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Christensen SJ, Madsen MS, Zinck SS, Hedberg C, Sørensen OB, Svensson B, Meyer AS. Bioinformatics and functional selection of GH77 4-α-glucanotransferases for potato starch modification. N Biotechnol 2024; 79:39-49. [PMID: 38097138 DOI: 10.1016/j.nbt.2023.12.002] [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] [Received: 07/29/2023] [Revised: 11/26/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023]
Abstract
4-α-glucanotransferases (4αGTs, EC 2.4.1.25) from glycoside hydrolase family 77 (GH77) catalyze chain elongation of starch amylopectin chains and can be utilized to structurally modify starch to tailor its gelation properties. The potential relationship between the structural design of 4αGTs and functional starch modification is unknown. Here, family GH77 was mined in silico for enzyme candidates based on sub-grouping guided by Conserved Unique Peptide Patterns (CUPP) bioinformatics categorization. From + 12,000 protein sequences a representative set of 27 4αGTs, representing four different domain architectures, different bacterial origins and diverse CUPP groups, was selected for heterologous expression and further study. Most of the enzymes catalyzed starch modification, but their efficacies varied substantially. Five of the 4αGTs were characterized in detail, and their action was compared to that of the industrial benchmark enzyme, Tt4αGT (CUPP 77_1.2), from Thermus thermophilus. Reaction optima of the five 4αGTs ranged from ∼40-60 °C and pH 7.3-9.0. Several were stable for a minimum 4 h at 70 °C. Domain architecture type A proteins, consisting only of a catalytic domain, had high thermal stability and high starch modification ability. All five novel 4αGTs (and Tt4αGT) induced enhanced gelling of potato starch. One, At4αGT from Azospirillum thermophilum (CUPP 77_2.4), displayed distinct starch modifying abilities, whereas T24αGT from Thermus sp. 2.9 (CUPP 77_1.2) modified the starch similarly to Tt4αGT, but slightly more effectively. T24αGT and At4αGT are thus interesting candidates for industrial starch modification. A model is proposed to explain the link between the 4αGT induced molecular modifications and macroscopic starch gelation.
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Affiliation(s)
- Stefan Jarl Christensen
- Protein Chemistry and Enzyme Technology, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark; KMC, Brande, Denmark
| | - Michael Schmidt Madsen
- Protein Chemistry and Enzyme Technology, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Signe Schram Zinck
- Protein Chemistry and Enzyme Technology, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark; KMC, Brande, Denmark
| | | | | | - Birte Svensson
- Protein Chemistry and Enzyme Technology, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Anne S Meyer
- Protein Chemistry and Enzyme Technology, DTU Bioengineering, Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark.
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Zinck SS, Christensen SJ, Sørensen OB, Svensson B, Meyer AS. Importance of Inactivation Methodology in Enzymatic Processing of Raw Potato Starch: NaOCl as Efficient α-Amylase Inactivation Agent. Molecules 2023; 28:molecules28072947. [PMID: 37049710 PMCID: PMC10095898 DOI: 10.3390/molecules28072947] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Efficient inactivation of microbial α-amylases (EC 3.2.1.1) can be a challenge in starch systems as the presence of starch has been shown to enhance the stability of the enzymes. In this study, commonly used inactivation methods, including multistep washing and pH adjustment, were assessed for their efficiency in inactivating different α-amylases in presence of raw potato starch. Furthermore, an effective approach for irreversible α-amylase inactivation using sodium hypochlorite (NaOCl) is demonstrated. Regarding inactivation by extreme pH, the activity of five different α-amylases was either eliminated or significantly reduced at pH 1.5 and 12. However, treatment at extreme pH for 5 min, followed by incubation at pH 6.5, resulted in hydrolysis yields of 42–816% relative to controls that had not been subjected to extreme pH. “Inactivation” by multistep washing with water, ethanol, and acetone followed by gelatinization as preparation for analysis gave significant starch hydrolysis compared to samples inactivated with NaOCl before the wash. This indicates that the further starch degradation observed in samples subjected to washing only took place during the subsequent gelatinization. The current study demonstrates the importance of inactivation methodology in α-amylase-mediated raw starch depolymerization and provides a method for efficient α-amylase inactivation in starch systems.
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Christensen SJ, Madsen MS, Zinck SS, Hedberg C, Sørensen OB, Svensson B, Meyer AS. Enzymatic potato starch modification and structure-function analysis of six diverse GH77 4-alpha-glucanotransferases. Int J Biol Macromol 2022; 224:105-114. [DOI: 10.1016/j.ijbiomac.2022.10.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/18/2022] [Accepted: 10/12/2022] [Indexed: 11/05/2022]
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Hennessy RC, Nielsen SD, Greve-Poulsen M, Larsen LB, Sørensen OB, Stougaard P. Discovery of a Bacterial Gene Cluster for Deglycosylation of Toxic Potato Steroidal Glycoalkaloids α-Chaconine and α-Solanine. J Agric Food Chem 2020; 68:1390-1396. [PMID: 31935098 DOI: 10.1021/acs.jafc.9b07632] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Potato juice is a byproduct of starch processing currently used as feed. However, potato proteins are an untapped source of high-protein food for human nutrition if harmful constituents notably glycoalkaloids (GAs) are detoxified. The two principle GAs found in potato are α-chaconine and α-solanine, both consisting of a solanidine aglycone with a carbohydrate side chain. The first step in the detoxification of these compounds is the removal of the trisaccharide. Whole-genome sequencing of a bacterial isolate, Arthrobacter sp. S41, capable of completely degrading α-chaconine and α-solanine, revealed the presence of a gene cluster possibly involved in the deglycosylation of GAs. Functional characterization confirmed the enzymatic activity of the gene cluster involved in the complete deglycosylation of both α-chaconine and α-solanine. The novel enzymes described here may find value in the bioconversion of feed proteins to food proteins suitable for human nutrition.
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Affiliation(s)
- Rosanna C Hennessy
- Department of Plant and Environmental Sciences , University of Copenhagen , Thorvaldsensvej 40 , 1871 Frederiksberg C , Denmark
| | - Søren D Nielsen
- Department of Food Science-Food Chemistry and Technology , Aarhus University , Agro Food Park 48 , 8200 Aarhus N , Denmark
| | | | - Lotte Bach Larsen
- Department of Food Science-Food Chemistry and Technology , Aarhus University , Agro Food Park 48 , 8200 Aarhus N , Denmark
| | | | - Peter Stougaard
- Department of Environmental Science , Aarhus University , Frederiksborgvej 399 , P.O. Box 358, 4000 Roskilde , Denmark
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Larsen N, de Souza CB, Krych L, Kot W, Leser TD, Sørensen OB, Blennow A, Venema K, Jespersen L. Effect of potato fiber on survival of Lactobacillus species at simulated gastric conditions and composition of the gut microbiota in vitro. Food Res Int 2019; 125:108644. [DOI: 10.1016/j.foodres.2019.108644] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 07/05/2019] [Accepted: 08/23/2019] [Indexed: 01/13/2023]
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Holland C, Perzon A, Cassland PRC, Jensen JP, Langebeck B, Sørensen OB, Whale E, Hepworth D, Plaice-Inglis R, Moestrup Ø, Ulvskov P, Jørgensen B. Nanofibers Produced from Agro-Industrial Plant Waste Using Entirely Enzymatic Pretreatments. Biomacromolecules 2018; 20:443-453. [DOI: 10.1021/acs.biomac.8b01435] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Claire Holland
- Department of Plant and Environmental Sciences, Section for Glycobiology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Alixander Perzon
- Department of Plant and Environmental Sciences, Section for Glycobiology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | | | - John P. Jensen
- Nordzucker, Technology and Innovation, Falckvænget 1, 4900 Nakskov, Denmark
| | - Birger Langebeck
- Nordzucker, Technology and Innovation, Falckvænget 1, 4900 Nakskov, Denmark
| | | | - Eric Whale
- Cellucomp Ltd., Unit 3, West
Dock, Harbour Place, Burntisland, Fife KY3 9DW, United Kingdom
| | - David Hepworth
- Cellucomp Ltd., Unit 3, West
Dock, Harbour Place, Burntisland, Fife KY3 9DW, United Kingdom
| | - Robyn Plaice-Inglis
- Cellucomp Ltd., Unit 3, West
Dock, Harbour Place, Burntisland, Fife KY3 9DW, United Kingdom
| | - Øjvind Moestrup
- Department of Biology, University of Copenhagen, 2100 København Ø, Denmark
| | - Peter Ulvskov
- Department of Plant and Environmental Sciences, Section for Glycobiology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Bodil Jørgensen
- Department of Plant and Environmental Sciences, Section for Glycobiology, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
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Hennessy RC, Jørgensen NOG, Scavenius C, Enghild JJ, Greve-Poulsen M, Sørensen OB, Stougaard P. A Screening Method for the Isolation of Bacteria Capable of Degrading Toxic Steroidal Glycoalkaloids Present in Potato. Front Microbiol 2018; 9:2648. [PMID: 30455676 PMCID: PMC6230958 DOI: 10.3389/fmicb.2018.02648] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [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: 07/23/2018] [Accepted: 10/17/2018] [Indexed: 01/07/2023] Open
Abstract
Potato juice, a by-product of starch processing, is a potential high-value food ingredient due to its high protein content. However, conversion from feed to human protein requires the removal of the toxic antinutritional glycoalkaloids (GAs) α-chaconine and α-solanine. Detoxification by enzymatic removal could potentially provide an effective and environmentally friendly process for potato-derived food protein production. While degradation of GAs by microorganisms has been documented, there exists limited knowledge on the enzymes involved and in particular how bacteria degrade and metabolize GAs. Here we describe a series of methods for the isolation, screening, and selection of GA-degrading bacteria. Bacterial cultures from soils surrounding greened potatoes, including the potato peels, were established and select bacterial isolates were studied. Screening of bacterial crude extracts for the ability to hydrolyze GAs was performed using a combination of thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and liquid chromatography mass spectrometry (LC-MS). Analysis of the 16S rRNA sequences revealed that bacteria within the genus Arthrobacter were among the most efficient GA-degrading strains.
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Affiliation(s)
- Rosanna C. Hennessy
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Niels O. G. Jørgensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Carsten Scavenius
- Department of Molecular Biology and Genetics – Protein Science, Aarhus University, Aarhus, Denmark
| | - Jan. J. Enghild
- Department of Molecular Biology and Genetics – Protein Science, Aarhus University, Aarhus, Denmark
| | | | | | - Peter Stougaard
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
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