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Dianat M, Münchberg U, Blank LM, Freier E, Ebert BE. Non-invasive monitoring of microbial triterpenoid production using nonlinear microscopy techniques. Front Bioeng Biotechnol 2023; 11:1106566. [PMID: 36926686 PMCID: PMC10012247 DOI: 10.3389/fbioe.2023.1106566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/23/2023] [Indexed: 03/08/2023] Open
Abstract
Introduction: Bioproduction of plant-derived triterpenoids in recombinant microbes is receiving great attention to make these biologically active compounds industrially accessible as nutraceuticals, pharmaceutics, and cosmetic ingredients. So far, there is no direct method for detecting triterpenoids under physiological conditions on a cellular level, information yet highly relevant to rationalizing microbial engineering. Methods: Here, we show in a proof-of-concept study, that triterpenoids can be detected and monitored in living yeast cells by combining coherent anti-Stokes Raman scattering (CARS) and second-harmonic-generation (SHG) microscopy techniques. We applied CARS and SHG microscopy measurements, and for comparison classical Nile Red staining, on immobilized and growing triterpenoid-producing, and non-producing reference Saccharomyces cerevisiae strains. Results and Discussion: We found that the SHG signal in triterpenoid-producing strains is significantly higher than in a non-producing reference strain, correlating with lipophile content as determined by Nile red staining. In growing cultures, both CARS and SHG signals showed changes over time, enabling new insights into the dynamics of triterpenoid production and storage inside cells.
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Affiliation(s)
- Mariam Dianat
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Ute Münchberg
- University Development and Strategy, Ruhr University Bochum, Bochum, Germany
| | - Lars M Blank
- Institute of Applied Microbiology (iAMB), Aachen Biology and Biotechnology (ABBt), RWTH Aachen University, Aachen, Germany
| | - Erik Freier
- Interdisciplinary Center for Machine Learning and Data Analytics (IZMD), University of Wuppertal, Wuppertal, Germany
| | - Birgitta E Ebert
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
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2
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Karataş E, Tülek A, Çakar MM, Tamtürk F, Aktaş F, Binay B. From secretion in Pichia pastoris to application in apple juice processing: Exo-polygalacturonase from Sporothrix schenckii 1099-18. Protein Pept Lett 2021; 28:817-830. [PMID: 33413052 DOI: 10.2174/1871530321666210106110400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Polygalacturonases are a group of enzymes under pectinolytic enzymes related to enzymes that hydrolyse pectic substances. Polygalacturonases have been used in various industrial applications such as fruit juice clarification, retting of plant fibers, wastewater treatment drinks fermentation, and oil extraction. OBJECTIVES The study was evaluated at the heterologous expression, purification, biochemical characterization, computational modeling, and performance in apple juice clarification of a new exo-polygalacturonase from Sporothrix schenckii 1099-18 (SsExo-PG) in Pichia pastoris. METHODS Recombinant DNA technology was used in this study. Two different pPIC9K plasmids were constructed with native signal sequence-ssexo-pg and alpha signal sequence-ssexo-pg separately. Protein expression and purification performed after plasmids transformed into the Pichia pastoris. Biochemical and structural analyses were performed by using pure SsExo-PG. RESULTS The purification of SsExo-PG was achieved using a Ni-NTA chromatography system. The enzyme was found to have a molecular mass of approximately 52 kDa. SsExo-PG presented as stable at a wide range of temperature and pH values, and to be more storage stable than other commercial pectinolytic enzyme mixtures. Structural analysis revealed that the catalytic residues of SsExo-PG are somewhat similar to other Exo-PGs. The KM and kcat values for the degradation of polygalacturonic acid (PGA) by the purified enzyme were found to be 0.5868 µM and 179 s-1, respectively. Cu2+ was found to enhance SsExo-PG activity while Ag2+ and Fe2+ almost completely inhibited enzyme activity. The enzyme reduced turbidity up to 80% thus enhanced the clarification of apple juice. SsExo-PG showed promising performance when compared with other commercial pectinolytic enzyme mixtures. CONCLUSION The clarification potential of SsExo-PG was revealed by comparing it with commercial pectinolytic enzymes. The following parameters of the process of apple juice clarification processes showed that SsExo-PG is highly stable and has a novel performance.
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Affiliation(s)
- Ersin Karataş
- Department of Molecular Biology and Genetics, Gebze Technical University, Gebze 41400, Kocaeli. Turkey
| | - Ahmet Tülek
- Department of Molecular Biology and Genetics, Gebze Technical University, Gebze 41400, Kocaeli. Turkey
| | - Mehmet Mervan Çakar
- Department of Molecular Biology and Genetics, Gebze Technical University, Gebze 41400, Kocaeli. Turkey
| | - Faruk Tamtürk
- Döhler Food & Beverage Ingredients, 70100 Merkez, Karaman. Turkey
| | - Fatih Aktaş
- Department of Environment Engineering, Duzce University, Konuralp 81100, Düzce. Turkey
| | - Barış Binay
- Department of Bioengineering, Gebze Technical University, Gebze 41400, Kocaeli. Turkey
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3
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Cheng Z, Xian L, Chen D, Lu J, Wei Y, Du L, Wang Q, Chen Y, Lu B, Bi D, Zhang Z, Huang R. Development of an Innovative Process for High-Temperature Fruit Juice Extraction Using a Novel Thermophilic Endo-Polygalacturonase From Penicillium oxalicum. Front Microbiol 2020; 11:1200. [PMID: 32595621 PMCID: PMC7303257 DOI: 10.3389/fmicb.2020.01200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/12/2020] [Indexed: 11/30/2022] Open
Abstract
Efficient and cost-effective production of thermophilic endo-polygalacturonase is desirable for industrial fruit juice production, because its application could shorten the processing time and lower the production cost, by eliminating the separate step of pectin degradation. However, no endo-polygalacturonase that both functions well at sufficiently high temperature and can be manufactured economically, has been reported previously. In this study, the cDNA encoding a thermophilic endo-polygalacturonase from Penicillium oxalicum CZ1028, was cloned and over-expressed in Pichia pastoris GS115 and Escherichia coli BL21(DE3). The recombinant proteins PoxaEnPG28B-Pp (from P. pastoris) and PoxaEnPG28B-Ec (from E. coli) were isolated and purified. PoxaEnPG28B-Pp was sufficiently thermostable for potential industrial use, but PoxaEnPG28B-Ec was not. The optimal pH and temperature of PoxaEnPG28B-Pp were pH 5.0 and 65°C, respectively. The enzyme had a low Km of 1.82 g/L and a high Vmax of 77882.2 U/mg, with polygalacturonic acid (PGA) as substrate. The performance of PoxaEnPG28B-Pp in depectinization of papaya, plantain and banana juices at 65°C for 15 min was superior to that of a reported mesophilic endo-polygalacturonase. PoxaEnPG28B-Pp is the first endo-polygalacturonase reported to show excellent performance at high temperature. An innovative process, including a step of simultaneous heat-treatment and depectinization of fruit pulps with PoxaEnPG28B-Pp, is reported for the first time.
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Affiliation(s)
- Zhong Cheng
- College of Mechatronic and Quality Technology Engineering, Nanning University, Nanning, China.,State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Liang Xian
- National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Dong Chen
- National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Jian Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yutuo Wei
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Liqin Du
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Qingyan Wang
- National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Yunlai Chen
- School of Environment and Life Science, Nanning Normal University, Nanning, China
| | - Bo Lu
- National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Dewu Bi
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China.,National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Zhikai Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China.,National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Ribo Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China.,National Engineering Research Center for Non-food Biorefinery, State Key Laboratory of Non-food Biomass Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, Nanning, China
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4
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Microfluidic Irreversible Electroporation-A Versatile Tool to Extract Intracellular Contents of Bacteria and Yeast. Metabolites 2019; 9:metabo9100211. [PMID: 31574935 PMCID: PMC6835232 DOI: 10.3390/metabo9100211] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 02/06/2023] Open
Abstract
Exploring the dynamic behavior of cellular metabolism requires a standard laboratory method that guarantees rapid sampling and extraction of the cellular content. We propose a versatile sampling technique applicable to cells with different cell wall and cell membrane properties. The technique is based on irreversible electroporation with simultaneous quenching and extraction by using a microfluidic device. By application of electric pulses in the millisecond range, permanent lethal pores are formed in the cell membrane of Escherichia coli and Saccharomyces cerevisiae, facilitating the release of the cellular contents; here demonstrated by the measurement of glucose-6-phosphate and the activity of the enzyme glucose-6-phosphate dehydrogenase. The successful application of this device was demonstrated by pulsed electric field treatment in a flow-through configuration of the microfluidic chip in combination with sampling, inactivation, and extraction of the intracellular content in a few seconds. Minimum electric field strengths of 10 kV/cm for E. coli and 7.5 kV/cm for yeast S. cerevisiae were required for successful cell lysis. The results are discussed in the context of applications in industrial biotechnology, where metabolomics analyses are important.
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5
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Ebert BE, Czarnotta E, Blank LM. Physiologic and metabolic characterization of Saccharomyces cerevisiae reveals limitations in the synthesis of the triterpene squalene. FEMS Yeast Res 2019; 18:5056161. [PMID: 30053028 DOI: 10.1093/femsyr/foy077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/17/2018] [Indexed: 12/30/2022] Open
Abstract
Heterologous synthesis of triterpenoids in Saccharomyces cerevisiae from its native metabolite squalene has been reported to offer an alternative to chemical synthesis and extraction from plant material if productivities can be increased.Here, we physiologically characterized a squalene overproducing S. cerevisiae CEN.PK strain to elucidate the effect of cultivation conditions on the production of this central triterpenoid precursor. The maximum achievable squalene concentration was substantially influenced by nutritional conditions, medium composition and cultivation mode. Batch growth on glucose resulted in minimal squalene accumulation, while squalene only significantly accumulated during ethanol consumption (up to 59 mg/gCDW), probably due to increased acetyl-CoA supply on this carbon source. Likewise, low squalene concentrations were observed in glucose-limited chemostat cultivations and improved up to 8-fold upon increasing the ethanol fraction in the feed. In those experiments, a constant, growth-rate-independent specific squalene accumulation rate (2.2 mg/gCDW/h) was recorded resulting in a maximal squalene loading of 30 mg/gCDW at low dilution rates with longer residence times. Coenzyme A availability was identified as possible bottleneck as increased vitamin concentrations, including the Coenzyme A precursor pantothenate, improved squalene titers in batch and chemostat cultivations. This analysis demonstrates that thorough physiologic characterization of production strains is valuable for the identification of bottlenecks already in early stages of strain development and for guiding further optimization efforts.
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Affiliation(s)
- Birgitta E Ebert
- iAMB-Institute of Applied Microbiology, ABBt-Aachen Biology and Biotechnology, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany
| | - Eik Czarnotta
- iAMB-Institute of Applied Microbiology, ABBt-Aachen Biology and Biotechnology, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany
| | - Lars M Blank
- iAMB-Institute of Applied Microbiology, ABBt-Aachen Biology and Biotechnology, RWTH Aachen University, Worringer Weg 1, 52074 Aachen, Germany
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6
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Sawatzki A, Hans S, Narayanan H, Haby B, Krausch N, Sokolov M, Glauche F, Riedel SL, Neubauer P, Cruz Bournazou MN. Accelerated Bioprocess Development of Endopolygalacturonase-Production with Saccharomyces cerevisiae Using Multivariate Prediction in a 48 Mini-Bioreactor Automated Platform. Bioengineering (Basel) 2018; 5:E101. [PMID: 30469407 PMCID: PMC6316240 DOI: 10.3390/bioengineering5040101] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/09/2018] [Accepted: 11/14/2018] [Indexed: 01/04/2023] Open
Abstract
Mini-bioreactor systems enabling automatized operation of numerous parallel cultivations are a promising alternative to accelerate and optimize bioprocess development allowing for sophisticated cultivation experiments in high throughput. These include fed-batch and continuous cultivations with multiple options of process control and sample analysis which deliver valuable screening tools for industrial production. However, the model-based methods needed to operate these robotic facilities efficiently considering the complexity of biological processes are missing. We present an automated experiment facility that integrates online data handling, visualization and treatment using multivariate analysis approaches to design and operate dynamical experimental campaigns in up to 48 mini-bioreactors (8⁻12 mL) in parallel. In this study, the characterization of Saccharomyces cerevisiae AH22 secreting recombinant endopolygalacturonase is performed, running and comparing 16 experimental conditions in triplicate. Data-driven multivariate methods were developed to allow for fast, automated decision making as well as online predictive data analysis regarding endopolygalacturonase production. Using dynamic process information, a cultivation with abnormal behavior could be detected by principal component analysis as well as two clusters of similarly behaving cultivations, later classified according to the feeding rate. By decision tree analysis, cultivation conditions leading to an optimal recombinant product formation could be identified automatically. The developed method is easily adaptable to different strains and cultivation strategies, and suitable for automatized process development reducing the experimental times and costs.
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Affiliation(s)
- Annina Sawatzki
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | - Sebastian Hans
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | | | - Benjamin Haby
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | - Niels Krausch
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | - Michael Sokolov
- ETH Zürich, Rämistrasse 101, CH-8092 Zurich, Switzerland.
- DataHow AG, c/o ETH Zürich, HCl, F137, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland.
| | - Florian Glauche
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | - Sebastian L Riedel
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | - Peter Neubauer
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
| | - Mariano Nicolas Cruz Bournazou
- Department of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 71-76, ACK24, D-13355 Berlin, Germany.
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7
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Demuth I, Krebs SK, Dutrannoy V, Linke C, Krobitsch S, Varon R, Lang C, Raab A, Sperling K, Digweed M. Yeast XRS2 and human NBN gene: Experimental evidence for homology using codon optimized cDNA. PLoS One 2018; 13:e0207315. [PMID: 30440001 PMCID: PMC6237358 DOI: 10.1371/journal.pone.0207315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 10/28/2018] [Indexed: 11/19/2022] Open
Abstract
The genes, XRS2 in Saccharomyces cerevisiae and NBN in mammals, have little sequence identity at the amino acid level. Nevertheless, they are both found together with MRE11 and RAD50 in a highly conserved protein complex which functions in the repair of DNA double-strand breaks. Here, we have examined the evolutionary and functional relationship of these two genes by cross-complementation experiments. These experiments necessitated sequence correction for specific codon usage before they could be successfully conducted. We present evidence that despite extreme sequence divergence nibrin can, at least partially, replace Xrs2 in the cellular DNA damage response, and Xrs2 is able to promote nuclear localization of MRE11 in NBS cells. We discuss that the extreme sequence divergence reflects a unique adaptive pressure during evolution related to the specific eukaryotic role for both Xrs2 and nibrin in the subcellular localisation of the DNA repair complex. This, we suggest, is of particular relevance when cells are infected by viruses. The conflict hypothesis of co-evolution of DNA repair genes and DNA viruses may thus explain the very low sequence identity of these two homologous genes.
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Affiliation(s)
- Ilja Demuth
- Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Lipid Clinic at the Interdisciplinary Metabolism Center, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Medicine (BCRT), Charité University Medicine Berlin, Berlin, Germany
- * E-mail:
| | - Simon K. Krebs
- Institute of Biotechnology, Technical University Berlin, Berlin, Germany
| | - Véronique Dutrannoy
- Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Medical and Human Genetics, Berlin, Germany
| | - Christian Linke
- Otto Warburg Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Sylvia Krobitsch
- Otto Warburg Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Raymonda Varon
- Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Medical and Human Genetics, Berlin, Germany
| | | | | | - Karl Sperling
- Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Medical and Human Genetics, Berlin, Germany
| | - Martin Digweed
- Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Medical and Human Genetics, Berlin, Germany
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8
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Glauche F, Glazyrina J, Cruz Bournazou MN, Kiesewetter G, Cuda F, Goelling D, Raab A, Lang C, Neubauer P. Detection of growth rate-dependent product formation in miniaturized parallel fed-batch cultivations. Eng Life Sci 2017; 17:1215-1220. [PMID: 32624749 PMCID: PMC6999230 DOI: 10.1002/elsc.201600029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 04/28/2017] [Accepted: 07/24/2017] [Indexed: 12/22/2022] Open
Abstract
Saccharomyces cerevisiae is a popular expression system for recombinant proteins. In most cases, production processes are performed as carbon-limited fed-batch cultures to avoid aerobic ethanol formation. Especially for constitutive expression systems, the specific product formation rate depends on the specific growth rate. The development of optimal feeding strategies strongly depends on laboratory-scale cultivations, which are time and resource consuming, especially when continuous experiments are carried out. It is therefore beneficial for accelerated process development to look at alternatives. In this study, S. cerevisiae AH22 secreting a heterologous endo-polygalacturonase (EPG) was characterized in microwell plates with an enzyme-based fed-batch medium. Through variation of the glucose release rate, different growth profiles were established and the impact on EPG secretion was analyzed. Product formation rates of 200-400 U (gx h)-1 were determined. As a reference, bioreactor experiments using the change-stat cultivation technique were performed. The growth-dependent product formation was analyzed over dilution rates of D = 0.01-0.35 with smooth change of D at a rate of 0.003 h-2. EPG production was found to be comparable with a qp of 400 U (gx h)-1 at D = 0.27 h-1. The presented results indicate that parallel miniaturized fed-batch cultures can be applied to determine product formation profiles of putative production strains. With further automation and parallelization of the concept, strain characterization can be performed in shorter time.
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Affiliation(s)
- Florian Glauche
- Chair of Bioprocess EngineeringTechnische Universität BerlinBerlinGermany
| | - Julia Glazyrina
- Chair of Bioprocess EngineeringTechnische Universität BerlinBerlinGermany
| | | | | | - Fabian Cuda
- Chair of Bioprocess EngineeringTechnische Universität BerlinBerlinGermany
| | | | | | | | - Peter Neubauer
- Chair of Bioprocess EngineeringTechnische Universität BerlinBerlinGermany
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9
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Czarnotta E, Dianat M, Korf M, Granica F, Merz J, Maury J, Baallal Jacobsen SA, Förster J, Ebert BE, Blank LM. Fermentation and purification strategies for the production of betulinic acid and its lupane-type precursors in Saccharomyces cerevisiae. Biotechnol Bioeng 2017; 114:2528-2538. [DOI: 10.1002/bit.26377] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/02/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Eik Czarnotta
- iAMB-Institute of Applied Microbiology; ABBt-Aachen Biology and Biotechnology; RWTH Aachen University; Aachen Germany
| | - Mariam Dianat
- iAMB-Institute of Applied Microbiology; ABBt-Aachen Biology and Biotechnology; RWTH Aachen University; Aachen Germany
| | - Marcel Korf
- APT-Laboratory of Plant and Process Design; Department of Biochemical and Chemical Engineering; TU Dortmund University; Dortmund Germany
| | - Fabian Granica
- APT-Laboratory of Plant and Process Design; Department of Biochemical and Chemical Engineering; TU Dortmund University; Dortmund Germany
| | - Juliane Merz
- APT-Laboratory of Plant and Process Design; Department of Biochemical and Chemical Engineering; TU Dortmund University; Dortmund Germany
| | - Jérôme Maury
- Technical University of Denmark; Novo Nordisk Foundation Center for Biosustainability; Kgs. Lyngby Denmark
| | - Simo A. Baallal Jacobsen
- Technical University of Denmark; Novo Nordisk Foundation Center for Biosustainability; Kgs. Lyngby Denmark
| | - Jochen Förster
- Technical University of Denmark; Novo Nordisk Foundation Center for Biosustainability; Kgs. Lyngby Denmark
| | - Birgitta E. Ebert
- iAMB-Institute of Applied Microbiology; ABBt-Aachen Biology and Biotechnology; RWTH Aachen University; Aachen Germany
| | - Lars M. Blank
- iAMB-Institute of Applied Microbiology; ABBt-Aachen Biology and Biotechnology; RWTH Aachen University; Aachen Germany
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10
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Schmacht M, Lorenz E, Stahl U, Senz M. Medium optimization based on yeast's elemental composition for glutathione production in Saccharomyces cerevisiae. J Biosci Bioeng 2017; 123:555-561. [DOI: 10.1016/j.jbiosc.2016.12.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 01/27/2023]
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11
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Lorenz E, Runge D, Marbà-Ardébol AM, Schmacht M, Stahl U, Senz M. Systematic development of a two-stage fed-batch process for lipid accumulation in Rhodotorula glutinis. J Biotechnol 2017; 246:4-15. [DOI: 10.1016/j.jbiotec.2017.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 01/20/2017] [Accepted: 02/13/2017] [Indexed: 01/17/2023]
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12
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Herold S, Krämer D, Violet N, King R. Rapid process synthesis supported by a unified modular software framework. Eng Life Sci 2017; 17:1202-1214. [PMID: 32624748 DOI: 10.1002/elsc.201600020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 10/12/2016] [Accepted: 01/05/2017] [Indexed: 11/11/2022] Open
Abstract
Although known to be very powerful, the widespread application of model-based techniques is still significantly hampered in the area of bio-processes. Reasons for this situation can be found along the whole chain to set up and implement such approaches. In a time-consuming step, models are typically hand-crafted. Whether alternatives of better models exist to actually fulfill the final goals is undocumented, most often even unknown. In a next step, model-based process control methods are hand-coded in an error-prone procedure. For many of these methods given in the literature, only simulation studies are shown, leaving the interested reader with the unanswered question whether the implementation of a specific method in a real process is viable. As the potentially time-consuming implementation of such a method presents a risk for a rapid process development, promising candidates may be overlooked. To remediate this unsatisfactory situation, a combination of theoretical methods and information technology is proposed here. By an exemplarily realized software tool, it is shown how such an environment helps to promote model-based optimization, supervision, and control of bio-processes and allows for an inexpensive test of new ideas as well in real-life experiments. The contribution concentrates on an overview of a possible software architecture with respect to necessary methods and a meaningful information strategy, highlighting some of the more crucial building blocks. Experimental results exploiting parts of the proposed methods are given for a yeast strain synthesizing a product of industrial interest.
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Affiliation(s)
- Sebastian Herold
- Chair of Measurement and Control Technische Universität Berlin Berlin Germany
| | - Dominik Krämer
- Chair of Measurement and Control Technische Universität Berlin Berlin Germany
| | - Norman Violet
- Department Experimental Toxicology and ZEBET Federal Institute for Risk Assessment Berlin Germany
| | - Rudibert King
- Chair of Measurement and Control Technische Universität Berlin Berlin Germany
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Lorenz E, Schmacht M, Senz M. Evaluation of cysteine ethyl ester as efficient inducer for glutathione overproduction in Saccharomyces spp. Enzyme Microb Technol 2016; 93-94:122-131. [DOI: 10.1016/j.enzmictec.2016.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/13/2016] [Accepted: 08/05/2016] [Indexed: 01/23/2023]
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Lorenz E, Schmacht M, Stahl U, Senz M. Enhanced incorporation yield of cysteine for glutathione overproduction by fed-batch fermentation of Saccharomyces cerevisiae. J Biotechnol 2015; 216:131-9. [DOI: 10.1016/j.jbiotec.2015.10.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 10/08/2015] [Accepted: 10/19/2015] [Indexed: 02/07/2023]
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15
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Glauche F, John GT, Arain S, Knepper A, Neubauer A, Goelling D, Lang C, Violet N, King R, Neubauer P. Toward Microbioreactor Arrays. ACTA ACUST UNITED AC 2015; 20:438-46. [DOI: 10.1177/2211068215573924] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Indexed: 11/16/2022]
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16
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Patzschke A, Steiger MG, Holz C, Lang C, Mattanovich D, Sauer M. Enhanced glutathione production by evolutionary engineering of
Saccharomyces cerevisiae
strains. Biotechnol J 2015; 10:1719-26. [DOI: 10.1002/biot.201400809] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/23/2015] [Accepted: 04/21/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Anett Patzschke
- Department of Biotechnology, BOKU‐VIBT University of Natural Resources and Life Sciences, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Vienna, Austria
| | - Matthias G. Steiger
- Department of Biotechnology, BOKU‐VIBT University of Natural Resources and Life Sciences, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Vienna, Austria
| | | | | | - Diethard Mattanovich
- Department of Biotechnology, BOKU‐VIBT University of Natural Resources and Life Sciences, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Vienna, Austria
| | - Michael Sauer
- Department of Biotechnology, BOKU‐VIBT University of Natural Resources and Life Sciences, Vienna, Austria
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Vienna, Austria
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Pereira EO, Kolotilin I, Conley AJ, Menassa R. Production and characterization of in planta transiently produced polygalacturanase from Aspergillus niger and its fusions with hydrophobin or ELP tags. BMC Biotechnol 2014; 14:59. [PMID: 24970673 PMCID: PMC4083859 DOI: 10.1186/1472-6750-14-59] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 06/18/2014] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Pectinases play an important role in plant cell wall deconstruction and have potential in diverse industries such as food, wine, animal feed, textile, paper, fuel, and others. The demand for such enzymes is increasing exponentially, as are the efforts to improve their production and to implement their use in several industrial processes. The goal of this study was to examine the potential of producing polygalacturonase I from Aspergillus niger in plants and to investigate the effects of subcellular compartmentalization and protein fusions on its accumulation and activity. RESULTS Polygalacturonase I from Aspergillus niger (AnPGI) was transiently produced in Nicotiana benthamiana by targeting it to five different cellular compartments: apoplast, endoplasmic reticulum (ER), vacuole, chloroplast and cytosol. Accumulation levels of 2.5%, 3.0%, and 1.9% of total soluble protein (TSP) were observed in the apoplast, ER, and vacuole, respectively, and specific activity was significantly higher in vacuole-targeted AnPGI compared to the same enzyme targeted to the ER or apoplast. No accumulation was found for AnPGI when targeted to the chloroplast or cytosol. Analysis of AnPGI fused with elastin-like polypeptide (ELP) revealed a significant increase in the protein accumulation level, especially when targeted to the vacuole where the protein doubles its accumulation to 3.6% of TSP, while the hydrophobin (HFBI) fusion impaired AnPGI accumulation and both tags impaired activity, albeit to different extents. The recombinant protein showed activity against polygalacturonic acid with optimum conditions at pH 5.0 and temperature from 30 to 50°C, depending on its fusion. In vivo analysis of reducing sugar content revealed a higher release of reducing sugars in plant tissue expressing recombinant AnPGI compared to wild type N. benthamiana leaves. CONCLUSION Our results demonstrate that subcellular compartmentalization of enzymes has an impact on both the target protein accumulation and its activity, especially in the case of proteins that undergo post-translational modifications, and should be taken into consideration when protein production strategies are designed. Using plants to produce heterologous enzymes for the degradation of a key component of the plant cell wall could reduce the cost of biomass pretreatment for the production of cellulosic biofuels.
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Affiliation(s)
- Eridan Orlando Pereira
- Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3, Canada
- Department of Biology, Western University, London, ON N6A 5B7, Canada
- Current address: Universidade Estadual do Ceará, Av. Dr. Silas Munguba, 1700 - Campus do Itaperi, Fortaleza 60714-903, Brazil
| | - Igor Kolotilin
- Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3, Canada
| | | | - Rima Menassa
- Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3, Canada
- Department of Biology, Western University, London, ON N6A 5B7, Canada
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Shin GH, Veen M, Stahl U, Lang C. Overexpression of genes of the fatty acid biosynthetic pathway leads to accumulation of sterols in Saccharomyces cerevisiae. Yeast 2012; 29:371-83. [DOI: 10.1002/yea.2916] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 07/02/2012] [Accepted: 07/11/2012] [Indexed: 11/08/2022] Open
Affiliation(s)
| | | | - Ulf Stahl
- Technische Universität Berlin; Institut für Biotechnologie, FG Mikrobiologie und Genetik; Berlin; Germany
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Heterologous expression of polygalacturonase genes isolated from Galactomyces citri-aurantii IJ-1 in Pichia pastoris. J Microbiol 2012; 50:332-40. [PMID: 22538664 DOI: 10.1007/s12275-012-1290-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 01/04/2012] [Indexed: 10/28/2022]
Abstract
ABSTACT: The objective of this work was to isolate the polygalacturonase genes of Galactomyces citri-aurantii IJ-1 harvested from rotten citrus peels and to heterologously express these genes in Pichia pastoris. Two polygalacturonase (PG) genes from G. citri-aurantii IJ-1 were obtained and tentatively named PG1 and PG2. The genes were cloned into pPICZαC, and expressed in Pichia pastoris strain GS115 with a native signal peptide or the α-factor secretion signal peptide of Saccharomyces cerevisiae. All of the recombinant proteins were successfully secreted into the culture media and confirmed as a single band with a molecular weight of 35 to 38 kDa by SDS-PAGE. The specific enzyme activities of recombinant PG1 and PG2 purified by His-tag affinity resin were 4,749 and 6,719 U/mg, respectively, with an optimal pH and temperature of pH 4.0 and 50°C. The Michaelis-Menten kinetic constants for PG1 and PG2, K (m), were confirmed to be 0.94 and 0.84 mM, respectively. In the presence of Mn(2+), the activity of PG1 and PG2 were increased to 160.8 and 146.4% of normal levels, respectively. In contrast, Cu(2+) and Fe(3+) acted as strong inhibitors to the PGs.
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van Rensburg E, den Haan R, Smith J, van Zyl WH, Görgens JF. The metabolic burden of cellulase expression by recombinant Saccharomyces cerevisiae Y294 in aerobic batch culture. Appl Microbiol Biotechnol 2012; 96:197-209. [PMID: 22526794 DOI: 10.1007/s00253-012-4037-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/14/2012] [Accepted: 03/16/2012] [Indexed: 12/29/2022]
Abstract
Two recombinant strains of Saccharomyces cerevisiae Y294 producing cellulase using different expression strategies were compared to a reference strain in aerobic culture to evaluate the potential metabolic burden that cellulase expression imposed on the yeast metabolism. In a chemically defined mineral medium with glucose as carbon source, S. cerevisiae strain Y294[CEL5] with plasmid-borne cellulase genes produced endoglucanase and β-glucosidase activities of 0.038 and 0.30 U mg dry cell weight(-1), respectively. Chromosomal expression of these two cellulases in strain Y294[Y118p] resulted in no detectable activity, although low levels of episomally co-expressed cellobiohydrolase (CBH) activity were detected. Whereas the biomass concentration of strain Y294[CEL5] was slightly greater than that of a reference strain, CBH expression by Y294[Y118p] resulted in a 1.4-fold lower maximum specific growth rate than that of the reference. Supplementation of the growth medium with amino acids significantly improved culture growth and enzyme production, but only partially mitigated the physiological effects and metabolic burden of cellulase expression. Glycerol production was decreased significantly, up to threefold, in amino acid-supplemented cultures, apparently due to redox balancing. Disproportionately higher levels of glycerol production by Y294[CEL5] indicated a potential correlation between the redox balance of anabolism and the physiological stress of cellulase production. With the reliance on cellulase expression in yeast for the development of consolidated bioprocesses for bioethanol production, this work demonstrates the need for development of yeasts that are physiologically robust in response to burdens imposed by heterologous enzyme production.
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Affiliation(s)
- Eugéne van Rensburg
- Department of Process Engineering, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
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21
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Alimardani-Theuil P, Gainvors-Claisse A, Duchiron F. Yeasts: An attractive source of pectinases—From gene expression to potential applications: A review. Process Biochem 2011. [DOI: 10.1016/j.procbio.2011.05.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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22
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Shifting the fermentative/oxidative balance in Saccharomyces cerevisiae by transcriptional deregulation of Snf1 via overexpression of the upstream activating kinase Sak1p. Appl Environ Microbiol 2011; 77:1981-9. [PMID: 21257817 DOI: 10.1128/aem.02219-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
With the aim to reduce fermentation by-products and to promote respiratory metabolism by shifting the fermentative/oxidative balance, we evaluated the constitutive overexpression of the SAK1 and HAP4 genes in Saccharomyces cerevisiae. Sak1p is one of three kinases responsible for the phosphorylation, and thereby the activation, of the Snf1p complex, while Hap4p is the activator subunit of the Hap2/3/4/5 transcriptional complex. We compared the physiology of a SAK1-overexpressing strain with that of a strain overexpressing the HAP4 gene in wild-type and sdh2 deletion (respiratory-deficient) backgrounds. Both SAK1 and HAP4 overexpressions led to the upregulation of glucose-repressed genes and to reduced by-product formation rates (ethanol and glycerol). SAK1 overexpression had a greater impact on growth rates than did HAP4 overexpression. Elevated transcript levels of SAK1, but not HAP4, resulted in increased biomass yields in batch cultures grown on glucose (aerobic and excess glucose) as well as on nonfermentable carbon sources. SAK1 overexpression, but not the combined overexpression of SAK1 and HAP4 or the overexpression of HAP4 alone, restored growth on ethanol in an sdh2 deletion strain. In glucose-grown shake flask cultures, the sdh2 deletion strain with SAK1 and HAP4 overexpression produced succinic acid at a titer of 8.5 g liter(-1) and a yield of 0.26 mol (mol glucose)(-1) within 216 h. We here report for the first time that a constitutively high level of expression of SAK1 alleviates glucose repression and shifts the fermentative/oxidative balance under both glucose-repressed and -derepressed conditions.
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Raab AM, Gebhardt G, Bolotina N, Weuster-Botz D, Lang C. Metabolic engineering of Saccharomyces cerevisiae for the biotechnological production of succinic acid. Metab Eng 2010; 12:518-25. [DOI: 10.1016/j.ymben.2010.08.005] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 08/05/2010] [Accepted: 08/17/2010] [Indexed: 11/26/2022]
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Martín-Granados C, Riechers SP, Stahl U, Lang C. Absence of See1p, a widely conservedSaccharomyces cerevisiaeprotein, confers both deficient heterologous protein production and endocytosis. Yeast 2008; 25:871-7. [DOI: 10.1002/yea.1641] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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25
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Gasser B, Sauer M, Maurer M, Stadlmayr G, Mattanovich D. Transcriptomics-based identification of novel factors enhancing heterologous protein secretion in yeasts. Appl Environ Microbiol 2007; 73:6499-507. [PMID: 17766460 PMCID: PMC2075068 DOI: 10.1128/aem.01196-07] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Efficient production of heterologous proteins with yeasts and other eukaryotic hosts is often hampered by inefficient secretion of the product. Limitation of protein secretion has been attributed to a low folding rate, and a rational solution is the overexpression of proteins supporting folding, like protein disulfide isomerase (Pdi), or the unfolded protein response transcription factor Hac1. Assuming that other protein factors which are not directly involved in protein folding may also support secretion of heterologous proteins, we set out to analyze the differential transcriptome of a Pichia pastoris strain overexpressing human trypsinogen versus that of a nonexpressing strain. Five hundred twenty-four genes were identified to be significantly regulated. Excluding those genes with totally divergent functions (like, e.g., core metabolism), we reduced this number to 13 genes which were upregulated in the expression strain having potential function in the secretion machinery and in stress regulation. The respective Saccharomyces cerevisiae homologs of these genes, including the previously characterized secretion helpers PDI1, ERO1, SSO2, KAR2/BiP, and HAC1 as positive controls, were cloned and overexpressed in a P. pastoris strain expressing a human antibody Fab fragment. All genes except one showed a positive effect on Fab fragment secretion, as did the controls. Six out of these novel secretion helper factors, more precisely Bfr2 and Bmh2 (involved in protein transport), the chaperones Ssa4 and Sse1, the vacuolar ATPase subunit Cup5, and Kin2 (a protein kinase connected to exocytosis), proved their benefits for practical application in laboratory-scale production processes by increasing both specific production rates and the volumetric productivity of an antibody fragment up to 2.5-fold in fed-batch fermentations of P. pastoris.
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Affiliation(s)
- Brigitte Gasser
- Institute of Applied Microbiology, Department of Biotechnology, University of Natural Resources and Applied Life Sciences Vienna, Muthgasse 18, A-1190 Vienna, Austria
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26
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Hornbogen T, Riechers SP, Prinz B, Schultchen J, Lang C, Schmidt S, Mügge C, Turkanovic S, Süssmuth RD, Tauberger E, Zocher R. Functional Characterization of the RecombinantN-Methyltransferase Domain from the Multienzyme Enniatin Synthetase. Chembiochem 2007; 8:1048-54. [PMID: 17471480 DOI: 10.1002/cbic.200700076] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 51 kDa fusion protein incorporating the N-methyltransferase domain of the multienzyme enniatin synthetase from Fusarium scirpi was expressed in Saccharomyces cerevisiae. The protein was purified and found to bind S-adenosyl methionine (AdoMet) as demonstrated by cross-linking experiments with (14)C-methyl-AdoMet under UV irradiation. Cofactor binding at equilibrium conditions was followed by saturation transfer difference (STD) NMR spectroscopy, and the native conformation of the methyltransferase was assigned. STD NMR spectroscopy yielded significant signals for H(2) and H(8) of the adenine moiety, H(1') of D-ribose, and S-CH(3) group of AdoMet. Methyl group transfer catalyzed by the enzyme was demonstrated by using aminoacyl-N-acetylcysteamine thioesters (aminoacyl-SNACs) of L-Val, L-Ile, and L-Leu, which mimic the natural substrate amino acids of enniatin synthetase presented by the enzyme bound 4'-phosphopantetheine arm. In these experiments the enzyme was incubated in the presence of the corresponding aminoacyl-SNAC and (14)C-methyl-AdoMet for various lengths of time, for up to 30 min. N-[(14)C-Methyl]-aminoacyl-SNAC products were extracted with EtOAc and separated by TLC. Acid hydrolysis of the isolated labeled compounds yielded the corresponding N-[(14)C-methyl] amino acids. Further proof for the formation of N-(14)C-methyl-aminoacyl-SNACs came from MALDI-TOF mass spectrometry which yielded 23 212 Da for N-methyl-valyl-SNAC, accompanied by the expected postsource decay (PSD) pattern. Interestingly, L-Phe, which is not a substrate amino acid of enniatin synthetase, also proved to be a methyl group acceptor. D-Val was not accepted as a substrate; this indicates selectivity for the L isomer.
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Affiliation(s)
- Till Hornbogen
- Technische Universität Berlin, Fakultät II-Institut für Chemie, AG Biochemie und Molekulare Biologie, Franklinstrasse 29, 10997 Berlin, Germany
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27
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28
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Locatelli-Hoops S, Remmel N, Klingenstein R, Breiden B, Rossocha M, Schoeniger M, Koenigs C, Saenger W, Sandhoff K. Saposin A Mobilizes Lipids from Low Cholesterol and High Bis(monoacylglycerol)phosphate-containing Membranes. J Biol Chem 2006; 281:32451-60. [PMID: 16905746 DOI: 10.1074/jbc.m607281200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Saposin A (Sap-A) is one of five known sphingolipid activator proteins required for the lysosomal degradation of sphingolipids and for the loading of lipid antigens onto antigen-presenting molecules of the CD1 type. Sap-A assists in the degradation of galactosylceramide by galactosylceramide-beta-galactosidase in vivo, which takes place at the surface of intraendosomal/intralysosomal vesicles. Sap-A is believed to mediate the interaction between the enzyme and its membrane-bound substrate. Its dysfunction causes a variant form of Krabbe disease. In the present study we prepared glycosylated Sap-A free of other Saps, taking advantage of the Pichia pastoris expression system. Using liposomes and surface plasmon resonance spectroscopy, we tested the binding and lipid mobilization capacity of Sap-A under different conditions. Along the endocytic pathway, the pH value decreases, and the lipid composition of intraendosomal and intralysosomal membranes changes drastically. In the inner membranes the cholesterol concentration decreases, and that of the anionic phospholipid bis(monoacylglycero)phosphate increases. Here, we show that Sap-A is able to bind to liposomes and to mobilize lipids out of them at acidic pH values below pH 4.7. Low cholesterol levels and increasing concentrations of bis(monoacylglycero)phosphate favor lipid extraction significantly. Galactosylceramide as a bilayer component is not essential for lipid mobilization by Sap-A, which requires intact disulfide bridges for activity. We also show for the first time that glycosylation of Sap-A is essential for its lipid extraction activity. Variant Sap-A proteins, which cause storage of galactosylceramide in humans (Krabbe disease, Spiegel, R., Bach, G., Sury, V., Mengistu, G., Meidan, B., Shalev, S., Shneor, Y., Mandel, H., and Zeigler, M. (2005) Mol. Genet. Metab. 84, 160-166) and in mutant mice (Matsuda, J., Vanier, M. T., Saito, Y., Tohyama, J., and Suzuki, K. (2001) Hum. Mol. Genet. 10, 1191-1199) are deficient in lipid extraction capacity.
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Affiliation(s)
- Silvia Locatelli-Hoops
- Kekulé-Institut für Organische Chemie und Biochemie, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany
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Neukamm B, Weimann A, Wu S, Danevad M, Lang C, Gessner R. Novel two-stage screening procedure leads to the identification of a new class of transfection enhancers. J Gene Med 2006; 8:745-53. [PMID: 16532511 DOI: 10.1002/jgm.887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Non-viral gene transfer efficiency is low as compared to viral vector systems. Here we describe the discovery of new drugs that are capable of enhancing non-viral gene transfer into mammalian cells using a novel two-stage screening procedure. METHODS First, potential candidates are preselected from a molecular library at various concentrations by a semi-automated yeast transfection screen (YTS). The maximal transfection efficiency of every positive drug is subsequently determined in independent experiments at the optimal concentration and compared to the inhibitory effect of the drug on cell growth (IC50). In a subsequent mammalian cell transfection screen (MTS), the maximal transfection efficiency and the IC50 are determined for all preselected drugs using a human cell line and a luciferase reporter gene construct. RESULTS Employing our novel system we have been able to identify a new class of transfection enhancers, the tricyclic antidepressants (i.e. doxepin, maprotiline, desipramine and amoxapine). All positive drugs enhanced gene transfer in both yeast and human cell lines, but lower concentrations were sufficient for mammalian cells. With a triple combination of doxepin, amoxapine and chloroquine we obtained a transfection efficiency that exceeded that of chloroquine, one of the best-known transfection enhancers of mammalian cells, by nearly one order of magnitude. CONCLUSIONS Non-viral gene transfer efficiency can be increased significantly using new transfection enhancers that are identified by a novel, semi-automated two-stage screening system employing yeast cells in the first and specific human target cells in the second round.
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Affiliation(s)
- Birgit Neukamm
- Institute of Microbiology and Genetics, Technical University Berlin, Gustav-Meyer-Allee 25, D-13355 Berlin
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Fernández-González M, Ubeda JF, Cordero-Otero RR, Thanvanthri Gururajan V, Briones AI. Engineering of an oenological Saccharomyces cerevisiae strain with pectinolytic activity and its effect on wine. Int J Food Microbiol 2005; 102:173-83. [PMID: 15992616 DOI: 10.1016/j.ijfoodmicro.2004.12.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Revised: 12/27/2004] [Accepted: 12/29/2004] [Indexed: 11/20/2022]
Abstract
A pectinolytic industrial yeast strain of Saccharomyces cerevisiae was generated containing the S. cerevisiae endopolygalacturonase gene (PGU1) constitutively expressed under the control of the 3-phosphoglycerate kinase gene (PGK1) promoter. The new strain contains DNA derived exclusively from yeast and expresses a high polygalacturonic acid hydrolyzing activity. Yeast transformation was carried out by an integrative process targeting a dispensable upstream region of the acetolactate synthase locus (ILV2), which determines sulfometuron methyl resistance. Microvinification assays were performed on white and red musts with the transformed UCLMS-1M strain and with the same strain untransformed. It was found that the changes in the pectic polysaccharide contents did not directly affect the taste or flavor of the wine. From the data reported, it is deduced that the chief advantage of using the modified strain is that it improves the yield of must/wine extraction, while it also positively affects some variables relating to appearance.
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Affiliation(s)
- M Fernández-González
- Tecnología de Alimentos, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain
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Shimizu T, Shibata H, Araya T, Nakatsu T, Miyairi K, Okuno T, Kato H. Expression, purification, and crystallization of endopolygalacturonase from a pathogenic fungus, Stereum purpureum, in Escherichia coli. Protein Expr Purif 2005; 44:130-5. [PMID: 16061394 DOI: 10.1016/j.pep.2005.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 05/30/2005] [Accepted: 06/02/2005] [Indexed: 11/20/2022]
Abstract
Endopolygalacturonases (EC 3.2.1.15) catalyze random hydrolysis of the alpha-1,4 glycosidic linkages in polygalacturonic acid, a component of pectin. Previously, we reported crystal structures of endogenously produced Stereum purprureum endopolygalacturonase I (endoPG I), both in its native form and complexed with its product, galacturonate. However, the substrate-binding mechanism of endoPG I is still unclear, because crystals have not yet been obtained with a substrate analog, or with mutant enzymes that can bind substrates. We describe here an expression system using Escherichia coli and a purification method to prepare functionally active endoPG I for such mutation and crystallographic studies. Expression in E. coli strain Origami (DE3) provided a soluble and active enzyme with proper disulfide bond formation, whereas the enzyme expressed in BL21 (DE3) was localized in inclusion bodies. A sufficient amount of recombinant endoPG I produced by Origami (DE3) was purified by a single-step procedure using cation exchange chromatography. The specific activity of recombinant endoPG I was equivalent to that of the enzyme produced by S. purpureum. Recombinant endoPG I was crystallized under the same conditions as those used for the native enzyme produced by S. purpureum. The crystals diffracted beyond 1.0 A resolution with synchrotron radiation.
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Affiliation(s)
- Tetsuya Shimizu
- Kinetic Crystallography Research Team, Membrane Dynamics Research Group, RIKEN, Harima Institute at SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan
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Veen M, Stahl U, Lang C. Combined overexpression of genes of the ergosterol biosynthetic pathway leads to accumulation of sterols in. FEMS Yeast Res 2003; 4:87-95. [PMID: 14554200 DOI: 10.1016/s1567-1356(03)00126-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Genes of the post-squalene ergosterol biosynthetic pathway in Saccharomyces cerevisiae have been overexpressed in a systematic approach with the aim to construct yeast strains that produce high amounts of sterols from a squalene-accumulating strain. This strain had previously been deregulated by overexpressing a truncated HMG-CoA reductase (tHMG1) in the main bottleneck of the early ergosterol pathway. The overexpression of the gene ERG1 (squalene epoxidase) induced a significant decrease of the direct substrate squalene, a high increase of lanosterol, and a small increase of later sterols. The overexpression of the ERG11 gene encoding the sterol-14alpha-demethylase resulted in a decrease of lanosterol and an increase of downstream sterols. When these two genes were simultaneously overexpressed, later sterols from zymosterol to ergosterol accumulated and the content of squalene was decreased about three-fold, indicating that these steps had limited the transformation of squalene into sterols. The total sterol content in this strain was three-fold higher than in a wild-type strain.
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Affiliation(s)
- Markus Veen
- Technische Universität Berlin, Institut für Biotechnologie, FG Mikrobiologie und Genetik, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany
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33
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Gonzalez R, Andrews BA, Molitor J, Asenjo JA. Metabolic analysis of the synthesis of high levels of intracellular human SOD in Saccharomyces cerevisiae rhSOD 2060 411 SGA122. Biotechnol Bioeng 2003; 82:152-69. [PMID: 12584757 DOI: 10.1002/bit.10556] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The synthesis of human superoxide dismutase (SOD) in batch cultures of a Saccharomyces cerevisiae strain using a glucose-limited minimal medium was studied through metabolic flux analysis. A stoichiometric model was built, which included 78 reactions, according to metabolic pathways operative in these strains during respirofermentative and oxidative metabolism. It allowed calculation of the distribution of metabolic fluxes during diauxic growth on glucose and ethanol. Fermentation profiles and metabolic fluxes were analyzed at different phases of diauxic growth for the recombinant strain (P+) and for its wild type (P-). The synthesis of SOD by the strain P+ resulted in a decrease in specific growth rate of 34 and 54% (growth on glucose and ethanol respectively) in comparison to the wild type. Both strains exhibited similar flux of glucose consumption and ethanol synthesis but important differences in carbon distribution with biomass/substrate yields and ATP production 50% higher in P-. A higher contribution of fermentative metabolism, with 64% of the energy produced at the phosphorylation level, was observed during SOD production. The flux of precursors to amino acids and nucleotides was higher in the recombinant strain, in agreement with the higher total RNA and protein levels. Lower specific growth rates in strain P+ appear to be related to the decrease in the rate of synthesis of nonrecombinant protein, as well as a decrease in the activities of the pentose phosphate (PP) pathway and TCA cycle. A very different way of entry into the stationary phase was observed for each strain: in the wild-type strain most metabolic fluxes decreased and fluxes related to energy reserve synthesis increased, while in the P+ strain the flux of 22 reactions (including PP pathway and amino acids biosynthesis) related to SOD production increased their fluxes. Changes in SOD production rates at different physiological states appear to be related to the differences in building blocks availability between respirofermentative and oxidative metabolism. Using the present expression system, ideal conditions for SOD synthesis are represented by either active growth during respirofermentative metabolism or transition from a growing to a nongrowing state. An increase in SOD flux could be achieved using an expression system nonassociated to growth and potentially eliminating part of the metabolic burden.
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Affiliation(s)
- Ramon Gonzalez
- Department of Chemical Engineering, Millennium Institute for Advanced Studies In Cell Biology and Biotechnology, University of Chile, Beauchef 861, Santiago, Chile
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Boettner M, Prinz B, Holz C, Stahl U, Lang C. High-throughput screening for expression of heterologous proteins in the yeast Pichia pastoris. J Biotechnol 2002; 99:51-62. [PMID: 12204557 DOI: 10.1016/s0168-1656(02)00157-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The methylotrophic yeast Pichia pastoris has become a powerful host for the heterologous expression of proteins. In order to provide proteins for the 'protein structure factory', a structural genomics initiative, we are working on the high-throughput expression of human proteins. Therefore, cDNAs are cloned for intracellular expression. The resulting fusion proteins carry affinity tags (6*HIS and StrepII, respectively) at the N- and C-terminus for the immunological detection and chromatographic purification of full-length proteins. Expression is controlled by the tightly regulated and highly inducible alcoholoxidase 1 (AOX1) promoter. We have developed a cultivation and induction protocol amendable to automation to increase the number of clones screened for protein expression. The screening procedure is based on a culture volume of 2 ml in a 24-well format. Lysis of the cells occurs via a chemical lysis without mechanical disruption. Using the optimized feeding and induction protocol, we are now able to screen for and identify expression clones which produce heterologous protein with a yield of 5 mg l(-1) culture volume or higher.
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Affiliation(s)
- Mewes Boettner
- Proteinstrukturfabrik, Heubnerweg 6, D-14059 Berlin, Germany
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35
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Neukamm B, Stahl U, Lang C. Endocytosis is involved in DNA uptake in yeast. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1572:67-76. [PMID: 12204334 DOI: 10.1016/s0304-4165(02)00279-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The transfection of mammalian cells by endocytosis is frequently hampered by low efficiency. To identify the bottlenecks, a system that allows the analysis of the intracellular pathway of DNA along the endocytic compartments in the eukaryote Saccharomyces cerevisiae was developed. DNA uptake in yeast cells was achieved by endocytosis when the cells were incubated with episomal DNA in the presence of 34% sucrose and subsequently shifted to a hypotonic medium to induce osmotical lysis of accumulated endocytic intermediates. The compartments of the endocytic pathway after the intersection of the endocytic and the vacuolar sorting pathway are preferred sites of DNA degradation. Either a transport blockade before this point or, even better, the presence of chloroquine, which is known as an adjuvant for transfection in mammalian cells, are required for successful transfection. The transport blockade can be achieved by deleting a GTPase of the endocytic pathway, Ypt51p, or ethanol. Chloroquine affects the compartments of the late endocytic pathway, and no effect is seen on transfection in a strain that is defective for YPT51 and accumulates the DNA in the early endocytic intermediates. To our knowledge, this is the first report on endocytic DNA uptake in S. cerevisiae.
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Affiliation(s)
- Birgit Neukamm
- Department of Microbiology and Genetics, Institute for Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany
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36
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Holz C, Hesse O, Bolotina N, Stahl U, Lang C. A micro-scale process for high-throughput expression of cDNAs in the yeast Saccharomyces cerevisiae. Protein Expr Purif 2002; 25:372-8. [PMID: 12182816 DOI: 10.1016/s1046-5928(02)00029-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Methods have been developed aimed at applying at high-throughput technology for expression of cloned cDNAs in yeast. Yeast is a eukaryotic host, which produces soluble recombinant proteins and is capable of introducing post-translational modifications of protein. It is, thus, an appropriate expression system both for the routine expression of various cDNAs or protein domains and for the expression of proteins, which are not correctly expressed in Escherichia coli. Here, we describe a standard system in Saccharomyces cerevisiae, based on a vector for intracellular protein expression, where the gene products are fused to specific peptide sequences (tags). These epitope tags, the N-terminal His(6) tag and the C-terminal StrepII tag, allow subsequent immunological identification and purification of the gene products by a two-step affinity chromatography. This method of dual-tagged recombinant protein purification eliminates contamination by degraded protein products. A miniaturization of the procedures for cloning, expression, and detection was performed to allow all steps to be carried out in 96-well microtiter plates. The system is, thus, suitable for automation. We were able to analyze the simultaneous protein expression of a large number of cDNA clones due to the highly parallel approach of protein production and purification. The microtiter plate technology format was extended to quantitative analysis. An ELISA-based assay was developed that detects StrepII-tagged proteins. The application of this high-throughput expression system for protein production will be a useful tool for functional and structural analyses of novel genes, identified by the Human Genome Project and other large-scale sequencing projects.
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Affiliation(s)
- Caterina Holz
- Department of Microbiology and Genetics, Institute for Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany
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37
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de Vries RP, Visser J. Aspergillus enzymes involved in degradation of plant cell wall polysaccharides. Microbiol Mol Biol Rev 2001; 65:497-522, table of contents. [PMID: 11729262 PMCID: PMC99039 DOI: 10.1128/mmbr.65.4.497-522.2001] [Citation(s) in RCA: 542] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a more and more attractive alternative to chemical and mechanical processes. Over the past 15 years, much progress has been made in elucidating the structural characteristics of these polysaccharides and in characterizing the enzymes involved in their degradation and the genes of biotechnologically relevant microorganisms encoding these enzymes. The members of the fungal genus Aspergillus are commonly used for the production of polysaccharide-degrading enzymes. This genus produces a wide spectrum of cell wall-degrading enzymes, allowing not only complete degradation of the polysaccharides but also tailored modifications by using specific enzymes purified from these fungi. This review summarizes our current knowledge of the cell wall polysaccharide-degrading enzymes from aspergilli and the genes by which they are encoded.
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Affiliation(s)
- R P de Vries
- Molecular Genetics of Industrial Microorganisms, Wageningen University, 6703 HA Wageningen, The Netherlands.
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38
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Görgens JF, van Zyl WH, Knoetze JH, Hahn-Hägerdal B. The metabolic burden of the PGK1 and ADH2 promoter systems for heterologous xylanase production by Saccharomyces cerevisiae in defined medium. Biotechnol Bioeng 2001; 73:238-45. [PMID: 11257606 DOI: 10.1002/bit.1056] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Five recombinant S. cerevisiae strains were cultivated under identical conditions to quantify the molecular basis of the metabolic burden of heterologous gene expression, and to evaluate mechanisms for the metabolic burden. Two recombinant S. cerevisiae strains, producing Trichoderma reesei xylanase II under control of either the PGK1 or ADH2 promoters, were compared quantitatively with three references strains, where either the heterologous xylanase II (XYN2) gene, or the heterologous gene and the promoter and terminator were omitted from the recombinant plasmid. Neither the replication of multiple copies of the 2-microm-based YEp352 plasmid nor the replication the foreign XYN2 gene represented a metabolic burden to the cell, as the growth of the host organism was not affected. The inclusion of a glycolytic promoter on the recombinant plasmid, however, reduced the maximum specific growth rate (12% to 15%), biomass yield on glucose (8% to 11%), and specific glucose consumption rate (6% to 10%) of the recombinant strains. The presence of the heterologous XYN2 gene on the recombinant plasmid caused a further reduction in the maximum specific growth rate (11% to 14%), biomass yield (4%), and specific glucose consumption rate (12%) of the host strain during active gene expression, which was dictated by the regulatory characteristics of the promoter utilized. The metabolic effect of foreign gene expression was disproportionally large, with respect to on the amount of heterologous protein produced. This was most likely due to an increased energetic demand for the expression of a foreign gene and/or a competition for limiting amounts of transcription or translation factors, biosynthetic precursors or metabolic energy.
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Affiliation(s)
- J F Görgens
- Department of Applied Microbiology, Lund University, Box 124, S-221 00 Lund, Sweden
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39
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Nevoigt E, Fassbender A, Stahl U. Cells of the yeast Saccharomyces cerevisiae are transformable by DNA under non-artificial conditions. Yeast 2000; 16:1107-10. [PMID: 10953082 DOI: 10.1002/1097-0061(20000915)16:12<1107::aid-yea608>3.0.co;2-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Transformants of bakers' yeast (Saccharomyces cerevisiae) can be generated when non-growing cells metabolize sugars (without additional nutrients) in the presence of plasmid DNA. These results suggest that there is a mechanism by which DNA can naturally be taken up by the yeast cell. Natural transformation does not take place in common complete or minimal yeast culture media such as YPD and YNB. The starvation conditions used in our experiments thus seem to be an important prerequisite for such transformation events.
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Affiliation(s)
- E Nevoigt
- Institut für Biotechnologie, Fachgebiet Mikrobiologie und Genetik, Technische Universität Berlin, Seestrasse 13, D-13353 Berlin, Germany
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40
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Siekstele R, Bartkeviciute D, Sasnauskas K. Cloning, targeted disruption and heterologous expression of the Kluyveromyces marxianus endopolygalacturonase gene (EPG1). Yeast 1999; 15:311-22. [PMID: 10206190 DOI: 10.1002/(sici)1097-0061(19990315)15:4<311::aid-yea379>3.0.co;2-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The yeast Kluyveromyces marxianus strain BKM Y-719 produces an efficient pectin-degrading endopolygalacturonase (EPG) that cleaves the internal alpha-1,4-D-glycosidic linkages to yield oligomers of varying sizes. The EPG1 gene encoding this industrially important EPG was cloned by using the polymerase chain reaction (PCR) technique and degenerate primers to generate a 135 bp DNA fragment with which a genomic library was screened. The cloned fragment contained an open reading frame (ORF) of 1083 bp, encoding a 361 amino acid polypeptide. The predicted amino acid (aa) sequence of EPG showed similarity with polygalacturonases (PGs) of fungi. Analysis of the aa sequence indicated that the first 25 aa constitute a signal sequence and a motif (C218XGGHGXSIGSVG230) that is usually associated with a PG active site. Pulsed-field gel electrophoresis resolved chromosomal bands for K. marxianus BKM Y-719 and using chromoblotting it seems that EPG1 is present as only a single copy in the genome.
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Affiliation(s)
- R Siekstele
- Institute of Biotechnology, Vilnius, Lithuania.
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41
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Abstract
Enzymes from filamentous fungi are already widely exploited, but new applications for known enzymes and new enzymic activities continue to be found. In addition, enzymes from less amenable non-fungal sources require heterologous production and fungi are being used as the production hosts. In each case there is a need to improve production and to ensure quality of product. While conventional, mutagenesis-based, strain improvement methods will continue to be applied to enzyme production from filamentous fungi the application of recombinant DNA techniques is beginning to reveal important information on the molecular basis of fungal enzyme production and this knowledge is now being applied both in the laboratory and commercially. We review the current state of knowledge on the molecular basis of enzyme production by filamentous fungi. We focus on transcriptional and post-transcriptional regulation of protein production, the transit of proteins through the secretory pathway and the structure of the proteins produced including glycosylation.
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Affiliation(s)
- D B Archer
- Genetics and Microbiology Department, Institute of Food Research, Norwich, UK
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