Viable Yeast Cells Research Articles

Respiratory Deficient Mutants Induced in Baker's Yeast by the Action of Acridine Orange and some Plant Growth Hormones طفرات نقص التنفس المستحدثة فی خمیرة الخباز کنتیجة للمعاملة بالأکریدین وهرمونات النمو النباتیة

The present study aimed to investigate the mutagenic effect of acriflavine and some plant growth hormones on mitochondrial DNA of Saccharomyces cerevisiae. Two yeast isolates isolated from different sources were used in this work. The results of acriflavine treatments showed significant toxicity on the viability of yeast cells via a dose – response appeared. This means that the survival of cells was decreased with the increasing in acriflavine concentrations. This is a clear evidence for the toxic action of acriflavine on yeast cells. At the concentration of 1 ppm the parent cells of isolate – A retain the normal respiratory abilities, while the isolate – B was less affected. The high rate of petite mutants appeared when the cells were exposed to 4 ppm. Isolate – B was more sensitive to acriflavine than isolate – A regarding the decline in the viability of cells and respiratory deficient mutants induced. In addition, kinetin and naphthyl acetic acid showed a dose – response for the viability of yeast cells without respiratory deficient mutants induced. This indicated that both plant growth hormones enhances the division of yeast cells leading the cells to continue growing. In addition, plant growth hormones plays several vital roles in biochemical processes related to cell cycle of yeast cells. The signaling molecules regulated cell growth must received significant attention because it is alarm sounds for the potential of carcinogenicity.

The biological effect of 2.45 GHz microwaves on the viability and permeability of bacterial and yeast cells

Microwaves are a form of non-ionizing radiation composed of electric (E) and magnetic (H) fields and are absorbed by biological tissues with a high water content. Our study investigated the effect of the E field, H field, and a combination of both (E + H) field’s exposure of structurally diverse micro-organisms, at a frequency of 2.45 GHz. We observed that the exposure to a microwave E field of an amplitude of 9.3 kV/m had no significant effect on cell viability; however, it did increase membrane permeability of Mycobacterium smegmatis to propidium iodide and to a range of different sized dextran particles in Escherichia coli, Staphylococcus aureus, Candida albicans, and M. smegmatis. The permeability of propidium iodide was observed in microwave treated cells (M. smegmatis) but not in heat-treated cells. Permeability of 3 kDa sized fluorescently labeled dextrans was observed across all cell types; however, this was found not to be the case for larger 70 kDa dextran particles. In terms of efflux, DNA was detected following E field exposure of M. smegmatis. In contrast, H field exposure had no effect on cell viability and did not contribute to increase cell’s membrane to dextran particles. In conclusion, this study shows that microwave generated E fields can temporarily disrupt membrane integrity without detrimentally impacting on cell viability. This approach has the potential to be developed as a high efficiency electropermeabilization method and as a means of releasing host DNA to support diagnostic applications.

Elucidation of rheological properties and baking performance of frozen doughs under different thawing conditions

The effects of thawing methods (refrigerator, ambient, proofer, and microwave thawing) on the quality attributes of frozen doughs were investigated mainly in terms of dough rheology and baking performance. While the use of microwave shortened the thawing times, it caused the dough samples to have uneven temperature distribution, which was thermo-graphically confirmed. The highest weight loss was observed in the microwave-thawed samples, followed by ambient, refrigerator, and proofer thawed ones. The dough samples thawed in a proofer and microwave tended to have lower and higher resistance against mixing, respectively. The microwave-thawing produced doughs with higher storage and loss moduli that were related to a harder and more chewy texture. The dough thawed at refrigerated and ambient temperatures produced bread samples with higher loaf volume, showing a highly linear correlation with the number of viable yeast cells (R2 = 0.9957). The refrigerator and ambient thawing produced breads with a softer texture.

Efficacy of Allicin against Plant Pathogenic Fungi and Unveiling the Underlying Mode of Action Employing Yeast Based Chemogenetic Profiling Approach

Allicin (diallylthiosulfinate) is the principal organosulfur compound present in freshly damaged garlic tissue which exhibits a wide range of biological actions including antibacterial, antifungal, antiviral and anticancer properties. The antifungal activities of allicin were investigated against plant pathogenic fungi of agriculture importance. Furthermore, a yeast genome haploinsufficiency screening was also employed to decipher the antifungal mode of action of allicin. Wildtype and 1152 yeast mutant strains (each deprived of one specific allele of an essential gene in a diploid strain) were screened against allicin. Allicin exhibited promising antifungal properties against all the tested plant pathogens. Haploinsufficiency screening revealed three hypersensitive yeast mutants with gene deletions coding for proteins involved in DNA replication, mitochondrial translation and chromatids cohesion. These processes play a vital role in the cell cycle, growth and viability of yeast cells. Taken together, the results of the present study unravel the excellent antifungal activities and mechanisms and modes of action of allicin. These findings also indicate the potential use of allicin as an alternative “green” fungicide (fumigant) in agriculture.

Rapid Yeast Cell Viability Analysis by Using a Portable Microscope Based on the Fiber Optic Array and Simple Image Processing.

A fiber optic array (FOA) can be used as an alternative or a supplement to the lens in a microscope due to its large magnification, high coupling efficiency and extremely low distortion. Based on our previous research, this paper first demonstrated the resolution and field-of-view (FOV) of the microscope based on the FOA. To further validate the FOA microscope’s imaging capability, yeast activity and concentration were investigated by simple image processing. The results showed that the percentages of live and dead yeast cells correctly identified were 92.1% and 84.8%, except for the clusters, which agreed well with the manual counting methods. Then, the performances of the portable microscopes based on the FOA and lens were compared and the factors that affect the FOA microscope imaging performance were analyzed.

Low false positive and accurate detection of yeast cell viability and concentration using an automatic staining and lensfree imaging platform

Yeast cell viability and concentration are the crucial factors affecting product quality in food industry and bio-fuel production, as well as the evaluation basis for environmental toxic compounds. To overcome the drawbacks of existing methods, including high error, false positive and low automation, we propose a highly accurate approach based on an automatic staining and high-throughput lensfree imaging platform. A precisely controlled staining process is implemented automatically, which largely avoids the error caused by inappropriate exposure times. Based on optical simulation analysis, energy distribution characteristics are proposed. They are better with steady theoretical evidence for live yeast cell recognition. The parameters are directly extracted from raw cell fingerprints without any reconstruction. Those progresses improve robustness and increase efficiency. Availability of this approach is validated by compared the detection results with gold-standard PI counting method in a H2O2 toxicity test. So it is expected to be widely used in industrial production and environmental toxicity assessment.

Cellular mechanism for the improvement of multiple stress tolerance in brewer's yeast by potassium ion supplementation

SummaryThe ethanol fermentation efficiency was affected by multiple stress tolerance of yeast during brewing and bioethanol industry. The effect of KCl on the multiple stress tolerance of yeast cells was examined. Results showed that KCl addition significantly enhanced the tolerance of yeast cells to osmotic and ethanol stress, which correlated with the decreased membrane permeability, the increased intracellular ergosterol and ATP content, and the improved activity of complex II and complex III in yeast cells. Biomass and viability of yeast cells under osmotic and ethanol stress were increased significantly by KCl addition. Supplementation of 4 and 10 g L−1 KCl exhibited the best promotion activity for yeast cells present in medium with 500 g L−1 sucrose and 10% (v v−1) ethanol, respectively. These results suggested that exogenous potassium addition might be an effective strategy to improve yeast tolerance and fermentation efficiency during industrial very‐high‐gravity (VHG) fermentation.

BioSentinel: Long-Term Saccharomyces cerevisiae Preservation for a Deep Space Biosensor Mission.

The biological risks of the deep space environment must be elucidated to enable a new era of human exploration and scientific discovery beyond low earth orbit (LEO). There is a paucity of deep space biological missions that will inform us of the deleterious biological effects of prolonged exposure to the deep space environment. To safely undertake long-term missions to Mars and space habitation beyond LEO, we must first prove and optimize autonomous biosensors to query the deep space radiation environment. Such biosensors must contain organisms that can survive for extended periods with minimal life support technology and must function reliably with intermittent communication with Earth. NASA's BioSentinel mission, a nanosatellite containing the budding yeast Saccharomyces cerevisiae, is such a biosensor and one of the first biological missions beyond LEO in nearly half a century. It will help fill critical gaps in knowledge about the effects of uniquely composed, chronic, low-flux deep space radiation on biological systems and in particular will provide valuable insight into the DNA damage response to highly ionizing particles. Due to yeast's robustness and desiccation tolerance, it can survive for periods analogous to that of a human Mars mission. In this study, we discuss our optimization of conditions for long-term reagent storage and yeast survival under desiccation in preparation for the BioSentinel mission. We show that long-term yeast cell viability is maximized when cells are air-dried in trehalose solution and stored in a low-relative humidity and low-temperature environment and that dried yeast is sensitive to low doses of deep space-relevant ionizing radiation under these conditions. Our findings will inform the design and development of improved future long-term biological missions into deep space.

Correlation between Ethanol Productivity and Biomass Formation from Sugarcane Juice Industrial Wastes by Genetically Recombinant Saccharomyces Cerevisiae

Sugarcane juice sub- products was the main source of carbohydrates for ethanol productivity and biomass formation . It contains sugars as a good alternative material for ethanol production from yeast to meet the large scale consumption of petroleum fuels . Therefore, the main objective of this study was undertaken to determine the correlation between ethanol productivity and biomass formation using different concentrations of sugarcane juice industrial by - products as a main source of carbon .15 hybrids of Saccharomyces cerevisiae derived from three crosses conducted between five parental strains were used in this study . The results of fermentation process on bioethanol production were graphically diagrammatic. The data showed in most cases negative correlations between ethanol production and biomass formation as shown from genotypes of crosses P1 x P4 and P3 x P5 . This indicated that high productivity of ethanol was associated with a lower biomass formation due to ethanol toxicity on the viability of yeast cells . On the contrary , genotypes resulted from cross between P2 x P5 showed positive correlation between both parameters at 0.02 and 0.06 g of sugarcane juice sub - products . Therefore, it is possible that genotypes derived from this cross may be more tolerant to ethanol inhibitor. In addition , the greater use of sugars for growing yeast cells resulting in a lower ethanol productivity and vice – versa . The results indicated that genome shuffling via hybridization is a powerful tool for inducing genetic recombinants in yeast for desirable industrial phenotypes.

Sourdough Fermentation of Carob Flour and Its Application in Wheat Bread.

SUMMARYResearch backgroundCarob is widely cultivated Mediterranean plant, but its flour is scarcely used in bread making. Previous studies investigated the quality of wheat bread with added carob flour showing discrepant results. This study aims to investigate the fermentation performance, antioxidant activity, rheological behaviour and baking application of carob sourdough.Experimental approachCarob sourdough was fermented with Lactobacillus brevis or Lactobacillus fermentum combined with Saccharomyces cerevisiae for 24 h at 30 °C. At the end of sourdough fermentation, number of viable lactic acid bacteria and yeast cells, total titratable acidity, pH value, antioxidant activity, phenolics and sugar content were determined. Carob flour (12% flour mass fraction) or sourdough equivalent (22.5% dough mass fraction) was applied in making composite partially baked frozen bread. Dough rheology was monitored using a farinograph. Nutritive value, physical properties and sensory attributes of the rebaked bread samples were evaluated using a hedonic test.Results and conclusionsBy the end of fermentation, carob sourdough reached pH=4.2-4.5 and total acidity 9.9-12.3 mL of 0.1 M NaOH, sugar content on dry mass basis was reduced by 8 g/100 g, while total phenolics and antioxidant activity were increased up to 21%, depending on the starter culture. Addition of carob flour or sourdough to wheat dough resulted in firmer consistency, longer development time, and lower quality number. Regardless, bread with carob flour had significantly improved specific volume. Compared with common wheat bread, carob bread had increased dietary fibre content (46%), total phenolics (140-200%) and antioxidant activity (240-300%), higher shape, larger volume, reduced crumbliness, unchanged firmness and darker crumb colour. Consumer preference and overall acceptability scores of carob sour bread were comparable to those of wheat bread, falling into the category of ’liking very much’.Novelty and scientific contributionTo our knowledge, this is the first study that proved the feasibility of carob sourdough fermentation using mixed starter cultures, where L. brevis together with S. cerevisiae was better adapted to the substrate than L. fermentum. The carob sourdough could be used as a natural ingredient for improvement of nutritive value and reduction of crumbliness of partially baked frozen bread.

Effects of a high-dose Saccharomyces cerevisiae inoculum alone or in combination with Lactobacillus plantarum on the nutritional composition and fermentation traits of maize silage

Context The inoculation of silage with Saccharomyces cerevisiae to deliver viable yeast cells is a novel concept. Aims The effects of a high-dose S. cerevisiae inoculum alone or combined with Lactobacillus plantarum on the nutritional composition, fermentation traits and aerobic stability of maize silage were studied after 30, 60 and 90 days of storage. Methods Whole-crop maize (309.3 g dry matter (DM)/kg as fed) was subjected to one of three treatments: deionised water (untreated control); S. cerevisiae at an estimated concentration of 108 CFU/g fresh forage (S); or S. cerevisiae at an estimated concentration of 108 CFU/g and L. plantarum at an estimated concentration of 105 CFU/g of fresh forage (SL). Key results Compared with the control, the S and SL groups showed increases (P < 0.001) in average pH (3.98 in S and 4.01 in SL vs 3.65 in the control), crude protein (85 g/kg DM in S and 80 g/kg DM in SL vs 63 g/kg DM in the control) and ammonia nitrogen/total nitrogen (122.2 g/kg in S and 163.9 g/kg in SL vs 52.9 g/kg in the control) but a lower (P < 0.001) average concentration of water-soluble carbohydrate (0.9 g/kg DM in S and 0.7 g/kg DM in SL vs 2.3 g/kg DM in the control). The levels of neutral detergent fibre and acid detergent fibre were greater (P < 0.001) in S silage than in the control and SL silages, and the hemicellulose level was lower (P = 0.004) in the SL group than the control and S groups. Starch and aerobic stability were unaffected by treatment, and the average lactate and ethanol concentrations were higher (P < 0.001) in the S (53.7 g lactate/kg DM and 28.7 g ethanol/kg DM) and SL (56.9 g lactate/kg DM and 21.4 g ethanol/kg DM) groups than the control (40.1 g lactate/kg DM and 5.3 g ethanol/kg DM) over 90 days of ensiling. Conclusions Overall, a high-dose inoculum of S. cerevisiae alone or combined with L. plantarum affected the nutritional composition and fermentation traits of maize silage. Implications The inoculation of maize silage with a high dose of S. cerevisiae needs to be performed with caution.

A PhotoClick cholesterol-based quantitative proteomics screen for cytoplasmic sterol-binding proteins in Saccharomyces cerevisiae.

Ergosterol is a prominent component of the yeast plasma membrane and essential for yeast cell viability. It is synthesized in the endoplasmic reticulum and transported to the plasma membrane by nonvesicular mechanisms requiring carrier proteins. Oxysterol-binding protein homologues and yeast StARkin proteins have been proposed to function as sterol carriers. Although many of these proteins are capable of transporting sterols between synthetic lipid vesicles in vitro, they are not essential for ergosterol transport in cells, indicating that they may be functionally redundant with each other or with additional-as yet unidentified-sterol carriers. To address this point, we hypothesized that sterol transport proteins are also sterol-binding proteins (SBPs), and used an in vitro chemoproteomic strategy to identify all cytosolic SBPs. We generated a cytosol fraction enriched in SBPs and captured the proteins with a photoreactive clickable cholesterol analogue. Quantitative proteomics of the captured proteins identified 342 putative SBPs. Analysis of these identified proteins based on their annotated function, reported drug phenotypes, interactions with proteins regulating lipid metabolism, gene ontology, and presence of mammalian orthologues revealed a subset of 62 characterized and nine uncharacterized candidates. Five of the uncharacterized proteins play a role in maintaining plasma membrane integrity as their absence affects the ability of cells to grow in the presence of nystatin or myriocin. We anticipate that the dataset reported here will be a comprehensive resource for functional analysis of sterol-binding/transport proteins and provide insights into novel aspects of non-vesicular sterol trafficking.

Inhibitory Effects of Iso-α and β Hop Acids Against Pediococcus pentosaceus

The goal of the research was to assess the inhibitory effects of hop extracts, iso-α and β acids, against Pediococcus pentosaceus bacteria, during a short incubation period, both in liquid selective media (high pH values) and beer wort fermentation (low pH values) and testing if the identified iso-α acid stress changes the activity of S. cerevisiae boulardii yeast and ethanol production. Flow cytometry analysis was used for bacterial and yeast cell viability. In relation to the antibacterial activity of β-acids, a lower viability of Pediococcus pentosaceus cells was observed after a short incubation period in selective media, under iso-α acid stress. In beer wort, for a mixed culture with P. pentosaceus bacteria and S. cerevisiae boulardii yeast, under iso-α acid stress conditions at pH 4.0-5.0, Pediococcus pentosaceus exhibited lower cell viability (20.7%) than in selective media (61.4%). Regarding iso-α hop acid on S. cerevisiae boulardii yeast, the results showed that iso-α does not change the S. cerevisiae activity but prevents the culture from being contaminated by Pediococcus pentosaceus. The results highlighted reliable inhibitory effects of iso-α and β-acids against P. pentosaceus, both at pH 6.0-7.0 and pH 4.0-5.0, which open the possibility of hops being used as a supplement to prevent beverage contamination with spoilage microorganisms.
 
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 In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.
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Temperature profiled simultaneous saccharification and co-fermentation of corn stover increases ethanol production at high solid loading

Trade-off temperature used in traditional SScF process always resulted in inhibition on enzymatic hydrolysis (low temperature inhibition, LTI). Thus, effect of temperature and solid loading on LTI was investigated in this study. Results showed that LTI was more severe at lower temperature and higher solid loading. Accordingly, a novel temperature profiled SScF process was designed. Two specific yeast strains, high temperature resistant Saccharomyces cerevisiae and xylose utilizing S. cerevisiae were co-cultured in the novel SScF process. Through eliminating sugars accumulation and alleviating ethanol repression by process optimization, 59.8 g/L ethanol was achieved in temperature profiled SScF at 12% glucan loading. Cell viability of yeast in co-culture SScF was ten times, sometimes even thousands of times, of that in mono-culture SScF during the late phase of the fermentation (48–108 h). It suggested that high temperature resistant strain helped the xylose utilizing strain maintain cell viability in SScF at high temperature (42 ℃). Based on the results, the designed novel temperature profiled SScF process showed appealing potential for bioethanol production at high solid loading and high temperature.

Electrospray patterning of yeast cells for applications in alcoholic fermentation

Yeast cells patterned by pulsed jet electrospray showed a high alcoholic fermentation rate. Multi-dimensional patterns of individual yeast cells were produced by varying the experimental parameters of the electrospray system. The electrospray process, which employed a vibrational electric field, could control patterns of viable yeast cells at a cellular resolution. This novel system for electrospraying viable cells can be applied to biological process engineering including whole cell biochip techniques and micro fermentation processes for biochemical studies.

Brazilian “Flex Mills”: Ethanol from Sugarcane Molasses and Corn Mash

This manuscript shows an ethanol production from two simultaneously processed raw materials: corn grains and molasses residue from sugarcane production. This process is new in countries such as Brazil, which has industrialized these raw materials in the same plant (Flex Mills), and the effects promoted on ethanol production (fermentation process) have not been studied. This paper shows that the uses of yeast CAT-1 (isolated for ethanol production using sugarcane) are not adequate to fermentation of broth obtained from 100% corn. However, the mixture of 50% corn broth and 50% molasses broth results in increase of cell viability, budding and bud viability of yeast, and the ethanol yield process. Another point to highlight is the high level of phenolic compounds showed by molasses, which could decrease cell viability and yeast budding rate during the recycling of this microorganism. The mixture with corn broth standardizes the phenolic compounds in the molasses broth.

Experimental investigation and numerical modeling of pilot-scale fluidized-bed drying of yeast: Part B — Viability measurements and modeling

In this work, we have examined the effect of drying conditions on the viability of yeast cells in order to understand and model viability losses during the drying process. An extensive range of experimental data including bed temperatures from 10 to 60°C, inlet air temperatures from 30 to 110°C and moisture contents from 70 to 4% on a wet-basis were examined. Flow cytometry was used to measure the viability of the yeast, it was found that the major losses in viability occurred when the moisture content was below 15%. When the moisture content was below 15%, lower temperatures (30−40°C) resulted in fewer compromised cells compared with higher temperatures. We have developed a response surface model to estimate the viability as a function of both temperature and moisture content. This model was combined with a physical model to give estimations of the viability as a function of the operating conditions. The model predictions and experimental observations showed good agreement, with the root-mean-square error of less than 3% in the predictions of cell viability. This modeling approach has clear applications in the design, operation and optimization of dryers used in the food industry.

Application of Protein Hydrolysates from Defatted Walnut Meal in High-Gravity Brewing to Improve Fermentation Performance of Lager Yeast.

Protein hydrolysates were prepared from an industrially defatted walnut meal (DWMPH) by enzymolysis employing Neutrase, Protamex, and Flavorzyme, respectively, with/without ultrasonic treatment. The effects of DWMPH supplementations on fermentation performance of lager yeast in high-gravity brewing were investigated. Results showed that ultrasonic-assisted enzymolysis simultaneous treatment (UAE) and ultrasonic pretreatment followed by enzymolysis (UPE) significantly increased degree of hydrolysis (DH) by 1.43 times and 0.71 times of traditional enzymolysis (TE) at least, respectively, Protamex treatment exhibited higher DH (13.3-32.8%) than Neutrase (9.2-25.3%) or Flavorzyme (11.8-28.7%). Compared with control, DWMPH supplementations prepared by UAE using Protamex (UAE-P), Neutrase (UAE-N), or Flavorzyme (UAE-F) significantly improved fermentation performance of lager yeast, especially for UAE-P with the highest major fractions of Mw < 1kDa, increased wort fermentability and ethanol production by 15% and 17%, respectively, while UAE-F with the highest major fractions of Mw > 3kDa obviously improved the foam stability of final beers. Furthermore, DWMPH supplementations significantly increased yeast growth and cell viability, promoted glycogen and trehalose accumulation, upregulated stress markers HSP12 and SSA3 expression in yeast cells, improved the formation of higher alcohols and esters, and increased the ratio of higher alcohol to ester indicating a better balanced taste of final beers.

Evaluating the roles of OH radicals, H2O2, ORP and pH in the inactivation of yeast cells on a tissue model by surface micro-discharge plasma

Surface micro-discharge (SMD) plasma holds great potential as an effective, economical and safe method for the treatment of diverse skin infections. Although the antimicrobial effect of SMD plasma is undisputed, the factors most responsible for the inactivation effect and their corresponding killing mechanisms are still not fully understood. Herein, we evaluate the roles of hydroxyl radicals (·OH), hydrogen peroxide (H2O2), oxidation–reduction potential (ORP) and pH in the inactivation of yeast cells on an agarose tissue model by helium SMD plasma over different irradiation distances and time periods. The ·OH distribution pattern shows that ·OH is mostly produced in the center of every hexagon mesh electrode, whose concentration is closely related to humidity and is markedly increased at a shorter irradiation distance and longer treatment time. Meanwhile, the killing pattern of yeast cells corresponds to ·OH distribution and the inactivation efficiency has a similar trend to that of ·OH concentration. The results of Pearson correlation analysis reveal that the inactivation efficiency is more dependent on ·OH and pH compared with H2O2 and ORP. Furthermore, we investigated the effects of ·OH and pH on yeast cell viability, membrane integrity and intracellular ROS and pH homeostasis by using a specific ·OH scavenger D-mannitol (D-man) and phosphate buffer solution (PBS). The results showed that D-man could significantly reduce the inactivation efficiency by maintaining cell membrane integrity and intracellular ROS and pH homeostasis, while PBS only slightly mitigates the plasma-caused damage on yeast cells. Based on the results, it is concluded that ·OH contributes most to the inactivation of yeast cells on a tissue model by helium SMD plasma studied here.

Coordination of the Cell Wall Integrity and High-Osmolarity Glycerol Pathways in Response to Ethanol Stress in Saccharomyces cerevisiae.

During fermentation, a high ethanol concentration is a major stress that influences the vitality and viability of yeast cells, which in turn leads to a termination of the fermentation process. In this study, we show that the BCK1 and SLT2 genes encoding mitogen-activated protein kinase kinase kinase (MAPKKK) and mitogen-activated protein kinase (MAPK) of the cell wall integrity (CWI) pathway, respectively, are essential for ethanol tolerance, suggesting that the CWI pathway is involved in the response to ethanol-induced cell wall stress. Upon ethanol exposure, the CWI pathway induces the expression of specific cell wall-remodeling genes, including FKS2, CRH1, and PIR3 (encoding β-1,3-glucan synthase, chitin transglycosylase, and O-glycosylated cell wall protein, respectively), which eventually leads to the remodeling of the cell wall structure. Our results revealed that in response to ethanol stress, the high-osmolarity glycerol (HOG) pathway plays a collaborative role with the CWI pathway in inducing cell wall remodeling via the upregulation of specific cell wall biosynthesis genes such as the CRH1 gene. Furthermore, the substantial expression of CWI-responsive genes is also triggered by external hyperosmolarity, suggesting that the adaptive changes in the cell wall are crucial for protecting yeast cells against not only cell wall stress but also osmotic stress. On the other hand, the cell wall stress-inducing agent calcofluor white has no effect on promoting the expression of GPD1, a major target gene of the HOG pathway. Collectively, these findings suggest that during ethanol stress, the CWI and HOG pathways collaboratively regulate the transcription of specific cell wall biosynthesis genes, thereby leading to adaptive changes in the cell wall.IMPORTANCE The budding yeast Saccharomyces cerevisiae has been widely used in industrial fermentations, including the production of alcoholic beverages and bioethanol. During fermentation, an increased ethanol concentration is the main stress that affects yeast metabolism and inhibits ethanol production. This work presents evidence that in response to ethanol stress, both CWI and HOG pathways cooperate to control the expression of cell wall-remodeling genes in order to build the adaptive strength of the cell wall. These findings will contribute to a better understanding of the molecular mechanisms underlying adaptive responses and tolerance of yeast to ethanol stress, which is essential for successful engineering of yeast strains for improved ethanol tolerance.