1
|
Gupta M, Choudhury B, Navani NK. Production and characterization of an organic solvent activated protease from haloalkaliphilic bacterium Halobiforma sp. strain BNMIITR. Heliyon 2024; 10:e25084. [PMID: 38314259 PMCID: PMC10837622 DOI: 10.1016/j.heliyon.2024.e25084] [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: 08/26/2023] [Revised: 01/19/2024] [Accepted: 01/19/2024] [Indexed: 02/06/2024] Open
Abstract
An unusual haloalkaliphilic bacterium known as Halobiforma sp. strain BNMIITR, which was noticed to produce an extracellular alkaline protease, was found in a soil sample from Northern India's Sambhar Lake. On the generation of protease, the effects of dietary elements including nitrogen and carbon sources, amino acids, and growth conditions like temperature and pH were investigated. When low-cost agricultural by-products were employed as nitrogen sources, the manufacturing of enzymes was significantly boosted. In the present study, protease production was enhanced by 2.94 fold and 2.17 fold. By solvent precipitation and Hydrophobic interaction chromatography (HIC) on Phenyl Sepharose 6 Fast Flow matrix, the enzyme was purified 31.67 fold. It was determined that the apparent molecular mass was 21 kDa. The pH range where the enzyme was most stable was 6.0-12.0, with a temperature of 50 °C as optimum. When there was alkaline earth metals and heavy metals, protease was discovered to be active. It was evident that the enzyme was a serine type of protease because it was active in the presence of a variety of surfactants, oxidizing and reducing chemicals, and phenylmethylsulfonyl fluoride (PMSF) completely inhibited activity. Enzyme exhibited a wide range of substrate specificity. Amazingly, enzyme remained stable both in polar and nonpolar solvents. The most interesting aspect of this enzyme is enhanced activity in polar solvents like dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). It was discovered that the protease was stable and compatible with a number of widely available detergents.
Collapse
Affiliation(s)
- Meenu Gupta
- Botany Department, J. D. Women's College Patna, Bihar, 800023, India
- Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India
| | - Bijan Choudhury
- Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India
| | - Naveen Kumar Navani
- Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India
| |
Collapse
|
2
|
Conacher CG, Rossouw D, Bauer FFB. Peer pressure: evolutionary responses to biotic pressures in wine yeasts. FEMS Yeast Res 2020; 19:5593956. [PMID: 31626300 DOI: 10.1093/femsyr/foz072] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/16/2019] [Indexed: 12/19/2022] Open
Abstract
In the macroscopic world, ecological interactions between multiple species of fauna and flora are recognised as major role-players in the evolution of any particular species. By comparison, research on ecological interactions as a driver of evolutionary adaptation in microbial ecosystems has been neglected. The evolutionary history of the budding yeast Saccharomyces cerevisiae has been extensively researched, providing an unmatched foundation for exploring adaptive evolution of microorganisms. However, in most studies, the habitat is only defined by physical and chemical parameters, and little attention is paid to the impact of cohabiting species. Such ecological interactions arguably provide a more relevant evolutionary framework. Within the genomic phylogenetic tree of S. cerevisiae strains, wine associated isolates form a distinct clade, also matched by phenotypic evidence. This domestication signature in genomes and phenomes suggests that the wine fermentation environment is of significant evolutionary relevance. Data also show that the microbiological composition of wine fermentation ecosystems is dominated by the same species globally, suggesting that these species have co-evolved within this ecosystem. This system therefore presents an excellent model for investigating the origins and mechanisms of interspecific yeast interactions. This review explores the role of biotic stress in the adaptive evolution of wine yeast.
Collapse
Affiliation(s)
- C G Conacher
- Institute for Wine Biotechnology, Department of Oenology and Viticulture, Private Bag X1, Stellenbosch University, Stellenbosch 7600, South Africa
| | - D Rossouw
- Institute for Wine Biotechnology, Department of Oenology and Viticulture, Private Bag X1, Stellenbosch University, Stellenbosch 7600, South Africa
| | - F F B Bauer
- Institute for Wine Biotechnology, Department of Oenology and Viticulture, Private Bag X1, Stellenbosch University, Stellenbosch 7600, South Africa
| |
Collapse
|
3
|
Biogenic synthesis of silica nanoparticles from corn cobs husks. Dependence of the productivity on the method of raw material processing. Bioorg Chem 2020; 99:103773. [DOI: 10.1016/j.bioorg.2020.103773] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 11/19/2022]
|
4
|
Dolz‐Edo L, van der Deen M, Brul S, Smits GJ. Caloric restriction controls stationary phase survival through Protein Kinase A (PKA) and cytosolic pH. Aging Cell 2019; 18:e12921. [PMID: 30790427 PMCID: PMC6516148 DOI: 10.1111/acel.12921] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 12/30/2018] [Accepted: 01/23/2019] [Indexed: 11/28/2022] Open
Abstract
Calorie restriction is the only physiological intervention that extends lifespan throughout all kingdoms of life. In the budding yeast Saccharomyces cerevisiae, cytosolic pH (pHc) controls growth and responds to nutrient availability, decreasing upon glucose depletion. We investigated the interactions between glucose availability, pHc and the central nutrient signalling cAMP‐Protein Kinase A (PKA) pathway. Glucose abundance during the growth phase enhanced acidification upon glucose depletion, via modulation of PKA activity. This actively controlled reduction in starvation pHc correlated with reduced stationary phase survival. Whereas changes in PKA activity affected both acidification and survival, targeted manipulation of starvation pHc showed that cytosolic acidification was downstream of PKA and the causal agent of the reduced chronological lifespan. Thus, caloric restriction controls stationary phase survival through PKA and cytosolic pH.
Collapse
Affiliation(s)
- Laura Dolz‐Edo
- Department of Molecular Biology and Microbial Food Safety Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam The Netherlands
| | - Margaretha van der Deen
- Department of Molecular Biology and Microbial Food Safety Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam The Netherlands
| | - Stanley Brul
- Department of Molecular Biology and Microbial Food Safety Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam The Netherlands
| | - Gertien Jacoba Smits
- Department of Molecular Biology and Microbial Food Safety Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam The Netherlands
| |
Collapse
|
5
|
Yang L, Zheng C, Chen Y, Ying H. FLO Genes Family and Transcription Factor MIG1 Regulate Saccharomyces cerevisiae Biofilm Formation During Immobilized Fermentation. Front Microbiol 2018; 9:1860. [PMID: 30210459 PMCID: PMC6119776 DOI: 10.3389/fmicb.2018.01860] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/24/2018] [Indexed: 01/26/2023] Open
Abstract
Saccharomyces cerevisiae immobilization is commonly used for efficient ethanol fuel production in industry due to the relatively higher ethanol stress resistance of S. cerevisiae in biofilms relative to planktonic cells. The mechanisms of biofilm formation and stress resistance, however, remain ambiguous. By analyzing biofilm and planktonic cell transcriptomes, this study observed that MIG1 (encoding a transcription factor) expression in cells increases during the biofilm formation process. To identify the role of MIG1 in yeast biofilm formation and the ethanol resistance of these cells, MIG1 was deleted and complemented in S. cerevisiae 1308. Results showed the MIG1 deletion mutant strain demonstrated weaker biofilm formation ability both on fibers and plastic than the wild-type and these could be restored by expressing MIG1 in deletion mutant. To verify the ability of MIG1 to regulate the expression of FLO genes, which encode adhesions responsible for yeast biofilm formation, FLO gene transcription levels were measured via qRT-PCR. Relative to wild-type S. cerevisiae, the adhesion genes FLO1, 5, and 9 which also demonstrate increased expression in the transcriptome of yeast cells during biofilm formation, but not FLO11, were down-regulated in the MIG1 mutant strain. Additionally, the MIG1 mutant lost a majority of its flocculation ability, which depended on cell-cell adhesions and its slightly invasive growth ability, dependent on cell-substrate adhesion. Deleting FLO1, 5, and 9 decreased biofilm formation on plastics, suggesting these FLO genes contribute to the biofilm formation process alongside FLO11. Moreover, the ethanol tolerance of yeast decreased in the MIG1 deletion mutant as well as the FLO11 deletion mutant, resulting in reduced biofilm formation during fermentation. It remains possible that in the later period of fermentation, when ethanol has accumulated, an over-expression of the FLO1, 5, and 9 genes regulated by MIG1 would enhanced cell-cell adhesions and thus protect cells in the outer layer of biofilms from ethanol, a function primarily dependent on cell-cell adhesions. This work offers a possible explanation for how biofilm formation is regulated during the immobilized fermentation process, and can enhance environmental tolerance in industrial production.
Collapse
Affiliation(s)
- Leyun Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Cheng Zheng
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Yong Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Hanjie Ying
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,National Engineering Research Center for Biotechnology, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| |
Collapse
|
6
|
Nsogning SD, Zarnkow M, Becker T, Merz A, Schönenberg S. Use of Exogenous Enzymes and Process Management to Improve the Shelf Life of Traditional Opaque Beer. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2015-0121-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Sorelle D. Nsogning
- Chair of Brewing and Beverage Technology, Technische Universität München, Weihenstephaner Steig 20, D-85354 Freising, Germany
| | - Martin Zarnkow
- Chair of Brewing and Beverage Technology, Technische Universität München, Weihenstephaner Steig 20, D-85354 Freising, Germany
| | - Thomas Becker
- Chair of Brewing and Beverage Technology, Technische Universität München, Weihenstephaner Steig 20, D-85354 Freising, Germany
| | | | | |
Collapse
|
7
|
Matallana E, Aranda A. Biotechnological impact of stress response on wine yeast. Lett Appl Microbiol 2016; 64:103-110. [DOI: 10.1111/lam.12677] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/09/2016] [Accepted: 09/29/2016] [Indexed: 01/07/2023]
Affiliation(s)
- E. Matallana
- Institute of Agrochemistry and Food Technology (IATA-CSIC); Paterna Spain
- Department of Biochemistry and Molecular Biology; University of Valencia; Paterna Spain
| | - A. Aranda
- Institute of Agrochemistry and Food Technology (IATA-CSIC); Paterna Spain
| |
Collapse
|
8
|
Altıntaş A, Martini J, Mortensen UH, Workman CT. Quantification of oxidative stress phenotypes based on high-throughput growth profiling of protein kinase and phosphatase knockouts. FEMS Yeast Res 2015; 16:fov101. [PMID: 26564984 DOI: 10.1093/femsyr/fov101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2015] [Indexed: 12/21/2022] Open
Abstract
Cellular responses to oxidative stress are important for restoring redox balance and ensuring cell survival. Genetic defects in response factors can lead to impaired response to oxidative damage and contribute to disease and aging. In single cell organisms, such as yeasts, the integrity of the oxidative stress response can be observed through its influences on growth characteristics. In this study, we investigated the time-dependent batch growth effects as a function of oxidative stress levels in protein kinase and phosphatase deletion backgrounds of Saccharomyces cerevisiae. In total, 41 different protein kinases and phosphatase mutants were selected for their known activities in oxidative stress or other stress response pathways and were investigated for their dosage-dependent response to hydrogen peroxide. Detailed growth profiles were analyzed after the induction of stress for growth rate, lag time duration and growth efficiency, and by a novel method to identify stress-induced diauxic shift delay. This approach extracts more phenotypic information than traditional plate-based methods due to the assessment of time dynamics in the time scale of minutes. With this approach, we were able to identify surprisingly diverse sensitivity and resistance patterns as a function of gene knockout.
Collapse
Affiliation(s)
- Ali Altıntaş
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Building 208, Kongens Lyngby, DK-2800, Denmark
| | - Jacopo Martini
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Building 208, Kongens Lyngby, DK-2800, Denmark
| | - Uffe H Mortensen
- Eukaryotic Biotechnology, Department of Systems Biology, Technical University of Denmark, Building 223, Kongens Lyngby, DK-2800, Denmark
| | - Christopher T Workman
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Building 208, Kongens Lyngby, DK-2800, Denmark
| |
Collapse
|
9
|
Spitzmüller Z, Kwon NJ, Szilágyi M, Keserű J, Tóth V, Yu JH, Pócsi I, Emri T. γ-Glutamyl transpeptidase (GgtA) of Aspergillus nidulans is not necessary for bulk degradation of glutathione. Arch Microbiol 2014; 197:285-97. [PMID: 25519188 DOI: 10.1007/s00203-014-1057-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 10/27/2014] [Accepted: 10/28/2014] [Indexed: 12/31/2022]
Abstract
Aspergillus nidulans exhibited high γ-glutamyl transpeptidase (γGT) activity in both carbon-starved and carbon-limited cultures. Glucose repressed, but casein peptone increased γGT production. Null mutation of creA did not influence γGT formation, but the functional meaB was necessary for the γGT induction. Deletion of the AN10444 gene (ggtA) completely eliminated the γGT activity, and the mRNA levels of ggtA showed strong correlation with the observed γGT activities. While ggtA does not contain a canonical signal sequence, the γGT activity was detectable both in the fermentation broth and in the hyphae. Deletion of the ggtA gene did not prevent the depletion of glutathione observed in carbon-starved and carbon-limited cultures. Addition of casein peptone to carbon-starved cultures lowered the formation of reactive species (RS). Deletion of ggtA could hinder this decrease and resulted in elevated RS formation. This effect of γGT on redox homeostasis may explain the reduced cleistothecia formation of ΔggtA strains in surface cultures.
Collapse
Affiliation(s)
- Zsolt Spitzmüller
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H4032, Hungary
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Rúa J, de Castro C, de Arriaga D, García-Armesto MR, Busto F, del Valle P. Stress in Phycomyces blakesleeanus by glucose starvation and acetate growth: Response of the antioxidant system and reserve carbohydrates. Microbiol Res 2014; 169:788-93. [DOI: 10.1016/j.micres.2013.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 12/05/2013] [Accepted: 12/20/2013] [Indexed: 01/01/2023]
|
11
|
Szilágyi M, Miskei M, Karányi Z, Lenkey B, Pócsi I, Emri T. Transcriptome changes initiated by carbon starvation in Aspergillus nidulans. MICROBIOLOGY-SGM 2012; 159:176-190. [PMID: 23154970 DOI: 10.1099/mic.0.062935-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Carbon starvation is a common stress for micro-organisms both in nature and in industry. The carbon starvation stress response (CSSR) involves the regulation of several important processes including programmed cell death and reproduction of fungi, secondary metabolite production and extracellular hydrolase formation. To gain insight into the physiological events of CSSR, DNA microarray analyses supplemented with real-time RT-PCR (rRT-PCR) experiments on 99 selected genes were performed. These data demonstrated that carbon starvation induced very complex changes in the transcriptome. Several genes contributing to protein synthesis were upregulated together with genes involved in the unfolded protein stress response. The balance between biosynthesis and degradation moved towards degradation in the case of cell wall, carbohydrate, lipid and nitrogen metabolism, which was accompanied by the production of several hydrolytic enzymes and the induction of macroautophagy. These processes provide the cultures with long-term survival by liberating nutrients through degradation of the cell constituents. The induced synthesis of secondary metabolites, antifungal enzymes and proteins as well as bacterial cell wall-degrading enzymes demonstrated that carbon-starving fungi should have marked effects on the micro-organisms in their surroundings. Due to the increased production of extracellular and vacuolar enzymes during carbon starvation, the importance of the endoplasmic reticulum increased considerably.
Collapse
Affiliation(s)
- Melinda Szilágyi
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Márton Miskei
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Zsolt Karányi
- Department of Medicine, University of Debrecen, Nagyerdei Körút 98, 4032 Debrecen, Hungary
| | - Béla Lenkey
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - István Pócsi
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Tamás Emri
- Department of Microbial Biotechnology and Cell Biology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| |
Collapse
|
12
|
Ogata T. Nitrogen starvation induces expression of Lg-FLO1 and flocculation in bottom-fermenting yeast. Yeast 2012; 29:487-94. [PMID: 23065862 DOI: 10.1002/yea.2928] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/27/2012] [Accepted: 09/04/2012] [Indexed: 11/10/2022] Open
Abstract
When exponentially growing cells of bottom-fermenting yeast were starved for nitrogen or were grown on proline (a non-preferred nitrogen source), flocculation was induced. This flocculation was not induced by starvation for either carbon or amino acids. Expression of Lg-FLO1, which is required for flocculation of bottom-fermenting yeast, was also found to be induced by starvation for nitrogen. This suggests that the flocculation of bottom-fermenting yeast is under the control of a nitrogen catabolite repression (NCR)-like mechanism.
Collapse
Affiliation(s)
- Tomoo Ogata
- Research Laboratories for Brewing, Asahi Breweries Ltd, Ibaraki, Japan.
| |
Collapse
|
13
|
Smets B, De Snijder P, Engelen K, Joossens E, Ghillebert R, Thevissen K, Marchal K, Winderickx J. Genome-wide expression analysis reveals TORC1-dependent and -independent functions of Sch9. FEMS Yeast Res 2008; 8:1276-88. [DOI: 10.1111/j.1567-1364.2008.00432.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
14
|
Sosa OA, de Nadra MCM, Farías ME. Modification by glucose of the flocculent phenotype of a Kloeckera apiculata wine strain. J Ind Microbiol Biotechnol 2008; 35:851-7. [PMID: 18425542 DOI: 10.1007/s10295-008-0357-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 04/04/2008] [Indexed: 11/24/2022]
Abstract
We have evaluated the induction of the flocculent phenotype of Kloeckera apiculata by glucose mc1 and propose a pathway involved in carbohydrate flocculation induction. Pulses of glucose were given to cells growing in glucose-poor medium (2 g l(-1)) and the flocculation percentage was measured. To elucidate the mechanism involved in flocculation induction, cycloheximide was injected into the cultures 120 min before the glucose pulse. 2,4-Dinitrophenol or cAMP was added to the media instead, or simultaneously with glucose, while a protein kinase A (PKA) inhibitor was added 30 min before the glucose pulse. With 20 and 50 g l(-1) glucose pulse, the yeast flocculation percentage arises to 55 and 65%, respectively. The quantity of proteins and the reflocculating capacity of a lectinic protein extract from the yeast cell wall increase as the concentration of glucose pulse was higher. Cycloheximide prevented the glucose-induced flocculation, while cAMP or 2,4-dinitrophenol increased it 4- and 5-fold, respectively. PKA inhibitor completely prevented the glucose induction flocculation. The flocculent phenotype of K. apiculata mc1 was induced by glucose and the mechanism seems to imply de novo protein (lectin) synthesis via the PKA transduction pathway. This work contributes to the elucidation of the mechanism involved in flocculation induction by glucose of a non-Saccharomyces wine yeast, K. apiculata, which has not been reported. The induction of flocculation by glucose could be a biotechnological tool for the early removal of the indigenous microorganisms from the grape must before the inoculation of a selected starter strain to conduct the alcohol fermentation.
Collapse
Affiliation(s)
- Oscar A Sosa
- Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán and Centro de Referencia para Lactobacilos, Chacabuco 145, 4000, Tucumán, Argentina
| | | | | |
Collapse
|
15
|
Abstract
Yeast cells possess a remarkable capacity to adhere to abiotic surfaces, cells and tissues. These adhesion properties are of medical and industrial relevance. Pathogenic yeasts such as Candida albicans and Candida glabrata adhere to medical devices and form drug-resistant biofilms. In contrast, cell-cell adhesion (flocculation) is a desirable property of industrial Saccharomyces cerevisiae strains that allows the easy separation of cells from the fermentation product. Adhesion is conferred by a class of special cell wall proteins, called adhesins. Cells carry several different adhesins, each allowing adhesion to specific substrates. Several signalling cascades including the Ras/cAMP/PKA and MAP kinase (MAPK)-dependent filamentous growth pathways tightly control synthesis of the different adhesins. Together, these pathways trigger adhesion in response to stress, nutrient limitation or small molecules produced by the host, such as auxin in plants or NAD in mammals. In addition, adhesins are subject to subtelomeric epigenetic switching, resulting in stochastic expression patterns. Internal tandem repeats within adhesin genes trigger recombination events and the formation of novel adhesins, thereby offering fungi an endless reservoir of adhesion properties. These aspects of fungal adhesion exemplify the impressive phenotypic plasticity of yeasts, allowing them to adapt quickly to stressful environments and exploit new opportunities.
Collapse
Affiliation(s)
- Kevin J Verstrepen
- Harvard University Bauer Center for Genomics Research, 7 Divinity Avenue, Room 104, Cambridge, MA 02138, USA.
| | | |
Collapse
|
16
|
Swinnen E, Rosseels J, Winderickx J. The minimum domain of Pho81 is not sufficient to control the Pho85-Rim15 effector branch involved in phosphate starvation-induced stress responses. Curr Genet 2005; 48:18-33. [PMID: 15926040 DOI: 10.1007/s00294-005-0583-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 04/14/2005] [Accepted: 04/19/2005] [Indexed: 10/25/2022]
Abstract
The phosphate regulatory mechanism in yeast, known as the PHO pathway, is regulated by inorganic phosphate to control the expression of genes involved in the acquisition of phosphate from the medium. This pathway is also reported to contribute to other nutritional responses and as such it affects several phenotypic characteristics known also to be regulated by protein kinase A, including the transcription of genes involved in the general stress response and trehalose metabolism. We now demonstrate that transcription of post-diauxic shift (PDS)-controlled stress-responsive genes is solely regulated by the Pho85-Pho80 complex, whereas regulation of trehalose metabolism apparently involves several Pho85 cyclins. Interestingly, both read-outs depend on Pho81 but, while the previously described minimum domain of Pho81 is sufficient to sustain phosphate-regulated transcription of PHO genes, full-length Pho81 is required to control trehalose metabolism and the PDS targets. Consistently, neither the expression control of stress-regulated genes nor the trehalose metabolism relies directly on Pho4. Finally, we present data supporting that the PHO pathway functions in parallel to the fermentable growth medium- or Sch9-controlled pathway and that both pathways may share the protein kinase Rim15, which was previously reported to play a central role in the integration of glucose, nitrogen and amino acid availability.
Collapse
Affiliation(s)
- Erwin Swinnen
- Functional Biology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, 3001 Heverlee, Belgium
| | | | | |
Collapse
|
17
|
Verstrepen KJ, Iserentant D, Malcorps P, Derdelinckx G, Van Dijck P, Winderickx J, Pretorius IS, Thevelein JM, Delvaux FR. Glucose and sucrose: hazardous fast-food for industrial yeast? Trends Biotechnol 2005; 22:531-7. [PMID: 15450747 DOI: 10.1016/j.tibtech.2004.08.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Yeast cells often encounter a mixture of different carbohydrates in industrial processes. However, glucose and sucrose are always consumed first. The presence of these sugars causes repression of gluconeogenesis, the glyoxylate cycle, respiration and the uptake of less-preferred carbohydrates. Glucose and sucrose also trigger unexpected, hormone-like effects, including the activation of cellular growth, the mobilization of storage compounds and the diminution of cellular stress resistance. In an industrial context, these effects lead to several yeast-related problems, such as slow or incomplete fermentation, 'off flavors' and poor maintenance of yeast vitality. Recent studies indicate that the use of mutants with altered responses to carbohydrates can significantly increase productivity. Alternatively, avoiding unnecessary exposure to glucose and sucrose could also improve the performance of industrial yeasts.
Collapse
Affiliation(s)
- Kevin J Verstrepen
- MIT Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Verstrepen KJ, Derdelinckx G, Dufour JP, Winderickx J, Pretorius IS, Thevelein JM, Delvaux FR. The Saccharomyces cerevisiae alcohol acetyl transferase gene ATF1 is a target of the cAMP/PKA and FGM nutrient-signalling pathways. FEMS Yeast Res 2004; 4:285-96. [PMID: 14654433 DOI: 10.1016/s1567-1356(03)00166-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The ATF1-encoded Saccharomyces cerevisiae yeast alcohol acetyl transferase I is responsible for the formation of several different volatile acetate esters during fermentations. A number of these volatile esters, e.g. ethyl acetate and isoamyl acetate, are amongst the most important aroma compounds in fermented beverages such as beer and wine. Manipulation of the expression levels of ATF1 in brewing yeast strains has a significant effect on the ester profile of beer. Northern blot analysis of ATF1 and its closely related homologue, Lg-ATF1, showed that these genes were rapidly induced by the addition of glucose to anaerobically grown carbon-starved cells. This induction was abolished in a protein kinase A (PKA)-attenuated strain, while a PKA-overactive strain showed stronger ATF1 expression, indicating that the Ras/cAMP/PKA signalling pathway is involved in this glucose induction. Furthermore, nitrogen was needed in the growth medium in order to maintain ATF1 expression. Long-term activation of ATF1 could also be obtained by the addition of the non-metabolisable amino acid homologue beta-L-alanine, showing that the effect of the nitrogen source did not depend on its metabolism. In addition to nutrient regulation, ATF1 and Lg-ATF1 expression levels were also affected by heat and ethanol stress. These findings help in the understanding of the effect of medium composition on volatile ester synthesis in industrial fermentations. In addition, the complex regulation provides new insights into the physiological role of Atf1p in yeast.
Collapse
Affiliation(s)
- Kevin J Verstrepen
- Centre for Malting and Brewing Science, Department of Food and Microbial Technology, K.U. Leuven, Kasteelpark Arenberg 22, 3001 (Heverlee), Leuven, Belgium.
| | | | | | | | | | | | | |
Collapse
|