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Alkalbani NS, Osaili TM, Al-Nabulsi AA, Olaimat AN, Liu SQ, Shah NP, Apostolopoulos V, Ayyash MM. Assessment of Yeasts as Potential Probiotics: A Review of Gastrointestinal Tract Conditions and Investigation Methods. J Fungi (Basel) 2022; 8:jof8040365. [PMID: 35448596 PMCID: PMC9027893 DOI: 10.3390/jof8040365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/27/2022] [Accepted: 03/31/2022] [Indexed: 12/22/2022] Open
Abstract
Probiotics are microorganisms (including bacteria, yeasts and moulds) that confer various health benefits to the host, when consumed in sufficient amounts. Food products containing probiotics, called functional foods, have several health-promoting and therapeutic benefits. The significant role of yeasts in producing functional foods with promoted health benefits is well documented. Hence, there is considerable interest in isolating new yeasts as potential probiotics. Survival in the gastrointestinal tract (GIT), salt tolerance and adherence to epithelial cells are preconditions to classify such microorganisms as probiotics. Clear understanding of how yeasts can overcome GIT and salt stresses and the conditions that support yeasts to grow under such conditions is paramount for identifying, characterising and selecting probiotic yeast strains. This study elaborated the adaptations and mechanisms underlying the survival of probiotic yeasts under GIT and salt stresses. This study also discussed the capability of yeasts to adhere to epithelial cells (hydrophobicity and autoaggregation) and shed light on in vitro methods used to assess the probiotic characteristics of newly isolated yeasts.
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Affiliation(s)
- Nadia S. Alkalbani
- Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates;
| | - Tareq M. Osaili
- Department Clinical Nutrition and Dietetics, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates;
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid 22110, Jordan;
| | - Anas A. Al-Nabulsi
- Department of Nutrition and Food Technology, Jordan University of Science and Technology, Irbid 22110, Jordan;
| | - Amin N. Olaimat
- Department of Clinical Nutrition and Dietetics, Faculty of Applied Medical Sciences, The Hashemite University, P. O. Box 330127, Zarqa 13133, Jordan;
| | - Shao-Quan Liu
- Department of Food Science and Technology, Faculty of Science, National University of Singapore, S14 Level 5, Science Drive 2, Singapore 117542, Singapore;
| | - Nagendra P. Shah
- Food and Nutritional Science, School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong 999077, China;
| | - Vasso Apostolopoulos
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3030, Australia;
- Immunology Program, Australian Institute for Musculoskeletal Science (AIMSS), Melbourne, VIC 3021, Australia
| | - Mutamed M. Ayyash
- Department of Food Science, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates;
- Correspondence:
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Coradini ALV, da Silveira Bezerra de Mello F, Furlan M, Maneira C, Carazzolle MF, Pereira GAG, Teixeira GS. QTL mapping of a Brazilian bioethanol strain links the cell wall protein-encoding gene GAS1 to low pH tolerance in S. cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:239. [PMID: 34915919 PMCID: PMC8675505 DOI: 10.1186/s13068-021-02079-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/17/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Saccharomyces cerevisiae is largely applied in many biotechnological processes, from traditional food and beverage industries to modern biofuel and biochemicals factories. During the fermentation process, yeast cells are usually challenged in different harsh conditions, which often impact productivity. Regarding bioethanol production, cell exposure to acidic environments is related to productivity loss on both first- and second-generation ethanol. In this scenario, indigenous strains traditionally used in fermentation stand out as a source of complex genetic architecture, mainly due to their highly robust background-including low pH tolerance. RESULTS In this work, we pioneer the use of QTL mapping to uncover the genetic basis that confers to the industrial strain Pedra-2 (PE-2) acidic tolerance during growth at low pH. First, we developed a fluorescence-based high-throughput approach to collect a large number of haploid cells using flow cytometry. Then, we were able to apply a bulk segregant analysis to solve the genetic basis of low pH resistance in PE-2, which uncovered a region in chromosome X as the major QTL associated with the evaluated phenotype. A reciprocal hemizygosity analysis revealed the allele GAS1, encoding a β-1,3-glucanosyltransferase, as the casual variant in this region. The GAS1 sequence alignment of distinct S. cerevisiae strains pointed out a non-synonymous mutation (A631G) prevalence in wild-type isolates, which is absent in laboratory strains. We further showcase that GAS1 allele swap between PE-2 and a low pH-susceptible strain can improve cell viability on the latter of up to 12% after a sulfuric acid wash process. CONCLUSION This work revealed GAS1 as one of the main causative genes associated with tolerance to growth at low pH in PE-2. We also showcase how GAS1PE-2 can improve acid resistance of a susceptible strain, suggesting that these findings can be a powerful foundation for the development of more robust and acid-tolerant strains. Our results collectively show the importance of tailored industrial isolated strains in discovering the genetic architecture of relevant traits and its implications over productivity.
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Affiliation(s)
- Alessandro L V Coradini
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089-2910, USA
| | - Fellipe da Silveira Bezerra de Mello
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Monique Furlan
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Carla Maneira
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Marcelo F Carazzolle
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Gonçalo Amarante Guimaraes Pereira
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil.
| | - Gleidson Silva Teixeira
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
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Amalia AV, Fibriana F, Widiatningrum T, Hardianti RD. Bioconversion and valorization of cassava-based industrial wastes to bioethanol gel and its potential application as a clean cooking fuel. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102093] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fletcher E, Mercurio K, Walden EA, Baetz K. A yeast chemogenomic screen identifies pathways that modulate adipic acid toxicity. iScience 2021; 24:102327. [PMID: 33889823 PMCID: PMC8050732 DOI: 10.1016/j.isci.2021.102327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/19/2021] [Accepted: 03/15/2021] [Indexed: 11/18/2022] Open
Abstract
Adipic acid production by yeast fermentation is gaining attention as a renewable source of platform chemicals for making nylon products. However, adipic acid toxicity inhibits yeast growth and fermentation. Here, we performed a chemogenomic screen in Saccharomyces cerevisiae to understand the cellular basis of adipic acid toxicity. Our screen revealed that KGD1 (a key gene in the tricarboxylic acid cycle) deletion improved tolerance to adipic acid and its toxic precursor, catechol. Conversely, disrupting ergosterol biosynthesis as well as protein trafficking and vacuolar transport resulted in adipic acid hypersensitivity. Notably, we show that adipic acid disrupts the Membrane Compartment of Can1 (MCC) on the plasma membrane and impacts endocytosis. This was evidenced by the rapid internalization of Can1 for vacuolar degradation. As ergosterol is an essential component of the MCC and protein trafficking mechanisms are required for endocytosis, we highlight the importance of these cellular processes in modulating adipic acid toxicity. Deletion of the TCA cycle gene KGD1 improves tolerance to adipic acid and catechol Ergosterol and Pdr12 play non-overlapping roles protecting cell from adipic acid Adipic acid-induced plasma membrane localization of Pdr12 is independent of ergosterol Adipic acid disrupts the Membrane Compartment of Can1 (MCC) and induces endocytosis
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Affiliation(s)
- Eugene Fletcher
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Kevin Mercurio
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Elizabeth A. Walden
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Kristin Baetz
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
- Corresponding author
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5
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Microbiological and biochemical performances of six yeast species as potential starter cultures for wet fermentation of coffee beans. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2020.110430] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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6
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Lucena RM, Dolz-Edo L, Brul S, de Morais MA, Smits G. Extreme Low Cytosolic pH Is a Signal for Cell Survival in Acid Stressed Yeast. Genes (Basel) 2020; 11:genes11060656. [PMID: 32560106 PMCID: PMC7349538 DOI: 10.3390/genes11060656] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 12/18/2022] Open
Abstract
Yeast biomass is recycled in the process of bioethanol production using treatment with dilute sulphuric acid to control the bacterial population. This treatment can lead to loss of cell viability, with consequences on the fermentation yield. Thus, the aim of this study was to define the functional cellular responses to inorganic acid stress. Saccharomyces cerevisiae strains with mutation in several signalling pathways, as well as cells expressing pH-sensitive GFP derivative ratiometric pHluorin, were tested for cell survival and cytosolic pH (pHc) variation during exposure to low external pH (pHex). Mutants in calcium signalling and proton extrusion were transiently sensitive to low pHex, while the CWI slt2Δ mutant lost viability. Rescue of this mutant was observed when cells were exposed to extreme low pHex or glucose starvation and was dependent on the induced reduction of pHc. Therefore, a lowered pHc leads to a complete growth arrest, which protects the cells from lethal stress and keeps cells alive. Cytosolic pH is thus a signal that directs the growth stress-tolerance trade-off in yeast. A regulatory model was proposed to explain this mechanism, indicating the impairment of glucan synthesis as the primary cause of low pHex sensitivity.
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Affiliation(s)
- Rodrigo Mendonça Lucena
- Department of Genetics, Biosciences Centre, Federal University of Pernambuco, Recife 50670-901, Brazil;
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands; (L.D.-E.); (S.B.)
| | - Laura Dolz-Edo
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands; (L.D.-E.); (S.B.)
| | - Stanley Brul
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands; (L.D.-E.); (S.B.)
| | - Marcos Antonio de Morais
- Department of Genetics, Biosciences Centre, Federal University of Pernambuco, Recife 50670-901, Brazil;
- Correspondence: (G.S.); (M.A.d.M.J.)
| | - Gertien Smits
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, Netherlands; (L.D.-E.); (S.B.)
- Correspondence: (G.S.); (M.A.d.M.J.)
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The effects of starvation and acidification on lag phase duration of surviving yeast cells. J Biotechnol 2018; 275:60-64. [DOI: 10.1016/j.jbiotec.2018.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 04/12/2018] [Indexed: 11/18/2022]
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Okai M, Suwa C, Nagaoka S, Obara N, Mitsuya D, Kurihara A, Ishida M, Urano N. Neutralization of acidic drainage by Cryptococcus sp. T1 immobilized in alginate beads. Biosci Biotechnol Biochem 2017; 81:2216-2224. [PMID: 28914179 DOI: 10.1080/09168451.2017.1373586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We isolated Cryptococcus sp. T1 from Lake Tazawa's acidic water in Japan. Cryptococcus sp. T1 neutralized an acidic casamino acid solution (pH 3.0) and released ammonia from the casamino acids to aid the neutralization. The neutralization volume was estimated to be approximately 0.4 mL/h. The casamino acids' amino acids decreased (1.24→0.15 mM); ammonia increased (0.22→0.99 mM). We neutralized acidic drainage water (1 L) from a Tamagawa River neutralization plant, which was run through the column with the T1-immobilized alginate beads at a flow rate of 0.5 mL/min, and observed that the viscosity, particle size and amounts of the alginate beads affected the acidic drainage neutralization with an increase of the pH value from 5.26 to 6.61 in the last fraction. An increase in the Al concentration decreased Cryptococcus sp. T1's neutralization ability. After 48 h, the pH of acidic water with 50 mg/L Al was apparently lower than that without Al. Almost no pH increase was observed at 75 mg/L.
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Affiliation(s)
- Masahiko Okai
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Chisato Suwa
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Shintaro Nagaoka
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Nobuo Obara
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Daisuke Mitsuya
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Ayako Kurihara
- b Department of Marine Biosciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Masami Ishida
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Naoto Urano
- a Department of Ocean Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
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de Lucena RM, Elsztein C, Barros de Souza R, de Barros Pita W, Paiva SDSL, de Morais MA. Genetic Interaction between HOG1 and SLT2 Genes in Signalling the Cellular Stress Caused by Sulphuric Acid in Saccharomyces cerevisiae. J Mol Microbiol Biotechnol 2016; 25:423-7. [PMID: 26845706 DOI: 10.1159/000443309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/09/2015] [Indexed: 11/19/2022] Open
Abstract
In fuel ethanol production, recycling of yeast biomass includes treatment of cells with diluted sulphuric acid in order to control bacterial population. However, this strategy might lead to a loss of cell viability, with potential negative consequences to the fermentation yield. In a recent paper we showed that the proteins Slt2 and Hog1 are essential for yeast tolerance to sulphuric acid. As a complement of the aforementioned work, we used DNA microarray technology to search for differentially expressed genes in hog1Δ and slt2Δ deletion mutants after treatment with sulphuric acid. Our results show how Slt2p and Hog1p could coordinate the interplay among protein kinase A (PKA), protein kinase C and high-osmolarity glycerol pathways. Moreover, the SSK22 and KDX1 genes may be part of this network, although their proteins were shown to be non-essential for cell growth/survival at low pH. These proteins might work by enhancing the signal which downregulates the PKA pathway leading to cell cycle arrest, in order to regenerate the integrity of yeast cell wall and cell homeostasis under acid shock.
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Affiliation(s)
- Rodrigo Mendonça de Lucena
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, Brazil
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10
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Fletcher E, Feizi A, Kim S, Siewers V, Nielsen J. RNA-seq analysis of Pichia anomala reveals important mechanisms required for survival at low pH. Microb Cell Fact 2015; 14:143. [PMID: 26376644 PMCID: PMC4574170 DOI: 10.1186/s12934-015-0331-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/31/2015] [Indexed: 02/08/2023] Open
Abstract
Background The product yield and titers of biological processes involving the conversion of biomass to desirable chemicals can be limited by environmental stresses encountered by the microbial hosts used for the bioconversion. One of these main stresses is growth inhibition due to exposure to low pH conditions. In order to circumvent this problem, understanding the biological mechanisms involved in acid stress response and tolerance is essential. Characterisation of wild yeasts that have a natural ability to resist such harsh conditions will pave the way to understand the biological basis underlying acid stress resistance. Pichia anomala possesses a unique ability to adapt to and tolerate a number of environmental stresses particularly low pH stress giving it the advantage to outcompete other microorganisms under such conditions. However, the genetic basis of this resistance has not been previously studied. Results To this end, we isolated an acid resistant strain of P. anomala, performed a gross phenotypic characterisation at low pH and also performed a whole genome and total RNA sequencing. By integrating the RNA-seq data with the genome sequencing data, we found that several genes associated with different biological processes including proton efflux, the electron transfer chain and oxidative phosphorylation were highly expressed in P. anomala cells grown in low pH media. We therefore present data supporting the notion that a high expression of proton pumps in the plasma membrane coupled with an increase in mitochondrial ATP production enables the high level of acid stress tolerance of P. anomala. Conclusions Our findings provide insight into the molecular and genetic basis of low pH tolerance in P. anomala which was previously unknown. Ultimately, this is a step towards developing non-conventional yeasts such as P. anomala for the production of industrially relevant chemicals under low pH conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0331-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eugene Fletcher
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden.
| | - Amir Feizi
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden.
| | - SungSoo Kim
- Samsung Advanced Institute of Technology, 130 Samsung-Ro YoungTong-Ku, Suwon, Kyunggi-do, South Korea. .,Biotech Research Team, Dongbu Farm Hannong Co., Ltd., Daejeon, 305-708, Republic of Korea.
| | - Verena Siewers
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden.
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970, Hørsholm, Denmark.
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Transcriptomic response of Saccharomyces cerevisiae for its adaptation to sulphuric acid-induced stress. Antonie van Leeuwenhoek 2015; 108:1147-60. [DOI: 10.1007/s10482-015-0568-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/20/2015] [Indexed: 01/13/2023]
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Abstract
Yeast cells need to respond to a variety of stresses found in such different conditions as gastrointestinal tract after probiotic ingestion or fermentation vat during ethanol production. In the present study, H+ neutralisation capacity, membrane fatty acid composition, H+-ATPase activity, and cytosolic Ca2+ concentration were evaluated in yeast cells used for probiotic (Saccharomyces boulardii) and laboratory (Saccharomyces cerevisiae W303) purposes, as well as in some W303 mutant strains for ENA1 gene and S. cerevisiae BY4741. Results show that the H+ internal concentration of yeast is regulated by several systems, including the plasma membrane H+-ATPase, and that Ena1p has an important but undefined role in the cellular response to acid. Membrane fatty acid composition of S. cerevisiae W303 strain was affected by exposure to acidic pH, but the presence of 86 mM NaCl prevented this effect, whereas membrane fatty acid composition of S. boulardii was unaffected by acidic pH. We also demonstrated that the acid stress response is dependent on calcium metabolism and blocked by FK 506.
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de Lucena RM, Elsztein C, Simões DA, de Morais MA. Participation of CWI, HOG and Calcineurin pathways in the tolerance of Saccharomyces cerevisiae to low pH by inorganic acid. J Appl Microbiol 2012; 113:629-40. [PMID: 22702539 DOI: 10.1111/j.1365-2672.2012.05362.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 05/26/2012] [Accepted: 06/12/2012] [Indexed: 02/03/2023]
Abstract
AIMS The present work aimed at identifying the metabolic response to acid stress and the mechanisms that lead to cell tolerance and adaptation. METHODS AND RESULTS Two strategies were used: screening deletion mutants for cell growth at neutral and acid pH compared to wild type and measurement by qPCR of the expression of yeast genes involved in different pathways. CONCLUSIONS The results complement our previous findings and showed that the Cell Wall Integrity pathway is the main mechanism for cell tolerance to acid pH, and this damage triggers the protein kinase C (PKC) pathway mainly via the Wsc1p membrane sensor. In addition, cell wall injury might mimic the effects of high osmotic shock and activates the High Osmolarity Glycerol pathway, which amplifies the signal in the upper part of PKC pathway and leads to the activation of Ca(2+) channels by SLT2 overexpression and this Ca(2+) influx further activates calcineurin. Together, these mechanisms induce the expression of genes involved in cell cycle regulation and cell wall regeneration. SIGNIFICANCE AND IMPACT OF THE STUDY These interactions are responsible for long-term adaptation of yeast cells to the acidic environment, and the results could drive future work on the genetic modification of yeast strains for high tolerance to the stresses of the bioethanol fermentation process.
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Affiliation(s)
- R M de Lucena
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, Brazil
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14
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do Carmo FL, dos Santos HF, Martins EF, van Elsas JD, Rosado AS, Peixoto RS. Bacterial structure and characterization of plant growth promoting and oil degrading bacteria from the rhizospheres of mangrove plants. J Microbiol 2011; 49:535-43. [DOI: 10.1007/s12275-011-0528-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 02/24/2011] [Indexed: 10/17/2022]
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Pang Y, Wang H, Song WQ, Zhu YX. The cotton ATP synthase δ1 subunit is required to maintain a higher ATP/ADP ratio that facilitates rapid fibre cell elongation. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:903-9. [PMID: 21040305 DOI: 10.1111/j.1438-8677.2009.00313.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The δ subunit of mitochondrial ATP synthase serves as a linker between the F(0) and F(1) sectors. Here, through microarray and quantitative RT-PCR, we found that the δ1 subunit was significantly up-regulated during cotton fibre cell elongation. Both the relative level and duration of GhATPδ1 transcripts correlated positively with the final length of different cotton germplasms. Elongating fibre cells had a significantly elevated ATP/ADP ratio, suggesting that a higher energy input is probably required for primary fibre cell wall formation and elongation. We obtained a putative full-length GhATPδ1 cDNA that shows 37% sequence identity to the Saccharomyces cerevisiae ATP16 at the deduced amino acid level. An almost wild-type growth rate was restored in atp16Δ cells that expressed GhATPδ1, with a resultant ATP/ADP ratio similar to that found in wild-type cells, indicating that the cotton gene was functional in yeast. Mitochondria prepared from 10 dpa wild-type fibre cells showed significantly higher ATP synthase activity in comparison to ovule samples from wild type and leaf samples. Exogenous application of piceatannol (PA) or oligomycin (OM), inhibitors of ATP synthase F(1) or F(0) subunits, respectively, in ovule culture media resulted in much shorter fibre cells and a significantly lower ATP/ADP ratio. Our data suggest that GhATPδ1 is important for activity of mitochondrial ATP synthase and is probably related to cotton fibre elongation.
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Affiliation(s)
- Y Pang
- The National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing, China
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Zheng DQ, Wu XC, Wang PM, Chi XQ, Tao XL, Li P, Jiang XH, Zhao YH. Drug resistance marker-aided genome shuffling to improve acetic acid tolerance in Saccharomyces cerevisiae. J Ind Microbiol Biotechnol 2010; 38:415-22. [PMID: 20652356 DOI: 10.1007/s10295-010-0784-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 07/07/2010] [Indexed: 11/28/2022]
Abstract
Acetic acid existing in a culture medium is one of the most limiting constraints in yeast growth and viability during ethanol fermentation. To improve acetic acid tolerance in Saccharomyces cerevisiae strains, a drug resistance marker-aided genome shuffling approach with higher screen efficiency of shuffled mutants was developed in this work. Through two rounds of genome shuffling of ultraviolet mutants derived from the original strain 308, we obtained a shuffled strain YZ2, which shows significantly faster growth and higher cell viability under acetic acid stress. Ethanol production of YZ2 (within 60 h) was 21.6% higher than that of 308 when 0.5% (v/v) acetic acid was added to fermentation medium. Membrane integrity, higher in vivo activity of the H+-ATPase, and lower oxidative damage after acetic acid treatment are the possible reasons for the acetic acid-tolerance phenotype of YZ2. These results indicated that this novel genome shuffling approach is powerful to rapidly improve the complex traits of industrial yeast strains.
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Affiliation(s)
- Dao-Qiong Zheng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058 Zhejiang, People's Republic of China
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Miyazaki T, Inamine T, Yamauchi S, Nagayoshi Y, Saijo T, Izumikawa K, Seki M, Kakeya H, Yamamoto Y, Yanagihara K, Miyazaki Y, Kohno S. Role of the Slt2 mitogen-activated protein kinase pathway in cell wall integrity and virulence in Candida glabrata. FEMS Yeast Res 2010; 10:343-52. [PMID: 20214686 DOI: 10.1111/j.1567-1364.2010.00611.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The Slt2 mitogen-activated protein kinase pathway plays a major role in maintaining fungal cell wall integrity. In this study, we investigated the effects of SLT2 deletion and overexpression on drug susceptibility and virulence in the opportunistic fungal pathogen Candida glabrata. While the Deltaslt2 strain showed decreased tolerance to elevated temperature and cell wall-damaging agents, the SLT2-overexpressing strain exhibited increased tolerance to these stresses. A mutant lacking Rlm1, a transcription factor downstream of Slt2, displayed a cell wall-associated phenotype intermediate to that of the Deltaslt2 strain. When RLM1 was overexpressed, micafungin tolerance was increased in the wild-type strain and partial restoration of the drug tolerance was observed in the Deltaslt2 background. It was also demonstrated that echinocandin-class antifungals were more effective against C. glabrata under acidic conditions or when used concurrently with the chitin synthesis inhibitor nikkomycin Z. Finally, in a mouse model of disseminated candidiasis, the deletion and overexpression of C. glabrata SLT2 resulted in mild decreases and increases, respectively, in the CFUs from murine organs compared with the wild-type strain. These fundamental data will help in further understanding the mechanisms of cell wall stress response in C. glabrata and developing more effective treatments using echinocandin antifungals in clinical settings.
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Affiliation(s)
- Taiga Miyazaki
- Department of Molecular Microbiology and Immunology, Nagasaki University School of Medicine, Nagasaki, Japan.
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