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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]

[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]

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.

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]

With rapid progress in the yeast fermentation industry, a comprehensive commercial yeast quality assessment approach integrating efficiency, accuracy, sensitivity, and cost-effectiveness is required. In this study, a new yeast quality assessment method based on single-cell Raman technology was developed and contrasted with traditional methods. The findings demonstrated significant associations (Pearson correlation coefficient of 0.933 on average) between the two methods in measuring physiological indicators, including cell viability and intracellular trehalose content, demonstrating the credibility of the Raman method compared to the traditional method. Furthermore, the sensitivity of the Raman method in viable but non-culturable cells was higher in measuring yeast cell viability (17.9 % more sensitive). According to the accurate quantitative analysis of metabolic activity level (MAL) of yeast cells, the cell vitality was accurately quantified at population and single-cell levels, offering a more comprehensive assessment of yeast fermentation performance. Overall, the single-cell Raman method integrates credibility, feasibility, accuracy, and sensitivity in yeast quality assessment, offering a new technological framework for quality assessments of live-cell yeast products., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

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]