoding cbbm expression cassette from 15 to 2 reduced acetaldehyde and acetate production by 67% and 29%, respectively. Additional C-terminal fusion of a 19-amino-acid tag to PRK reduced its protein level by 13-fold while acetaldehyde and acetate production decreased by 94% and 61%, respectively, relative to the 15 × cbbm strain. These modifications did not affect glycerol production at 0.05 h−1 but caused a 4.6 fold higher glycerol production per amount of biomass in fast-growing (0.29 h−1) anaerobic batch cultures than observed for the 15 × cbbm strain. In another strategy, the promoter of ANB1, whose transcript level positively correlated with growth rate, was used to control PRK synthesis in a 2 × cbbm strain. At 0.05 h−1, this strategy reduced acetaldehyde and acetate production by 79% and 40%, respectively, relative to the 15 × cbbm strain, without affecting glycerol production. The maximum growth rate of the resulting strain equalled that of the reference strain, while its glycerol production was 72% lower.ConclusionsAcetaldehyde and acetate formation by slow-growing cultures of engineered S. cerevisiae strains carrying a PRK/RuBisCO bypass of yeast glycolysis was attributed to an in vivo overcapacity of PRK and RuBisCO. Reducing the capacity of PRK and/or RuBisCO was shown to mitigate this undesirable byproduct formation. Use of a growth rate-dependent promoter for PRK expression highlighted the potential of modulating gene expression in engineered strains to respond to growth-rate dynamics in industrial batch processes.

Saccharomyces cerevisiae Culture’s Dose–Response Effects on Ruminal Nutrient Digestibility and Microbial Community: An In Vitro Study

Supplementation with saccharomyces cerevisiae culture products (SCs) has shown effectiveness in alleviating or improving the health and productivity of ruminants at a high risk of digestive and metabolic problems as a consequence of their physiological state and feeding system (i.e., Holstein cows during peak lactation). However, the effects of SC supplementation on ruminal digestion and microbial population are not yet well-understood. Hence, this study aimed to contribute to the knowledge of the effects of in vitro SC supplementation on ruminal nutrient digestibility and microbial community. This study included three treatment groups: a control group (CON, 0% SC proportion of substrate DM), a low-dose SC group (LSC, 0.10% SC proportion of substrate DM), and a high-dose SC group (HSC, 0.30% SC proportion of substrate DM). The SC product contained 7.0 × 109 CFU/g. After 48 h of fermentation at 39 °C, the incubation fluid and residue were collected to measure the ruminal nutrient digestibility and microbial community. The results showed that supplemental SC tended (p = 0.096) to increase DM digestibility due to an increase (9.6%, p = 0.03) in CP digestibility and via a tendency (0.05 &lt; p &lt; 0.08) to increase the fiber fraction. Additionally, the 16S rRNA high-throughput sequencing results revealed that the richness and diversity of the microbiota were unchanged by SC supplementation, while the abundances of Spirochaetes, Tenericutes, and Spirochaetaceae were lower in the SC groups than those in the CON group (p &lt; 0.05). At the genus level, the abundances of Selenomonas and Succinivibrio were increased by SC supplementation (p &lt; 0.05), while SC supplementation decreased the abundances of Ruminococcaceae_UCG-014 and Treponema_2 (p &lt; 0.05). Furthermore, the predicted function of the microbiota showed that carbohydrate metabolism and lipid metabolism were enriched in the SC groups compared with the CON group (p &lt; 0.05). Except for the increases in ADF digestibility (p = 0.032) and pH (p = 0.076) at 0.30%, the supplemental level did not result in additional effects. In summary, our results demonstrate that SC supplementation could improve ruminal nutrient degradation digestibility and alter microbiota composition.

Development of a feed-forward control system for medium in shake-flask culture

Shake-flask culture is used in various applications and is one of the most widely used aerobic culture methods at the laboratory scale. Most shake-flask cultures used upstream of bioprocess development use a batch mode strategy, necessitating the expansion of culture conditions in upstream bioprocess development not limited to batch mode. Hence, the development of convenient small-scale fed-batch culture methods is necessary. The aim of this study was to develop a system that can provide a feed strategy for shaking cultures using an Erlenmeyer flask with a breathable culture stopper. The developed system comprises commercial products, is equipped with a sampling unit that does not interfere with the feeding strategy when collecting culture broth during shaking culture, and is applied to a shake-flask culture of Saccharomyces cerevisiae. The set values for bacterial yield and specific growth rate were fixed at 0.5 g-dry cell/g-D-glucose and 0.2 /h, respectively, whereas the measured values were observed to be 0.55 g-dry cell/g-D-glucose and 0.22 /h, respectively (batch mode: 0.22 g-dry cell/g-D-glucose and 0.45 /h, respectively). These results indicate that the developed system enables highly accurate feed-forward control of the feeding solution without changing the conventional components used in the shake-flask culture methods.

Bioconvertibility of fermentative vert wine: a comparative study of blue- green algae, pineapple, and longan fruits

This research delves into the innovative fermentation of wines using blue-green algae (spirulina), pineapple, and longan fruit. Traditional wine consumption, often synonymous with alcohol content, has seen a shift in value and health appeal with the infusion of spirulina. The fermentation process was monitored using both single and mixed cultures of Saccharomyces cerevisiae until it achieved 12% alcohol content. Sensory evaluations by fruit wine consumers revealed gender-based preferences in the acceptability of tangerine wine formulations. Specifically, females showed a higher liking for 5 out of 9 wine formulas, with sugar and acidity playing pivotal roles in flavours preference. Three distinct algae wine recipes were fermented at room temperature, with chemical analyses post-fermentation indicating standard pH levels for wine (3.0 - 4.0). Among them, the seaweed-pineapple blend was the standout, with a pH of 3.55 and a 72.96% approval rate among taste testers. The economic analysis highlighted the pineapple-seaweed variant's high production cost, though pure spirulina wine boasted the most significant return on investment. In conclusion, pineapple-infused spirulina wine emerges as a frontrunner in terms of taste, standard adherence, and economic viability, presenting a solution to the regional fruit surplus.

Metabolomic analysis of the effects of a mixed culture of Saccharomyces cerevisiae and Lactiplantibacillus plantarum on the physicochemical and quality characteristics of apple cider vinegar.

This study compared differences in physicochemical characteristics of the vinegar made by a mixed culture (MC) of Saccharomyces cerevisiae and Lactiplantibacillus plantarum and a pure culture (PC) of Saccharomyces cerevisiae. The fermentation process was monitored, and metabolomics analysis by Liquid Chromagraphy-Mass Spectrometry (LC-MS) was applied to the compositional differences between PC and MC vinegars, combined with quantification of organic acids, amino acids and B vitamins. A total of 71 differential metabolites including amino acids, organic acids and carbohydrates, and six possible key metabolic pathways were identified. MC enhanced the malic acid utilization and pyruvate acid metabolism during fermentation, increasing substrate-level phosphorylation, and supplying more energy for cellular metabolism. Higher acidity at the beginning of acetic acid fermentation, resulting from lactic acid production by Lactiplantibacillus plantarum in MC, suppressed the cellular metabolism and growth of Acetobacter pasteurianus, but enhanced its alcohol metabolism and acetic acid production in MC. MC vinegar contained more vitamin B, total flavonoids, total organic acids, amino acids and had a higher antioxidant capacity. MC enhanced the volatile substances, particularly ethyl lactate, ethyl caprate and ethyl caproate, which contributed to a stronger fruity aroma. These results indicated the mixed culture in alcoholic fermentation can effectively enhance the flavor and quality of apple cider vinegar.

Expanding the diversity of Chardonnay aroma through the metabolic interactions of Saccharomyces cerevisiae cocultures.

Yeast co-inoculations in winemaking are often studied in the framework of modulating the aromatic profiles of wines. Our study aimed to investigate the impact of three cocultures and corresponding pure cultures of Saccharomyces cerevisiae on the chemical composition and the sensory profile of Chardonnay wine. Coculture makes it possible to obtain completely new aromatic expressions that do not exist in the original pure cultures attributed to yeast interactions. Esters, fatty acids and phenol families were identified as affected. The sensory profiles and metabolome of the cocultures, corresponding pure cultures and associated wine blends from both pure cultures were found to be different. The coculture did not turn out to be the addition of the two pure culture wines, indicating the impact of interaction. High resolution mass spectrometry revealed thousands of cocultures biomarkers. The metabolic pathways involved in these wine composition changes were highlighted, most of them belonging to nitrogen metabolism.

Optimizing the balance between heterologous acetate- and CO2-reduction pathways in anaerobic cultures of Saccharomyces cerevisiae strains engineered for low-glycerol production.

In anaerobic Saccharomyces cerevisiae cultures, NADH (reduced form of nicotinamide adenine dinucleotide)-cofactor balancing by glycerol formation constrains ethanol yields. Introduction of an acetate-to-ethanol reduction pathway based on heterologous acetylating acetaldehyde dehydrogenase (A-ALD) can replace glycerol formation as 'redox-sink' and improve ethanol yields in acetate-containing media. Acetate concentrations in feedstock for first-generation bioethanol production are, however, insufficient to completely replace glycerol formation. An alternative glycerol-reduction strategy bypasses the oxidative reaction in glycolysis by introducing phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). For optimal performance in industrial settings, yeast strains should ideally first fully convert acetate and, subsequently, continue low-glycerol fermentation via the PRK-RuBisCO pathway. However, anaerobic batch cultures of a strain carrying both pathways showed inferior acetate reduction relative to a strain expressing only the A-ALD pathway. Complete A-ALD-mediated acetate reduction by a dual-pathway strain, grown anaerobically on 50g L-1 glucose and 5mmol L-1 acetate, was achieved upon reducing PRK abundance by a C-terminal extension of its amino acid sequence. Yields of glycerol and ethanol on glucose were 55% lower and 6% higher, respectively, than those of a nonengineered reference strain. The negative impact of the PRK-RuBisCO pathway on acetate reduction was attributed to sensitivity of the reversible A-ALD reaction to intracellular acetaldehyde concentrations.

Yeast (Saccharomyces cerevisiae) Culture Promotes the Performance of Fattening Sheep by Enhancing Nutrients Digestibility and Rumen Development

Paraprobiotics are potential agents for improving animal health and performance. This experiment investigated the effect of dietary supplementation of yeast (Saccharomyces cerevisiae) culture (YC) on the growth performance, nutrient digestibility, rumen development and microbiome of fattening sheep. Ninety male Hu sheep weighed 38 ± 1.47 kg were randomly assigned to three treatments: CON diet (basal diet), LYC diet (basal diet supplied with 10 and 20 g/d yeast culture at the early and late stages, respectively), and HYC diet (basal diet supplied with 20 and 40 g/d yeast culture at the early and late stages, respectively). Treatments (LYC or HYC) were sprinkled on the feed surface according to the required dosage before feeding the basal diet to each sheep throughout the trial. The trial included early (60 days) and later (30 days) fattening periods. The results showed that average daily gain and feed efficiency were higher (p &lt; 0.05) in the LYC group compared with CON in later and whole stages. Digestibility of DM, OM, CP, NDF and ADF were higher (p &lt; 0.05) in LYC and HYC compared with CON. The retained N, the utilization efficiency of N and the biological value of N were higher (p &lt; 0.05) in LYC compared with CON and HYC. Rumen NH3-N was higher (p &lt; 0.05) in LYC and HYC. The papillary height of the rumen was higher (p &lt; 0.05) in LYC when compared with CON and HYC, whereas rumen wall thickness and muscular layer thickness were higher (p &lt; 0.05) in HYC compared with CON and LYC. The dressing percentage of LYC and HYC was higher (p &lt; 0.05) compared with CON. The diversity, richness and structure of rumen microbiota showed no significant difference (p &gt; 0.05); however, still observed remarkable increases in the relative abundance of several specific genera including Succiniclasticum and Fibrobacter with increasing doses of yeast culture. In addition, at the ASV level, ASV83, ASV123 (Succiniclasticum), and ASV148, ASV250 (Fibrobacter) were increased in YC groups. In conclusion, we confirmed that the supplementation of YC in diet could improve the growth and slaughter performance of fattening Hu sheep through improving nutrient digestion, especially nitrogen utilization, rumen microbial environment and the development of rumen epithelium, which proves the benefits of paraprobiotics in animal production.