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Oleszkiewicz A, Schriever VA, Valder C, Agosin E, Altundag A, Avni H, Cao Van H, Cornejo C, Fishman G, Guarneros M, Gupta N, Kamel R, Knaapila A, Konstantinidis I, Landis BN, Larsson M, Lundström JN, Macchi A, Marino-Sanchez F, Mori E, Mullol J, Parma V, Propst EJ, Sandell MA, Sorokowska A, Vodicka J, Hummel T, Gellrich J. Hedonic perception of odors in children aged 5-8 years is similar across 18 countries: Preliminary data. Int J Pediatr Otorhinolaryngol 2022; 157:111129. [PMID: 35443229 DOI: 10.1016/j.ijporl.2022.111129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/27/2022] [Accepted: 04/08/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Olfactory preference emerges very early in life, and the sense of smell in children rapidly develops until the second decade of life. It is still unclear whether hedonic perception of odors is shared in children inhabiting different regions of the globe. METHODS Five-hundred ten healthy children (N = 510; ngirls = 256; nboys = 254) aged from 5 to 8 years from 18 countries rated the pleasantness of 17 odors. RESULTS The hedonic perception of odors in children aged between 5 and 8 years was rather consistent across 18 countries and mainly driven by the qualities of an odor and the overall ability of children to label odorants. CONCLUSION Conclusions from this study, being a secondary analysis, are limited to the presented set of odors that were initially selected for the development of U-Sniff test and present null findings for the cross-cultural variability in hedonic perception of odors across 18 countries. These two major issues should be addressed in the future to either contradict or replicate the results presented herewith. This research lays fundament for posing further research questions about the developmental aspects of hedonic perception of odors and opens a new door for investigating cross-cultural differences in chemosensory perception of children.
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Affiliation(s)
- A Oleszkiewicz
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany; Institute of Psychology, University of Wroclaw, Poland.
| | - V A Schriever
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany; Charité - Universitätsmedizin Berlin, Center for Chronically Sick Children (Sozialpädiatrisches Zentrum, SPZ), Berlin, Germany.
| | - C Valder
- Systema Natura GmbH, Flintbek, Germany.
| | - E Agosin
- College of Engineering, Pontifical Catholic University of Chile, Santiago, Chile.
| | - A Altundag
- Otorhinolaryngology Department of Biruni University Medical Faculty, Acibadem Taksim Hospital Otorhinolaryngology Department, Istanbul, Turkey.
| | - H Avni
- Pediatric Feeding Disorders Clinic, Dana Children's Hospital, Tel Aviv Medical Center, Tel Aviv, Israel.
| | - H Cao Van
- Pediatric ENT Unit, Department of Otorhinolaryngologie Head and Neck Surgery, University Hospital of Geneva, Switzerland.
| | - C Cornejo
- Escuela de Psicología, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - G Fishman
- Pediatric Otolaryngology, Dana Children's Hospital, Tel-Aviv Medical Center, Sackler School of Medicine, Tel-Aviv, Israel.
| | - M Guarneros
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico.
| | - N Gupta
- Department of Otorhinolaryngology, University College of Medical Sciences and GTB Hospital, Delhi, India.
| | - R Kamel
- Department of Otorhinolaryngology, Head and Neck Surgery, Cairo University, Cairo, Egypt.
| | - A Knaapila
- Department of Food and Nutrition, University of Helsinki, Helsinki, Finland.
| | - I Konstantinidis
- 2nd Otorhinolaryngology Department of Aristotle University, Thessaloniki, Greece.
| | - B N Landis
- Rhinology-Olfactology Unit, Department of Otorhinolaryngologie Head and Neck Surgery, University Hospital of Geneva, Switzerland.
| | - M Larsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden.
| | - J N Lundström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - A Macchi
- ENT Clinic, University of Insubriae Varese, ASST Settelaghi, Italy.
| | - F Marino-Sanchez
- Unidad de Rinología y Cirugía de Base de Cráneo, Servicio de Otorrinolaringología. Hospital Universitario Ramón y Cajal, Madrid, Spain.
| | - E Mori
- Department of Otorhinolaryngology, Jikei University School of Medicine, Tokyo, Japan.
| | - J Mullol
- Rhinology Unit & Smell Clinic, ENT Department, Hospital Clínic, IDIBAPS, Universitat de Barcelona, CIBERES, Barcelona, Catalonia, Spain.
| | - V Parma
- Temple University, Department of Psychology, Philadelphia, USA; Monell Chemical Senses Center, Philadelphia, USA.
| | - E J Propst
- Department of Otolaryngology - Head & Neck Surgery, Hospital for Sick Children, University of Toronto, Canada.
| | - M A Sandell
- Department of Food and Nutrition, University of Helsinki, Helsinki, Finland.
| | - A Sorokowska
- Institute of Psychology, University of Wroclaw, Poland.
| | - J Vodicka
- Department of Otorhinolaryngology and Head and Neck Surgery, Faculty of Health Studies, University of Pardubice, Pardubice, Czech Republic.
| | - T Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany.
| | - J Gellrich
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany; Klinik und Poliklinik für Kinder- und Jugendheilkunde, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany.
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Mendoza SN, Saa PA, Teusink B, Agosin E. Metabolic Modeling of Wine Fermentation at Genome Scale. Methods Mol Biol 2022; 2399:395-454. [PMID: 35604565 DOI: 10.1007/978-1-0716-1831-8_16] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Wine fermentation is an ancient biotechnological process mediated by different microorganisms such as yeast and bacteria. Understanding of the metabolic and physiological phenomena taking place during this process can be now attained at a genome scale with the help of metabolic models. In this chapter, we present a detailed protocol for modeling wine fermentation using genome-scale metabolic models. In particular, we illustrate how metabolic fluxes can be computed, optimized and interpreted, for both yeast and bacteria under winemaking conditions. We also show how nutritional requirements can be determined and simulated using these models in relevant test cases. This chapter introduces fundamental concepts and practical steps for applying flux balance analysis in wine fermentation, and as such, it is intended for a broad microbiology audience as well as for practitioners in the metabolic modeling field.
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Affiliation(s)
| | - Pedro A Saa
- Laboratory of Biotechnology, Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Bas Teusink
- Systems Biology Lab, AIMMS, Vrije Universiteit, Amsterdam, The Netherlands
| | - Eduardo Agosin
- Laboratory of Biotechnology, Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Eyheramendy S, Saa PA, Undurraga EA, Valencia C, López C, Méndez L, Pizarro-Berdichevsky J, Finkelstein-Kulka A, Solari S, Salas N, Bahamondes P, Ugarte M, Barceló P, Arenas M, Agosin E. Screening of COVID-19 cases through a Bayesian network symptoms model and psychophysical olfactory test. iScience 2021; 24:103419. [PMID: 34786538 PMCID: PMC8580551 DOI: 10.1016/j.isci.2021.103419] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/12/2021] [Accepted: 11/05/2021] [Indexed: 01/08/2023] Open
Abstract
The sudden loss of smell is among the earliest and most prevalent symptoms of COVID-19 when measured with a clinical psychophysical test. Research has shown the potential impact of frequent screening for olfactory dysfunction, but existing tests are expensive and time consuming. We developed a low-cost ($0.50/test) rapid psychophysical olfactory test (KOR) for frequent testing and a model-based COVID-19 screening framework using a Bayes Network symptoms model. We trained and validated the model on two samples: suspected COVID-19 cases in five healthcare centers (n = 926; 33% prevalence, 309 RT-PCR confirmed) and healthy miners (n = 1,365; 1.1% prevalence, 15 RT-PCR confirmed). The model predicted COVID-19 status with 76% and 96% accuracy in the healthcare and miners samples, respectively (healthcare: AUC = 0.79 [0.75-0.82], sensitivity: 59%, specificity: 87%; miners: AUC = 0.71 [0.63-0.79], sensitivity: 40%, specificity: 97%, at 0.50 infection probability threshold). Our results highlight the potential for low-cost, frequent, accessible, routine COVID-19 testing to support society's reopening.
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Affiliation(s)
- Susana Eyheramendy
- Faculty of Engineering and Science, Universidad Adolfo Ibáñez, Santiago, Chile
- Millennium Institute for Foundational Research on Data (IMFD), Santiago, Chile
| | - Pedro A. Saa
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Mathematical and Computational Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo A. Undurraga
- School of Government, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Initiative for Collaborative Research in Bacterial Resistance (MICROB-R), Santiago, Chile
- Research Center for Integrated Disaster Risk Management (CIGIDEN), Santiago, Chile
- CIFAR Azrieli Global Scholars Program, Toronto, Canada
| | | | - Carolina López
- Center for Aromas and Flavors, DICTUC SA., Santiago, Chile
| | - Luis Méndez
- Endoscopy Unit, Hospital Padre Hurtado, Santiago, Chile
- Department of Gastroenterology, Clínica Alemana de Santiago, Santiago, Chile
| | - Javier Pizarro-Berdichevsky
- Center for Innovation in Pelvic Floor, Hospital Sótero del Río, Santiago, Chile
- Department of Obstetrics and Gynecology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Andrés Finkelstein-Kulka
- Department of Otolaryngology, Clínica Alemana de Santiago, Santiago, Chile
- Faculty of Medicine, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Sandra Solari
- Department of Clinical Laboratory, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nicolás Salas
- Millennium Institute for Foundational Research on Data (IMFD), Santiago, Chile
| | - Pedro Bahamondes
- Millennium Institute for Foundational Research on Data (IMFD), Santiago, Chile
| | - Martín Ugarte
- Millennium Institute for Foundational Research on Data (IMFD), Santiago, Chile
| | - Pablo Barceló
- Millennium Institute for Foundational Research on Data (IMFD), Santiago, Chile
- Institute for Mathematical and Computational Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Marcelo Arenas
- Millennium Institute for Foundational Research on Data (IMFD), Santiago, Chile
- Institute for Mathematical and Computational Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
- Department of Computer Science, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center for Aromas and Flavors, DICTUC SA., Santiago, Chile
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López J, Bustos D, Camilo C, Arenas N, Saa PA, Agosin E. Engineering Saccharomyces cerevisiae for the Overproduction of β-Ionone and Its Precursor β-Carotene. Front Bioeng Biotechnol 2020; 8:578793. [PMID: 33102463 PMCID: PMC7556307 DOI: 10.3389/fbioe.2020.578793] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/08/2020] [Indexed: 11/30/2022] Open
Abstract
β-ionone is a commercially attractive industrial fragrance produced naturally from the cleavage of the pigment β-carotene in plants. While the production of this ionone is typically performed using chemical synthesis, environmentally friendly and consumer-oriented biotechnological production is gaining increasing attention. A convenient cell factory to address this demand is the yeast Saccharomyces cerevisiae. However, current β-ionone titers and yields are insufficient for commercial bioproduction. In this work, we optimized S. cerevisiae for the accumulation of high amounts of β-carotene and its subsequent conversion to β-ionone. For this task, we integrated systematically the heterologous carotenogenic genes (CrtE, CrtYB and CrtI) from Xanthophyllomyces dendrorhous using markerless genome editing CRISPR/Cas9 technology; and evaluated the transcriptional unit architecture (bidirectional or tandem), integration site, and impact of gene dosage, first on β-carotene accumulation, and later, on β-ionone production. A single-copy insertion of the carotenogenic genes in high expression loci of the wild-type yeast CEN.Pk2 strain yielded 4 mg/gDCW of total carotenoids, regardless of the transcriptional unit architecture employed. Subsequent fine-tuning of the carotenogenic gene expression enabled reaching 16 mg/gDCW of total carotenoids, which was further increased to 32 mg/gDCW by alleviating the known pathway bottleneck catalyzed by the hydroxymethylglutaryl-CoA reductase (HMGR1). The latter yield represents the highest total carotenoid concentration reported to date in S. cerevisiae for a constitutive expression system. For β-ionone synthesis, single and multiple copies of the carotene cleavage dioxygenase 1 (CCD1) gene from Petunia hybrida (PhCCD1) fused with a membrane destination peptide were expressed in the highest β-carotene-producing strains, reaching up to 33 mg/L of β-ionone in the culture medium after 72-h cultivation in shake flasks. Finally, interrogation of a contextualized genome-scale metabolic model of the producer strains pointed to PhCCD1 unspecific cleavage activity as a potentially limiting factor reducing β-ionone production. Overall, the results of this work constitute a step toward the industrial production of this ionone and, more broadly, they demonstrate that biotechnological production of apocarotenoids is technically feasible.
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Affiliation(s)
- Javiera López
- Centro de Aromas y Sabores, DICTUC S.A., Santiago, Chile
| | - Diego Bustos
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Conrado Camilo
- Centro de Aromas y Sabores, DICTUC S.A., Santiago, Chile
| | - Natalia Arenas
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pedro A Saa
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Agosin
- Centro de Aromas y Sabores, DICTUC S.A., Santiago, Chile.,Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
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Acevedo W, Cañón P, Gómez-Alvear F, Huerta J, Aguayo D, Agosin E. l-Malate (-2) Protonation State is Required for Efficient Decarboxylation to l-Lactate by the Malolactic Enzyme of Oenococcus oeni. Molecules 2020; 25:molecules25153431. [PMID: 32731627 PMCID: PMC7435853 DOI: 10.3390/molecules25153431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 11/22/2022] Open
Abstract
Malolactic fermentation (MLF) is responsible for the decarboxylation of l-malic into lactic acid in most red wines and some white wines. It reduces the acidity of wine, improves flavor complexity and microbiological stability. Despite its industrial interest, the MLF mechanism is not fully understood. The objective of this study was to provide new insights into the role of pH on the binding of malic acid to the malolactic enzyme (MLE) of Oenococcus oeni. To this end, sequence similarity networks and phylogenetic analysis were used to generate an MLE homology model, which was further refined by molecular dynamics simulations. The resulting model, together with quantum polarized ligand docking (QPLD), was used to describe the MLE binding pocket and pose of l-malic acid (MAL) and its l-malate (−1) and (−2) protonation states (MAL− and MAL2−, respectively). MAL2− has the lowest ∆Gbinding, followed by MAL− and MAL, with values of −23.8, −19.6, and −14.6 kJ/mol, respectively, consistent with those obtained by isothermal calorimetry thermodynamic (ITC) assays. Furthermore, molecular dynamics and MM/GBSA results suggest that only MAL2− displays an extended open conformation at the binding pocket, satisfying the geometrical requirements for Mn2+ coordination, a critical component of MLE activity. These results are consistent with the intracellular pH conditions of O. oeni cells—ranging from pH 5.8 to 6.1—where the enzymatic decarboxylation of malate occurs.
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Affiliation(s)
- Waldo Acevedo
- Institute of Chemistry, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile;
| | - Pablo Cañón
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile;
| | - Felipe Gómez-Alvear
- Center for Bioinformatics and Integrative Biology (CBIB), Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile; (F.G.-A.); (J.H.); (D.A.)
| | - Jaime Huerta
- Center for Bioinformatics and Integrative Biology (CBIB), Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile; (F.G.-A.); (J.H.); (D.A.)
| | - Daniel Aguayo
- Center for Bioinformatics and Integrative Biology (CBIB), Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile; (F.G.-A.); (J.H.); (D.A.)
- Interdisciplinary Center for Neuroscience of Valparaíso, Faculty of Science, University of Valparaíso, Valparaíso 2340000, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago 7810000, Chile;
- Correspondence: ; Tel.: +562-2354-4253
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Cataldo VF, Arenas N, Salgado V, Camilo C, Ibáñez F, Agosin E. Heterologous production of the epoxycarotenoid violaxanthin in Saccharomyces cerevisiae. Metab Eng 2020; 59:53-63. [PMID: 32001334 DOI: 10.1016/j.ymben.2020.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [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: 11/08/2019] [Revised: 12/16/2019] [Accepted: 01/18/2020] [Indexed: 12/28/2022]
Abstract
Microbial production of carotenoids has mainly focused towards a few products, such as β-carotene, lycopene and astaxanthin. However, other less explored carotenoids, like violaxanthin, have also shown unique properties and promissory applications. Violaxanthin is a plant-derived epoxidated carotenoid with strong antioxidant activity and a key precursor of valuable compounds, such as fucoxanthin and β-damascenone. In this study, we report for the first time the heterologous production of epoxycarotenoids in yeast. We engineered the yeast Saccharomyces cerevisiae following multi-level strategies for the efficient accumulation of violaxanthin. Starting from a β-carotenogenic yeast strain, we first evaluated the performance of several β-carotene hydroxylases (CrtZ), and zeaxanthin epoxidases (ZEP) from different species, together with their respective N-terminal truncated variants. The combined expression of CrtZ from Pantoea ananatis and truncated ZEP of Haematococcus lacustris showed the best performance and led to a yield of 1.6 mg/gDCW of violaxanthin. Further improvement of the epoxidase activity was achieved by promoting the transfer of reducing equivalents to ZEP by expressing several redox partner systems. The co-expression of the plant truncated ferredoxin-3, and truncated root ferredoxin oxidoreductase-1 resulted in a 2.2-fold increase in violaxanthin yield (3.2 mg/gDCW). Finally, increasing gene copy number of carotenogenic genes enabled reaching a final production of 7.3 mg/gDCW in shake flask cultures and batch bioreactors, which is the highest yield of microbially produced violaxanthin reported to date.
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Affiliation(s)
- Vicente F Cataldo
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile
| | - Natalia Arenas
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile
| | - Valeria Salgado
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile
| | - Conrado Camilo
- Centro de Aromas y Sabores, DICTUC S.A., Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile
| | - Francisco Ibáñez
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile; Centro de Aromas y Sabores, DICTUC S.A., Santiago, Chile, Postal Address: Av. Vicuña Mackenna 4860, 7820436, Santiago, Chile.
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Cataldo VF, Salgado V, Saa PA, Agosin E. Genomic integration of unclonable gene expression cassettes in Saccharomyces cerevisiae using rapid cloning-free workflows. Microbiologyopen 2020; 9:e978. [PMID: 31944620 PMCID: PMC7066455 DOI: 10.1002/mbo3.978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/22/2019] [Accepted: 11/22/2019] [Indexed: 11/11/2022] Open
Abstract
Most DNA assembly methods require bacterial amplification steps, which restrict its application to genes that can be cloned in the bacterial host without significant toxic effects. However, genes that cannot be cloned in bacteria do not necessarily exert toxic effects on the final host. In order to tackle this issue, we adapted two DNA assembly workflows for rapid, cloning-free construction and genomic integration of expression cassettes in Saccharomyces cerevisiae. One method is based on a modified Gibson assembly, while the other relies on a direct assembly and integration of linear PCR products by yeast homologous recombination. The methods require few simple experimental steps, and their performance was evaluated for the assembly and integration of unclonable zeaxanthin epoxidase expression cassettes in yeast. Results showed that up to 95% integration efficiency can be reached with minimal experimental effort. The presented workflows can be employed as rapid gene integration tools for yeast, especially tailored for integrating unclonable genes.
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Affiliation(s)
- Vicente F Cataldo
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Valeria Salgado
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pedro A Saa
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
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Torres P, Saa PA, Albiol J, Ferrer P, Agosin E. Contextualized genome-scale model unveils high-order metabolic effects of the specific growth rate and oxygenation level in recombinant Pichia pastoris. Metab Eng Commun 2019; 9:e00103. [PMID: 31720218 PMCID: PMC6838487 DOI: 10.1016/j.mec.2019.e00103] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/04/2019] [Accepted: 10/08/2019] [Indexed: 11/26/2022] Open
Abstract
Pichia pastoris is recognized as a biotechnological workhorse for recombinant protein expression. The metabolic performance of this microorganism depends on genetic makeup and culture conditions, amongst which the specific growth rate and oxygenation level are critical. Despite their importance, only their individual effects have been assessed so far, and thus their combined effects and metabolic consequences still remain to be elucidated. In this work, we present a comprehensive framework for revealing high-order (i.e., individual and combined) metabolic effects of the above parameters in glucose-limited continuous cultures of P. pastoris, using thaumatin production as a case study. Specifically, we employed a rational experimental design to calculate statistically significant metabolic effects from multiple chemostat data, which were later contextualized using a refined and highly predictive genome-scale metabolic model of this yeast under the simulated conditions. Our results revealed a negative effect of the oxygenation on the specific product formation rate (thaumatin), and a positive effect on the biomass yield. Notably, we identified a novel positive combined effect of both the specific growth rate and oxygenation level on the specific product formation rate. Finally, model predictions indicated an opposite relationship between the oxygenation level and the growth-associated maintenance energy (GAME) requirement, suggesting a linear GAME decrease of 0.56 mmol ATP/gDCW per each 1% increase in oxygenation level, which translated into a 44% higher metabolic cost under low oxygenation compared to high oxygenation. Overall, this work provides a systematic framework for mapping high-order metabolic effects of different culture parameters on the performance of a microbial cell factory. Particularly in this case, it provided valuable insights about optimal operational conditions for protein production in P. pastoris.
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Affiliation(s)
- Paulina Torres
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna, 4860, Santiago, Chile
| | - Pedro A Saa
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna, 4860, Santiago, Chile
| | - Joan Albiol
- Department of Chemical, Biological, and Environmental Engineering, Universitat Autònoma de Barcelona, 08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Pau Ferrer
- Department of Chemical, Biological, and Environmental Engineering, Universitat Autònoma de Barcelona, 08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna, 4860, Santiago, Chile
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López J, Cataldo VF, Peña M, Saa PA, Saitua F, Ibaceta M, Agosin E. Build Your Bioprocess on a Solid Strain-β-Carotene Production in Recombinant Saccharomyces cerevisiae. Front Bioeng Biotechnol 2019; 7:171. [PMID: 31380362 PMCID: PMC6656860 DOI: 10.3389/fbioe.2019.00171] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/03/2019] [Indexed: 11/19/2022] Open
Abstract
Robust fermentation performance of microbial cell factories is critical for successful scaling of a biotechnological process. From shake flask cultivations to industrial-scale bioreactors, consistent strain behavior is fundamental to achieve the production targets. To assert the importance of this feature, we evaluated the impact of the yeast strain design and construction method on process scalability -from shake flasks to bench-scale fed-batch fermentations- using two recombinant Saccharomyces cerevisiae strains capable of producing β-carotene; SM14 and βcar1.2 strains. SM14 strain, obtained previously from adaptive evolution experiments, was capable to accumulate up to 21 mg/gDCW of β-carotene in 72 h shake flask cultures; while the βcar1.2, constructed by overexpression of carotenogenic genes, only accumulated 5.8 mg/gDCW of carotene. Surprisingly, fed-batch cultivation of these strains in 1L bioreactors resulted in opposite performances. βcar1.2 strain reached much higher biomass and β-carotene productivities (1.57 g/L/h and 10.9 mg/L/h, respectively) than SM14 strain (0.48 g/L/h and 3.1 mg/L/h, respectively). Final β-carotene titers were 210 and 750 mg/L after 80 h cultivation for SM14 and βcar1.2 strains, respectively. Our results indicate that these substantial differences in fermentation parameters are mainly a consequence of the exacerbated Crabtree effect of the SM14 strain. We also found that the strategy used to integrate the carotenogenic genes into the chromosomes affected the genetic stability of strains, although the impact was significantly minor. Overall, our results indicate that shake flasks fermentation parameters are poor predictors of the fermentation performance under industrial-like conditions, and that appropriate construction designs and performance tests must be conducted to properly assess the scalability of the strain and the bioprocess.
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Affiliation(s)
- Javiera López
- Centro de Aromas and Sabores, DICTUC S.A., Santiago, Chile.,Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Vicente F Cataldo
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Manuel Peña
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pedro A Saa
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Maximiliano Ibaceta
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eduardo Agosin
- Centro de Aromas and Sabores, DICTUC S.A., Santiago, Chile.,Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
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Werner N, Ramirez-Sarmiento CA, Agosin E. Protein engineering of carotenoid cleavage dioxygenases to optimize β-ionone biosynthesis in yeast cell factories. Food Chem 2019; 299:125089. [PMID: 31319343 DOI: 10.1016/j.foodchem.2019.125089] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [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: 03/06/2019] [Revised: 06/24/2019] [Accepted: 06/26/2019] [Indexed: 10/26/2022]
Abstract
Synthesis of β-ionone in recombinant Saccharomyces cerevisiae is limited by the efficiency of Carotenoid Cleavage Dioxygenases (CCD), membrane-tethered enzymes catalyzing the last step in the pathway. We performed in silico design and membrane affinity analysis, focused on single-point mutations of PhCCD1 to improve membrane anchoring. The resulting constructs were tested in a β-carotene hyper-producing strain by comparing colony pigmentation against colonies transformed with native PhCCD1 and further analyzed by β-ionone quantification via RP-HPLC. Two single-point mutants increased β-ionone yields almost 3-fold when compared to native PhCCD1. We also aimed to improve substrate accessibility of PhCCD1 through the amino-terminal addition of membrane destination peptides directed towards the endoplasmic reticulum or plasma membrane. Yeast strains expressing peptide-PhCCD1 constructs showed β-ionone yields up to 4-fold higher than the strain carrying the native enzyme. Our results demonstrate that protein engineering of CCDs significantly increases the yield of β-ionone synthesized by metabolically engineered yeast.
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Affiliation(s)
- Nicole Werner
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
| | - César A Ramirez-Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile.
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11
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Saa PA, Cortés MP, López J, Bustos D, Maass A, Agosin E. Expanding Metabolic Capabilities Using Novel Pathway Designs: Computational Tools and Case Studies. Biotechnol J 2019; 14:e1800734. [DOI: 10.1002/biot.201800734] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/22/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Pedro A. Saa
- Departamento de Ingeniería Química y BioprocesosPontificia Universidad Católica de Chile Av. Vicuña Mackenna 4860 7820436 Santiago Chile
| | - María P. Cortés
- Centro de Modelamiento MatemáticoUniversidad de Chile Av. Beaucheff 851 Santiago 8370456 Chile
- Centro de Regulación del GenomaUniversidad de Chile Av. Beaucheff 851 Santiago 8370456 Chile
| | - Javiera López
- Centro de Aromas y SaboresDICTUC S.A Av. Vicuña Mackenna 4860 Santiago 7820436 Chile
| | - Diego Bustos
- Centro de Aromas y SaboresDICTUC S.A Av. Vicuña Mackenna 4860 Santiago 7820436 Chile
| | - Alejandro Maass
- Centro de Modelamiento MatemáticoUniversidad de Chile Av. Beaucheff 851 Santiago 8370456 Chile
- Departmento de Ingeniería MatemáticaUniversidad de Chile Av. Beaucheff 851 Santiago 8370456 Chile
| | - Eduardo Agosin
- Departamento de Ingeniería Química y BioprocesosPontificia Universidad Católica de Chile Av. Vicuña Mackenna 4860 7820436 Santiago Chile
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Acevedo W, Ramírez-Sarmiento CA, Agosin E. Identifying the interactions between natural, non-caloric sweeteners and the human sweet receptor by molecular docking. Food Chem 2018; 264:164-171. [DOI: 10.1016/j.foodchem.2018.04.113] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/03/2018] [Accepted: 04/25/2018] [Indexed: 11/16/2022]
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Acevedo W, Capitaine C, Rodríguez R, Araya-Durán I, González-Nilo F, Pérez-Correa JR, Agosin E. Selecting optimal mixtures of natural sweeteners for carbonated soft drinks through multi-objective decision modeling and sensory validation. J SENS STUD 2018. [DOI: 10.1111/joss.12466] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Waldo Acevedo
- Department of Chemical and Bioprocess Engineering; School of Engineering, Pontificia Universidad Católica de Chile; Santiago Chile
- Institute of Chemistry, Pontificia Universidad Católica de Valparaíso; Valparaíso Chile
| | | | | | - Ingrid Araya-Durán
- Universidad Andrés Bello; Faculty of Biological Sciences, Center for Bioinformatics and Integrative Biology; Santiago Chile
| | - Fernando González-Nilo
- Universidad Andrés Bello; Faculty of Biological Sciences, Center for Bioinformatics and Integrative Biology; Santiago Chile
| | - José R. Pérez-Correa
- Department of Chemical and Bioprocess Engineering; School of Engineering, Pontificia Universidad Católica de Chile; Santiago Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering; School of Engineering, Pontificia Universidad Católica de Chile; Santiago Chile
- Centro de Aromas y Sabores; DICTUC; Santiago Chile
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Schriever VA, Agosin E, Altundag A, Avni H, Cao Van H, Cornejo C, de Los Santos G, Fishman G, Fragola C, Guarneros M, Gupta N, Hudson R, Kamel R, Knaapila A, Konstantinidis I, Landis BN, Larsson M, Lundström JN, Macchi A, Mariño-Sánchez F, Martinec Nováková L, Mori E, Mullol J, Nord M, Parma V, Philpott C, Propst EJ, Rawan A, Sandell M, Sorokowska A, Sorokowski P, Sparing-Paschke LM, Stetzler C, Valder C, Vodicka J, Hummel T. Development of an International Odor Identification Test for Children: The Universal Sniff Test. J Pediatr 2018; 198:265-272.e3. [PMID: 29730147 DOI: 10.1016/j.jpeds.2018.03.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 03/05/2018] [Accepted: 03/07/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To assess olfactory function in children and to create and validate an odor identification test to diagnose olfactory dysfunction in children, which we called the Universal Sniff (U-Sniff) test. STUDY DESIGN This is a multicenter study involving 19 countries. The U-Sniff test was developed in 3 phases including 1760 children age 5-7 years. Phase 1: identification of potentially recognizable odors; phase 2: selection of odorants for the odor identification test; and phase 3: evaluation of the test and acquisition of normative data. Test-retest reliability was evaluated in a subgroup of children (n = 27), and the test was validated using children with congenital anosmia (n = 14). RESULTS Twelve odors were familiar to children and, therefore, included in the U-Sniff test. Children scored a mean ± SD of 9.88 ± 1.80 points out of 12. Normative data was obtained and reported for each country. The U-Sniff test demonstrated a high test-retest reliability (r27 = 0.83, P < .001) and enabled discrimination between normosmia and children with congenital anosmia with a sensitivity of 100% and specificity of 86%. CONCLUSIONS The U-Sniff is a valid and reliable method of testing olfaction in children and can be used internationally.
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Affiliation(s)
- Valentin A Schriever
- Smell and Taste Clinic, Department of Otorhinolaryngology, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany; Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany.
| | - Eduardo Agosin
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Hadas Avni
- Pediatric Feeding Disorders clinic, Dana Children's Hospital, Tel Aviv Medical Center, Tel Aviv, Israel
| | - Helene Cao Van
- Pediatric Otolaryngology Unit, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospitals of Geneva, Geneva, Switzerland
| | - Carlos Cornejo
- Escuela de Psicología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gonzalo de Los Santos
- Unidad de Rinología y Cirugía de Base de Cráneo. Servicio de Otorrinolaringología. Hospital Universitario Ramón y Cajal. Madrid, Spain
| | - Gad Fishman
- Pediatric Otolaryngology, Dana Children's Hospital, Tel-Aviv Medical Center, Sackler School of Medicine, Tel-Aviv, Israel
| | - Claudio Fragola
- Unidad de Rinología y Cirugía de Base de Cráneo. Servicio de Otorrinolaringología. Hospital Universitario Ramón y Cajal. Madrid, Spain
| | - Marco Guarneros
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico
| | - Neelima Gupta
- Department of Otorhinolaryngology, University College of Medical Sciences and GTB Hospital, Delhi, India
| | - Robyn Hudson
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico
| | - Reda Kamel
- Department of Otorhinolaryngology, Head and Neck Surgery, Cairo University, Cairo, Egypt
| | - Antti Knaapila
- Food Chemistry and Food Development, Department of Biochemistry, University of Turku, Turku, Finland; Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | | | - Basile N Landis
- Rhinology-Olfactology Unit, Department of Otorhinolaryngology Head and Neck Surgery, University Hospital of Geneva, Switzerland
| | - Maria Larsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Johan N Lundström
- Monell Chemical Senses Center, Philadelphia, PA; Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Alberto Macchi
- ORL Clinica, Università of Insubriae Varese, ASST Settelaghi, Varese, Italy
| | - Franklin Mariño-Sánchez
- Unidad de Rinología y Cirugía de Base de Cráneo. Servicio de Otorrinolaringología. Hospital Universitario Ramón y Cajal. Madrid, Spain; INGENIO, Immunoal.lèrgia Respiratòria Clínica i Experimental (IRCE), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERES, Barcelona, Catalonia, Spain
| | - Lenka Martinec Nováková
- Department of Anthropology, Faculty of Humanities, Charles University, Czech Republic; National Institute of Mental Health, Klecany, Czech Republic
| | - Eri Mori
- Department of Otorhinolaryngology, The Jikei University School of Medicine, Tokyo, Japan
| | - Joaquim Mullol
- INGENIO, Immunoal.lèrgia Respiratòria Clínica i Experimental (IRCE), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERES, Barcelona, Catalonia, Spain
| | - Marie Nord
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Valentina Parma
- Monell Chemical Senses Center, Philadelphia, PA; International School for Advanced Studies (SISSA), Neuroscience Area, Trieste, Italy
| | - Carl Philpott
- Smell and Taste Clinic, James Paget University Hospital, Gorleston, United Kingdom; Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Evan J Propst
- Department of Otolaryngology-Head & Neck Surgery, Hospital for Sick Children, University of Toronto, Canada
| | - Ahmed Rawan
- Department of Otorhinolaryngology, Head and Neck Surgery, Cairo University, Cairo, Egypt
| | - Mari Sandell
- Functional Foods Forum, University of Turku, Turku, Finland
| | - Agnieszka Sorokowska
- Smell and Taste Research Lab, Institute of Psychology, University of Wroclaw, Poland; Department of Psychotherapy and Psychosomatic Medicine, TU Dresden, Dresden, Germany
| | - Piotr Sorokowski
- Smell and Taste Research Lab, Institute of Psychology, University of Wroclaw, Poland
| | - Lisa-Marie Sparing-Paschke
- Smell and Taste Clinic, Department of Otorhinolaryngology, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - Carolin Stetzler
- Smell and Taste Clinic, Department of Otorhinolaryngology, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany
| | | | - Jan Vodicka
- Department of Otorhinolaryngology and Head and Neck Surgery, Pardubice Hospital, Faculty of Health Studies, University of Pardubice, Czech Republic
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany
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Rubat S, Varas I, Sepúlveda R, Almonacid D, González-Nilo F, Agosin E. Increasing the intracellular isoprenoid pool in Saccharomyces cerevisiae by structural fine-tuning of a bifunctional farnesyl diphosphate synthase. FEMS Yeast Res 2018; 17:3869469. [PMID: 28854674 DOI: 10.1093/femsyr/fox032] [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: 01/21/2017] [Accepted: 05/16/2017] [Indexed: 11/13/2022] Open
Abstract
Farnesyl diphosphate synthase (FPPS) is a key enzyme responsible for the supply of isoprenoid precursors for several essential metabolites, including sterols, dolichols and ubiquinone. In Saccharomyces cerevisiae, FPPS catalyzes the sequential condensation of two molecules of isopentenyl diphosphate (IPP) with dimethylallyl diphosphate (DMAPP), producing geranyl diphosphate (GPP) and farnesyl diphosphate (FPP). Critical amino acid residues that determine product chain length were determined by a comparative study of strict GPP synthases versus strict FPPS. In silico ΔΔG, i.e. differential binding energy between a protein and two different ligands-of yeast FPPS mutants was evaluated, and F96, A99 and E165 residues were identified as key determinants for product selectivity. A99X variants were evaluated in vivo, S. cerevisiae strains carrying A99R and A99H variants showed significant differences on GPP concentrations and specific growth rates. The FPPS A99T variant produced unquantifiable amounts of FPP and no effect on GPP production was observed. Strains carrying A99Q, A99Y and A99K FPPS accumulated high amounts of DMAPP-IPP, with a decrease in GPP and FPP. Our results demonstrated the relevance of the first residue before FARM (First Aspartate Rich Motif) over substrate consumption and product specificity of S. cerevisiae FPPS in vivo. The presence of A99H significantly modified product selectivity and appeared to be relevant for GPP synthesis.
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Affiliation(s)
- Sebastián Rubat
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
| | - Ignacio Varas
- Center for Bioinformatics and Integrative Biology (CBIB), Universidad Andres Bello, Republica 239, Santiago 8370146, Chile
| | - Romina Sepúlveda
- Center for Bioinformatics and Integrative Biology (CBIB), Universidad Andres Bello, Republica 239, Santiago 8370146, Chile
| | - Daniel Almonacid
- Center for Bioinformatics and Integrative Biology (CBIB), Universidad Andres Bello, Republica 239, Santiago 8370146, Chile
| | - Fernando González-Nilo
- Center for Bioinformatics and Integrative Biology (CBIB), Universidad Andres Bello, Republica 239, Santiago 8370146, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
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16
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Contreras A, Ribbeck M, Gutiérrez GD, Cañon PM, Mendoza SN, Agosin E. Mapping the Physiological Response of Oenococcus oeni to Ethanol Stress Using an Extended Genome-Scale Metabolic Model. Front Microbiol 2018; 9:291. [PMID: 29545779 PMCID: PMC5838312 DOI: 10.3389/fmicb.2018.00291] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 02/07/2018] [Indexed: 11/13/2022] Open
Abstract
The effect of ethanol on the metabolism of Oenococcus oeni, the bacterium responsible for the malolactic fermentation (MLF) of wine, is still scarcely understood. Here, we characterized the global metabolic response in O. oeni PSU-1 to increasing ethanol contents, ranging from 0 to 12% (v/v). We first optimized a wine-like, defined culture medium, MaxOeno, to allow sufficient bacterial growth to be able to quantitate different metabolites in batch cultures of O. oeni. Then, taking advantage of the recently reconstructed genome-scale metabolic model iSM454 for O. oeni PSU-1 and the resulting experimental data, we determined the redistribution of intracellular metabolic fluxes, under the different ethanol conditions. Four growth phases were clearly identified during the batch cultivation of O. oeni PSU-1 strain, according to the temporal consumption of malic and citric acids, sugar and amino acids uptake, and biosynthesis rates of metabolic products - biomass, erythritol, mannitol and acetic acid, among others. We showed that, under increasing ethanol conditions, O. oeni favors anabolic reactions related with cell maintenance, as the requirements of NAD(P)+ and ATP increased with ethanol content. Specifically, cultures containing 9 and 12% ethanol required 10 and 17 times more NGAM (non-growth associated maintenance ATP) during phase I, respectively, than cultures without ethanol. MLF and citric acid consumption are vital at high ethanol concentrations, as they are the main source for proton extrusion, allowing higher ATP production by F0F1-ATPase, the main route of ATP synthesis under these conditions. Mannitol and erythritol synthesis are the main sources of NAD(P)+, countervailing for 51-57% of its usage, as predicted by the model. Finally, cysteine shows the fastest specific consumption rate among the amino acids, confirming its key role for bacterial survival under ethanol stress. As a whole, this study provides a global insight into how ethanol content exerts a differential physiological response in O. oeni PSU-1 strain. It will help to design better strategies of nutrient addition to achieve a successful MLF of wine.
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Affiliation(s)
- Angela Contreras
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Magdalena Ribbeck
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Guillermo D Gutiérrez
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pablo M Cañon
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Sebastián N Mendoza
- Mathomics, Center for Mathematical Modeling, Universidad de Chile, Santiago, Chile.,Center for Genome Regulation, Universidad de Chile, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
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Saitua F, Torres P, Pérez-Correa JR, Agosin E. Dynamic genome-scale metabolic modeling of the yeast Pichia pastoris. BMC Syst Biol 2017; 11:27. [PMID: 28222737 PMCID: PMC5320773 DOI: 10.1186/s12918-017-0408-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 02/09/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND Pichia pastoris shows physiological advantages in producing recombinant proteins, compared to other commonly used cell factories. This yeast is mostly grown in dynamic cultivation systems, where the cell's environment is continuously changing and many variables influence process productivity. In this context, a model capable of explaining and predicting cell behavior for the rational design of bioprocesses is highly desirable. Currently, there are five genome-scale metabolic reconstructions of P. pastoris which have been used to predict extracellular cell behavior in stationary conditions. RESULTS In this work, we assembled a dynamic genome-scale metabolic model for glucose-limited, aerobic cultivations of Pichia pastoris. Starting from an initial model structure for batch and fed-batch cultures, we performed pre/post regression diagnostics to ensure that model parameters were identifiable, significant and sensitive. Once identified, the non-relevant ones were iteratively fixed until a priori robust modeling structures were found for each type of cultivation. Next, the robustness of these reduced structures was confirmed by calibrating the model with new datasets, where no sensitivity, identifiability or significance problems appeared in their parameters. Afterwards, the model was validated for the prediction of batch and fed-batch dynamics in the studied conditions. Lastly, the model was employed as a case study to analyze the metabolic flux distribution of a fed-batch culture and to unravel genetic and process engineering strategies to improve the production of recombinant Human Serum Albumin (HSA). Simulation of single knock-outs indicated that deviation of carbon towards cysteine and tryptophan formation improves HSA production. The deletion of methylene tetrahydrofolate dehydrogenase could increase the HSA volumetric productivity by 630%. Moreover, given specific bioprocess limitations and strain characteristics, the model suggests that implementation of a decreasing specific growth rate during the feed phase of a fed-batch culture results in a 25% increase of the volumetric productivity of the protein. CONCLUSION In this work, we formulated a dynamic genome scale metabolic model of Pichia pastoris that yields realistic metabolic flux distributions throughout dynamic cultivations. The model can be calibrated with experimental data to rationally propose genetic and process engineering strategies to improve the performance of a P. pastoris strain of interest.
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Affiliation(s)
- Francisco Saitua
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
| | - Paulina Torres
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
| | - José Ricardo Pérez-Correa
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
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Salinas F, Rojas V, Delgado V, Agosin E, Larrondo LF. Optogenetic switches for light-controlled gene expression in yeast. Appl Microbiol Biotechnol 2017; 101:2629-2640. [DOI: 10.1007/s00253-017-8178-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 02/06/2023]
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C. Zuniga-Lopez M, Felipe Laurie V, Barriga-Gonzalez G, Folch-Cano C, Fuentes J, Agosin E, Olea-Azar C. Chemical and Biological Properties of Phenolics in Wine: Analytical Determinations and Health Benefits. CURR ORG CHEM 2017. [DOI: 10.2174/1385272821666161110112514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
Stevia is one of the sweeteners with the greatest consumer demand because of its natural origin and minimal calorie content. Steviol glycosides (SG) are the main active compounds present in the leaves of Stevia rebaudiana and are responsible for its sweetness. However, recent in vitro studies in HEK 293 cells revealed that SG specifically activate the hT2R4 and hT2R14 bitter taste receptors, triggering this mouth feel. The objective of this study was to characterize the interaction of SG with these two receptors at the molecular level. The results showed that SG have only one site for orthosteric binding to these receptors. The binding free energy (ΔGbinding) between the receptor and SG was negatively correlated with SG bitterness intensity, for both hT2R4 (r = -0.95) and hT2R14 (r = -0.89). We also determined, by steered molecular dynamics simulations, that the force required to extract stevioside from the receptors was greater than that required for rebaudioside A, in accordance with the ΔG values obtained by molecular docking. Finally, we identified the loop responsible for the activation by SG of both receptors. As a whole, these results contribute to a better understanding of the resulting off-flavor perception of these natural sweeteners in foods and beverages, allowing for better prediction, and control, of the resulting bitterness.
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Affiliation(s)
- Waldo Acevedo
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile , Avenida Vicuña Mackenna, 4860 Santiago, Chile
| | - Fernando González-Nilo
- Universidad Andrés Bello , Center for Bioinformatics and Integrative Biology, Faculty of Biological Sciences, Avenida República 239, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile , Avenida Vicuña Mackenna, 4860 Santiago, Chile
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Cataldo VF, López J, Cárcamo M, Agosin E. Chemical vs. biotechnological synthesis of C13-apocarotenoids: current methods, applications and perspectives. Appl Microbiol Biotechnol 2016; 100:5703-18. [PMID: 27154347 DOI: 10.1007/s00253-016-7583-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [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: 02/18/2016] [Revised: 04/23/2016] [Accepted: 04/26/2016] [Indexed: 11/30/2022]
Abstract
Apocarotenoids are natural compounds derived from the oxidative cleavage of carotenoids. Particularly, C13-apocarotenoids are volatile compounds that contribute to the aromas of different flowers and fruits and are highly valued by the Flavor and Fragrance industry. So far, the chemical synthesis of these terpenoids has dominated the industry. Nonetheless, the increasing consumer demand for more natural and sustainable processes raises an interesting opportunity for bio-production alternatives. In this regard, enzymatic biocatalysis and metabolically engineered microorganisms emerge as attractive biotechnological options. The present review summarizes promising bioengineering approaches with regard to chemical production methods for the synthesis of two families of C13-apocarotenoids: ionones/dihydroionones and damascones/damascenone. We discuss each method and its applicability, with a thorough comparative analysis for ionones, focusing on the production process, regulatory aspects, and sustainability.
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Affiliation(s)
- Vicente F Cataldo
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
| | - Javiera López
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
| | - Martín Cárcamo
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile.
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Pavez C, Agosin E, Steinhaus M. Odorant Screening and Quantitation of Thiols in Carmenere Red Wine by Gas Chromatography-Olfactometry and Stable Isotope Dilution Assays. J Agric Food Chem 2016; 64:3417-3421. [PMID: 27070203 DOI: 10.1021/acs.jafc.6b00411] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The sensory impact of thiols in Vitis vinifera 'Carmenere' red wines was evaluated. For this purpose, aroma extract dilution analysis was applied to the thiols isolated from a Carmenere red wine by affinity chromatography with a mercurated agarose gel. Results revealed the presence of four odorants, identified as 2-furanylmethanethiol, 3-sulfanylhexyl acetate, 3-sulfanyl-1-hexanol, and 2-methyl-3-sulfanyl-1-butanol, with the latter being described here for the first time in Carmenere red wines. Quantitation of the four thiols in the Carmenere wine screened by aroma extract dilution analysis and in three additional Carmenere wines by stable isotope dilution assays resulted in concentrations above the respective orthonasal odor detection threshold values. Triangle tests applied to wine model solutions with and without the addition of the four thiols showed significant differences, thus suggesting that the compounds do have the potential to influence the overall aroma of red wine.
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Affiliation(s)
- Carolina Pavez
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile , Avenida Vicuña Mackenna, 4860 Macul, Santiago, Chile
- Centro de Aromas y Sabores, DICTUC , Avenida Vicuña Mackenna, 4860 Macul, Santiago, Chile
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile , Avenida Vicuña Mackenna, 4860 Macul, Santiago, Chile
- Centro de Aromas y Sabores, DICTUC , Avenida Vicuña Mackenna, 4860 Macul, Santiago, Chile
| | - Martin Steinhaus
- Deutsche Forschungsanstalt für Lebensmittelchemie (German Research Center for Food Chemistry) , Lise-Meitner-Straße 34, 85354 Freising, Germany
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Latorre G, Besa P, Parodi CG, Ferrer V, Azocar L, Quirola M, Villarroel L, Miquel JF, Agosin E, Chianale J. Prevalence of lactose intolerance in Chile: a double-blind placebo study. Digestion 2015; 90:18-26. [PMID: 25096822 DOI: 10.1159/000363229] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 04/28/2014] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND STUDY AIMS Lactase non-persistence (LNP), or primary hypolactasia, is a genetic condition that mediates lactose malabsorption and can cause lactose intolerance. Here we report the prevalence of lactose intolerance in a double-blind placebo study. METHODS The LCT C>T-13910 variant was genotyped by RT-PCR in 121 volunteers and lactose malabsorption was assessed using the hydrogen breath test (HBT) after consuming 25 g of lactose. Lactose intolerance was assessed by scoring symptoms (SS) using a standardized questionnaire following challenge with a lactose solution or saccharose placebo. RESULTS The LNP genotype was observed in 57% of the volunteers, among whom 87% were HBT⁺. In the HBT⁺ group the median SS was 9 and in the HBT⁻ group the median SS was 3 (p < 0.001). No difference was observed in the SS when both groups were challenged with the placebo. The most common symptoms included audible bowel sounds, abdominal pain and meteorism. In the ROC curve analysis, an SS ≥ 6 demonstrated 72% sensitivity and 81% specificity for predicting a positive HBT. To estimate prevalence, lactose intolerance was defined as the presence of an SS ≥ 6 points after subtracting the placebo effect and 34% of the study population met this definition. CONCLUSIONS The LNP genotype was present in more than half of subjects evaluated and the observed prevalence of lactose intolerance was 34%.
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Affiliation(s)
- Gonzalo Latorre
- Medical Student, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
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López J, Essus K, Kim IK, Pereira R, Herzog J, Siewers V, Nielsen J, Agosin E. Production of β-ionone by combined expression of carotenogenic and plant CCD1 genes in Saccharomyces cerevisiae. Microb Cell Fact 2015; 14:84. [PMID: 26063466 PMCID: PMC4464609 DOI: 10.1186/s12934-015-0273-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 05/08/2015] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Apocarotenoids, like the C13-norisoprenoids, are natural compounds that contribute to the flavor and/or aroma of flowers and foods. They are produced in aromatic plants-like raspberries and roses-by the enzymatic cleavage of carotenes. Due to their pleasant aroma and flavour, apocarotenoids have high commercial value for the cosmetic and food industry, but currently their production is mainly assured by chemical synthesis. In the present study, a Saccharomyces cerevisiae strain that synthesizes the apocarotenoid β-ionone was constructed by combining integrative vectors and high copy number episomal vectors, in an engineered strain that accumulates FPP. RESULTS Integration of an extra copy of the geranylgeranyl diphosphate synthase gene (BTS1), together with the carotenogenic genes crtYB and crtI from the ascomycete Xanthophyllomyces dendrorhous, resulted in carotenoid producing cells. The additional integration of the carotenoid cleavage dioxygenase gene from the plant Petunia hybrida (PhCCD1) let to the production of low amounts of β-ionone (0.073 ± 0.01 mg/g DCW) and changed the color of the strain from orange to yellow. The expression of the crtYB gene from a high copy number plasmid in this former strain increased β-ionone concentration fivefold (0.34 ± 0.06 mg/g DCW). Additionally, the episomal expression of crtYB together with the PhCCD1 gene in the same vector resulted in a final 8.5-fold increase of β-ionone concentration (0.63 ± 0.02 mg/g DCW). Batch fermentations with this strain resulted in a final specific concentration of 1 mg/g DCW at 50 h, which represents a 15-fold increase. CONCLUSIONS An efficient β-ionone producing yeast platform was constructed by combining integrative and episomal constructs. By combined expression of the genes BTS1, the carotenogenic crtYB, crtI genes and the plant PhCCD1 gene-the highest β-ionone concentration reported to date by a cell factory was achieved. This microbial cell factory represents a starting point for flavor production by a sustainable and efficient process that could replace current methods.
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Affiliation(s)
- Javiera López
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile.
| | - Karen Essus
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile.
| | - Il-kwon Kim
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Bio R&D Center, Paikkwang Industrial Co. Ltd., 57 Oehang-4 gil, Gunsan, Korea.
| | - Rui Pereira
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden. .,Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, Braga, Portugal.
| | - Jan Herzog
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile.
| | - 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, 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, 412 96, Gothenburg, Sweden. .,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970, Hørsholm, Denmark.
| | - Eduardo Agosin
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile.
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Espinoza MI, Vincken JP, Sanders M, Castro C, Stieger M, Agosin E. Identification, quantification, and sensory characterization of steviol glycosides from differently processed Stevia rebaudiana commercial extracts. J Agric Food Chem 2014; 62:11797-11804. [PMID: 25393842 DOI: 10.1021/jf502878k] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Stevia rebaudiana is known for its sweet-tasting ent-kaurene diterpenoid glycosides. Several manufacturing strategies are currently employed to obtain Stevia sweeteners with the lowest possible off-flavors. The chemical composition of four commercial S. rebaudiana extracts, obtained by different technologies, was characterized using UHPLC-ESI-MS(n). The composition of one of the ethanol-crystallized extracts (EC2) was entirely rebaudioside A, whereas the enzymatically modified (EM) extract contained the lowest concentration of this compound (2.7 mg/100 mg). The membrane-purified (MP) extract had the highest content of minor natural steviol glycosides (23.7 mg/100 mg total extract) versus an average of 2.4 mg/100 mg total extract for the EC samples. Thirteen trained panelists evaluated sweetness, bitterness, licorice, and metallic attributes of all four extracts. The highest licorice intensity (p ≤ 0.05) was found for MP. Both samples EC1 and EC2, despite their different chemical compositions, showed no significant differences in sensory perception.
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Affiliation(s)
- María Inés Espinoza
- Centro de Aromas y Sabores, DICTUC S.A., Av. Vicuña Mackenna 4860, Macul, Santiago, Chile
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Sánchez BJ, Pérez-Correa JR, Agosin E. Construction of robust dynamic genome-scale metabolic model structures of Saccharomyces cerevisiae through iterative re-parameterization. Metab Eng 2014; 25:159-73. [DOI: 10.1016/j.ymben.2014.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/28/2014] [Accepted: 07/10/2014] [Indexed: 12/16/2022]
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Zúñiga MC, Pérez-Roa RE, Olea-Azar C, Laurie VF, Agosin E. Contribution of metals, sulfur-dioxide and phenolic compounds to the antioxidant capacity of Carménère wines. J Food Compost Anal 2014. [DOI: 10.1016/j.jfca.2014.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Prat L, Espinoza MI, Agosin E, Silva H. Identification of volatile compounds associated with the aroma of white strawberries (Fragaria chiloensis). J Sci Food Agric 2014; 94:752-9. [PMID: 24115051 DOI: 10.1002/jsfa.6412] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 09/12/2013] [Accepted: 09/20/2013] [Indexed: 05/23/2023]
Abstract
BACKGROUND Fragaria chiloensis (L.) Mill spp. chiloensis form chiloensis, is a strawberry that produces white fruits with unique aromas. This species, endemic to Chile, is one of the progenitors of Fragaria x ananassa Duch. In order to identify the volatile compounds that might be responsible for aroma, these were extracted, and analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O) and compared with sensory analyses. RESULTS Three methods of extraction were used: solvent-assisted evaporation (SAFE), headspace solid phase micro-extraction (HS-SPME) and liquid-liquid extraction (LLE). Ninety-nine volatile compounds were identified by GC-MS, of which 75 showed odor activity using GC-O. Based on the highest dilution factor (FD = 1000) and GC-O intensity ≥2, we determined 20 major compounds in white strawberry fruit that contribute to its aroma. We chose 51 compounds to be tested against their commercial standards. The identities were confirmed by comparison of their linear retention indices against the commercial standards. The aroma of white strawberry fruits was reconstituted with a synthetic mixture of most of these compounds. CONCLUSION The volatile profile of white strawberry fruit described as fruity, green-fresh, floral, caramel, sweet, nutty and woody will be a useful reference for future strawberry breeding programs.
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Affiliation(s)
- Loreto Prat
- Universidad de Chile, Facultad de Ciencias Agronómicas, Departamento de Producción Agrícola, Laboratorio de Genómica Funcional & Bioinformática, 8820808, La Pintana, Santiago, Chile
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Orellana M, Aceituno FF, Slater AW, Almonacid LI, Melo F, Agosin E. Metabolic and transcriptomic response of the wine yeast Saccharomyces cerevisiae strain EC1118 after an oxygen impulse under carbon-sufficient, nitrogen-limited fermentative conditions. FEMS Yeast Res 2014; 14:412-24. [PMID: 24387769 DOI: 10.1111/1567-1364.12135] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [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: 09/03/2013] [Revised: 12/09/2013] [Accepted: 12/29/2013] [Indexed: 11/27/2022] Open
Abstract
During alcoholic fermentation, Saccharomyces cerevisiae is exposed to continuously changing environmental conditions, such as decreasing sugar and increasing ethanol concentrations. Oxygen, a critical nutrient to avoid stuck and sluggish fermentations, is only discretely available throughout the process after pump-over operation. In this work, we studied the physiological response of the wine yeast S. cerevisiae strain EC1118 to a sudden increase in dissolved oxygen, simulating pump-over operation. With this aim, an impulse of dissolved oxygen was added to carbon-sufficient, nitrogen-limited anaerobic continuous cultures. Results showed that genes related to mitochondrial respiration, ergosterol biosynthesis, and oxidative stress, among other metabolic pathways, were induced after the oxygen impulse. On the other hand, mannoprotein coding genes were repressed. The changes in the expression of these genes are coordinated responses that share common elements at the level of transcriptional regulation. Beneficial and detrimental effects of these physiological processes on wine quality highlight the dual role of oxygen in 'making or breaking wines'. These findings will facilitate the development of oxygen addition strategies to optimize yeast performance in industrial fermentations.
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Affiliation(s)
- Marcelo Orellana
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Macul, Santiago, Chile
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Moenne MI, Saa P, Laurie VF, Pérez-Correa JR, Agosin E. Oxygen Incorporation and Dissolution During Industrial-Scale Red Wine Fermentations. FOOD BIOPROCESS TECH 2014. [DOI: 10.1007/s11947-014-1257-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Vergara-Salinas JR, Bulnes P, Zúñiga MC, Pérez-Jiménez J, Torres JL, Mateos-Martín ML, Agosin E, Pérez-Correa JR. Effect of pressurized hot water extraction on antioxidants from grape pomace before and after enological fermentation. J Agric Food Chem 2013; 61:6929-6936. [PMID: 23790192 DOI: 10.1021/jf4010143] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Grape pomace was extracted with pressurized hot water at laboratory scale before and after fermentation to explore the effects of fermentation and extraction temperature (50-200 °C) and time (5 and 30 min) on total extracted antioxidant levels and activity and to determine the content and recovery efficiency of main grape polyphenols, anthocyanins, and tannins. Fermented pomace yielded more total antioxidants (TAs), antioxidant activity, and tannins, than unfermented pomace but fewer anthocyanins. Elevating the extraction temperature increased TA extraction and antioxidant activity. Maximum anthocyanin extraction yields were achieved at 100 °C and at 150 °C for tannins and tannin-anthocyanin adducts. Using higher temperatures and longer extraction times resulted in a sharp decrease of polyphenol extraction yield. Relevant proanthocyanidin amounts were extracted only at 50 and 100 °C. Finally, TA recovery and activity were not directly related to the main polyphenol content when performing pressurized hot water grape pomace extraction.
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Affiliation(s)
- José R Vergara-Salinas
- Pontificia Universidad Católica de Chile, Department of Chemical and Bioprocesses Engineering, Santiago, Chile
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Vergara-Salinas JR, Pérez-Jiménez J, Torres JL, Agosin E, Pérez-Correa JR. Effects of temperature and time on polyphenolic content and antioxidant activity in the pressurized hot water extraction of deodorized thyme (Thymus vulgaris). J Agric Food Chem 2012; 60:10920-10929. [PMID: 23075096 DOI: 10.1021/jf3027759] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The effects of temperature (50-200 °C) and contact time (5-30 min) on the pressurized hot water extraction of deodorized thyme were explored for antioxidant activity, polyphenol profiles, and total antioxidants. Six not previously reported polyphenolic compounds were identified in thyme. An inverse correlation was found between the antioxidant activity and total antioxidants with the amount and diversity of polyphenols. The highest total extract yield and antioxidant activity were obtained at 200 °C, although maximum polyphenol extraction yields of hydroxycinnamic acids, flavones, flavonols/flavanones, and total polyphenols were detected at 100 °C and 5 min. Higher temperatures and longer exposure times reduced extract polyphenol diversity. Dihydroxyphenyllactic acid was the only phenolic compound for which extraction yield increased with temperature, probably as a product of the thermal degradation of rosmarinic acid. Consequently, for extracting phenolics from thyme, 100 °C and 5 min would be appropriate operating conditions, whereas antioxidant-active nonphenolic compounds were favored at higher temperatures and exposure times.
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Affiliation(s)
- José R Vergara-Salinas
- Department of Chemical and Bioprocesses Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago, Chile
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Mariotti M, Granby K, Fromberg A, Risum J, Agosin E, Pedreschi F. Furan occurrence in starchy food model systems processed at high temperatures: effect of ascorbic acid and heating conditions. J Agric Food Chem 2012; 60:10162-10169. [PMID: 22985355 DOI: 10.1021/jf3022699] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Furan, a potential carcinogen, has been detected in highly consumed starchy foods, such as bread and snacks; however, research on furan generation in these food matrixes has not been undertaken, thus far. The present study explored the effect of ascorbic acid addition and cooking methods (frying and baking) over furan occurrence and its relation with the non-enzymatic browning in a wheat flour starchy food model system. Results showed that furan generation significantly increased in the presence of ascorbic acid after 7 min of heating (p < 0.05). The strongest effect was observed for baked products. Additionally, the furan content in fried products increased with the increase of the oil uptake levels. As for Maillard reactions, in general, the furan level in all samples linearly correlated with their degree of non-enzymatic browning, represented by L* and a* color parameters (e.g., wheat flour baked samples showed a R(2) of 0.88 and 0.87 for L* and a*, respectively), when the sample moisture content decreased during heating.
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Affiliation(s)
- María Mariotti
- Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile (PUC) , Box 306, 6904411 Santiago, Chile
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Vargas FA, Pizarro F, Pérez-Correa JR, Agosin E. Expanding a dynamic flux balance model of yeast fermentation to genome-scale. BMC Syst Biol 2011; 5:75. [PMID: 21595919 PMCID: PMC3118138 DOI: 10.1186/1752-0509-5-75] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Accepted: 05/19/2011] [Indexed: 12/03/2022]
Abstract
Background Yeast is considered to be a workhorse of the biotechnology industry for the production of many value-added chemicals, alcoholic beverages and biofuels. Optimization of the fermentation is a challenging task that greatly benefits from dynamic models able to accurately describe and predict the fermentation profile and resulting products under different genetic and environmental conditions. In this article, we developed and validated a genome-scale dynamic flux balance model, using experimentally determined kinetic constraints. Results Appropriate equations for maintenance, biomass composition, anaerobic metabolism and nutrient uptake are key to improve model performance, especially for predicting glycerol and ethanol synthesis. Prediction profiles of synthesis and consumption of the main metabolites involved in alcoholic fermentation closely agreed with experimental data obtained from numerous lab and industrial fermentations under different environmental conditions. Finally, fermentation simulations of genetically engineered yeasts closely reproduced previously reported experimental results regarding final concentrations of the main fermentation products such as ethanol and glycerol. Conclusion A useful tool to describe, understand and predict metabolite production in batch yeast cultures was developed. The resulting model, if used wisely, could help to search for new metabolic engineering strategies to manage ethanol content in batch fermentations.
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Affiliation(s)
- Felipe A Vargas
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Casilla, Correo, Santiago CHILE
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Molina AM, Guadalupe V, Varela C, Swiegers JH, Pretorius IS, Agosin E. Differential synthesis of fermentative aroma compounds of two related commercial wine yeast strains. Food Chem 2009. [DOI: 10.1016/j.foodchem.2009.03.116] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Urtubia A, Pérez-correa JR, Pizarro F, Agosin E. Exploring the applicability of MIR spectroscopy to detect early indications of wine fermentation problems. Food Control 2008. [DOI: 10.1016/j.foodcont.2007.04.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
The yeast Saccharomyces cerevisiae is an important industrial microorganism. Nowadays, it is being used as a cell factory for the production of pharmaceuticals such as insulin, although this yeast has long been utilized in the bakery to raise dough, and in the production of alcoholic beverages, fermenting the sugars derived from rice, wheat, barley, corn and grape juice. S. cerevisiae has also been extensively used as a model eukaryotic system. In the last decade, genomic techniques have revealed important features of its molecular biology. For example, DNA array technologies are routinely used for determining gene expression levels in cells under different physiological conditions or environmental stimuli. Laboratory strains of S. cerevisiae are different from wine strains. For instance, laboratory yeasts are unable to completely transform all the sugar in the grape must into ethanol under winemaking conditions. In fact, standard culture conditions are usually very different from winemaking conditions, where multiple stresses occur simultaneously and sequentially throughout the fermentation. The response of wine yeasts to these stimuli differs in some aspects from laboratory strains, as suggested by the increasing number of studies in functional genomics being conducted on wine strains. In this paper we review the most recent applications of post-genomic techniques to understand yeast physiology in the wine industry. We also report recent advances in wine yeast strain improvement and propose a reference framework for integration of genomic information, bioinformatic tools and molecular biology techniques for cellular and metabolic engineering. Finally, we discuss the current state and future perspectives for using 'modern' biotechnology in the wine industry.
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Affiliation(s)
- Francisco Pizarro
- Department of Chemical and Bioprocess Engineering, College of Engineering, Pontificia Universidad Católica de Chile, Casilla 306, Correo 22, Santiago, Chile
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Pizarro F, Varela C, Martabit C, Bruno C, Pérez-Correa JR, Agosin E. Coupling kinetic expressions and metabolic networks for predicting wine fermentations. Biotechnol Bioeng 2008; 98:986-98. [PMID: 17497743 DOI: 10.1002/bit.21494] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Problematic fermentations are commonplace and cause wine industry producers substantial economic losses through wasted tank capacity and low value final products. Being able to predict such fermentations would enable enologists to take preventive actions. In this study we modeled sugar uptake kinetics and coupled them to a previously developed stoichiometric model, which describes the anaerobic metabolism of Saccharomyces cerevisiae. The resulting model was used to predict normal and slow fermentations under winemaking conditions. The effects of fermentation temperature and initial nitrogen concentration were modeled through an efficiency factor incorporated into the sugar uptake expressions. The model required few initial parameters to successfully reproduce glucose, fructose, and ethanol profiles of laboratory and industrial fermentations. Glycerol and biomass profiles were successfully predicted in nitrogen rich cultures. The time normal or slow wine fermentations needed to complete the process was predicted accurately, at different temperatures. Simulations with a model representing a genetically modified yeast fermentation, reproduced qualitatively well literature results regarding the formation of minor compounds involved in wine complexity and aroma. Therefore, the model also proves useful to explore the effects of genetic modifications on fermentation profiles.
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Affiliation(s)
- Francisco Pizarro
- Departamento de Ingeniería Química y Bioprocesos, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
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Fernández K, Labarca X, Bordeu E, Guesalaga A, Agosin E. Comparative study of wine tannin classification using Fourier transform mid-infrared spectrometry and sensory analysis. Appl Spectrosc 2007; 61:1163-1167. [PMID: 18028694 DOI: 10.1366/000370207782597120] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Wine tannins are fundamental to the determination of wine quality. However, the chemical and sensorial analysis of these compounds is not straightforward and a simple and rapid technique is necessary. We analyzed the mid-infrared spectra of white, red, and model wines spiked with known amounts of skin or seed tannins, collected using Fourier transform mid-infrared (FT-MIR) transmission spectroscopy (400-4000 cm(-1)). The spectral data were classified according to their tannin source, skin or seed, and tannin concentration by means of discriminant analysis (DA) and soft independent modeling of class analogy (SIMCA) to obtain a probabilistic classification. Wines were also classified sensorially by a trained panel and compared with FT-MIR. SIMCA models gave the most accurate classification (over 97%) and prediction (over 60%) among the wine samples. The prediction was increased (over 73%) using the leave-one-out cross-validation technique. Sensory classification of the wines was less accurate than that obtained with FT-MIR and SIMCA. Overall, these results show the potential of FT-MIR spectroscopy, in combination with adequate statistical tools, to discriminate wines with different tannin levels.
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Affiliation(s)
- Katherina Fernández
- Department of Chemical Engineering and Bio-Processes, Pontificia Universidad Católica de Chile, Santiago, Chile
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Abstract
Tannin content and composition are critical quality components of red wines. No spectroscopic method assessing these phenols in wine has been described so far. We report here a new method using Fourier transform mid-infrared (FT-MIR) spectroscopy and chemometric techniques for the quantitative analysis of red wine tannins. Calibration models were developed using protein precipitation and phloroglucinolysis as analytical reference methods. After spectra preprocessing, six different predictive partial least-squares (PLS) models were evaluated, including the use of interval selection procedures such as iPLS and CSMWPLS. PLS regression with full-range (650-4000 cm(-1)), second derivative of the spectra and phloroglucinolysis as the reference method gave the most accurate determination for tannin concentration (RMSEC = 2.6%, RMSEP = 9.4%, r = 0.995). The prediction of the mean degree of polymerization (mDP) of the tannins also gave a reasonable prediction (RMSEC = 6.7%, RMSEP = 10.3%, r = 0.958). These results represent the first step in the development of a spectroscopic methodology for the quantification of several phenolic compounds that are critical for wine quality.
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Affiliation(s)
- Katherina Fernandez
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile
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Fernández K, Kennedy JA, Agosin E. Characterization of Vitis vinifera L. Cv. Carménère grape and wine proanthocyanidins. J Agric Food Chem 2007; 55:3675-80. [PMID: 17407309 DOI: 10.1021/jf063232b] [Citation(s) in RCA: 32] [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] [Indexed: 05/14/2023]
Abstract
A formal compositional study of the proanthocyanidins of Vitis vinifera L. cv. Carménère was conducted in this work. We first characterized the polymeric proanthocyanidins of Carménère skins, seeds, and wines. In addition, the wine astringency was analyzed and compared with Cabernet Sauvignon. Although Carménère wines had a higher proanthocyanidin concentration and mean degree of polymerization than Cabernet Sauvignon wines, the former wines were perceived as less astringent. The low seed/skin proportion in Carménère wines as compared to other varieties, as evidenced by the reduced number of seeds per berry and the higher amount of epigallocatechin subunits of Carménère wine proanthocyanidins, could explain this apparent paradox.
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Affiliation(s)
- Katherina Fernández
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile
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Carpinelli J, Krämer R, Agosin E. Metabolic engineering of Corynebacterium glutamicum for trehalose overproduction: role of the TreYZ trehalose biosynthetic pathway. Appl Environ Microbiol 2006; 72:1949-55. [PMID: 16517642 PMCID: PMC1393185 DOI: 10.1128/aem.72.3.1949-1955.2006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trehalose has many potential applications in biotechnology and the food industry due to its protective effect against environmental stress. Our work explores microbiological production methods based on the capacity of Corynebacterium glutamicum to excrete trehalose. We address here raising trehalose productivity through homologous overexpression of maltooligosyltrehalose synthase and the maltooligosyltrehalose trehalohydrolase genes. In addition, heterologous expression of the UDP-glucose pyrophosphorylase gene from Escherichia coli improved the supply of glycogen. Gene expression effects were tested on enzymatic activities and intracellular glycogen content, as well as on accumulated and excreted trehalose. Overexpression of the treY gene and the treY/treZ synthetic operon significantly increased maltooligosyltrehalose synthase activity, the rate-limiting step, and improved the specific productivity and the final titer of trehalose. Furthermore, a strong decrease was noted in glycogen accumulation. Expression of galU/treY and galU/treYZ synthetic operons showed a partial recovery in the intracellular glycogen levels and a significant improvement in both intra- and extracellular trehalose content.
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Affiliation(s)
- Jorge Carpinelli
- Departamento de Ingeniería Química y Bioprocesos, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile, Institut für Biochemie, Universität zu Köln, Cologne, Germany
| | - Reinhard Krämer
- Departamento de Ingeniería Química y Bioprocesos, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile, Institut für Biochemie, Universität zu Köln, Cologne, Germany
| | - Eduardo Agosin
- Departamento de Ingeniería Química y Bioprocesos, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile, Institut für Biochemie, Universität zu Köln, Cologne, Germany
- Corresponding author. Mailing address: Pontificia Universidad Católica de Chile, Casilla 306 Correo 22, Santiago, Chile. Phone: 562 354 49 27. Fax: 562 354 58 03. E-mail:
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Lillo MPY, Agosin E, Belancic A, Latrille E. Chemical Markers for Tracking the Sensory Contribution of Production Stages in Muscat Wine Distillates. J Food Sci 2005. [DOI: 10.1111/j.1365-2621.2005.tb11488.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Consumer perceptions of flavors are associated with the chemical composition of foods. However, consumer preferences change; therefore, it is necessary for food manufacturers to be able to adapt their products. Unlike in aged spirits, the chemical composition of young spirits is determined during distillation; therefore, this is where distillers must tailor their operating recipes to the new trends. Even for an experienced distiller, the complexity of the process makes adapting the operating recipe far from straightforward. In this study, we developed a methodology for generating practical recipes that makes use of computer simulations and optimization techniques. We used Pisco Brandy, a young Muscat wine distillate from Chile and Peru as our case study. Even so, because our methodology is independent of the chemical composition of the broth, it can be applied throughout the industry. Drawing on the experience and preferences of industry enologists, we designed a preferred distillate and used our methodology to obtain the appropriate recipe. This recipe was validated in lab scale experiments, and we obtained a much closer distillate to the desired prescription than commercial products.
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Affiliation(s)
- Daniel Osorio
- Departamento de Ingeniería Química y Bioprocesos, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
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Corona A, Sáez D, Agosin E. Effect of water activity on gibberellic acid production by Gibberella fujikuroi under solid-state fermentation conditions. Process Biochem 2005. [DOI: 10.1016/j.procbio.2004.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Padilla L, Agosin E. Heterologous expression of Escherichia coli ppsA (phosphoenolpyruvate synthetase) and galU (UDP-glucose pyrophosphorylase) genes in Corynebacterium glutamicum, and its impact on trehalose synthesis. Metab Eng 2005; 7:260-8. [PMID: 15949962 DOI: 10.1016/j.ymben.2005.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Revised: 03/14/2005] [Accepted: 04/05/2005] [Indexed: 11/25/2022]
Abstract
Trehalose is a disaccharide with a wide range of applications in the food industry. We recently proposed a strategy for trehalose production based on a Corynebacterium glutamicum strain expressing the Escherichia coli enzyme UDP-glucose pyrophosphorylase (GalU). Biochemical network analysis suggest a further bottleneck for trehalose synthesis resulting from the coupling of phosphotransferase (PTS) mediated glucose uptake, and glucose catabolism in C. glutamicum. To overcome this coupling, we propose the expression of E. coli phosphoenolpyruvate synthetase (PpsA), in addition to GalU expression, in C. glutamicum. Although GalU expression improved trehalose synthesis in C. glutamicum, the simultaneous expression of GalU and PpsA did not result in a further increase in trehalose yield, but resulted in an increased catabolic rate of glucose, which could be ascribed to the operation of a futile cycle between phosphoenolpyruvate and pyruvate. The impact of GalU and PpsA expression on polysaccharide content, side product excretion and metabolic fluxes is discussed, as well as alternative ways to decouple glucose uptake and catabolism, in order to increase trehalose yield.
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Affiliation(s)
- Leandro Padilla
- Departamento de Ingeniería Química y Bioprocesos, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
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Abstract
Wine fermentation is a dynamic and complex process in which the yeast cell is subjected to multiple stress conditions. A successful adaptation involves changes in gene expression profiles where a large number of genes are up- or downregulated. Functional genomic approaches are commonly used to obtain global gene expression profiles, thereby providing a comprehensive view of yeast physiology. We used SAGE to quantify gene expression profiles in an industrial strain of Saccharomyces cerevisiae under winemaking conditions. The transcriptome of wine yeast was analysed at three stages during the fermentation process, mid-exponential phase, and early- and late-stationary phases. Upon correlation with the yeast genome, we found three classes of transcripts: (a) sequences that corresponded to ORFs; (b) expressed sequences from intergenic regions; and (c) messengers that did not match the published reference yeast genome. In all fermentation phases studied, the most highly expressed genes related to energy production and stress response. For many pathways, including glycolysis, different transcript levels were observed during each phase. Different isoenzymes, including hexose transporters (HXT), were differentially induced, depending on the growth phase. About 10% of transcripts matched non-annotated ORF regions within the yeast genome and could correspond to small novel genes originally omitted in the first gene annotation effort. Up to 22% of transcripts, particularly at late-stationary phase, did not match any known location within the genome. As the available reference yeast genome was obtained from a laboratory strain, these expressed sequences could represent genes only expressed by an industrial yeast strain. Further studies are necessary to identify the role of these potential genes during wine fermentation.
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Affiliation(s)
- Cristian Varela
- Departamento de Ingeniería Química y Bioprocesos, Facultad de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
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