Yeast Saccharomyces Cerevisiae Research Articles

Chemical composition and biological activity of essential oil from anise hyssop

Anise hyssop (Agastache foeniculum (Pursh) Kuntze) is a perennial plant belonging to the Lamiaceae family mainly used in folk medicine to treat various ailments. This study determined the chemical composition of the essential oil and evaluated its antimicrobial and antioxidant activity. The essential oil was obtained from plants cultivated in the experimental field at the Institute of Roses, Essential and Medical Plants, Kazanlak, Bulgaria. The plants were processed by steam distillation, with the essential oil yielding 0.37%, and its main components being methyl chavicol (82.03%) and limonene (9.90%). The most potent antimicrobial action was observed against the gram-positive bacteria Staphylococcus aureus (25.7 mm inhibition zone) and Bacillus cereus (12.3 mm), the yeast Saccharomyces cerevisiae (16.3 mm) and Candida albicans (16.5 mm). The remaining gram-positive bacteria (Staphylococcus epidermidis and Bacillus subtilis), gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Salmonella ebony), and fungi (Aspergillus brasiliensis and Fusarium moniliforme) were resistant to the action of the essential oil. The antioxidant activity of the essential oil was ABTS (32.36 µmol TE/mL), DPPH (21.61 µmol TE/mL), CUPRAC (19.94 µmol TE/mL), and FRAP (29.56 µmol TE/mL) in vitro. Overall, the results from this study revealed the biological potential of anise hyssop as a source in pharmaceutical, food, and cosmetic applications.

Expression of human RECQL5 in Saccharomyces cerevisiae causes transcription defects and transcription-associated genome instability

RECQL5 is a member of the conserved RecQ family of DNA helicases involved in the maintenance of genome stability that is specifically found in higher eukaryotes and associates with the elongating RNA polymerase II. To expand our understanding of its function we expressed human RECQL5 in the yeast Saccharomyces cerevisiae, which does not have a RECQL5 ortholog. We found that RECQL5 expression leads to cell growth inhibition, increased genotoxic sensitivity and transcription-associated hyperrecombination. Chromatin immunoprecipitation and transcriptomic analysis of yeast cells expressing human RECQL5 shows that this is recruited to transcribed genes and although it causes only a weak impact on gene expression, in particular at G + C-rich genes, it leads to a transcription termination defect detected as readthrough transcription. The data indicate that the interaction between RNAPII and RECQL5 is conserved from yeast to humans. Unexpectedly, however, the RECQL5-ID mutant, previously shown to have reduced the association with RNAPII in vitro, associates with the transcribing polymerase in cells. As a result, expression of RECQL5-ID leads to similar although weaker phenotypes than wild-type RECQL5 that could be transcription-mediated. Altogether, the data suggests that RECQL5 has the intrinsic ability to function in transcription-dependent and independent genome dynamics in S. cerevisiae.

Bioprospecting and Selection of Indigenous Saccharomyces cerevisiae Yeasts from Pozo de Los Algarrobos (Argentina) for the Production of Genuine White Wines

Bioprospecting and Selection of Indigenous Saccharomyces cerevisiae Yeasts from Pozo de Los Algarrobos (Argentina) for the Production of Genuine White Wines

Autolyzed yeast and sodium butyrate supplemented alone to diets promoted improvements in performance, intestinal health and nutrient transporter in weaned piglets

This study investigated the effects of supplemental nucleotides, autolyzed yeast (Saccharomyces cerevisiae), and sodium butyrate in diets for nursery pigs on growth performance, diarrhea incidence, blood profile, intestinal morphology, mRNA expression of nutrient transporters, inflammatory markers, antioxidant profile, and tight junction proteins in the small intestine. One hundred eighty 21-day-old pigs (5.17 ± 0.57 kg) were assigned in a randomized block design to 1 of 4 dietary treatments: (1) CON: control, basal diet, (2) NUC: CON + nucleotides, (3) YSC: CON + lysed yeast S. cerevisiae, (4) ASB: CON + acidifier sodium butyrate. Pigs were fed for 24 days, phase 1 (21–32 days) and 2 (32–45 days). During phase 1, YSC and ASB improved average daily gain (ADG) and feed conversion (FC) compared with CON. At the overall period, ASB improved ADG and YSC improved FC compared with CON. The NUC diet did not affect growth performance. The ASB increased ileal villus height compared to CON. The YSC and ASB reduced the number of Peyer’s patches in the ileum compared with CON. The YSC increased mRNA expression of nutrient transporters (SMCT2, MCT1, and PepT1), tight junction proteins (OCL and ZO-1), antioxidants (GPX), and IL1-β in the jejunum compared with CON. The ASB increased mRNA expression of nutrient transporters (SGLT1 and MCT1), tight junction proteins (OCL and ZO-1), and antioxidants (GPX and SOD) compared with CON. In conclusion, autolyzed yeast and sodium butyrate promoted growth performance by improving the integrity of the intestinal barrier, the mRNA expression of nutrient transporters, and antioxidant enzymes in the jejunum of nursery pigs whereas supplementation of nucleotides did not show such effects.

Improving Muscat Hamburg Wine Quality with Innovative Fermentation Strategies Using Schizosaccharomyces pombe Derived from Fermented Grains of Sauce-Flavor Baijiu

This study investigates innovative approaches to improve the quality and aroma characteristics of Muscat Hamburg wine production by substituting the conventional Saccharomyces cerevisiae yeast with an efficient fermentation strain of Schizosaccharomyces pombe. The typical use of S. cerevisiae in Muscat Hamburg wine often leads to uniformity and prolonged processing times, requiring subsequent malolactic fermentation to degrade excessive malic acid. The study advocates for the replacement of S. cerevisiae with a specific S. pombe strain, Sp-410, isolated from the fermented grains of sauce-flavor Baijiu, a Chinese spirit. Muscat Hamburg wine fermented with the S. pombe strain demonstrates decreased malic acid levels, offering a potential alternative to malolactic fermentation. However, exclusive S. pombe fermentation may result in an overproduction of acetic acid metabolites, leading to a monotonous taste. In response, the study proposes a mixed fermentation approach, combining the S. pombe strain with a Saccharomyces uvarum strain and a non-Saccharomyces yeast, Torulaspora delbrueckii. The optimized mixed fermentation strategies (M:SP+TD and M60SP+TD) involve specific proportions and intervals of inoculation, aiming to enhance the quality and aroma complexity of Muscat Hamburg wine. In conclusion, this research contributes to advancing the production of high-quality Muscat Hamburg wines, utilizing S. pombe as the primary yeast strain and implementing mixed fermentation methodologies.

Unexpected Behavior of a Maltose-Negative Saccharomyces cerevisiae Yeast: Higher Release of Polyfunctional Thiols from Glutathionylated Than from Cysteinylated S-Conjugates

At present, non-alcoholic and low-alcoholic beers (NABLABs), in addition to their premature sensitivity to oxidation, still suffer from a lack of fruity fermentation aromas. Maltose/maltotriose-negative yeasts offer a highly attractive alternative for creating diversified pleasant aromas and/or eliminating off-flavors in NABLAB production. The aim of this study was to explore the potential of Saccharomyces cerevisiae var. chevalieri, SafBrewTM LA-01 to release fruity polyfunctional thiols from glutathionylated (G-) and cysteinylated (Cys-) precursors. Interestingly, it proved to release free thiols from their glutathionylated S-conjugate much more efficiently (0.34% from G-3-sulfanylhexanol in 15 °P wort after seven days at 24 °C) than the best S. pastorianus strains previously screened (0.13% for lager yeast L7). On the other hand, despite its classification as a S. cerevisiae strain, it showed an inefficient use of cysteinylated precursors, although the release efficiency was slightly higher under NABLAB fermentation conditions (6 °P; 3 days at 20 °C). Under these conditions, as expected, LA-01 consumed only glucose, fructose, and saccharose (0.4% v/v ethanol formation) and produced only low levels of fermentation esters (1.6 mg/L in total) and dimethylsulfide (5 µg/L). The POF+ character of LA-01 also brought significant levels of 4-vinylguaiacol (810 μg/L), which could give to NABLABs the flavors of a white beer.

Engineering Implementation of the Acosta Fermentation Method to Obtain Cuban Schnapps with Reduced Concentrations of Higher Alcohols

The Acosta method involves rewiring the yeast metabolic pathway to enhance biomass production and prevent a significant increase in higher alcohols during the late stages of fermentation. This study aimed to assess fermentation conditions to achieve Cuban schnapps with reduced concentrations of higher alcohols and replicate the process on an industrial scale. To achieve this, the quality of final sugarcane molasses for fermentation by Saccharomyces cerevisiae (S. cerevisiae) yeast was evaluated. Industrial pre-fermentation and fermentation processes were successfully conducted, followed by laboratory-scale fermentation using the Acosta fermentation method to determine crucial parameters for industrial implementation. Operational parameters for fermentation were identified from the following results: 13.5 °Brix seeding, metabolic pathway inversion of S. cerevisiae at 16 h, and an air concentration of 0.1 m3/min. The resulting Cuban schnapps obtained using this method exhibited a concentration of higher alcohols of 132.5 mg/L, a value that is within the standard parameters, showing a positive impact of this fermentation method on the quality of the schnapps. Scaling up this method to an industrial level, in addition to offering higher quality products and being an economically viable alternative, also stands out for its sustainable and environmentally friendly aspect, and results in higher production of yeast biomass as a byproduct, which can be used for various purposes, such as animal feed. This method constitutes an important update to the schnapps production process as a technological improvement that respects sustainable production trends and the characteristics of the final product.

Cymoxanil disrupts RNA synthesis through inhibiting the activity of dihydrofolate reductase.

The agricultural fungicide cymoxanil (CMX) is commonly used in the treatment of plant pathogens, such as Phytophthora infestans. Although the use of CMX is widespread throughout the agricultural industry and internationally, the exact mechanism of action behind this fungicide remains unclear. Therefore, we sought to elucidate the biocidal mechanism underlying CMX. This was accomplished by first performing a large-scale chemical-genomic screen comprising the 4000 haploid non-essential gene deletion array of the yeast Saccharomyces cerevisiae. We found that gene families related to de novo purine biosynthesis and ribonucleoside synthesis were enriched in the presence of CMX. These results were confirmed through additional spot-test and colony counting assays. We next examined whether CMX affects RNA biosynthesis. Using qRT-PCR and expression assays, we found that CMX appears to target RNA biosynthesis possibly through the yeast dihydrofolate reductase (DHFR) enzyme Dfr1. To determine whether DHFR is a target of CMX, we performed an in-silico molecular docking assay between CMX and yeast, human, and P. infestans DHFR. The results suggest that CMX directly interacts with the active site of all tested forms of DHFR using conserved residues. Using an in vitro DHFR activity assay we observed that CMX inhibits DHFR activity in a dose-dependent relationship.

Tissue-specific deposition, speciation and transport of antimony in rice.

Rice (Oryza sativa) as a staple food is a potential intake source of antimony (Sb), a toxic metalloid. However, how rice accumulates this element is still poorly understood. Here, we investigated tissue-specific deposition, speciation, and transport of Sb in rice. We found that Sb(III) is the preferential form of Sb uptake in rice, but most Sb accumulates in the roots, resulting in a very low root-to-shoot translocation (less than 2%). Analysis of Sb deposition with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) showed that most Sb deposits at the root exodermis. Furthermore, we found that Sb is mainly present as Sb(III) in the root cell sap after uptake. Further characterization showed that Sb(III) uptake is mediated by Low silicon rice 1 (Lsi1), a Si permeable transporter. Lsi1 showed transport activity for Sb(III) rather than Sb(V) in yeast (Saccharomyces cerevisiae). Knockout of Lsi1 resulted in a significant decrease in Sb accumulation in both roots and shoots. Sb concentration in the root cell sap of two independent lsi1 mutants decreased to less than 3% of that in wild-type rice, indicating that Lsi1 is a major transporter for Sb(III) uptake. Knockout of Lsi1 also enhanced rice tolerance to Sb toxicity. However, knockout of Si efflux transporter genes, including Lsi2 and Lsi3, did not affect Sb accumulation. Taken together, our results showed that Sb(III) is taken up by Lsi1 localized at the root exodermis and is deposited at this cell layer due to lack of Sb efflux transporters in rice.

Laccase is a multitasking protein for synthetic gene circuits in the yeast Saccharomycescerevisiae

Laccase is a multicopper oxidase enzyme that oxidizes a variety of substrates, including polyphenols and polycyclic aromatic hydrocarbons (PAHs). It catalyzes the four-electron reduction of molecular oxygen that results in the production of water as a by-product. Thus, laccase can play an important role in environmental care. Previously, we have successfully expressed Trametes trogii laccase (TtLcc1) in the yeast Saccharomyces cerevisiae. In this work, we have expressed in yeast another laccase, LacA from Trametes sp. AH28-2, and tested its function on PAHs. Yeast cells engineered to produce the two laccases performed efficient PAH degradation. Both TtLcc1 and LacA led to the construction of spatiotemporal fluorescence-pulse generators when combined with a benzoate/salicylate yeast biosensor in a two-population system. Moreover, laccases returned a visual output signal in yeast synthetic circuits—upon reacting with ABTS (2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)). Thus, in S. cerevisiae, laccases are a powerful alternative to fluorescent reporter proteins.

Impact of Encapsulated Saccharomyces cerevisiae Yeasts on the Chemical and Sensory Profiles of Sparkling Cider Produced by the Champenoise Method

The cider market has been significantly expanding and gaining momentum in Eastern Europe. As such, the aim of this study was to obtain sparkling cider via the Champenoise method using two Romanian apple varieties (Topaz and Red Topaz) alongside the employment of two fermentations. Four yeast strains were used in the first fermentation, while encapsulated Saccharomyces cerevisiae was used in the second fermentation. The resulting cider was subjected to a comprehensive investigation to quantitatively determine the carbohydrates, organic acids, volatile and phenolic compounds, and amino acids from all the cider samples. A trained panel evaluated the sensory profile of the samples, and a chemometric analysis was used to interpret the data. Secondary fermentation increased the accumulation of malic acid and lactic acid, as well as the volatile profile complexity. The total polyphenol content in the sparkling cider samples increased by almost 20% in the S. cerevisiae sample and over 217% in the P. kluyveri + S. cerevisiae sample compared to the base cider. Additionally, studying the production and consumption trends of sparkling cider offers valuable insights for both producers and consumers. By understanding consumer preferences and refining production techniques, the industry can deliver higher-quality products that better align with market demands.

Reduction of Ferric Chloride in Yeast Growth Media, by Sugars and Aluminum

Iron compounds can be used in antimicrobial applications by exploiting the toxicity of divalent iron to living organisms due to the Fenton reaction. In this study, the growth inhibitory effects of ferrous sulfate FeSO4·7H2O and ferric chloride FeCl3·6H2O were observed on Metschnikowia clade and Saccharomyces cerevisiae yeast cells. The relatively high amount of reduced Fe3+ to Fe2+ in the growth medium determined by Mössbauer spectroscopy may contribute to the antimicrobial activity of ferric chloride. In order to test the reducing ability of sugars in the growth media of yeasts, the reaction of ferric chloride FeCl3·6H2O with sugars was investigated. In mixtures of FeCl3·6H2O and fructose, approximately two thirds of Fe3+ can be reduced to Fe2+. When the mixture of FeCl3·6H2O and fructose is placed on the surface of aluminum foil, an iron film is formed on the surface of the aluminum due to the reduction by both fructose and aluminum. The relative amount of Fe3+ which was reduced to Fe0 reached 68%.

Targeted Formation of Biofilms on the Surface of Graphite Electrodes as an Effective Approach to the Development of Biosensors for Early Warning Systems.

Biofilms based on bacteria Pseudomonas veronii (Ps. veronii) and Escherichia coli (E. coli) and yeast Saccharomyces cerevisiae (S. cerevisiae) were used for novel biosensor creation for rapid biochemical oxygen demand (BOD) monitoring. Based on the electrochemical measurement results, it was shown that the endogenous mediator in the matrix of E. coli and Ps. veronii biofilms and ferrocene form a two-mediator system that improves electron transport in the system. Biofilms based on Ps. veronii and E. coli had a high biotechnological potential for BOD assessment; bioreceptors based on such biofilms had high sensitivity (the lower limits of detectable BOD5 concentrations were 0.61 (Ps. veronii) and 0.87 (E. coli) mg/dm3) and high efficiency of analysis (a measurement time 5-10 min). The maximum biosensor response based on bacterial biofilms has been observed in the pH range of 6.6-7.2. The greatest protective effect was found for biofilms based on E. coli, which has high long-term stability (151 days for Ps. veronii and 163 days for E. coli). The results of the BOD5 analysis of water samples obtained using the developed biosensors had a high correlation with the results of the standard 5-day method (R2 = 0.9820, number of tested samples is 10 for Ps. veronii, and R2 = 0.9862, number of tested samples is 10 for E. coli). Thus, biosensors based on Ps. veronii biofilms and E. coli biofilms could be a novel analytical system to give early warnings of pollution.

Screening and In Silico Analyses of the Yeast Saccharomyces cerevisiae Σ1278b Bank Mutants Using Citral as a Natural Antimicrobial.

The antimicrobial function of citral, one of the main compounds of the essential oils (EO) of the Citrus genus, and widely used by the food industry toward spoilage yeast, was previously proven. In this study, the possible mode of action of citral against yeast cells was evaluated by using a global deletome approach. Firstly, the suitability of Saccharomyces cerevisiae Σ1278b to serve as model yeast was assessed by determining its sensitivity to citral (MIC = 0.5 μL/mL). Subsequently, the complete library of Σ1278b haploid mutants deleted in 4019 non-essential genes was screened to identify potential molecular targets of citral. Finally, the deleted genes in the 590 mutants showing increased citral resistance was analyzed with an in-silico approach (Gene Ontology). The significantly enriched GO Terms were "cytoplasm", "vacuole", and "mitochondrion" (cellular components); "catalytic activity" (molecular function); "pseudohyphal growth" (biological process). For molecular function, resistant mutants were grouped into thiosulfate sulfur transferase activity, transferase activity, and oxidoreductase activity; for cellular components, resistant mutants were grouped as: cytoplasm, intracellular organelle, membrane-bounded organelle, mitochondrion, organelle membrane, and vacuole; and finally, with regard to biological process, deleted genes were grouped as: pseudohyphal growth, mitochondrion organization, lipid metabolic process, DNA recombination and repair, and proteolysis. Interestingly, many identified genes were associated with the cellular response to oxidative stress and ROS scavenging. These findings have important implications for the development of citral-based antimicrobials and the elucidation of its mechanism of action.

Large enrichments in fatty acid 2H/1H ratios distinguish respiration from aerobic fermentation in yeast Saccharomyces cerevisiae

Shifts in the hydrogen stable isotopic composition (2H/1H ratio) of lipids relative to water (lipid/water 2H-fractionation) at natural abundances reflect different sources of the central cellular reductant, NADPH, in bacteria. Here, we demonstrate that lipid/water 2H-fractionation (2εfattyacid/water) can also constrain the relative importance of key NADPH pathways in eukaryotes. We used the metabolically flexible yeast Saccharomyces cerevisiae, a microbial model for respiratory and fermentative metabolism in industry and medicine, to investigate 2εfattyacid/water. In chemostats, fatty acids from glycerol-respiring cells were >550‰ 2H-enriched compared to those from cells aerobically fermenting sugars via overflow metabolism, a hallmark feature in cancer. Faster growth decreased 2H/1H ratios, particularly in glycerol-respiring cells by 200‰. Variations in the activities and kinetic isotope effects among NADP+-reducing enzymes indicate cytosolic NADPH supply as the primary control on 2εfattyacid/water. Contributions of cytosolic isocitrate dehydrogenase (cIDH) to NAPDH production drive large 2H-enrichments with substrate metabolism (cIDH is absent during fermentation but contributes up to 20 percent NAPDH during respiration) and slower growth on glycerol (11 percent more NADPH from cIDH). Shifts in NADPH demand associated with cellular lipid abundance explain smaller 2εfattyacid/water variations (<30‰) with growth rate during fermentation. Consistent with these results, tests of murine liver cells had 2H-enriched lipids from slower-growing, healthy respiring cells relative to fast-growing, fermenting hepatocellular carcinoma. Our findings point to the broad potential of lipid 2H/1H ratios as a passive natural tracker of eukaryotic metabolism with applications to distinguish health and disease, complementing studies that rely on complex isotope-tracer addition methods.

Effects of Mango Pectin Concentration on the Calcium Pectate Bead Properties and on the Cell Leakage of Yeast (Saccharomyces cerevisiae) Immobilized by Entrapment Technique

Immobilized yeast cells have advantages for use in industries due to their stability, viability, and productivity. As a support material, pectin is suitable because of its stability, strong mechanical attributes, and favorable absorption properties. In this study, the influence of mango pectin concentration on the CP bead characteristics and the leakage of immobilized yeast cells were determined. Results have indicated that yeast cells can be immobilized using low-methoxyl pectin (LMP) from mango peels via entrapment technique. Pectin concentration did not affect the size (3.0323 to 3.4315 mm) of the CP beads. Only 5% and 7% (w/v) pectin concentrations produced spherical beads (SF&lt;0.05). Increasing the pectin concentration from 3% to 7% (w/v) resulted in a 36.21% decrease in swelling ratio for CP beads with yeast. The pectin concentration significantly affects the cell leakage (p-value&lt;0.05). The results further indicate the feasibility of using locally available materials as a matrix for immobilization.

Species-wide quantitative transcriptomes and proteomes reveal distinct genetic control of gene expression variation in yeast

Gene expression varies between individuals and corresponds to a key step linking genotypes to phenotypes. However, our knowledge regarding the species-wide genetic control of protein abundance, including its dependency on transcript levels, is very limited. Here, we have determined quantitative proteomes of a large population of 942 diverse natural Saccharomyces cerevisiae yeast isolates. We found that mRNA and protein abundances are weakly correlated at the population gene level. While the protein coexpression network recapitulates major biological functions, differential expression patterns reveal proteomic signatures related to specific populations. Comprehensive genetic association analyses highlight that genetic variants associated with variation in protein (pQTL) and transcript (eQTL) levels poorly overlap (3%). Our results demonstrate that transcriptome and proteome are governed by distinct genetic bases, likely explained by protein turnover. It also highlights the importance of integrating these different levels of gene expression to better understand the genotype-phenotype relationship.

Interrelations Between Probiotics, Gut Microbiota, Intestinal Barrier, and Immune Response; Focusing on Diarrhea in Dairy Calves1

The interplay between gut microbiota and host health has attracted significant interest in the animal science community. Maintaining gut microbiota homeostasis by supplementing probiotics to treat clinical conditions like calf diarrhea is an emerging area of research nowadays because of increased concerns regarding antimicrobial resistance (AMR) and drug residues in animal products. Probiotics reduce the incidence of calf diarrhea by increasing the gut microbiota diversity and richness with more commensal bacteria such as Lactobacillus and Bifidobacterium that produce antimicrobial compounds, as well as modulating the immune response by increasing cytokines, Interleukin-2 (IL-2), IL-4, IL-6, IL-10, and reducing tumor necrosis factor-α (TNF-α), by increasing production of antibodies, especially immunoglobulin E (IgE), also IgG, differentiating naïve Th lymphocytes (Tho) into Th1, hence stimulate innate immunity and prime the adaptive immune response. Specific probiotic strains of bacteria and yeast (Saccharomyces cerevisiae) derived probiotics maintain the integrity of the intestinal barrier. In this review, data is being organized to address the role of probiotics in treating calf diarrhea by modulating gut microbiota and stimulating an immune response against notorious pathogens, to present animal and veterinary scientists and nutritionists with a new concept to treat infectious diseases from the perspective of the gut microbiota, increasing animal health, performance, and welfare. In conclusion, health status and gut microbiome are strongly interlinked. Research data indicated a significant reduction in the incidence of diarrhea after probiotic administration. If interrelations between probiotics and existing gut microbiota are explored more quantitatively, novel antibiotic substitutes can emerge in the future.

Mitochondrial citrate transporters Ctp1-Yhm2 and respiratory chain: A coordinated functional connection in Saccharomyces cerevisiae metabolism

The mitochondrial inner membrane contains some hydrophobic proteins that mediate the exchange of metabolites between the mitochondrial matrix and the cytosol. Ctp1 and Yhm2 are two carrier proteins in the yeast Saccharomyces cerevisiae responsible for the transport of citrate, a tricarboxylate involved in several metabolic pathways.Since these proteins also contribute to respiratory metabolism, in this study we investigated for the first time whether changes in citrate transport can affect the structural organization and functional properties of respiratory complexes.Through experiments in yeast mutant cells in which the gene encoding Ctp1 or Yhm2 was deleted, we found that in the absence of either mitochondrial citrate transporter, mitochondrial respiration was impaired. Structural analysis of the respiratory complexes III and IV revealed different expression levels of the catalytic and supernumerary subunits in the Δctp1 and Δyhm2 strains. In addition, Δyhm2 mitochondria appeared to be more sensitive than Δctp1 to the oxidative damage.Our results provide the first evidence for a coordinated modulation of mitochondrial citrate transport and respiratory chain activity in S. cerevisiae metabolism.

Optimization of Fermented White Glutinous Rice Tape for Ethanol Content Using the Gas Chromatography Method

One of the traditional foods that have health-preserving properties is tape which can prevent an increase in cholesterol and prevent a shortage of red blood cells. Tape products are the result of the fermentation of processed raw materials that contain starch, that is, these food ingredients become simple forms such as sugar with the addition of microbes such as yeast or yeast (Saccharomyces cerevisiae) which work to break down carbohydrate foods into alcohol and carbon dioxide by settling to form compounds. namely ethanol. The test was carried out to determine the fermentation time of the ethanol content in white sticky rice tape. The test used the gas chromatography method. The location of the testing carried out at the Pharmacy and Food Analysis Campus was obtained. The results obtained for the system suitability test analysis consisted of precision, column efficiency, and accompanying factors that met the requirements. Meanwhile, the ethanol content in samples carried out continuously for five days on days I, II, III, IV, and V respectively was 2.94%; 3.03%; 3.12%; 3.14%, and 3.28%. The greatest ethanol content obtained on day V was 3.28%, and the smallest content on day I was 2.94%. So it can be concluded that the ethanol content resulting from fermentation in white sticky rice tape increases every day and the quality of the tape decreases