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Teles GH, Xavier MR, Da Silva JM, De Souza RB, de Barros Pita W, de Morais MA. The Metabolism of Respiring Carbon Sources by Dekkera bruxellensis and Its Relation with the Production of Acetate. Appl Biochem Biotechnol 2023; 195:6369-6391. [PMID: 36867386 DOI: 10.1007/s12010-023-04398-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2023] [Indexed: 03/04/2023]
Abstract
Dekkera bruxellensis has been studied for several aspects of its metabolism over the past years, which has expanded our comprehension on its importance to industrial fermentation processes and uncovered its industrial relevance. Acetate is a metabolite often found in D. bruxellensis aerobic cultivations, whereas its production is linked to decreased ethanol yields. In a previous work, we aimed to understand how acetate metabolism affected the fermentation capacity of D. bruxellensis. In the present work, we evaluated the role of acetate metabolism in respiring cells using ammonium or nitrate as nitrogen sources. Our results showed that galactose is a strictly respiratory sugar and that a relevant part of its carbon is lost, while the remaining is metabolised through the Pdh bypass pathway before being assimilated into biomass. When this pathway was blocked, yeast growth was reduced while more carbon was assimilated to the biomass. In nitrate, more acetate was produced as expected, which increased carbon assimilation, although less galactose was uptaken from the medium. This scenario was not affected by the Pdh bypass inhibition. The confirmation that acetate production was crucial for carbon assimilation was brought by cultivations in pyruvate. All physiological data were connected to the expression patterns of PFK1, PDC1, ADH1, ALD3, ALD5 and ATP1 genes. Other respiring carbon sources could only be properly used by the cells when some external acetate was supplied. Therefore, the results reported herein helped in providing valuable contributions to the understanding of the oxidative metabolism in this potential industrial yeast.
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Affiliation(s)
- Gilberto Henrique Teles
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Av. Moraes Rego, 1235. Cidade Universitária, Recife, PE, 50.670-901, Brazil
| | - Mariana Rodrigues Xavier
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Av. Moraes Rego, 1235. Cidade Universitária, Recife, PE, 50.670-901, Brazil
| | | | - Rafael Barros De Souza
- Laboratory of Microbial Metabolism, Institute of Biological Sciences, University of Pernambuco, Recife, Brazil
| | | | - Marcos Antonio de Morais
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Av. Moraes Rego, 1235. Cidade Universitária, Recife, PE, 50.670-901, Brazil.
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Silva RK, de Barros Pita W, de Morais Junior MA, de Souza RB. Influence of mineral ions on the growth and fermentation performance of Dekkera bruxellensis GDB248. Lett Appl Microbiol 2023:7152595. [PMID: 37142415 DOI: 10.1093/lambio/ovad058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The excess of minerals in the industrial substrates is detrimental for Saccharomyces cerevisiae ethanol fermentation performance. In this work, we sought to understand the effect of some of those minerals on the physiology of Dekkera bruxellensis. Three groups of minerals were classified on the basis of the aerobic growth profiles on glucose: neutrals (K+, Mg2+, P5+ and Zn2+), inducers (Mn2+ and Ca2+) and inhibitors (Al3+, Cu2+ and Fe2+). Cu2+ showed the highest mineral toxicity, and its effect was dependent of the level of medium aeration. On the other hand, copper stimulated respiration by increasing growth on respiratory carbon sources. Most growth inhibitors also hampered glucose fermentation, with changes in carbon distribution to metabolic routes dedicated to anabolic reactions and for alternative reduced co-factors oxidations to maintain cellular homeostasis. The negative effect of Cu2+ on yeast fermentation was partially alleviated by Mg2+ and Mn2+, similar to magnesium antagonism observed for S. cerevisiae. All these results might contribute to understand the action of these minerals in sugarcane substrates on the physiology of D. bruxellensis cells. Therefore, it represents one more step for the consolidation of the industrial use of this yeast in the production of fuel-ethanol as well as other biotechnological goods.
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Affiliation(s)
- Rayssa Karla Silva
- Laboratory of Microbial Metabolism, Institute of Biological Sciences, University of Pernambuco. Recife, Brazil
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco. Recife, Brazil
| | - Will de Barros Pita
- Laboratory of Molecular Genetics, Department of Antibiotics, Federal University of Pernambuco. Recife, Brazil
| | | | - Rafael Barros de Souza
- Laboratory of Microbial Metabolism, Institute of Biological Sciences, University of Pernambuco. Recife, Brazil
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3
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Xavier MR, Teles GH, de Carvalho JM, Vieira LD, de Barros Pita W, Antonio de Morais M. The antioxidant defence of Dekkera bruxellensis against hydrogen peroxide and its relationship to nitrate metabolism. J Appl Microbiol 2023; 134:7093401. [PMID: 36990643 DOI: 10.1093/jambio/lxad065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/22/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023]
Abstract
AIMS The yeast Dekkera bruxellensis is a Crabtree positive yeast that tends towards the oxidative/respiratory metabolism in aerobiosis. However, it is more sensitive to H2O2 than Saccharomyces cerevisiae. In order to investigate this metabolic paradox, the present work aimed to uncover the biological defence mechanism used by this yeast to tolerate the presence of exogenous H2O2. METHODS AND RESULTS Growth curves and spot tests were performed to establish the values of Minimal Inhibitory Concentration and Minimal Biocidal Concentration of H2O2 for different combinations of carbon and nitrogen sources. Cells in exponential growth phase in different culture conditions were used to measure superoxide and thiols (protein and non-protein), enzyme activities and gene expression. CONCLUSIONS The combination of glutathione peroxidase and sulfhydryl-containing proteins formed the preferred defence mechanism against H2O2, which was more efficiently active under respiratory metabolism. However, the action of this mechanism was suppressed when the cells were metabolising nitrate. Significance and Impact of Study. These results were relevant to figure out the fitness of D. bruxellensis to metabolise industrial substrates containing oxidant molecules, such as molasses and plant hydrolysates, in the presence of cheaper nitrogen source such as nitrate.
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Affiliation(s)
- Mariana Rodrigues Xavier
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Recife, Brazil
| | - Gilberto Henrique Teles
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Recife, Brazil
| | | | - Leucio Duarte Vieira
- Laboratory of Molecular Genetics, Department of Antibiotics, Federal University of Pernambuco, Recife, Brazil
| | - Will de Barros Pita
- Laboratory of Renal Pathophysiology, Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Marcos Antonio de Morais
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Recife, Brazil
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Teles GH, da Silva JM, Xavier MR, de Souza RB, de Barros Pita W, de Morais Junior MA. Metabolic and biotechnological insights on the analysis of the Pdh bypass and acetate production in the yeast Dekkera bruxellensis. J Biotechnol 2022; 355:42-52. [PMID: 35760147 DOI: 10.1016/j.jbiotec.2022.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 06/01/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022]
Abstract
The advancement of knowledge about the physiology of Dekkera bruxellensis has shown its potential for the production of fuel ethanol very close to the conventional fermenting yeast S. cerevisiae. However, some aspects of its metabolism remain uncovered. In the present study, the respiro-fermentative parameters of D. bruxellensis GDB 248 were evaluated under different cultivation conditions. The results showed that sucrose was more efficiently converted to ethanol than glucose, regardless the nitrogen source, which points out for the industrial efficiency of this yeast in sucrose-based substrate. The blockage of the cytosolic acetate production incremented the yeast fermentative efficiency by 27% (in glucose) and 14% (in sucrose). On the other hand, the presence of nitrate as inducer of acetate production reducing the production of ethanol. Altogether, these results settled the hypothesis that acetate metabolism is the main constraint for ethanol production. Besides, this acetate-generating pathway seems to exert some regulatory action on the flux and distribution of the carbon flowing throught the central metabolism. These physiological aspects were corroborated by the relative expression analysis of key genes in the crossroad to ethanol, acetate and biomass formation. All the results were discussed in the light of the industrial potential of this yeast.
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Affiliation(s)
- Gilberto Henrique Teles
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Recife, Brazil
| | - Jackeline Maria da Silva
- Laboratory of Molecular Genetics, Department of Antibiotics, Federal University of Pernambuco, Recife, Brazil
| | - Mariana Rodrigues Xavier
- Laboratory of Microbial Genetics, Department of Genetics, Federal University of Pernambuco, Recife, Brazil
| | - Rafael Barros de Souza
- Laboratory of Microbial Metabolism, Institute of Biological Sciences, University of Pernambuco, Recife, Brazil
| | - Will de Barros Pita
- Laboratory of Molecular Genetics, Department of Antibiotics, Federal University of Pernambuco, Recife, Brazil
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da Silva JM, Ribeiro KC, Teles GH, Ribeiro E, de Morais Junior MA, de Barros Pita W. Fermentation profiles of the yeast Brettanomyces bruxellensis in d-xylose and l-arabinose aiming its application as a second-generation ethanol producer. Yeast 2020; 37:597-608. [PMID: 32889766 DOI: 10.1002/yea.3519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/28/2020] [Accepted: 09/01/2020] [Indexed: 11/07/2022] Open
Abstract
The yeast Brettanomyces bruxellensis is able to ferment the main sugars used in first-generation ethanol production. However, its employment in this industry is prohibitive because the ethanol productivity reached is significantly lower than the observed for Saccharomyces cerevisiae. On the other hand, a possible application of B. bruxellensis in the second-generation ethanol production has been suggested because this yeast is also able to use d-xylose and l-arabinose, the major pentoses released from lignocellulosic material. Although the latter application seems to be reasonable, it has been poorly explored. Therefore, we aimed to evaluate whether or not different industrial strains of B. bruxellensis are able to ferment d-xylose and l-arabinose, both in aerobiosis and oxygen-limited conditions. Three out of nine tested strains were able to assimilate those sugars. When in aerobiosis, B. bruxellensis cells exclusively used them to support biomass formation, and no ethanol was produced. Moreover, whereas l-arabinose was not consumed under oxygen limitation, d-xylose was only slightly used, which resulted in low ethanol yield and productivity. In conclusion, our results showed that d-xylose and l-arabinose are not efficiently converted to ethanol by B. bruxellensis, most likely due to a redox imbalance in the assimilatory pathways of these sugars. Therefore, despite presenting other industrially relevant traits, the employment of B. bruxellensis in second-generation ethanol production depends on the development of genetic engineering strategies to overcome this metabolic bottleneck.
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Affiliation(s)
| | | | | | - Ester Ribeiro
- Department of Antibiotics, Federal University of Pernambuco, Recife, Brazil
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Mendonça AA, da Silva PKN, Calazans TLS, de Souza RB, de Barros Pita W, Elsztein C, de Morais Junior MA. Lactobacillus vini: mechanistic response to stress by medium acidification. Microbiology (Reading) 2019; 165:26-36. [DOI: 10.1099/mic.0.000738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
| | | | | | | | - Will de Barros Pita
- 3Department of Antibiotics, Federal University of Pernambuco, Recife, Brazil
| | - Carolina Elsztein
- 1Department of Genetics, Federal University of Pernambuco, Recife, Brazil
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Peña-Moreno IC, Castro Parente D, da Silva JM, Andrade Mendonça A, Rojas LAV, de Morais Junior MA, de Barros Pita W. Nitrate boosts anaerobic ethanol production in an acetate-dependent manner in the yeast Dekkera bruxellensis. J Ind Microbiol Biotechnol 2018; 46:209-220. [PMID: 30539327 DOI: 10.1007/s10295-018-2118-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 12/05/2018] [Indexed: 12/29/2022]
Abstract
In the past few years, the yeast Dekkera bruxellensis has gained much of attention among the so-called non-conventional yeasts for its potential in the biotechnological scenario, especially in fermentative processes. This yeast has been regarded as an important competitor to Saccharomyces cerevisiae in bioethanol production plants in Brazil and several studies have reported its capacity to produce ethanol. However, our current knowledge concerning D. bruxellensis is restricted to its aerobic metabolism, most likely because wine and beer strains cannot grow in full anaerobiosis. Hence, the present work aimed to fulfil a gap regarding the lack of information on the physiology of Dekkera bruxellensis growing in the complete absence of oxygen and the relationship with assimilation of nitrate as nitrogen source. The ethanol strain GDB 248 was fully capable of growing anaerobically and produces ethanol at the same level of S. cerevisiae. The presence of nitrate in the medium increased this capacity. Moreover, nitrate is consumed faster than ammonium and this increased rate coincided with a higher speed of glucose consumption. The profile of gene expression helped us to figure out that even in anaerobiosis, the presence of nitrate drives the yeast cells to an oxidative metabolism that ultimately incremented both biomass and ethanol production. These results finally provide the clues to explain most of the success of this yeast in industrial processes of ethanol production.
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Affiliation(s)
| | - Denise Castro Parente
- Department of Genetics, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | | | | | | | | | - Will de Barros Pita
- Department of Antibiotics, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil.
- Departamento de Antibióticos, Universidade Federal de Pernambuco, Avenida Professor Artur de Sá, Cidade Universitária, 50740520, Recife, PE, Brazil.
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8
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Teles GH, da Silva JM, Mendonça AA, de Morais Junior MA, de Barros Pita W. First aspects on acetate metabolism in the yeast Dekkera bruxellensis: a few keys for improving ethanol fermentation. Yeast 2018. [PMID: 30006941 DOI: 10.1002/yea.3348.molecularbiology,1,63-73] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Dekkera bruxellensis is continuously changing its status in fermentation processes, ranging from a contaminant or spoiling yeast to a microorganism with potential to produce metabolites of biotechnological interest. In spite of that, several major aspects of its physiology are still poorly understood. As an acetogenic yeast, minimal oxygen concentrations are able to drive glucose assimilation to oxidative metabolism, in order to produce biomass and acetate, with consequent low yield in ethanol. In the present study, we used disulfiram to inhibit acetaldehyde dehydrogenase activity to evaluate the influence of cytosolic acetate on cell metabolism. D. bruxellensis was more tolerant to disulfiram than Saccharomyces cerevisiae and the use of different carbon sources revealed that the former yeast might be able to export acetate (or acetyl-CoA) from mitochondria to cytoplasm. Fermentation assays showed that acetaldehyde dehydrogenase inhibition re-oriented yeast central metabolism to increase ethanol production and decrease biomass formation. However, glucose uptake was reduced, which ultimately represents economical loss to the fermentation process. This might be the major challenge for future metabolic engineering enterprises on this yeast.
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Affiliation(s)
- Gilberto Henrique Teles
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Jackeline Maria da Silva
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Allyson Andrade Mendonça
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Marcos Antonio de Morais Junior
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil.,Department of Genetics, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Will de Barros Pita
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil.,Department of Antibiotics, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
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9
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Teles GH, da Silva JM, Mendonça AA, de Morais Junior MA, de Barros Pita W. First aspects on acetate metabolism in the yeast Dekkera bruxellensis: a few keys for improving ethanol fermentation. Yeast 2018; 35:577-584. [PMID: 30006941 DOI: 10.1002/yea.3348] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/25/2018] [Accepted: 05/23/2018] [Indexed: 11/10/2022] Open
Abstract
Dekkera bruxellensis is continuously changing its status in fermentation processes, ranging from a contaminant or spoiling yeast to a microorganism with potential to produce metabolites of biotechnological interest. In spite of that, several major aspects of its physiology are still poorly understood. As an acetogenic yeast, minimal oxygen concentrations are able to drive glucose assimilation to oxidative metabolism, in order to produce biomass and acetate, with consequent low yield in ethanol. In the present study, we used disulfiram to inhibit acetaldehyde dehydrogenase activity to evaluate the influence of cytosolic acetate on cell metabolism. D. bruxellensis was more tolerant to disulfiram than Saccharomyces cerevisiae and the use of different carbon sources revealed that the former yeast might be able to export acetate (or acetyl-CoA) from mitochondria to cytoplasm. Fermentation assays showed that acetaldehyde dehydrogenase inhibition re-oriented yeast central metabolism to increase ethanol production and decrease biomass formation. However, glucose uptake was reduced, which ultimately represents economical loss to the fermentation process. This might be the major challenge for future metabolic engineering enterprises on this yeast.
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Affiliation(s)
- Gilberto Henrique Teles
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Jackeline Maria da Silva
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Allyson Andrade Mendonça
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Marcos Antonio de Morais Junior
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil.,Department of Genetics, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
| | - Will de Barros Pita
- Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil.,Department of Antibiotics, Federal University of Pernambuco, Recife, PE, 50760-901, Brazil
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Barros de Souza R, Silva RK, Ferreira DS, de Sá Leitão Paiva Junior S, de Barros Pita W, de Morais Junior MA. Magnesium ions in yeast: setting free the metabolism from glucose catabolite repression. Metallomics 2016; 8:1193-1203. [DOI: 10.1039/c6mt00157b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Castro Parente D, Vidal EE, Leite FCB, de Barros Pita W, de Morais MA. Production of sensory compounds by means of the yeast Dekkera bruxellensis in different nitrogen sources with the prospect of producing cachaça. Yeast 2014; 32:77-87. [PMID: 25345668 DOI: 10.1002/yea.3051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 10/16/2014] [Accepted: 10/16/2014] [Indexed: 11/05/2022] Open
Abstract
The distilled spirit made from sugar cane juice, also known as cachaça, is a traditional Brazilian beverage that in recent years has increased its market share among international distilled beverages. Several volatile compounds produced by yeast cells during the fermentation process are responsible for the unique taste and aroma of this drink. The yeast Dekkera bruxellensis has acquired increasing importance in the fermented beverage production, as the different metabolites produced by this yeast may be either beneficial or harmful to the end-product. Since D. bruxellensis is often found in the fermentation processes carried out in ethanol fuel distillation in Brazil, we employed this yeast to analyse the physiological profile and production of aromatic compounds and to examine whether it is feasible to regard it as a cachaça-producing microorganism. The assays were performed on a small scale and simulated the conditions for the production of handmade cachaça. The results showed that the presence of aromatic and branched-chain amino acids in the medium has a strong influence on the metabolism and production of flavours by D. bruxellensis. The assimilation of these alternative nitrogen sources led to different fermentation yields and the production of flavouring compounds. The influence of the nitrogen source on the metabolism of fusel alcohols and esters in D. bruxellensis highlights the need for further studies of the nitrogen requirements to obtain the desired level of sensory compounds in the fermentation. Our results suggest that D. bruxellensis has the potential to play a role in the production of cachaça.
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Affiliation(s)
- Denise Castro Parente
- Interdepartmental Research Group on Metabolic Engineering, Federal University of Pernambuco, Recife, PE, Brazil
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13
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Tiukova IA, de Barros Pita W, Sundell D, Haddad Momeni M, Horn SJ, Ståhlberg J, de Morais MA, Passoth V. Adaptation of Dekkera bruxellensis to lignocellulose-based substrate. Biotechnol Appl Biochem 2014; 61:51-7. [PMID: 23941546 DOI: 10.1002/bab.1145] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 07/18/2013] [Indexed: 11/10/2022]
Abstract
Adaptation of Dekkera bruxellensis to lignocellulose hydrolysate was investigated. Cells of D. bruxellensis were grown for 72 and 192 H in batch and continuous culture, respectively (adapted cells). Cultivations in semisynthetic medium were run as controls (nonadapted cells). To test the adaptation, cells from these cultures were reinoculated in the lignocellulose medium, and growth and ethanol production characteristics were monitored. Cells adapted to lignocellulose hydrolysate had a shorter lag phase, grew faster, and produced a higher ethanol concentration as compared with nonadapted cells. A stability test showed that after cultivation in rich medium, cells partially lost the adapted phenotype but still showed faster growth and higher ethanol production as compared with nonadapted cells. Because alcohol dehydrogenase genes have been described to be involved in the adaptation to furfural in Saccharomyces cerevisiae, an analogous mechanism of adaptation to lignocelluloses hydrolysate of D. bruxellensis was hypothesized. However, gene expression analysis showed that genes homologous to S. cerevisiae ADH1 were not involved in the adaptation to lignocelluloses hydrolysate in D. bruxellensis.
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Affiliation(s)
- Ievgeniia A Tiukova
- Uppsala Biocenter, Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025750 07, Uppsala, Sweden
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de Barros Pita W, Silva DC, Simões DA, Passoth V, de Morais MA. Physiology and gene expression profiles of Dekkera bruxellensis in response to carbon and nitrogen availability. Antonie van Leeuwenhoek 2013; 104:855-68. [DOI: 10.1007/s10482-013-9998-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 08/07/2013] [Indexed: 12/01/2022]
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Sehnem NT, Machado ADS, Leite FCB, Pita WDB, de Morais MA, Ayub MAZ. 5-Hydroxymethylfurfural induces ADH7 and ARI1 expression in tolerant industrial Saccharomyces cerevisiae strain P6H9 during bioethanol production. Bioresour Technol 2013; 133:190-196. [PMID: 23422309 DOI: 10.1016/j.biortech.2013.01.063] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/09/2013] [Accepted: 01/10/2013] [Indexed: 06/01/2023]
Abstract
The aims of this work were to obtain, by evolutionary engineering, an industrial strain of Saccharomyces cerevisiae tolerant to high concentrations of HMF and to determine the expression levels of genes previously described as responsible for this tolerance. Cells were grown under anaerobic and oxygen limited conditions, in the presence of glucose or sucrose as carbon sources. P6H9 strain presented high expression levels for genes ADH7 and ARI1 in presence of HMF. This tolerant strain also showed higher ethanol productivity, biomass formation and alcohol dehydrogenase activity comparing to sensitive strains. Results suggest that S. cerevisiae P6H9 strain presents potential to be used for second-generation ethanol production.
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Affiliation(s)
- Nicole Teixeira Sehnem
- Biotechnology & Biochemical Engineering Laboratory (BiotecLab), Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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de Barros Pita W, Tiukova I, Leite FCB, Passoth V, Simões DA, de Morais MA. The influence of nitrate on the physiology of the yeast Dekkera bruxellensis grown under oxygen limitation. Yeast 2013; 30:111-7. [PMID: 23440690 DOI: 10.1002/yea.2945] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 01/30/2013] [Indexed: 11/07/2022] Open
Abstract
A previous study showed that the use of nitrate by Dekkera bruxellensis might be an advantageous trait when ammonium is limited in sugarcane substrate for ethanol fermentation. The aim of the present work was to evaluate the influence of nitrate on the yeast physiology during cell growth in different carbon sources under oxygen limitation. If nitrate was the sole source of nitrogen, D. bruxellensis cells presented slower growth, diminished sugar consumption and growth-associated ethanol production, when compared to ammonium. These results were corroborated by the increased expression of genes involved in the pentose phosphate (PP) pathway, the tricarboxylic acid (TCA) cycle and ATP synthesis. The presence of ammonium in the mixed medium restored most parameters to the standard conditions. This work may open up a line of investigation to establish the connection between nitrate assimilation and energetic metabolism in D. bruxellensis and their influence on its fermentative capacity in oxygen-limited or oxygen-depleted conditions.
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Affiliation(s)
- Will de Barros Pita
- Interdepartmental Research Group on Metabolic Engineering, Federal University of Pernambuco, Recife, PE, Brazil
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de Barros Pita W, Leite FCB, de Souza Liberal AT, Pereira LF, Carazzolle MF, Pereira GA, de Morais MA. A new set of reference genes for RT-qPCR assays in the yeast Dekkera bruxellensis. Can J Microbiol 2012; 58:1362-7. [PMID: 23210993 DOI: 10.1139/cjm-2012-0457] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The yeast Dekkera bruxellensis has been recently regarded as an important microorganism for bioethanol production owing to its ability to convert glucose, sucrose, and cellobiose to ethanol. The aim of this work was to validate a new set of reference genes for gene expression analysis by quantitative real-time PCR in D. bruxellensis and compare the influence of the method of choice for quantification of mRNA levels with the reliability of our data. Three candidate reference genes, DbEFA1, DbEFB1, and DbYNA1, were used in a quantitative analysis of 4 genes of interest, DbYNR1, DbTPS1, DbADH7, and DbUBA4, based on an approach for calculating the normalization factors by means of the geNorm applet. Each reference gene was also individually used for a 2(-ΔΔC(q)) (comparative C(q) method) calculation of the relative expression of genes of interest. Our results showed that the 3 reference genes provided enough stability and were complementary to the normalization factors method in different culture conditions. This work was able to confirm the usefulness of a previously reported reference gene, EFA1/TEF1, and increased the set of possible reference genes in D. bruxellensis to 4. Moreover, this can improve the reliability of the analysis of the regulation of gene expression in the industrial yeast D. bruxellensis.
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Affiliation(s)
- Will de Barros Pita
- Interdepartmental Research Group on Metabolic Engineering, Federal University of Pernambuco, Av. Moraes Rego 1235, Recife, PE 50670-901, Brazil.
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Leite FCB, Basso TO, Pita WDB, Gombert AK, Simões DA, de Morais MA. Quantitative aerobic physiology of the yeast Dekkera bruxellensis, a major contaminant in bioethanol production plants. FEMS Yeast Res 2012; 13:34-43. [PMID: 23078341 DOI: 10.1111/1567-1364.12007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 08/07/2012] [Accepted: 09/07/2012] [Indexed: 12/01/2022] Open
Abstract
Dekkera bruxellensis has been described as the major contaminant yeast of industrial ethanol production, although little is known about its physiology. The aim of this study was to investigate the growth of this yeast in diverse carbon sources and involved conducting shake-flask and glucose- or sucrose-limited chemostats experiments, and from the chemostat data, the stoichiometry of biomass formation during aerobic growth was established. As a result of the shake-flask experiments with hexoses or disaccharides, the specific growth rates were calculated, and a different behavior in rich and mineral medium was observed concerning to profile of acetate and ethanol production. In C-limited chemostats conditions, the metabolism of this yeast was completely respiratory, and the biomass yields reached values of 0.62 gDW gS(-1) . In addition, glucose pulses were applied to the glucose- or sucrose-limited chemostats. These results showed that D. bruxellensis has a short-term Crabtree effect. While the glucose pulse was at the sucrose-limited chemostat, sucrose accumulated at the reactor, indicating the presence of a glucose repression mechanism in D. bruxellensis.
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de Barros Pita W, Leite FCB, de Souza Liberal AT, Simões DA, de Morais MA. The ability to use nitrate confers advantage to Dekkera bruxellensis over S. cerevisiae and can explain its adaptation to industrial fermentation processes. Antonie Van Leeuwenhoek 2011; 100:99-107. [PMID: 21350883 DOI: 10.1007/s10482-011-9568-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 02/18/2011] [Indexed: 10/18/2022]
Abstract
The yeast Dekkera bruxellensis has been regarded as a contamination problem in industrial ethanol production because it can replace the originally inoculated Saccharomyces cerevisiae strains. The present study deals with the influence of nitrate on the relative competitiveness of D. bruxellensis and S. cerevisiae in sugar cane ethanol fermentations. The industrial strain D. bruxellensis GDB 248 showed higher growth rates than S. cerevisiae JP1 strain in mixed ammonia/nitrate media, and nitrate assimilation genes were only slightly repressed by ammonia. These characteristics rendered D. bruxellensis cells with an ability to overcome S. cerevisiae populations in both synthetic medium and in sugar cane juice. The results were corroborated by data from industrial fermentations that showed a correlation between high nitrate concentrations and high D. bruxellensis cell counts. Moreover, the presence of nitrate increased fermentation efficiency of D. bruxellensis cells in anaerobic conditions, which may explain the maintenance of ethanol production in the presence of D. bruxellensis in industrial processes. The presence of high levels of nitrate in sugar cane juice may be due to its inefficient conversion by plant metabolism in certain soil types and could explain the periodical episodes of D. bruxellensis colonization of Brazilian ethanol plants.
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Affiliation(s)
- Will de Barros Pita
- Interdepartmental Research Group on Metabolic Engineering, Federal University of Pernambuco, Recife, PE, Brazil
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