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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]

We traced back a nationwide outbreak of human listeriosis in Switzerland to a persisting production line contamination of a factory producing baker’s yeast with Listeria monocytogenes serotype 1/2a sequence type 3141. We used whole-genome sequencing to match clinical isolates to isolates from product samples.

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]

Currently, the problem of deficiency of macro- and micronutrients in the diet of the population remains relevant. One of the promising areas for solving this problem is the development of methods for the production of domestic food ingredients with the aim of creating food products fortified with microelements on their basis. The biotechnological method for production of such ingredients is considered one of the most relevant. The most widely used microorganism in the food industry is the Saccharomyces cerevisiae yeast. The aim of the research was to study the possibility of baker’s yeast enrichment with microelements: zinc and chromium. The possibility of yeast fortification during batch fermentation on malt wort with the addition of salt solutions — sources of trace elements (zinc sulfate (ZnSO4×5H2O) and chromium (III) chloride (CrCl3×6H2O)) was confirmed. The optimal dosages of the selected trace element salts for fortification were 250 mg Zn/dm3 and 500 µg Cr/dm3. An increase in the crude protein content by 11.6±0.5% was also observed. When using this combination (250 mg Zn/dm3 + 500 µg Cr/dm3), it was possible to reach optimal results in the process of simultaneous enrichment of the object with two microelements. It makes possible to obtain a sample with a concentration of 263.4±13 mg Zn/100 g of yeast (percentage of incorporation was 58.8%) and 308.2±15 µg Cr/100 g of yeast (percentage of incorporation was 34.4%). An increase in the crude protein content by 30±1.5% was also observed. The possibility of including the produced experimental samples in food products was studied. Bread as a mass consumer product was chosen as a model. Experimental bread samples were produced with a complete replacement of yeast without enrichment with yeast fortified with zinc and chromium. Organoleptic evaluation and study of important parameters such as moisture and acidity demonstrated that the experimental samples can be used in the food industry after passing the necessary safety tests. The values of replenishing the norms of physiological needs in microelements when consuming 100 g of the experimental bread samp

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]

Biofilm formation by Escherichia coli presents a major challenge in the clinical settings, resulting in persistent infections and treatment failures. These bacterial communities, protected by a matrix, resist antibiotics and immune responses, thus causing a prolonged challenge to treat such infections. Developing effective strategies against E. coli biofilms is crucial for improving the patient outcomes and reducing the burden on the healthcare systems. This study aimed to extract, purify, and characterize mannan from Saccharomyces cerevisiae, then its antibiofilm activity was evaluated against the multi-drug resistant E. coli (MDR-E. coli) isolates obtained from various clinical sources (i.e., urine, stool, wound, and catheter). Using a standardized protocol with slight modifications, the crude mannan extraction yielded 37.6 %, and subsequent purification achieved an efficiency of 99.6 %. Characterization assays of the purified mannan included FT-IR; FE-SEM, carbohydrate content estimation, solubility, and melting point tests, which revealed the presence of α-1,6 and α-1,2 linked sugars; crystalline nature, high porosity (80 %) carbohydrate content, high solubility in water, and a melting point of 248 °C. The purified mannan exhibited a substantial ability to inhibit biofilm formation (37.50 %) and degrade the existing MDR-E. coli biofilms (37.43 %). These findings underscore the potential of S. cerevisiae mannan as an effective antibiofilm agent for the clinical applications. Further exploration and optimization of the mannan's therapeutic potential are essential to fully leverage its efficacy in combating the biofilm-associated infections caused by MDR-E. coli.

Abstract A suitable nutrient supply, especially of vitamins, is very significant for the deep display of the inherent genetic properties of microorganisms. Here, using the chemically defined minimal medium (MM) for yeast, nicotinamide and inositol were confirmed to be more beneficial for the performance of two industrial baker's yeasts, a conventional and a high-sugar-tolerant strain. Increasing nicotinamide or inositol to proper levels could enhance the both strains on cell growth and activity and product performance, including trehalose accumulation and leavening performance. The activity of key enzymes (PCK, TPS) and the content of intermediate metabolites (G6P, UDPG) in the trehalose synthesis pathway were promoted by a moderate supply of nicotinamide and inositol. That were also proved that an appropriate amount of niacinamide promoted the transcription of longevity-related genes (PNC1, SIR2), and the proper concentration of inositol altered the phospholipid composition in cells, namely, phosphatidylinositol and phosphatidyl choline. Furthermore, the cell growth and the leavening performance of the both strains were promoted after adjusting inositol to choline to the proper ratio, resulting directly in content changes of phosphatidylinositol and phosphatidyl choline in the cells. While the two strains responded to the different proper ratio of inositol to choline probably due to their specific physiological characteristics. Such beneficial effects of increased nicotinamide levels were confirmed in natural media, molasses and corn starch hydrolyzed sugar media. Meanwhile, such adjustment of inositol to choline ratio could lessen the inhibition of excess inositol on cell growth of the two tested strains in corn starch hydrolyzed sugar media. However, in molasse, such phenomenon was not observed probably since there was higher Ca2+ in it. The results indicated that the effects of nutrient factors, such as vitamins, on cell growth and other properties found out from the simple chemically defined minimal medium were an effective measure to use in improving the recipe of natural media at least for baker's yeast.

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]

Research background. Wine production, which is considered a major sector in food industry, often involves the use of a large amount of resources. Moreover, wine making generates a large amount of grape pomace, which is generally used for low-value applications such as fertiliser and animal feed. The aim of the present research is to explore the possibility of improving the overall sustainability of traditional winemaking. Experimental approach. A zero-waste process was developed. It includes the production of white wine and the substantial valorisation of grape pomace, which is converted into solid biofuel, tartaric acid and concentrated grape extract as feedstock for industrial baker's yeast production. Results and conclusions. We estimate that a significant surplus of renewable energy of approx. 3 MJ/kg processed grapes can be obtained during this conversion. The suitability of grape extract as a potential substrate for industrial baker's yeast production was evaluated and the feasibility of a partial replacement of molasses (up to 30 %) was demonstrated. Novelty and scientific contribution. We present a circular economy approach for the conversion of winery biowaste into high-value resources such as feedstock and solid biofuel. [ABSTRACT FROM AUTHOR]

ABSTRACTSelective 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.

Baker's yeast (BY) is very sensitive to moisture and can lose its activity by working at very low moisture contents. The main purpose of this study is to obtain dry yeast which can be used in ready flour mixtures with no negative effects by preventing moisture transfer from the environment, and which can be stored for a long period. In order to accomplish this purpose, BY was coated in a fluidized bed by using edible films and coating technology, which can be used in the food industry in order to increase the shelf life of foods and improve the product quality. The results show that the Wurster coating method was most effective in the coating of yeast on the fluidized bed drier, and the combination of palm oil, gelatin, and pectin ensured the best results in terms of low water vapor permeability, high yeast activity, and high solubility. [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]

A suitable nutrient supply, especially of vitamins, is very significant for the deep display of the inherent genetic properties of microorganisms. Here, using the chemically defined minimal medium (MM) for yeast, nicotinamide and inositol were confirmed to be more beneficial for the performance of two industrial baker's yeasts, a conventional and a high-sugar-tolerant strain. Increasing nicotinamide or inositol to proper levels could enhance the both strains on cell growth and activity and product performance, including trehalose accumulation and leavening performance. The activity of key enzymes (PCK, TPS) and the content of intermediate metabolites (G6P, UDPG) in the trehalose synthesis pathway were promoted by a moderate supply of nicotinamide and inositol. That were also proved that an appropriate amount of niacinamide promoted the transcription of longevity-related genes (PNC1, SIR2), and the proper concentration of inositol altered the phospholipid composition in cells, namely, phosphatidylinositol and phosphatidyl choline. Furthermore, the cell growth and the leavening performance of the both strains were promoted after adjusting inositol to choline to the proper ratio, resulting directly in content changes of phosphatidylinositol and phosphatidyl choline in the cells. While the two strains responded to the different proper ratio of inositol to choline probably due to their specific physiological characteristics. Such beneficial effects of increased nicotinamide levels were confirmed in natural media, molasses and corn starch hydrolyzed sugar media. Meanwhile, such adjustment of inositol to choline ratio could lessen the inhibition of excess inositol on cell growth of the two tested strains in corn starch hydrolyzed sugar media. However, in molasse, such phenomenon was not observed probably since there was higher Ca2+ in it. The results indicated that the effects of nutrient factors, such as vitamins, on cell growth and other properties found out from the simple chemically defined minimal medium were an effective measure to use in improving the recipe of natural media at least for baker's yeast. [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]

Abstract Background Saccharomyces cerevisiae (S. cerevisiae) has been demonstrated in vitro to sensitize several breast cancer cell lines and to be a safe, non-toxic drug with anti-skin cancer action in mice. Furthermore, plasmonic photothermal treatment using gold nanorods has been authorized as a novel method for in vitro and in vivo cancer therapy. Results When compared to tumor-free rats, the treatment with S. cerevisiae conjugated to gold nanospheres (GNSs) lowered Bcl-2 levels while increasing FasL, Bax, cytochrome c, and caspases 8, 9, and 3 levels. Histopathological results showed changes reflecting the ability of nanogold conjugated heat-killed yeast to induce apoptosis is greater than heat-killed yeast alone as the nanogold conjugated with heat-killed yeast showed no tumor, no hyperplasia, no granulation tissue formation, no ulceration, and no suppuration. Nanogold conjugated with heat-killed yeast-treated breast cancer group displayed normal levels of ALT and AST, indicating relatively healthy hepatic cells. Conclusion Our results proved that nanogold conjugated heat-killed yeast can initiate apoptosis and can be used as a safe non-invasive method for breast cancer treatment more effectively than the yeast alone. This, in turn, gives us new insight and a future hope for the first time that breast cancer can be treated by non-invasive, simple, safe, and naturally originated method and achieves a hopeful treatment and a novel method for in vivo cancer therapy.

Abstract 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.

Research background. Wine production, which is considered a major sector in food industry, often involves the use of a large amount of resources. Moreover, wine making generates a large amount of grape pomace, which is generally used for low-value applications such as fertiliser and animal feed. The aim of the present research is to explore the possibility of improving the overall sustainability of traditional winemaking. Experimental approach. A zero-waste process was developed. It includes the production of white wine and the substantial valorisation of grape pomace, which is converted into solid biofuel, tartaric acid and concentrated grape extract as feedstock for industrial baker’s yeast production. Results and conclusions. We estimate that a significant surplus of renewable energy of approx. 3 MJ/kg processed grapes can be obtained during this conversion. The suitability of grape extract as a potential substrate for industrial baker’s yeast production was evaluated and the feasibility of a partial replacement of molasses (up to 30 %) was demonstrated. Novelty and scientific contribution. We present a circular economy approach for the conversion of winery biowaste into high-value resources such as feedstock and solid biofuel.

The poultry population has substantially grown in recent years, and measures to ensure meat quality have also improved significantly. The exponential growth of the human population eventually resulted in increasing meat demand. In particular, poultry meat has been the more favorable and nutritive option. Research on feed additives has sparked an interest in many poultry specialists looking for ways to increase poultry performance. The use of baker's yeast, Saccharomyces cerevisiae, as an antibiotic alternative by acting as prebiotics and probiotics has received significant attention. Baker’s yeast contains β-glucans and mannan-oligosaccharides as its main components. Recent studies have shown that baker’s yeast, as an alternative protein source, positively affects poultry growth performance, blood parameters, and immune response. Furthermore, the application of baker's yeast as a fermented feed additive showed promising results for poultry production. The use of baker’s yeast in the diet improves the morphological structure of the poultry gut, thus increasing growth performance. More informatively, it stimulates feed intake, increases body weight gain, and improves the feed conversion ratio. Baker’s yeast also improves the immune system of poultry animals by reducing various numbers of harmful microorganisms by combating poultry diseases more effectively and eventually increasing poultry health. This paper aims to synthesize all aspects of the effect of baker’s yeast on the poultry industry and the role and application of baker's yeast in poultry productivity.

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]

Abstract 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.

Since the discovery of acrylamide in heat-treated foods (crisps and biscuits) in April 2002, by a Swedish study, many efforts have been made to reduce acrylamide levels in foods. Consideration was given to reducing acrylamide levels by reducing Maillard reaction products. However, the production of potato chips creates acrylamide, a carcinogenic compound. This study aimed to use a new quantitative index and formula for l-asparaginase, glucose oxidase, their 1:1 blending enzymes, baker's yeast and green tea powder (0.5 g/kg distilled water) to reduce acrylamide production in potato chips and evaluate the products on some new indicators, such as asparagine reduction (%), acrylamide reduction (%), Asparagine / Acrylamide ratio (AAR) and Asparagine content (mg/kg). The highest acrylamide concentrations were reduced from 1346.0 ± 7.9 mg/kg in the blank sample (control) to 285.7 ± 3.2 and 325.3 ± 10.5 mg/kg in the baker's yeast sample (CT4) and green tea sample (CT5) treated sample, respectively. The potato chips treated with 0.5 g/kg l-asparaginase (CT1) reduced the acrylamide level by approximately 70.65±0.31%, while the CT4 samples showed 78.77±0.21% and asparagine contents of 116.0 ± 5.3 mg/kg and 195.0 ± 5.0 mg/kg, respectively.The results showed that some enzymes, baker's yeast and green tea powder could control the formation of acrylamide, which was formed during the processing of potato chips, allowing the food industry to produce low acrylamide foods from high starch food products such as potatoes. It has the ability to be used as a functional food, as well as to protect the human body of school-age children and adolescents from absorbing 70–80% of their daily acrylamide intake without these treatments.

Background: Saccharomyces cerevisiae (S. cerevisiae) has been demonstrated in vitro to sensitize several breast cancer cell lines and to be a safe, non-toxic drug with anti-skin cancer action in mice. Furthermore, plasmonic photothermal treatment using gold nanorods has been authorized as a novel method for in vitro and in vivo cancer therapy. Results: When compared to tumor-free rats, the treatment with S. cerevisiae conjugated to gold nanospheres (GNSs) lowered Bcl-2 levels while increasing FasL, Bax, cytochrome c, and caspases 8, 9, and 3 levels. Histopathological results showed changes reflecting the ability of nanogold conjugated heat-killed yeast to induce apoptosis is greater than heat-killed yeast alone as the nanogold conjugated with heat-killed yeast showed no tumor, no hyperplasia, no granulation tissue formation, no ulceration, and no suppuration. Nanogold conjugated with heat-killed yeast-treated breast cancer group displayed normal levels of ALT and AST, indicating relatively healthy hepatic cells. Conclusion: Our results proved that nanogold conjugated heat-killed yeast can initiate apoptosis and can be used as a safe non-invasive method for breast cancer treatment more effectively than the yeast alone. This, in turn, gives us new insight and a future hope for the first time that breast cancer can be treated by non-invasive, simple, safe, and naturally originated method and achieves a hopeful treatment and a novel method for in vivo cancer therapy. [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]

Introduction: Bioproduction of plant-derived triterpenoids in recombinant microbes is receiving great attention to make these biologically active compounds industrially accessible as nutraceuticals, pharmaceutics, and cosmetic ingredients. So far, there is no direct method for detecting triterpenoids under physiological conditions on a cellular level, information yet highly relevant to rationalizing microbial engineering.Methods: Here, we show in a proof-of-concept study, that triterpenoids can be detected and monitored in living yeast cells by combining coherent anti-Stokes Raman scattering (CARS) and second-harmonic-generation (SHG) microscopy techniques. We applied CARS and SHG microscopy measurements, and for comparison classical Nile Red staining, on immobilized and growing triterpenoid-producing, and non-producing reference Saccharomyces cerevisiae strains.Results and Discussion: We found that the SHG signal in triterpenoid-producing strains is significantly higher than in a non-producing reference strain, correlating with lipophile content as determined by Nile red staining. In growing cultures, both CARS and SHG signals showed changes over time, enabling new insights into the dynamics of triterpenoid production and storage inside cells.

An efficient and reliable method has been developed for chemo-selective synthesis of Schiff bases (SB) (3a–n) by using Baker’s yeast (BY) as biocatalyst. The reaction is highly chemo-selective as only benzaldehydes take part in the reaction, whereas acetophenones fail to take part in this reaction. Furthermore, it was observed that amino acids (glycine, phenylalanine & tryptophan) and aliphatic amines (isopropyl amine and 1-amino butane) did not take part in the reaction. The present method is very efficient as it involves simple work up and gives the products in good to excellent yield. The reaction is totally carried out under eco- friendly and environmentally begin conditions by using ethanol (EtOH) as a green solvent. Thus it is anticipated that the present newly developed method will open a gateway for the chemist to prepare the selective SB (Aldimines) in the presence of ketones in facile and eco-friendly conditions.

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]

Cellulose-based nanofibers are a versatile material with broad applications, including wound-healing/dressing biomaterials, food packing, water treatments, sensors, and energy storage materials. In this work, a cellulose acetate (CA) nanofiber membrane obtained from the electrospinning process was hydrolyzed to a regenerated cellulose (RC) nanofiber membrane. The RC nanofiber membrane coupled with Reactive Orange 4 (RO4) as the dye ligand was used in the purification of malate dehydrogenase (MDH) from the disrupted baker's yeast in a single step. The optimal pH and the immobilized dye density for MDH adsorption were at pH 7.5 and ~ 520 mg dye/g membrane, respectively. The maximum equilibrium binding capacity for MDH was 3985.65 U/g, and the surface reaction was the main rate-limiting step for MDH transport to the nanofiber membrane throughout the adsorption process. The purification of the MDH process was performed by using a membrane contactor (i.d. 25 mm) in a flow system. An elution solution (pH 5) made of 10 mM NADH and 0.1 M NaCl resulted in high efficiency of MDH elution, recording a recovery yield of 89% and a purification factor of 78 folds. Similar performance of MDH purification was obtained using a larger membrane contactor (i.d. 47 mm), thereby proving the linear scalability of the purification process. [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]

We traced back a nationwide outbreak of human listeriosis in Switzerland to a persisting production line contamination of a factory producing baker's yeast with Listeria monocytogenes serotype 1/2a sequence type 3141. We used whole-genome sequencing to match clinical isolates to isolates from product samples.

Punicic acid (PuA), an unusual conjugated linolenic acid found in pomegranate, offers diverse health benefits and has potential applications in the food industry. Due to the limited availability of PuA from natural plant sources, there is growing interest in producing it through microbial fermentation. In this study, the yeast Saccharomyces cerevisiae , which is classified as "generally recognized as safe", was engineered to produce PuA using a results-driven approach. Genes potentially involved in PuA synthesis were integrated directly into the yeast genome, targeting Ty retrotransposon sites. Screening of the yeast transformants, followed by optimization of culture conditions, resulted in the production of 26.7% PuA within the yeast's total fatty acids. Further analysis revealed that the strain's triacylglycerol fraction contained over 22% PuA. By incorporating this health-promoting lipid into the nutritional profile of S. cerevisiae , the engineered strain could serve as a sustainable source of yeast biomass with enhanced nutritional value.

Yeasts are reported to be rich in folates, a group of vitamers known to be involved in several biosynthetic reactions such as methylation reactions, oxidation and reduction processes, and nucleotide synthesis. Not being able to synthesize folates, humans rely on external folate supply. Here, we show the application of LC/MS-MS methods using SIDA (stable isotope dilution analysis) assays for the quantitative analysis of different folate mono- and polyglutamates during growth of Saccharomyces cerevisiae. Molecular networking (MN) was applied for detailed analysis of further folate metabolites. Highest folate contents of 13,120 μg/100 g were observed after 20 h of cultivation. The main vitamers 5-CH3-H4folate and H4folate decreased during cultivation, while 5-CHO-H4folate increased during cultivation. The hexa- and heptaglutamate of 5-CH3-H4folate accounted for >96% of the total 5-CH3-H4folate content. A shift of the major polyglutamate from hexa- to heptaglutamate was observed after 29 h. MN unraveled two groups of novel folates which could be assigned to a potentially existing C2-metabolism in yeast. In detail, 5,10-ethenyl-tetrahydrofolate and a further CO-substituted 5-CH3-H4folate were identified as hexa- and heptaglutamates. The latter was neither identified as 5-acetyl-tetrahydrofolate nor as EthylFox, the oxidation product of 5-ethyl-tetrahydrofolate. The structure needs to be elucidated in future studies.

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]