Evolutionary and reverse engineering to increase Saccharomyces cerevisiae tolerance to acetic acid, acidic pH, and high temperature

As barley and oat production have recently increased in Canada, it has become prudent to investigate these cereal crops as potential feedstocks for alcoholic fermentation. Ethanol and other coproduct yields can vary substantially among fermented feedstocks, which currently consist primarily of wheat and corn. In this study, the liquified mash of milled grains from 28 barley (hulled and hull-less) and 12 oat cultivars were fermented with Saccharomyces cerevisiae to determine concentrations of fermentation products (ethanol, isopropanol, acetic acid, lactic acid, succinic acid, α-glycerylphosphorylcholine (α-GPC), and glycerol). On average, the fermentation of barley produced significantly higher amounts of ethanol, isopropanol, acetic acid, succinic acid, α-GPC, and glycerol than that of oats. The best performing barley cultivars were able to produce up to 78.48 g/L (CDC Clear) ethanol and 1.81 g/L α-GPC (CDC Cowboy). Furthermore, the presence of milled hulls did not impact ethanol yield amongst barley cultivars. Due to its superior ethanol yield compared to oats, barley is a suitable feedstock for ethanol production. In addition, the accumulation of α-GPC could add considerable value to the fermentation of these cereal crops.

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Translation machinery reprogramming in programmed cell death in Saccharomyces cerevisiae

Cell Death Discovery ◽

10.1038/s41420-020-00392-x ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Francesco Monticolo ◽

Emanuela Palomba ◽

Maria Luisa Chiusano

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Death ◽

Acetic Acid ◽

Programmed Cell Death ◽

Differential Expression ◽

Ribosomal Proteins ◽

Relative Proportion ◽

Duplication Event ◽

Genome Duplication Event ◽

Cell Death Pathway

AbstractProgrammed cell death involves complex molecular pathways in both eukaryotes and prokaryotes. In Escherichia coli, the toxin–antitoxin system (TA-system) has been described as a programmed cell death pathway in which mRNA and ribosome organizations are modified, favoring the production of specific death-related proteins, but also of a minor portion of survival proteins, determining the destiny of the cell population. In the eukaryote Saccharomyces cerevisiae, the ribosome was shown to change its stoichiometry in terms of ribosomal protein content during stress response, affecting the relative proportion between ohnologs, i.e., the couple of paralogs derived by a whole genome duplication event. Here, we confirm the differential expression of ribosomal proteins in yeast also during programmed cell death induced by acetic acid, and we highlight that also in this case pairs of ohnologs are involved. We also show that there are different trends in cytosolic and mitochondrial ribosomal proteins gene expression during the process. Moreover, we show that the exposure to acetic acid induces the differential expression of further genes coding for products related to translation processes and to rRNA post-transcriptional maturation, involving mRNA decapping, affecting translation accuracy, and snoRNA synthesis. Our results suggest that the reprogramming of the overall translation apparatus, including the cytosolic ribosome reorganization, are relevant events in yeast programmed cell death induced by acetic acid.

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Thermal adaptation of acetic acid bacteria for practical high-temperature vinegar fermentation

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbab009 ◽

2021 ◽

Vol 85 (5) ◽

pp. 1243-1251

Author(s):

Nami Matsumoto ◽

Naoki Osumi ◽

Minenosuke Matsutani ◽

Theerisara Phathanathavorn ◽

Naoya Kataoka ◽

...

Keyword(s):

Acetic Acid ◽

High Temperature ◽

Experimental Evolution ◽

Culture Medium ◽

Thermal Adaptation ◽

Acetic Acid Bacteria ◽

Acid Fermentation ◽

Acetic Acid Production ◽

Fermentation System ◽

Fermentor Culture

ABSTRACT Thermotolerant microorganisms are useful for high-temperature fermentation. Several thermally adapted strains were previously obtained from Acetobacter pasteurianus in a nutrient-rich culture medium, while these adapted strains could not grow well at high temperature in the nutrient-poor practical culture medium, “rice moromi.” In this study, A. pasteurianus K-1034 originally capable of performing acetic acid fermentation in rice moromi was thermally adapted by experimental evolution using a “pseudo” rice moromi culture. The adapted strains thus obtained were confirmed to grow well in such the nutrient-poor media in flask or jar-fermentor culture up to 40 or 39 °C; the mutation sites of the strains were also determined. The high-temperature fermentation ability was also shown to be comparable with a low-nutrient adapted strain previously obtained. Using the practical fermentation system, “Acetofermenter,” acetic acid production was compared in the moromi culture; the results showed that the adapted strains efficiently perform practical vinegar production under high-temperature conditions.

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Eukaryotic translation factor eIF5A contributes to acetic acid tolerance in Saccharomyces cerevisiae via transcriptional factor Ume6p

Biotechnology for Biofuels ◽

10.1186/s13068-021-01885-2 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Yanfei Cheng ◽

Hui Zhu ◽

Zhengda Du ◽

Xuena Guo ◽

Chenyao Zhou ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Acetic Acid ◽

Adaptive Response ◽

Acid Tolerance ◽

Peptide Bond ◽

Transcriptional Factor ◽

Yeast Cells ◽

Acetic Acid Tolerance ◽

Translation Factor ◽

Industrial Strains

Abstract Background Saccharomyces cerevisiae is well-known as an ideal model system for basic research and important industrial microorganism for biotechnological applications. Acetic acid is an important growth inhibitor that has deleterious effects on both the growth and fermentation performance of yeast cells. Comprehensive understanding of the mechanisms underlying S. cerevisiae adaptive response to acetic acid is always a focus and indispensable for development of robust industrial strains. eIF5A is a specific translation factor that is especially required for the formation of peptide bond between certain residues including proline regarded as poor substrates for slow peptide bond formation. Decrease of eIF5A activity resulted in temperature-sensitive phenotype of yeast, while up-regulation of eIF5A protected transgenic Arabidopsis against high temperature, oxidative or osmotic stress. However, the exact roles and functional mechanisms of eIF5A in stress response are as yet largely unknown. Results In this research, we compared cell growth between the eIF5A overexpressing and the control S. cerevisiae strains under various stressed conditions. Improvement of acetic acid tolerance by enhanced eIF5A activity was observed all in spot assay, growth profiles and survival assay. eIF5A prompts the synthesis of Ume6p, a pleiotropic transcriptional factor containing polyproline motifs, mainly in a translational related way. As a consequence, BEM4, BUD21 and IME4, the direct targets of Ume6p, were up-regulated in eIF5A overexpressing strain, especially under acetic acid stress. Overexpression of UME6 results in similar profiles of cell growth and target genes transcription to eIF5A overexpression, confirming the role of Ume6p and its association between eIF5A and acetic acid tolerance. Conclusion Translation factor eIF5A protects yeast cells against acetic acid challenge by the eIF5A-Ume6p-Bud21p/Ime4p/Bem4p axles, which provides new insights into the molecular mechanisms underlying the adaptive response and tolerance to acetic acid in S. cerevisiae and novel targets for construction of robust industrial strains.

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Cytochrome c Trp65Ser substitution results in inhibition of acetic acid-induced programmed cell death in Saccharomyces cerevisiae

Mitochondrion ◽

10.1016/j.mito.2011.08.007 ◽

2011 ◽

Vol 11 (6) ◽

pp. 987-991 ◽

Cited By ~ 5

Author(s):

Nicoletta Guaragnella ◽

Salvatore Passarella ◽

Ersilia Marra ◽

Sergio Giannattasio

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Death ◽

Acetic Acid ◽

Cytochrome C ◽

Programmed Cell Death

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Screening For Yeast Phytase Leads to the Identification of a New Cell-Bound and Secreted Activity in Cyberlindnera jadinii CJ2

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.662598 ◽

2021 ◽

Vol 9 ◽

Author(s):

Claudia Capusoni ◽

Immacolata Serra ◽

Silvia Donzella ◽

Concetta Compagno

Keyword(s):

High Temperature ◽

Phytic Acid ◽

Convenient Method ◽

Kluyveromyces Marxianus ◽

Food Industry ◽

Yeast Species ◽

Industrial Applications ◽

Industrial Processes ◽

Acidic Ph ◽

Initial Screening

Phytic acid is an anti-nutritional compound able to chelate proteins and ions. For this reason, the food industry is looking for a convenient method which allows its degradation. Phytases are a class of enzymes that catalyze the degradation of phytic acid and are used as additives in feed-related industrial processes. Due to their industrial importance, our goal was to identify new activities that exhibit best performances in terms of tolerance to high temperature and acidic pH. As a result of an initial screening on 21 yeast species, we focused our attention on phytases found in Cyberlindnera jadinii, Kluyveromyces marxianus, and Torulaspora delbrueckeii. In particular, C. jadinii showed the highest secreted and cell-bound activity, with optimum of temperature and pH at 50°C and 4.5, respectively. These characteristics suggest that this enzyme could be successfully used for feed as well as for food-related industrial applications.

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Improvement of acid solutions for stimulation of compacted high-temperature carbonate collectors

Technology audit and production reserves ◽

10.15587/2706-5448.2021.246604 ◽

2021 ◽

Vol 6 (3(62)) ◽

pp. 11-14

Author(s):

Oleh Zimin

Keyword(s):

Surface Tension ◽

Acetic Acid ◽

High Temperature ◽

Reaction Rate ◽

Methyl Acetate ◽

Surface Tension Coefficient ◽

Gradual Transition ◽

Acid Solutions ◽

Hydrocarbon Production ◽

Low Viscosity

The object of research in this work is the intensification of hydrocarbon production. The most problematic task of the study is the efficiency of intensification of compacted high-temperature carbonate reservoirs. Despite the gradual transition to renewable energy sources, natural gas and oil will play a dominant role in the world's energy balance in the next 20–30 years. Carbonate rocks have significant mining potential, but low filtration properties require intensification to improve reservoir permeability. High temperatures and pressures at great depths require the improvement of existing hydrocarbon production technologies. The most popular method for treating reservoirs containing carbonates is acid treatments in different variations, but for effective treatment it is necessary to achieve deep penetration of the solution into the formation. The study solves the problem of selection of effective carrier liquids for the preparation of acid solutions for the treatment of compacted high-temperature reservoirs with high carbonate content. To ensure quality treatment, acid solutions must have low viscosity and surface tension coefficient, low reaction rate, their chemical properties must ensure the absence of insoluble precipitates in the process of reactions with fluids and rocks, as well as be environmentally friendly. To select the most optimal carrier liquid, experiments were conducted to determine which candidate liquids provide the minimum reaction rate of acidic solutions with carbonates. Based on the analysis of industrial application data and literature sources, water, nephras, methanol, ethyl acetate, and methyl acetate were selected for further research. Widely studied acetic acid was chosen as the basic acid. Studies have shown that methyl acetate has a number of advantages, namely low reaction rate, low viscosity and surface tension coefficient. As well as the possibility of hydrolysis in the formation with the release of acetic acid, which significantly prolongs the reaction time of the solution with the rock and the depth of penetration of the active solution into the formation.

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The Influence of pH and Temperature on Water as a Pressurized Fluid in the Extraction of Bioactive Myconutrients from Chaga Mushroom (Inonotus obliquus)

10.20944/preprints202107.0186.v1 ◽

2021 ◽

Author(s):

Ibrahim M. Abu-Reidah ◽

Amber Critch ◽

Charles Manful ◽

Amanda Rajakaruna ◽

Natalia Prieto Vidal ◽

...

Keyword(s):

Mass Spectrometry ◽

High Temperature ◽

Phenolic Compounds ◽

Total Phenolic ◽

Acidic Ph ◽

Inonotus Obliquus ◽

Food Grade ◽

Green Food ◽

Fat Soluble Vitamins ◽

First Time

Mushrooms have long rich history in folk medicine, traditional and functional foods due to high content of dietary myco-nutrients. Currently, there is increased interest in finding appropriate food-grade green ex-traction systems capable of extracting these bioactive compounds from dietary mushrooms for applica-tions in various food, pharmacological or nutraceutical formulations. Herein, we evaluated a modified Swiss water process (SWP) method using alkaline and acidic pH at low and high temperature under pressurized conditions as a suitable green food grade solvent to obtained extracts enriched with my-co-nutrients (dietary phenolics, total antioxidants (TAA), vitamins, and minerals) from Chaga. Ultra-high performance liquid chromatography coupled to high resolution accurate mass tandem mass spectrometry (UHPLC-HRAMS-MS/MS) was used to assess the phenolic compounds and vitamin levels in the extracts, while inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the mineral con-tents. Over twenty phenolic compounds were quantitatively evaluated in the extracts and the highest total phenolic content and antioxidant activity was observed at pH11.5 at 100°C. The most abundant phenolic compounds present in Chaga extracts included phenolic acids such as protocatechuic acid 4-glucoside (0.7-1.08µg/mL), syringic acid (0.62-1.18µg/mL), and myricetin (0.68-1.3µg/mL). Vitamins are being reported for the first time in Chaga. pH 2.5 at 100°C treatment shows superior effects in extracting the B vitamins whereas pH 2.5 at 60 and 100°C treatments were outstanding for extraction of total fat-soluble vitamins. Vitamin E content was the highest for the fat-soluble vitamins in the Chaga extract under acidic pH (2.5) and high temp. (100°C) and ranges between 50 to 175 µg/100g Chaga. Antioxidant minerals ranged from 85.94 µg/g (pH7 at 100°C) to 113.86 µg/g DW (pH2.5 at 100°C). High temperature 100°C and a pH of 2.5 or 9.5. The treatment of pH11.5 at 100°C was the most useful for recovering phenolics and antioxidants from Chaga including several phenolic compounds reported for the first time in Chaga. SWP is being proposed herein for the first time as a novel, green food-grade solvent system for the extraction of myco-nutrients from Chaga and have potential applications as a suitable approach to extract nutrients from other matrices. Chaga extracts enriched with bioactive myconutrients and antioxidants may be suitable for further use or applications in the food and nutraceutical industries.

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