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A green and facile synthesis of 1-(α-aminoalkyl)-2-naphthols, generally called Betti bases (BB) in the presence of Baker's yeast (BY), acts as an efficient catalyst, and ethanol as a green solvent. In this methodology, the BY is used first time as a biocatalyst (enzyme). This protocol has some inherent advantages, such as mild reaction conditions, no environmental pollution, simple work up, no need of column chromatography, diversity of reactant and desired 1-(α-aminoalkyl)-2-naphthols (Betti bases) (4a-r) are obtained in good-to-excellent yields. This is the first report on Baker's yeast-catalyzed (BYC) synthesis for BB. This present bio-catalytical route for synthesizing BB in the presence of biocatalysts like BY is anticipated to open a gateway to synthesized complexed biological active molecules counting BB. HIGHLIGHTS: A green and facile synthesis of amino alkyl naphthols (4a-r) by using Baker's yeast as efficient catalyst and ethanol as green solvent. The Baker's Yeast is used first time as biocatalyst for the multi component Betti Reaction The advantages of the present methods are mild reaction conditions, no environmental pollution, diversity of reactant, simple work up, no coloumn chromatography and good-to-excellent yield of desired Betti bases (4a-r). The reaction is totally carried out under envirnmentally friendly condition by using green solvent EtOH. It is anticipated that this present bio-catalytical route for the s thesis of Betti bases by using Baker's Yeast as catalyst will open a new gateway to synthesized complexed biological active molecules counting Betti bases. [ABSTRACT FROM AUTHOR]

Radioactive liquid wastes contaminated by U are generated by solvent extraction of nuclear fuel materials in experiments of reprocessing technologies. We are focusing on baker's yeasts for their excellent metal ions adsorption characteristics, easy handling, and reasonable. We considered that chemically stable uranium oxides could be obtained by thermal decomposition of baker's yeast adsorbed with U, and investigated the waste liquid treatment process using baker's yeast. To clarify the adsorption mechanism, this study analyzed baker's yeast adsorbed with a simulant of the U. Uranium adsorption test was conducted to evaluate adsorption performance and identify issues in engineering-scale liquid waste treatment. [ABSTRACT FROM AUTHOR]

Hydrogen has received attention as a next-generation renewable energy source; accordingly, sustainable production and safe transportation are crucial for its effective utilization. In this study, we focused on dihydrolevoglucosenone (Cyrene TM ), which was a biodegradable ketone derived from cellulose, as a renewable organic hydride. Furthermore, hydrogenation using alcoholic fermentation with baker's yeast was proposed for a novel hydrogen storage, wherein water and nicotinamide adenine dinucleotide serve as hydrogen sources. Cyrene TM was hydrogenated with baker's yeast to produce 1,6-anhydro-3,4-dideoxy- β -D- threo -hexopyranose (Cyrene-OH). Cyrene-OH stored hydrogen via chemical bonding, and was dehydrogenated by warming in the presence of an iridium complex catalyst to produce hydrogen gas and reproduce Cyrene TM . Therefore, this study demonstrated a new sustainable and renewable hydrogen gas production and storage cycle. This cycle, which uses readily available Cyrene TM and baker's yeast, enables hydrogen energy production and storage in isolated areas and should contribute to Sustainable Development Goal 7 (Affordable and Clean Energy). • Cyrene TM derived from cellulose was used as a renewable organic hydride. • Hydrogenation and hydrogen storage using alcoholic fermentation was demonstrated. • A new sustainable hydrogen gas production and storage cycle was established. [ABSTRACT FROM AUTHOR]

Meiotic crossovers are initiated from programmed DNA double-strand breaks. The Msh4–Msh5 heterodimer is an evolutionarily conserved mismatch repair–related protein complex that promotes meiotic crossovers by stabilizing strand invasion intermediates and joint molecule structures such as Holliday junctions. In vivo studies using homozygous strains of the baker's yeast Saccharomyces cerevisiae (SK1) show that the Msh4–Msh5 complex associates with double-strand break hotspots, chromosome axes, and centromeres. Many organisms have heterozygous genomes that can affect the stability of strand invasion intermediates through heteroduplex rejection of mismatch-containing sequences. To examine Msh4–Msh5 function in a heterozygous context, we performed chromatin immunoprecipitation and sequencing (ChIP-seq) analysis in a rapidly sporulating hybrid S. cerevisiae strain (S288c-sp/YJM789, containing sporulation-enhancing QTLs from SK1), using SNP information to distinguish reads from homologous chromosomes. Overall, Msh5 localization in this hybrid strain was similar to that determined in the homozygous strain (SK1). However, relative Msh5 levels were reduced in regions of high heterozygosity, suggesting that high mismatch densities reduce levels of recombination intermediates to which Msh4–Msh5 binds. Msh5 peaks were also wider in the hybrid background compared to the homozygous strain (SK1). We determined regions containing heteroduplex DNA by detecting chimeric sequence reads with SNPs from both parents. Msh5 -bound double-strand break hotspots overlap with regions that have chimeric DNA, consistent with Msh5 binding to heteroduplex-containing recombination intermediates. [ABSTRACT FROM AUTHOR]

In order to prevent the moisture absorption of dried yeast from the flour mixture having a moisture content of 13% (wb), the coating process of dried baker's yeast was aimed and carried out at different conditions using the palm-gelatin-pectin coating material combination determined previously. At an optimum point, the highest bulk and tapped density, the lowest moisture absorption rate, the highest solubility in water, the highest yeast activity, and the highest bread volume values were targeted. At the optimal point, 50 grams of yeast, 0.25 MPa of nozzle pressure, and 13.09% of coating material to yeast ratio were found to be the best. Dried yeasts coated at optimum process conditions and uncoated yeast were added to the flour mixtures and stored at 25 °C for three months. In addition, the effect of different coating material combinations and exit drying temperatures on the effectiveness of the coating process was examined. The palm-Na caseinate-maltodextrin combination was chosen as an alternative coating based on the analysis results on coated yeasts. In conclusion, the coated yeasts demonstrated protective properties against moisture transfer until the end of the second month. [ABSTRACT FROM AUTHOR]

This research was carried out to examine the potential of yeast as a fish feed stabilizer and growth promoter on Clarias gariepienus with varying levels of baker's yeast (Saccharomyces cerevisae). Clarias gariepinus fingerlings with mean weight of 2.40 grams fingerlings were obtained from Aliu Farms, Kaduna and transported to the Fishery unit located in the Zoological Garden of the school, Kaduna State University, Kaduna State Nigeria. The fish were acclimatized for two weeks in 60 Liters' plastic tanks. Fish were stocked at 10 fingerlings per tank containing de-chlorinated tap water in triplicate. Four experimental diets with different inclusion levels of Saccharomyces cerevisiae as follows; Diet I (5%), Diet II (7.5%) Diet III (10%) and Diet IV (12.5%) and the control diet without Saccharomyces cerevisiae were formulated at 40% crude protein. Feed subjected to stability test clearly showed that stability increases with increased level of yeast with Diet IV (12.5%) having the highest at 30 minutes (76%) and 60 minutes (68%). The pelleted feeds were fed to fish at the rate of 5% of the fish biomass throughout the experimental period. The growth response was assessed in terms of daily weight gain, relative weight gain, specific growth rate, feed conversion ratio. The results showed that diet III (10%) gave the best growth performance with an average weight gain of 2.7 followed by diet IV (12.5%) of average weight gain of 2.39 g when compared to the control diet. Similarly, diet III (10%) recorded the highest survival rate of 80%. Thus, adding baker's yeast cells into commercial fish feed at 10% improved growth and survival of Clarias gariepinus. [ABSTRACT FROM AUTHOR]

Yeasts are widely distributed in nature and can be isolated from nutrient rich substrates such as fruit and vegetable, fermented foods and beverages. Yeasts have been employed for millions of years in biotechnological applications in the production of bread, beer and wine. Saccharomyces cerevisiae is most important species when it comes to practical application in industries. Many developing countries including Nigeria spent billions of dollars annually on importation of active dry yeasts used in their baking and brewery industries. In order to reverse this trend, an attempt was made at improving the leavening capacity of S. cerevisiae isolated from locally made traditional alcoholic beverages by mutation induced by N-methyl-N-Nitro-N-Nitrosoguanidine (NTG). The yeast isolates were identified by their morphological properties and biochemical tests using standard methods. The viable counts of yeast isolated from the five alcoholic beverages employed in this study ranged between 1.4x107 and 2.4x108 CFU/mL. The yeast with the lowest percentage of occurrence (1.67%) are Geotricum candidum, Schizosaccharomyces japanicus, Sch. pombe, Candida intermedia etc. while S. cerevisiae had highest percentage of occurrence of 26.67%. S. cerevisiae PWII exhibited the highest dough rising ability among the parent strains, but S. cerevisiae M3 had the best dough rising power among the mutants. Physical examinations of the baked revealed that the bread samples produced with mutant strains compared favorably well with ones produced with commercial yeasts in terms of height, weight and volume. On the other hand bread samples produced using parent strains (PT 14 and PWII) had longer shelf life than bread from mutant and commercial strains. Sensory evaluation by taste panelists showed that the ranges of scores obtained are appearance (5.6-7.9), texture (6.3-8.1), taste (5.5-7.0), crumb (6.0-7.1) and overall acceptability (6.2-7.2). It could be concluded from this study that the leavening ability of S. cerevisiae could be enhanced by chemical mutagens and therefore could by employed in bread baking. [ABSTRACT FROM AUTHOR]

Selective transport through the nuclear pore complex (NPC) depends on the dynamic binding of FG-repeat containing nucleoporins, the FG-nups, with each other and with Karyopherins (Kaps). Here, we assessed the specificity and mechanism by which the aliphatic alcohol 1,6-hexanediol (1,6HD) disrupts the permeability barrier of NPCs in live baker's yeast cells. After a 10-minute exposure to 5% 1,6HD, no notable changes were observed in cell growth, cytosolic pH and ATP levels, or the appearance of organelles. However, effects on the cytoskeleton and Hsp104 were noted. 1,6HD clearly affected the NPC permeability barrier, allowing passive nuclear entry of a 177kDa reporter protein that is normally confined to the cytosol. Moreover, multiple Kaps were displaced from NPCs, and the displacement of Kap122-GFP correlated with the observed passive permeability changes. 1,6HD thus temporarily permeates NPCs, and in line with Kap-centric models, the mechanism includes the release of numerous Kaps from the NPCs. [ABSTRACT FROM AUTHOR]

The growing awareness of the consumers on the advantages of a proper nutrition is deeply modifying their demands. Hence, the exploitation of innovative ingredients to enrich the nutritional values of staple foods is continuously explored by research institutions and food industries. This paper represents a feasibility study on the use of nonconventional ingredients, including house cricket (Acheta domesticus) powder and buckwheat (Fagopyrum esculentum) flour, for the production of novel flatbread formulations. Experimental flatbread prototypes were evaluated by analyzing microbiological, physico-chemical, textural, colorimetric, and volatile parameters. Microbiological viable counts revealed low levels of bacterial spores in the formulations comprising cricket powder. Water activity results showed adequate values, inhibiting the growth of spoilage and pathogenic bacteria, and preventing the germination of bacterial spores. The addition of cricket powder, influenced textural properties of flatbread samples, characterized by lower hardness values respect to those not containing insects seems likely due to a high content of dietary fiber (chitin from insects). As for the color analysis, flatbread samples added with cricket powder evidenced darker tones respect to those not containing insects, thus resulting visibly comparable with whole grain products. Worthy to mention that the addition of buckwheat flours did not cause hardness reduction or color variation of experimental prototypes. The volatile component analysis highlighted numerous compounds associated with enzymatic activities and nonconventional ingredients. Overall, the results collected demonstrated that cricket powder and buckwheat flour possess a great potential to produce innovative flatbreads. [ABSTRACT FROM AUTHOR]

In this research, new derivatives of spirooxadiazepines were prepared using multicomponent reactions (MCRs) of ninhydrin, secondary amines, Melderum's acid, carbonyl compounds such as aldehyde or ketones and hydrazonoyl chloride in water at room temperature in the presence of baker's yeast as catalyst in good yields. The short time of reaction, high yields of product, and easy separation of them are some advantages of this procedure. Another work in this research is investigation of antioxidant property of some synthesized compounds by diphenyl-picrylhydrazine (DPPH) radical trapping experiment. Presently, bacteria that are not destroyed with drug have generated many problems in the performance of many transferable disease. For this reason, discovering appropriate and new procedures for the dealing with these pathogens are important and recent study have focused on the investigation of the antibacterial effects on the prepared compounds. Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication, and applications of chemical products. Among solvents, water is a green solvents and very suitable for performing organic reaction. The present procedure avoids the use of toxic solvent. [ABSTRACT FROM AUTHOR]

Invertase, an industrially significant glycoenzyme, was purified from baker's yeast using poly (2-Hydroxyethyl methacrylate) [PHema-Pba] cryogels functionalized with boronic acid. At subzero temperatures, PHema-Pba cryogels were synthesized and characterized using swelling tests, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The surface area of the PHema-Pba cryogels was 14 m2/g with a swelling ratio of 88.3% and macroporosity of 72%. The interconnected macropores of PHema-Pba cryogels were shown via scanning electron microscopy. Invertase binding capacity of PHema-Pba cryogel was evaluated by binding studies in different pH, temperature, and interaction time conditions and the maximum Invertase binding of PHema-Pba cryogel was found as 15.2 mg/g. and 23.7 fold Invertase purification was achieved from baker's yeast using PHema-Pba cryogels. The results show that PHema-Pba cryogels have high Invertase binding capacity and may be used as an alternative method for enzyme purification via boronate affinity systems. [ABSTRACT FROM AUTHOR]

A biohybrid therapeutic system, consisting of responsive materials and living microorganisms with inter‐cooperative effects, is designed and investigated for tumor treatment. In this biohybrid system, S2O32−‐intercalated CoFe layered double hydroxides (LDH) are integrated at the surface of Baker's yeasts. Under the tumor microenvironment, functional interactions between yeast and LDH are effectively triggered, resulting in S2O32− release, H2S production, and in‐situ generation of highly catalytic agents. Meanwhile, the degradation of LDH in the tumor microenvironment induces the exposure of the surface antigen of yeast, leading to effective immune activation at the tumor site. By virtue of the inter‐cooperative phenomena, this biohybrid system exhibits significant efficacy in tumor ablation and strong inhibition of recurrence. This study has potentially offered an alternative concept by utilizing the metabolism of living microorganisms and materials in exploring effective tumor therapeutics. [ABSTRACT FROM AUTHOR]

Enrichment is one of the ways to increase the nutritional value of foods. In this research, enrichment of yogurt with Saccharomyces cerevisiae yeast was done as a cheap source of fiber, protein, vitamins and minerals to produce a functional food. Physico-chemical and sensory characteristics of enriched treatments were evaluated. Cow's fresh milk was mixed at 3 levels of fat (1.2, 1.8 and 3%) with yeast at 4 levels (0, 0.3, 0.6 and 0.9%) and used in preparing yogurt samples. The results showed that, in general, fat percentage, yeast percentage and duration of storage on pH and acidity changes were significant at the 95% confidence level. With increasing fat percentage, pH increased and acidity decreased. Increasing the percentage of yeast caused a decrease in pH and an increase in acidity. Synergy decreased with increasing the percentage of fat or yeast and also with increasing the duration of storage. The stifness of the tissue increased due to the increase of fat and decreased due with the increase of yeast. The highest level of tissue stifness was 0% in the yeast level and the lowest level was 0.9% in the yeast level. The amount of changes in fat, yeast and also the interaction of these two variables were significant and effective on the color index a* and b* with 95% confidence. However, only the variable of yeast percentage had a significant effect on the color index L*. Sensory evaluation results showed that only the variable of fat percentage had a significant effect on aroma, mouthfeel, internal texture, spoon acceptability and overall acceptance. [ABSTRACT FROM AUTHOR]

In this study, baker's yeast promoted one-pot synthesize of new 1,2,4-triazolpyrimidooxadiazole derivatives in high yields using multicomponent reactions of isatins, guanidine, alkyl bromides, aldehydes and hydrazonoyl chlorides in the presence of baker's yeast as a high performance catalyst in water at room temperature. Investigation of antioxidant ability of synthesized compounds using radical trapping of diphenyl-picrylhydrazine (DPPH) and ferric reduction power experiment is another purpose in this research. Also, the antimicrobial activity of some synthesized compounds proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. This procedure has some benefits such as short reaction time, product with excellent yields and simple, efficient, inexpensive, and environment-friendly catalyst. Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication and applications of chemical products. Among solvents, water is a green solvents and very suitable for performing organic reaction. The present procedure avoids the use of toxic solvent. 1,3,4-Oxadiazoles are a known class of compounds, reported to exhibit antibacterial, antifungal, analgesic and anti-inflammatory, anticonvulsant, hypoglycemic, and anticancer activities. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial respiration is central to cellular and organismal health in eukaryotes. In baker's yeast, however, respiration is dispensable under fermentation conditions. Because yeast are tolerant of this mitochondrial dysfunction, yeast are widely used by biologists as a model organism to ask a variety of questions about the integrity of mitochondrial respiration. Fortunately, baker's yeast also display a visually identifiable Petite colony phenotype that indicates when cells are incapable of respiration. Petite colonies are smaller than their Grande (wild-type) counterparts, and their frequency can be used to infer the integrity of mitochondrial respiration in populations of cells. Unfortunately, the computation of Petite colony frequencies currently relies on laborious manual colony counting methods which limit both experimental throughput and reproducibility. Results: To address these problems, we introduce a deep learning enabled tool, petiteFinder, that increases the throughput of the Petite frequency assay. This automated computer vision tool detects Grande and Petite colonies and computes Petite colony frequencies from scanned images of Petri dishes. It achieves accuracy comparable to human annotation but at up to 100 times the speed and outperforms semi-supervised Grande/Petite colony classification approaches. Combined with the detailed experimental protocols we provide, we believe this study can serve as a foundation to standardize this assay. Finally, we comment on how Petite colony detection as a computer vision problem highlights ongoing difficulties with small object detection in existing object detection architectures. Conclusion: Colony detection with petiteFinder results in high accuracy Petite and Grande detection in images in a completely automated fashion. It addresses issues in scalability and reproducibility of the Petite colony assay which currently relies on manual colony counting. By constructing this tool and providing details of experimental conditions, we hope this study will enable larger-scale experiments that rely on Petite colony frequencies to infer mitochondrial function in yeast. [ABSTRACT FROM AUTHOR]

Sourdough technology has been used to make bread for thousands of years. While simple, it involves complex interactions that determine microbial communities. However, evidence for lactic acid bacteria-yeast interactions in sourdough is not yet sufficiently available. The interaction between lactic acid bacteria and yeast has been examined. This study aimed to isolate lactic acid bacteria in wheat sourdough and determine their functional properties, such as acidification kinetics, microbiological counts, exopolysaccharide (EPS) production, and leavening ability. The characterization of the isolates revealed the presence of 32 different strains. In addition, six strains with the best performance were chosen to be used as starters for monoculture and co-culture with baker’s yeast. The lowest PH values and the highest total titratable acidity (TTA) values were observed with co-cultures. The growth rate analysis showed a negative interaction, whereas the lactic acid bacteria population was affected by yeast, while the yeast population size was rarely impacted, regardless of the strain. We found promising results for lactic acid bacteria strains regarding fermentation ability, which showed a higher ability to raise dough in monoculture. Two strains (2-1C2 and 13-1S2) showed interesting technological potential due to exopolysaccharide production and could be used to raise the dough without adding baker’s yeast. [ABSTRACT FROM AUTHOR]

[Display omitted] • The enantioselective synthesis of the C-ring fragment of fusicoccin A. • A chiral starting material was prepared using baker's yeast. • Michael reaction successfully constructed the asymmetric carbon in the side-chain. • Selective dihydroxylation was achieved using Admix-α. The enantioselective synthesis of the C-ring fragment of fusicoccin A is described. The TBS ether of hydroxyketone prepared by baker's yeast reduction was converted to the α-ethylidene ketone by aldol condensation with propionaldehyde, followed by Michael reaction with divinylcopper reagent and conversion to enol triflate to afford a single diastereomer. X-ray crystallographic analysis of the crystalline derivative of the single diastereomer showed that the asymmetric carbon formed by the Michael reaction was consistent with the configuration of the C15 asymmetric carbon of fusicoccin A. The vinyl group of the enol triflate was converted to a hydroxymethyl group by selective dihydroxylation with a bulky ligand, oxidative cleavage of the resultant 1,2-diol with lead tetraacetate, and DIBAL-H reduction. The hydroxymethyl group was subsequently converted to TBS ether, followed by the hydrogenolysis of the benzyl group and Dess–Martin oxidation, accomplishing the enantioselective synthesis of the desired C-ring fragment of fusicoccin A. [ABSTRACT FROM AUTHOR]

Summary: Pesticide residues might delay food fermentation. The aim of this study was to determine the effect of thirty‐one commercial pesticides (fourteen fungicides; eleven herbicides; one growth regulator; five insecticides) on the fermentative activity of baker's yeast in bread dough and sugared water. Yeast gas production after 3 h at 38 °C in dough or water was slightly inhibited by 10 mg kg−1 of a herbicide containing glufosinate‐ammonium and 100 mg kg−1 of fungicides with tebuconazole or metconazole. At the highest level assayed, 1000 mg kg−1, more than one‐third of the thirty‐one pesticides assayed did not impair baker's yeast gas production. Yeast cells were not inhibited by 300 mg active ingredients kg−1 in a mix of the pesticides, a concentration unlikely to be present in dough considering existing application rates in the field. Dough protected baker's yeast from pesticide residues. In sugared water, sub‐inhibitory concentrations of pesticides stimulated yeast fermentative activity. We conclude that it is unlikely that pesticide residues would impair baker's yeast gas production during bread dough fermentation. [ABSTRACT FROM AUTHOR]

The study aimed to produce instant dried baker's yeast (BY) by conventional or infrared‐assisted refractance window drying (RWD or InfraRWD, respectively) and compare their bakery performance with commercial BY. According to the findings of the study, the total yeast count was higher than 9.60 log cfu/g in all dried BY samples, and the lowest viability was obtained in BY dried by InfraRWD at 50°C. In general, BY produced by RWD increased the physical quality parameters of bread such as specific volume, total cell count, and the number of cell areas of bread crumbs. Moreover, bread leavened by BY dried by RWD slowed down the staling rate of bread, while infrared assistance accelerated the staling. Sensorial analysis showed that bread produced by refractance window dried BY was more acceptable than commercial BY. In a conclusion, RWD can be an effective alternative to the production of instant baker's yeast, but the most quality features of BY has negatively affected by infrared assistance. Practical Application: In the drying of baker's yeast, promising advantages can be obtained by refractance window drying. The higher specific volume and superior bread crumb with a retarded staling rate were determined when bread was produced by the refractance window. This is the first time that RWD and InfraRWD have been used for the production of instant baker's yeast and it has several practical applications for bread quality. [ABSTRACT FROM AUTHOR]

Aim: This study is to investigate the use of a constitutively expressed trehalose transport protein to directly control intracellular trehalose levels and protect baker's yeast (Saccharomyces cerevisiae) cells against freeze–thaw stress in vivo. Methods and Results: We used a constitutively overexpressed Agt1 transporter to investigate the role of trehalose in the freeze–thaw tolerance of yeast cells by regulating intracellular trehalose concentrations independently of intracellular biosynthesis. Using this method, we found that increasing intracellular trehalose in yeast cells improved cell survival rate after 8 days of freezing at −80 and −20°C. We also observed that freeze–thaw tolerance promoted by intracellular trehalose only occurs in highly concentrated cell pellets rather than cells in liquid suspension. Conclusions: Trehalose is sufficient to provide freeze–thaw tolerance using our Agt1 overexpression system. Freeze–thaw tolerance can be further enhanced by deletion of genes encoding intracellular trehalose degradation enzymes. Significance and Impact of Study: These findings are relevant to improving the freeze–thaw tolerance of baker's yeast in the frozen baked goods industry through engineering strains that can accumulate intracellular trehalose via a constitutively expressed trehalose transporter and inclusion of trehalose into the growth medium. [ABSTRACT FROM AUTHOR]

Background: Cereals are known to trigger for wheat allergy, celiac disease and non-celiac wheat sensitivity (NCWS). Inflammatory processes and intestinal barrier impairment are suspected to be involved in NCWS, although the molecular triggers are unclear. Aims: We were interested if different bread types influence inflammatory processes and intestinal barrier function in a mouse model of inflammatory bowel disease. Methods: Epithelial caspase-8 gene knockout (Casp8ΔIEC) and control (Casp8fl) mice were randomized to eight groups, respectively. The groups received different diets for 28 days (gluten-free diet, gluten-rich diet 5 g%, or different types of bread at 50 g%). Breads varied regarding grain, milling and fermentation. All diets were isocaloric. Results: Regardless of the diet, Casp8ΔIEC mice showed pronounced inflammation in colon compared to ileum, whereas Casp8fl mice were hardly inflamed. Casp8fl mice could tolerate all bread types. Especially yeast fermented rye and wheat bread from superfine flour but not pure gluten challenge increased colitis and mortality in Casp8ΔIEC mice. Hepatic expression of lipopolysaccharide-binding protein and colonic expression of tumor necrosis factor-α genes were inversely related to survival. The bread diets, but not the gluten-rich diet, also decreased colonic tight junction expression to variable degrees, without clear association to survival and inflammation. Conclusions: Bread components, especially those from yeast-fermented breads from wheat and rye, increase colitis and mortality in Casp8ΔIEC mice highly susceptible to intestinal inflammation, whereas control mice can tolerate all types of bread without inflammation. Yet unidentified bread components other than gluten seem to play the major role. [ABSTRACT FROM AUTHOR]

(1) Background: Bangladesh must has to spend a large amount of foreign currency to import commercial baker's yeast every year. We could save money by finding a potential Saccharomyces cerevisiae from natural sources compatible with commercial baker's yeast production. (2) Methods: Grapes, rice, pineapples were collected, processed, and inoculated on YMA plates and incubated at 30 °C for 48 h. Then 11 single morphologically well-formed colonies were isolated, purified, and identified, three as S. cerevisiae, three as S. rouxii, three as S. bisporus, and two as S. exigus based on standard cultural, morphological, and biochemical characteristics. Identified S. cerevisiae (designated as G2, P5 and R3) were then assessed for CO2 production as a measure of their baking potential during bread production and compared with two commercial strains (designated as C1 and C2). (3) Results: Isolate-G2 produced the maximum of 1830 mm3 of gas, whereas C1, C2, R3, and P5 produced 1520, 1680, 770, and 610 mm3 gas, respectively. No strain produced H2S which is associated with an off-flavor and unpleasant taste. These isolates showed maximum cell density at a pH range of 4–5.5 in 4–16% molasses broth at 30 °C after 4 days of incubation and maximum 4.75 × 109, 7.9 × 108, 1.472 × 1010, 2.08 × 1010 and 5.24 × 109 CFU mL−1 were produced by C1, C2, G2, P5 and R3, respectively. Isolate-G2 was found to have the most potential, whereas isolate-R3 and P5 have satisfactory potential. (4) Conclusions: G2 could be a good candidate for commercial trials. [ABSTRACT FROM AUTHOR]

Baker's yeast is mainly produced from molasses in various parts of the world, and other sources, including grape juice. In this study, the grape juice was chosen. This study aimed to produce a biomass from dry baker's yeast. Its physical and chemical properties was evaluated. The biomass from baker's yeast S. cerevisiae was equal to 41.50±0.01 g/L. The following fermentation conditions, i.e. temperature (30.1o C), pH (4.75), sugar concentration (158.36 g/L), ratio of carbon to nitrogen (11.9), and initial concentration of yeasts (2.5 g/L) were used. The fermentation was carried out for a period 12 h. Grape juice was subjected to four different heat treatments as follows: pasteurized grape juice at (65, 70, and 75o C) for 10 min, and sterilized grape juice in the au- toclave at 121o C for 20 min. The effect of each treatment was determined on inhibition of the enzyme polyphe- nol oxidase present in grape juice. The total phenolic content was determined in the yeast. Heat treatments gave the best phenolic content in the resulting yeast. The heat treatments of the juice succeeded in reducing the activity of the enzyme polyphenol oxidase and autoclave heat treatment gave the best phenolic content in the yeast. [ABSTRACT FROM AUTHOR]

Loss of Heterozygosity (LOH) due to mitotic recombination is frequently associated with the development of various cancers (e.g. retinoblastoma). LOH is also an important source of genetic diversity, especially in organisms where meiosis is infrequent. Irc20 is a putative helicase, and E3 ubiquitin ligase involved in DNA double-strand break repair pathway. We analyzed genome-wide LOH events, gross chromosomal changes, small insertion-deletions and single nucleotide mutations in eleven S. cerevisiae mutation accumulation lines of irc20∆ , which underwent 50 mitotic bottlenecks. LOH enhancement in irc20∆ was small (1.6 fold), but statistically significant as compared to the wild type. Short (≤ 1 kb) and long (> 10 kb) LOH tracts were significantly enhanced in irc20∆. Both interstitial and terminal LOH events were also significantly enhanced in irc20∆ compared to the wild type. LOH events in irc20∆ were more telomere proximal and away from centromeres compared to the wild type. Gross chromosomal changes, single nucleotide mutations and in-dels were comparable between irc20∆ and wild type. Locus based and genome-wide analysis of meiotic recombination showed that meiotic crossover frequencies are not altered in irc20∆. These results suggest Irc20 primarily regulates mitotic recombination and does not affect meiotic crossovers. Our results suggest that the IRC20 gene is important for regulating LOH frequency and distribution. • Loss of heterozygosity (LOH) is enhanced in irc20∆ mutant. • Short (≤ 1 kb) and long (> 10 kb) tract LOH events are enhanced in irc20∆. • Gross chromosomal changes, base mutations and in-dels are not enhanced in irc20∆. • Irc20 is expressed in meiosis but does not affect meiotic crossovers. • Irc20 is important for regulating the frequency and distribution of LOH events. [ABSTRACT FROM AUTHOR]

A microbial method using commercially available baker's yeast was developed for efficiently and selectively collecting aqueous Au(III) ions in aqua regia leachates from waste printed circuit boards (PCBs) through biosorption under air at temperatures ranging from 10 °C to 34 °C. Even when the total concentration of base metals was much higher than the initial Au concentration in the PCB leachate with high acid concentrations of 4.7–5.6 mol/L, commercial dry baker's yeast exhibited an excellent ability to selectively collect aqueous Au ions from the leachate within 60 min. When the biosorption test was repeated as a three-stage batch operation, the percentage biosorption of Au from the PCB leachate increased from 61% to 99% with 36 g/L dry yeast cells at 34 °C. The experimental results for the three-stage batch biosorption test were consistent with theoretical predictions based on the material balance of Au in multistage equilibrium operations and the distribution coefficient of Au. Equilibrium data of the Au biosorption conformed to the linear isotherm, regardless of the yeast concentration and the initial Au concentration in the leachate. The distribution coefficient K Au at 34 °C decreased by 30%, from 53.7 to 37.3 L/kg-dry cells, as the total base metal concentration in the leachate was increased tenfold, from 1.94 to 16.4–19.1 g/L. Moreover, the distribution coefficient of Au at 10 °C to 34 °C was analyzed to determine thermodynamic parameters according to the van't Hoff equation. The thermodynamic studies indicated that the biosorption of aqueous Au ions by baker's yeast was spontaneous and exothermic. • Baker's yeast (Saccharomyces cerevisiae) was used for recovery of Au ions. • Au ions were selectively recovered even in strong acid solutions containing high concentrations of base metals. • The results of the three-stage biosorption of Au ions were consistent with theoretical predictions. • Thermodynamic analysis indicated that the biosorption of Au ions by baker's yeast was spontaneous and exothermic. [ABSTRACT FROM AUTHOR]

Invertase enzyme is one of the food additives that our country is dependent on foreign sources. Industrial usage areas of invertase enzyme are invert sugar syrup production, chocolate production, fructo-oligosaccharide synthesis and baby food production. Studies on the production of invertase enzyme from domestic sources at low cost will serve to reduce the foreign dependency of our country in additives. In the present study, the production possibility of invertase enzyme from sieve residue yeast, by-product of baker’s yeast (Saccharomyces cerevisiae) factory, was investigated. Crude enzyme extracts obtained from sieve residue yeast (i) spray dried, (ii) lyophilized and (iii) collected in aqueous form were compared with (iv) industrial invertase enzyme sample in terms of enzymatic activity. Every sample was analyzed for enzymatic activity at constant temperature (40°C) and at different pH values between 4 and 7 in order to find out the optimum pH value for highest enzymatic activity. Then, the pH value was kept constant at optimum value and the enzymatic activity was determined at different temperature levels between 30- 65°C. Optimum pH value was determined as 4.5 for all samples and the enzymatic activity was found as 3.30, 2.90, 2.93 and 1.73 U/mL for industrial invertase enzyme, spray dried, lyophilized and aqueous extract, respectively. The analysis at optimum pH of 4.5 and at different temperatures showed that the highest enzymatic activity was screened at 40°C for all samples. Additionally, there was a significant loss of enzymatic activity over 60°C for all samples. Finally, the study showed that sieve residue yeast has a usage potential in invertase production. While this by-product is sold at low price for animal feeding purposes, advanced purification techniques can be used to create value-added product in this sector. [ABSTRACT FROM AUTHOR]

Biosorption ability of commercial dried Saccharomyces cerevisiae (Baker's yeast), to remove the Methyl green dye from water, was studied. This dye was chosen due to wide using of it in the different industries which is dumped into wastewater. With a view to explore the optimum conditions for adsorption of dye, Batch experiments were performed under various experimental affecting conditions, which are dye concentration, temperature, contact time. The experiment's batches were held using various initial concentrations of dye from 10 to 50 mg L-1, absorbent (Baker's yeast) dosage 0.075g at diverse temperatures (20, 30 and 40°C), and pH=7. In which the results have shown when the temperature increased the adsorption efficiency increased too. The removal percentage (%R) of dye by the baker's yeast reached equilibrium after 80 minutes. As well as, adsorption isotherm models (Freundlich and Langmuir) were studied. The maximum biosorption capacity values were calculated at mentioned conditions. Furthermore, Kinetic and Thermodynamic parameters were calculated for this adsorption process, which are indicating the process is endothermic, spontaneous process in nature and follow pseudo 2. Order model. [ABSTRACT FROM AUTHOR]

Context: Dietary supplementation especially feed residues improve by yeast affected rumen fermentation. Aims: The aim of the present experiment was to determine the nutritive value, fermentation efficiency and rumen ecology of yeast-fermented cassava pulp, under the use of two levels of protein in concentrate mixtures, in beef cattle. Methods: Four beef cattle, 2–3 years of age, were randomly assigned to the following treatments according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design: cassava pulp fermented either with baker's yeast or LDD 6 (Factor A), with 16% or 18% CP in concentrate (Factor B). Key results: CP digestibility and blood urea nitrogen were higher in animals fed both baker's yeast-fermented and LDD 6-fermented cassava pulp with 18% CP than in those fed baker's yeast-fermented cassava pulp with 16% CP and LDD 6-fermented cassava pulp with 16% CP. The highest total volatile fatty acid (TVFA) and butyrate (C4) concentrations were in animals fed baker's yeast-fermented cassava pulp with 16% CP. Moreover, CH4 production was at its lowest when animals were fed with baker's yeast-fermented cassava pulp together with a concentrate with 16% CP. Animal's fed baker's yeast-fermented and LDD 6-fermented cassava pulp with 18% CP had higher concentrations of purine derivatives, higher microbial nitrogen supply and efficiency of microbial protein synthesis than did those fed either baker's yeast-fermented or LDD 6-fermented cassava pulp with 16% CP. In addition, protozoa population in animals fed baker's yeast-fermented cassava pulp was lower than in those fed LDD 6-fermented cassava pulp, and baker's yeast-fermented cassava pulp with 16% CP had the lowest protozoa population. However, F. succinogenes was the highest in animals fed yeast-fermented and LDD 6-fermented cassava pulp with 18% CP. Conclusions: It is concluded that yeast-fermented cassava pulp can be nutritionally improved, especially when used in combination with a concentrate of 16% CP to achieve the highest level of TVFA and C3 and to reduce rumen protozoal population and CH4 production. Implications: The present study suggests that feeding animals with yeast-fermented cassava pulp with a concentrate of 16% CP could improve feed quality and, hence, beef animal performance in Thailand. So as to compare cassava pulp in two forms, namely, fermented with baker's yeast or the yeast from LDD 6, under the use of two levels of protein in concentrate mixtures (16% and 18% crude protein, CP), four beef cattle were randomly assigned to treatments according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. In conclusion, yeast-fermented cassava pulp with a concentrate of 16% CP resulted in the highest propionate production and a reduction of protozoal population and, hence, methane production in the rumen. [ABSTRACT FROM AUTHOR]

Iron is a vital micronutrient that functions as an essential cofactor in multiple biological processes, including oxygen transport, cellular respiration, and metabolic pathways, such as sterol biosynthesis. However, its low bioavailability at physiological pH frequently leads to nutritional iron deficiency. The yeast Saccharomyces cerevisiae is extensively used to study iron and lipid metabolisms, as well as in multiple biotechnological applications. Despite iron being indispensable for yeast ergosterol biosynthesis and growth, little is known about their interconnections. Here, we used lipid composition analyses to determine that changes in the pattern of sterols impair the response to iron deprivation of yeast cells. Yeast mutants defective in ergosterol biosynthesis display defects in the transcriptional activation of the iron-acquisition machinery and growth defects in iron-depleted conditions. The transcriptional activation function of the iron-sensing Aft1 factor is interrupted due to its mislocalization to the vacuole. These data uncover novel links between iron and sterol metabolisms that need to be considered when producing yeast-derived foods or when treating fungal infections with drugs that target the ergosterol biosynthesis pathway. [ABSTRACT FROM AUTHOR]

Immunoreceptors expressed on osteoclast precursor cells modify osteoclast differentiation and bone resorption activity. Dectin‐1 is a lectin receptor of β‐glucan and is specifically expressed in osteoclast precursor cells. In this study, we evaluated the bioactivity of β‐glucan on receptor activator of nuclear factor‐kappa B ligand (RANKL)‐induced osteoclastogenesis and observed that glucan from baker's yeast inhibited this process in mouse bone marrow cells and dectin‐1–overexpressing RAW264.7 (d‐RAW) cells. In conjunction, RANKL‐induced nuclear factor of activated T cell c1 expression was suppressed, subsequently downregulating TRAP and Oc‐stamp. Additionally, nuclear factor‐kappa B activation and the expression of c‐fos and Blimp1 were reduced in d‐RAW cells. Furthermore, glucan from baker's yeast induced the degradation of Syk protein, essential factor for osteoclastogenesis. These results suggest that glucan from baker's yeast suppresses RANKL‐induced osteoclastogenesis and can be applied as a new treatment strategy for bone‐related diseases. [ABSTRACT FROM AUTHOR]

One of the common causes of water pollution is the presence of toxic dye-based effluents, which can pose a serious threat to the ecosystem and human health. The application of Saccharomyces cerevisiae (S. cerevisiae) for wastewater decolorization has been widely investigated due to their efficient removal and eco-friendly treatments. This review attempts to create an awareness of different forms and methods of using Saccharomyces cerevisiae (S. cerevisiae) for wastewater decolorization through a systematic approach. Overall, some suggestions on classification of dyes and related environmental/health problems, and treatment methods are discussed. Besides, the mechanisms of dye removal by S. cerevisiae including biosorption, bioaccumulation, and biodegradation and cell immobilization methods such as adsorption, covalent binding, encapsulation, entrapment, and self-aggregation are discussed. This review would help to inspire the exploration of more creative methods for applications and modification of S. cerevisiae and its further practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In 2014, the EFSA NDA Panel concluded that UV‐treated baker's yeast containing up to 3.5 Mio IU of vitamin D/100 g, is safe under the proposed conditions of use for yeast‐leavened breads, rolls and fine bakery wares, and food supplements. Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on an application for an extension of the use of UV‐treated baker's yeast as a novel food (NF) pursuant to Regulation (EU) 2015/2283. In this extension of use, the applicant proposed a broad range of food categories to which the NF can be added. On the basis of the proposed uses and maximum use levels, the Panel estimated the potential exposure to vitamin D from the NF and the potential combined exposure to vitamin D including also exposure from the background diet and food supplements. The Panel notes that the upper level (UL) for one age group, i.e. children aged 4–10 years, is exceeded by 4%, when summing up the highest P95 estimate for the background diet (including food supplements) and the highest P95 estimate for vitamin D from the NF under the proposed uses and maximum use levels. The Panel notes, however, the highly conservative approach for estimating the potential intake of vitamin D from the NF, given that the applicant has proposed 34 FoodEx2 level 2 food categories. Thus, the Panel considers that the UL for children aged between 4 and 10 years is highly unlikely to be exceeded. The Panel concludes that the NF is safe under the proposed conditions of use. [ABSTRACT FROM AUTHOR]

Water mediated and baker’s yeast catalyzed, efficient synthetic routes have been first time developed for multicomponent cyclocondensations leading to bioactive tetrahydrobenzo[a]xanthene-11-ones (4a–h) and pyrazolo[3,4-b]quinolines (7a–i). The developed protocols are conducted at room temperature and gave better to excellent yields of the titled compounds. The biocatalytical resource, activated baker’s yeast is readily available, and biodegradable. These protocols are more convenient, scalable, and obey most of the green principles also. The developed protocols are cost effective and better in operation than existing ones. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the effect of consumption of ancient grain "Verna" bread obtained by two different leavening agents, sourdough (SD) and baker's yeast (BY), on inflammatory parameters and cardiometabolic risk factors. Seventeen clinically healthy subjects were included to consume SD or BY bread for 4 weeks each, and blood analyses were carried out. The consumption of "Verna" bread obtained with both leavening agents led to a significant improvement of LDL cholesterol. A reduction of -10.6% and -8.53% was observed after replacement with SD and BY bread, respectively. A significant increase in fasting blood glucose (+6%) was observed only after the intervention with BY bread. A 10.7% decrease of vascular endothelial growth factor was found after the SD bread replacement period. The consumption of "Verna" bread resulted significantly associated with an improvement in the cardiometabolic and inflammatory profile. However, only consumption of BY bread determined a significant increase in blood glucose levels. [ABSTRACT FROM AUTHOR]

As is widely accepted, the quality decay of freshly baked bread that affects product shelf life is the result of a complex multifactorial process that involves physical staling, together with microbiological, chemical and sensorial spoilage. In this context, this paper provides a critical review of the recent literature about the main factors affecting shelf life of bread during post‐baking. An overview of the recent findings about the mechanism of bread staling is firstly provided. Afterwards, the effect on staling induced by baker's yeasts and sourdough as well as by the extra ingredients commonly utilized for bread fortification is also addressed and discussed. As inclusion/exclusion criteria, only papers dealing with wheat bread and not with long‐life bread or gluten‐free bakery products are taken into consideration. Despite recent developments in international scientific literature, the whole mechanism that induces bread staling is far from being completely understood and the best analytical methods to be adopted to measure and/or describe in depth this process appear still debated. In this topic, the effects induced on bread shelf life by the use of biological leavening agents (baker's yeasts and sourdough) as well as by some extra ingredients included in the bread recipe have been individuated as two key issues to be addressed and discussed in terms of their influence on the kinetics of bread staling. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The results of modelling the effect of cell sizes on the microorganism disintegration process are presented. Experiments were conducted in a horizontal bead mill for baker's yeast Saccharomyces cerevisiae. The kinetics of the cell disruption process was investigated by optical image analysis and the release of intracellular protein by Bradford method. A large variation in the size of yeast from one production cycle has been demonstrated. A significant increase in the constant rate of the process with an increase in the range of the cell size class was demonstrated. More beneficial values of the coefficient of determination were obtained for the spherical model of the cell. Worse results of the process description were obtained for the ellipsoidal model. They may result from large variations in cell volume in individual size classes. The greatest changes in the cell Elongation parameter within one size class ranged from 1.00 to 1.54. Unlabelled Image • The theory of random transformation of dispersed matter were used for modelling. • Baker's yeast Saccharomyces cerevisiae has very different cell sizes and shapes. • The rate constant of yeast disintegration depends on the size of cells. • Process description results are better for a spherical cell model then ellipsoidal. • The resultant of linear component processes is a linear total process. [ABSTRACT FROM AUTHOR]

Background: The accumulation of intracellular fat depots is a polygenic trait. Therefore, the extent of lipid storage in the individuals of a species covers a broad range and is determined by many genetic factors. Quantitative trait loci analysis can be used to identify those genetic differences between two strains of the same species that are responsible for the differences in a given phenotype. We used this method and complementary approaches to identify genes in the yeast Saccharomyces cerevisiae that are involved in neutral lipid storage. Results: We selected two yeast strains, the laboratory strain BY4741 and the wine yeast AWRI1631, with a more than two-fold difference in neutral lipid content. After crossing, sporulation and germination, we used fluorescence activated cell sorting to isolate a subpopulation of cells with the highest neutral lipid content from the pool of segregants. Whole genome sequencing of this subpopulation and of the unsorted pool of segregants implicated several loci that are involved in lipid accumulation. Three of the identified genes, PIG1, PHO23 and RML2, were investigated in more detail. Deletions of these genes and the exchange of the alleles between the two parental strains confirmed that the encoded proteins contribute to neutral lipid storage in S. cerevisiae and that PIG1, PHO23 and RML2 are the major causative genes. Backcrossing of one of the segregants with the parental strains for seven generations revealed additional regions in the genomes of both strains with potential causative genes for the high lipid accumulation phenotype. Conclusions: We identified several genes that contribute to the phenotype of lipid accumulation in an allelespecific manner. Surprisingly, no allelic variations of genes with known functions in lipid metabolism were found, indicating that the level of storage lipid accumulation is determined by many cellular processes that are not directly related to lipid metabolism. [ABSTRACT FROM AUTHOR]

Background: The successful rearing of predators or parasitoids is one of the most important elements in biological control programs. The dried fruit mite, Carpoglyphus lactis (L.), can be used as an alternative prey for the phytoseiid predatory mite, Amblyseius swirs0kii (Athias-Henriot). Main body: This study aimed to evaluate the suitability of 3 different diets for C. lactis when rearing A. swirskii: brown sugar, baker's yeast, and the mixture of brown sugar and baker's yeast along with 3 initial predator:prey ratios (1:7, 1:12, and 1:20). After 30 days, both the baker's yeast and the mixture of brown sugar + baker's yeast diets resulted in the highest predator densities (40.5 times increase at an initial predator:prey ratio of 1:20, with the baker's yeast diet), whereas the mixture diet produced the highest density of prey. The brown sugar resulted in the lowest number of predator and prey mites. This may be due to lower feeding and predation rates of the prey and the predator mites on the brown sugar medium since its relative moisture content and adhesiveness inhibits mite movement. The final predator:prey ratio was also highest on the baker's yeast diet. Conclusions: This study demonstrated that the population growth of A. swirskii was the highest when C. lactis was reared on baker's yeast. [ABSTRACT FROM AUTHOR]

Yeast autolysis refers to the process in which cells degrade and release intracellular contents under specific conditions by endogenous enzymes such as proteases, nucleases and lipid enzymes. Protein-rich baker's yeast is widely used to produce yeast extract in food industry, however, the molecular mechanism related to baker's yeast autolysis is still unclear. In this study, RNA-seq technology and biochemical analysis were performed to analyze the autolysis processes in baker's yeast. The differentially expressed genes (DEGs), 27 autolysis-related euKaryotic Ortholog Groups (KOG) and three types of autolysis-induced Gene Ontology (GO) were identified and analyzed in detail. A total of 143 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways under autolysis were also assigned. Interestingly, the DEGs were significantly enriched in the mitogen-activated protein kinase (MAPK) signaling pathways and metabolic pathways, and key genes MID2 , MTL1 , SLT2 , PTP2 , HKR1 and GPD1 may play important roles in autolysis. Further quantitative PCR was performed to verify the expression pattern in baker's yeast autolysis. Together, all these results indicated that MAPK pathways might play an essential role during autolysis process through inhibiting the metabolism and disrupting cell wall in baker's yeast. This result may provide important clues for the in-depth interpretation of the yeast autolysis mechanism. [ABSTRACT FROM AUTHOR]

An efficient, green and facile route for the one-pot four-component synthesis of pyranopyrazole derivatives through the condensation of the aromatic aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate using baker's yeast as biocatalyst is presented. The important aspects of the present methodology are the use of an environmentally friendly catalyst, high yield of products and mild reaction conditions, i.e. at neutral pH and ambient temperature. [ABSTRACT FROM AUTHOR]

Baker's yeast was primarily used as a leavening agent in the food processing industry and later as biocatalyst in the brewing industry. Ready availability and low cost has made baker's yeast a primary research object among the scientific community. It is well known to reduce carbonyl groups. Several other simple single step transformations have also been carried out using baker's yeast. Multicomponent reactions are a close fit to the concept of "ideal" synthesis and, in recent years, they have become a rapid platform for the drug discovery process. Due to the promiscuous nature of enzymes, they were not explored as potential biocatalyst for multicomponent reactions. In this review, the application of baker's yeast in multicomponent reactions has been discussed. [ABSTRACT FROM AUTHOR]

Global outbreaks of drug-resistant fungi such as Candida auris are thought to be due at least in part to excessive use of antifungal drugs. Baker's yeast Saccharomyces cerevisiae has gained importance as an emerging opportunistic fungal pathogen that can cause infections in immunocompromised patients. Analyses of over 1000 S. cerevisiae isolates are providing rich resources to better understand how fungi can grow in human environments. A large percentage of clinical S. cerevisiae isolates are heterozygous across many nucleotide sites, and a significant proportion are of mixed ancestry and/or are aneuploid or polyploid. Such features potentially facilitate adaptation to new environments. These observations provide strong impetus for expanding genomic and molecular studies on clinical and wild isolates to understand the prevalence of genetic diversity and instability-generating mechanisms, and how they are selected for and maintained. Such work can also lead to the identification of new targets for antifungal drugs. Excessive use of antifungals in hospitals and agriculture is thought to promote the origin and spread of drug-resistant fungi that are pathogenic in humans. Hospital patients provide a unique and stressful environment for baker's yeast. Clinical yeast isolates are subjected to novel and repeated stresses such as high temperature and exposure to antifungals aimed at suppressing their growth and survival. Genomic heterozygosity, mosaicism, high mutation rates, aneuploidy, and polyploidy appear to be major sources of genetic raw material for adaptation in baker's yeast. Recent studies of natural baker's yeast isolate collections, including the sequencing of a set of 1011 isolates which contain >100 clinical samples, are providing useful models from which to gain insights into adaptation to stressful environments, identify antifungal targets, and develop strategies to limit the spread of drug-resistant fungi. [ABSTRACT FROM AUTHOR]

The feasibility of baker's yeast production using fruits and peels of Opuntia ficus indica (OFI) as carbohydrate feedstock was investigated. Two response surface methodologies involving central composite face centered design (CCFD) were successfully applied. The effects of four independent variables on baker's yeast production from OFI fruit juice was evaluated using the first CCFD. The best results were obtained with 24 H of inoculum age, 30 °C temperature, 200 rpm of agitation, and 10% inoculum size. At the maximum point, the biomass concentration reached 9.29 g/L. A second CCFD was performed to optimize the sugar extraction from OFI fruit peels. The potential of these latter as a fermentation substrate was determined. From the experimental results, the OFI fruit peel is an appropriate carbon source for the production of baker's yeast. The maximum biomass concentration was 12.51 g/L. Different nitrogen supplements were added to promote the yields of baker's yeast. Corn steep liquor was found to be the best alternative nutrient source of casein hydrolysate and yeast extract for baker's yeast production. [ABSTRACT FROM AUTHOR]

A simple generic toxicity method (test) is proposed using baker's yeast to mediate the reduction of the colourless triphenyltetrazolium chloride (TTC) to red, 1,3,5-triphenyl formazan, which can be extracted by dimethyl sulfoxide (DMSO), enabling the identification of reducible toxic compounds (e.g. cadmium, fipronil) in water for consumption. [ABSTRACT FROM AUTHOR]

The concomitant exploitation of two of the green chemistry tools viz., sonication and biocatalysis is reported here for the synthesis of natural alkaloid, tryptanthrin (indolo[2,1-b]quinazoline-6,12-dione). High intensity ultrasound has been applied to facilitate the release of enzymes by disruption of cells of baker's yeast (Saccharomyces cerevisae) as a biocatalyst. The coupled system is an excellent instance of enhanced rate of biocatalyzed reaction and has proven to be a green alternative to existing methodologies for the synthesis of tryptanthrins. The present method is bestowed with merits such as mild and clean reaction conditions, operational simplicity, tolerance for a wide variety of substituents, green aspects through the avoidance of toxic metal catalysts and highly selective conversion with no byproducts. [ABSTRACT FROM AUTHOR]

Summary: The potential of vinasse, gained from baker′s yeast production for the recovery of valuable molecules (invertase, food grade proteins and betaine), has been assessed. Particularly natural betaine, a trimethyl derivative of glycine, attracts more and more attention in human and animal nutrition. In this work, a straightforward membrane‐based process for the recovery of natural betaine and a very promising betaine‐rich protein fraction from fermentation broth of baker′s yeast was developed. The difficult separation of external invertase from yeast cells was observed in this work. Anyway, a residual invertase activity was found in vinasse, but it could not be efficiently purified to generate an industrial‐strength product. The presented process can be easily implemented in a conventional baker's yeast production plant by integrating an ultrafiltration station and an adsorption system. Based on our calculations, a potential recovery up to 1486 t year−1 of betaine‐rich proteins (5 € kg−1) and 593 t year−1 Betafin® similar natural betaine (6–7 € kg−1) may be achieved. [ABSTRACT FROM AUTHOR]

The high cell density culture of baker's yeast FX‐2 was investigated in a 50 L(A) automatic bioreactor. Herein, it was found firstly that the Crabtree effect clearly existed in batch fermentation with higher glucose content, then the critical initial glucose content range (≤2.00 g L−1) was reasonably ascertained to effectively avoid Crabtree effect. In the next fed‐batch fermentations with different strategies, the second strategy (maintain ethanol concentration lower than 0.10% and pH around 4.80) was confirmed to be more beneficial to yeast growth than the first strategy (keep reducing sugar not more than 2.00 g L−1 and control steady Carbon/Nitrogen ratio 3.05:1.00). After that, one optimal control strategy (maintain pH around 4.80 and keep respiratory quotient in the range of 0.90–1.00) was constructed to further enhance cell yield. Under an optimal control strategy, four schemes with the aim of achieving pH‐stat were compared, and yeast extract instead of other alkaline materials was selected as a better regulator. As a result, 148.37 g L−1 dry cell weight, 38.25 × 108 mL−1 living cells, and 8.24 g L−1 h−1 productivity were harvested, which respectively elevated 23.74%, 135.38%, and 24.47% compared to that obtained under the traditional scheme (regulate pH with ammonia); meanwhile, the maximum oxygen uptake rate and carbon dioxide excretion rate were both more than 250.00 mmol L−1 min−1. [ABSTRACT FROM AUTHOR]

Residuals are responsible for the polluting load increase of soft drink industry wastewater due to their high sugar contents. The present work proposes an upstream segregation of residuals to be biologically treated by the bioconversion of their carbohydrates content into baker's yeast biomass. Carbonated soft drinks (CSD) and nectars and juices (NJ) ranges were considered. Different incorporation ratios of NJ in the CSD (0-75%) have been investigated for balanced growth medium. Despite the nitrogen deficiency of media, results showed that NJ incorporation promoted the microbial growth. Media containing more than 50% of NJ exhibited ~25% sugar-biomass conversion rates. The chemical oxygen demand (COD) of the media exceeded 70% at the end of fermentation. Moreover, valuable components were recovered by yeast production. Nutrient consumption rates varied from 65.4% for sugar and calcium content to in excess of 99% for protein and other minerals. In order to investigate an available and low-cost source of nitrogen for yeast production, partial substitution of the soft drink growth medium by bactofugate whey was evaluated. The soft drink-whey mixture medium fermentation resulted in 63% COD removal rate after 28 h. Meanwhile, the biomass production yield revealed an improvement of about 25% compared to the balanced soft drink medium (NJ50). [ABSTRACT FROM AUTHOR]

In this study, commercial baker's yeast (Saccharomyces cerevisiae) was employed as a novel inoculum for a membrane bioreactor (MBRy). It was applied to landfill leachate (LFL) treatment to remove recalcitrant organic compounds as well as for the assimilation of recalcitrant compounds, since yeasts have a high ability to break such compounds down. The MBR was inoculated with 10 g L-1 of commercial baker's yeast and was operated at a hydraulic retention time of 48 h and pH of 3.5. The specific air demand based on the membrane area (SADm) was maintained at 0.6 m³h-1m-2. The MBRy achieved chemical oxygen demand (COD), color, NH3, and humic substances removal of 68, 79, 68, and 50%, respectively. Furthermore, the MBRy showed lower fouling potential, which can be attributed to the low extracellular polymeric substances production, as the formation of a cake layer was the major mechanism of membrane fouling. The work demonstrated that novel MBR is a promising technology for treating recalcitrant landfill leachate. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Finely dispersed fungal mycelium of Hirsutella rhossiliensis effectively parasitizes Heterodera schachtii. • Cellulose-based microcapsules proved to be a suitable delivery system for H. rhossiliensis. • In comparison to free mycelium biocontrol efficacy of encapsulated H. rhossiliensis was significantly increased. • The addition of baker's yeast to the formulation enhanced control efficacy of H. rhossiliensis. Abstract The nematophagous fungus Hirsutella rhossiliensis is a common antagonist of a number of important plant-parasitic nematodes including the beet cyst nematode Heterodera schachtii. Although H. rhossiliensis is highly pathogenic, slow growth characteristics and weak competiveness under field conditions limit its biocontrol potential. Cellulose-based microcapsules were tested for their ability to improve fungal competitiveness in the soil and nematode parasitism. In a first approach microcapsules containing 15% fungal mycelium plus 15% corn gluten and 0.5% yeast extract as additives gave low levels of H. schachtii control. Fungal parasitism was not observed and indicated that nematode mortality was most likely caused by non-specific accumulation of nematicidal compounds associated with decomposition of the additives in the microcapsules. Removal of the corn gluten additive resulted in a minor increase of 20% parasitism of H. schachtii juveniles. Furthermore, the yeast extract that acted as nutrient source for the fungus diffused through the semi-permeable membrane of the capsules during the formulation process and was ineffective. Replacing the corn gluten and yeast extract with 3% autoclaved baker's yeast and using finely dispersed mycelium instead of pelletized mycelium increased juvenile parasitism in the soil up to 90% and decreased number of juveniles per cm root length by over 80%. Cellulose-based microcapsules supplemented with autoclaved baker's yeast, therefore, proved to be an effective delivery system for H. rhossiliensis to control H. schachtii. [ABSTRACT FROM AUTHOR]