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Liu E, Segato F, Prade RA, Wilkins MR. Exploring lignin depolymerization by a bi-enzyme system containing aryl alcohol oxidase and lignin peroxidase in aqueous biocompatible ionic liquids. BIORESOURCE TECHNOLOGY 2021; 338:125564. [PMID: 34284293 DOI: 10.1016/j.biortech.2021.125564] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/09/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
Enzymatic depolymerization of lignin to produce low molecular weight products requires mild reaction conditions and exhibits higher selectivity compared to thermochemical lignin depolymerization. However, it remains challenging to depolymerize lignin enzymatically, partially due to the low solubility of lignin in aqueous phase. This study aimed to develop a novel approach to combine aqueous lignin extraction with enzymatic lignin depolymerization in biocompatible ionic liquids. A bi-enzyme system containing aryl alcohol oxidase (AAO) and lignin peroxidase (LiP) was developed to depolymerize lignin. Temperature and pH profiles for LiP and AAO were determined. Biocompatibilities of LiP and AAO in different deep eutectic solvents and ionic liquids were investigated. Aqueous cholinium glycinate was found to be an efficient and suitable solvent to solubilize lignin and serve as a biocompatible medium for enzymes to work. LiP and AAO together reduced lignin molecular weight in both solid and liquid phase after enzymatic lignin depolymerization.
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Affiliation(s)
- Enshi Liu
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Fernando Segato
- Department of Biotechnology, University of São Paulo, Lorena, SP, Brazil
| | - Rolf A Prade
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Mark R Wilkins
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln, NE, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, USA.
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Pecularities and applications of aryl-alcohol oxidases from fungi. Appl Microbiol Biotechnol 2021; 105:4111-4126. [PMID: 33997930 PMCID: PMC8140971 DOI: 10.1007/s00253-021-11337-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/03/2021] [Accepted: 05/06/2021] [Indexed: 12/16/2022]
Abstract
Abstract Aryl-alcohol oxidases (AAOs) are FAD-containing enzymes that oxidize a broad range of aromatic as well as aliphatic allylic alcohols to aldehydes. Their broad substrate spectrum accompanied by the only need for molecular oxygen as cosubstrate and production of hydrogen peroxide as sole by-product makes these enzymes very promising biocatalysts. AAOs were used in the synthesis of flavors, fragrances, and other high-value-added compounds and building blocks as well as in dye decolorization and pulp biobleaching. Furthermore, AAOs offer a huge potential as efficient suppliers of hydrogen peroxide for peroxidase- and peroxygenase-catalyzed reactions. A prerequisite for application as biocatalysts at larger scale is the production of AAOs in sufficient amounts. Heterologous expression of these predominantly fungal enzymes is, however, quite challenging. This review summarizes different approaches aiming at enhancing heterologous expression of AAOs and gives an update on substrates accepted by these promising enzymes as well as potential fields of their application. Key points • Aryl-alcohol oxidases (AAOs) supply ligninolytic peroxidases with H2O2. • AAOs accept a broad spectrum of aromatic and aliphatic allylic alcohols. • AAOs are potential biocatalysts for the production of high-value-added bio-based chemicals.
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Otero DM, Cavalcante Braga AR, Kalil SJ. Diversification of nitrogen sources as a tool to improve endo-xylanase enzyme activity produced by Cryptococcus laurentii. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.101941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Liu E, Wilkins MR. Process optimization and scale-up production of fungal aryl alcohol oxidase from genetically modified Aspergillus nidulans in stirred-tank bioreactor. BIORESOURCE TECHNOLOGY 2020; 315:123792. [PMID: 32659422 DOI: 10.1016/j.biortech.2020.123792] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Microbial production of aryl alcohol oxidase (AAO) has attracted increasing attention due to the central role of AAO in enzymatic lignin depolymerization. However, large-scale production of AAO has not been reached because of the low yield and inefficient fermentation process. This study aims to optimize the process parameters and scale-up production of AAO using Aspergillus nidulans in a stirred-tank bioreactor. Effects of pH and dissolved oxygen on AAO production at bioreactor scale were particularly investigated. Results revealed that pH control significantly affected protein production and increasing dissolved oxygen level stimulated AAO production. The greatest AAO activity (1906 U/L) and protein concentration (1.19 g/L) were achieved in 48 h at 60% dissolved oxygen with pH controlled at 6.0. The yield and productivity (in 48 h) were 31.2 U/g maltose and 39.7 U/L/h, respectively. In addition, crude AAO was concentrated and partially purified by ultrafiltration and verified by protein identification.
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Affiliation(s)
- Enshi Liu
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Mark R Wilkins
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
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Aspergillus nidulans: A Potential Resource of the Production of the Native and Heterologous Enzymes for Industrial Applications. Int J Microbiol 2020; 2020:8894215. [PMID: 32802076 PMCID: PMC7416255 DOI: 10.1155/2020/8894215] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 05/13/2020] [Accepted: 07/18/2020] [Indexed: 01/24/2023] Open
Abstract
Aspergillus nidulans is a filamentous fungus that is a potential resource for industrial enzymes. It is a versatile fungal cell factory that can synthesize various industrial enzymes such as cellulases, β-glucosidases, hemicellulases, laccases, lipases, proteases, β-galactosidases, tannases, keratinase, cutinases, and aryl alcohol oxidase. A. nidulans has shown the potential to utilize low-cost substrates such as wheat bran, rice straw, sugarcane bagasse, rice bran, coir pith, black gram residue, and chicken feathers to produce enzymes cost-effectively. A. nidulans has also been known as a model organism for the production of heterologous enzymes. Several studies reported genetically engineered strains of A. nidulans for the production of different enzymes. Native as well as heterologous enzymes of A. nidulans have been employed for various industrial processes.
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Kadowaki MAS, Higasi PMR, de Godoy MO, de Araújo EA, Godoy AS, Prade RA, Polikarpov I. Enzymatic versatility and thermostability of a new aryl-alcohol oxidase from Thermothelomyces thermophilus M77. Biochim Biophys Acta Gen Subj 2020; 1864:129681. [PMID: 32653619 DOI: 10.1016/j.bbagen.2020.129681] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/14/2020] [Accepted: 06/30/2020] [Indexed: 01/23/2023]
Abstract
Background Fungal aryl-alcohol oxidases (AAOx) are extracellular flavoenzymes that belong to glucose-methanol-choline oxidoreductase family and are responsible for the selective conversion of primary aromatic alcohols into aldehydes and aromatic aldehydes to their corresponding acids, with concomitant production of hydrogen peroxide (H2O2) as by-product. The H2O2 can be provided to lignin degradation pathway, a biotechnological property explored in biofuel production. In the thermophilic fungus Thermothelomyces thermophilus (formerly Myceliophthora thermophila), just one AAOx was identified in the exo-proteome. Methods The glycosylated and non-refolded crystal structure of an AAOx from T. thermophilus at 2.6 Å resolution was elucidated by X-ray crystallography combined with small-angle X-ray scattering (SAXS) studies. Moreover, biochemical analyses were carried out to shed light on enzyme substrate specificity and thermostability. Results This flavoenzyme harbors a flavin adenine dinucleotide as a cofactor and is able to oxidize aromatic substrates and 5-HMF. Our results also show that the enzyme has similar oxidation rates for bulky or simple aromatic substrates such as cinnamyl and veratryl alcohols. Moreover, the crystal structure of MtAAOx reveals an open active site, which might explain observed specificity of the enzyme. Conclusions MtAAOx shows previously undescribed structural differences such as a fully accessible catalytic tunnel, heavy glycosylation and Ca2+ binding site providing evidences for thermostability and activity of the enzymes from AA3_2 subfamily. General significance Structural and biochemical analyses of MtAAOx could be important for comprehension of aryl-alcohol oxidases structure-function relationships and provide additional molecular tools to be used in future biotechnological applications.
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Affiliation(s)
- Marco Antonio Seiki Kadowaki
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil.
| | - Paula Miwa Rabelo Higasi
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Mariana Ortiz de Godoy
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Evandro Ares de Araújo
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Andre Schutzer Godoy
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil
| | - Rolf Alexander Prade
- Departments of Microbiology & Molecular Genetics and Biochemistry & Molecular Biology, Oklahoma State University, OK, USA
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense, 400, São Carlos, SP 13566-590, Brazil.
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Liu E, Li M, Abdella A, Wilkins MR. Development of a cost-effective medium for submerged production of fungal aryl alcohol oxidase using a genetically modified Aspergillus nidulans strain. BIORESOURCE TECHNOLOGY 2020; 305:123038. [PMID: 32120232 DOI: 10.1016/j.biortech.2020.123038] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/13/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Aryl alcohol oxidase (AAO), an extracellular H2O2-providing enzyme, plays a central role in lignin depolymerization. Cost-effective production of AAO has not been achieved, due to the low yield of enzyme-producing microorganisms and the high cost of fermentation media. This study aims to develop a cost-effective medium for high-yield production of AAO in submerged culture using a recombinant Aspergillus nidulans strain. Results demonstrate that corn steep liquor (CSL) was a rich but inexpensive nitrogen source for AAO production, and CSL can provide enough trace metals and vitamins (i.e. pyridoxine) for A. nidulans. A 2-level Plackett-Burman design was utilized to determine the main affecting factors in AAO production. The medium was further optimized by a 3-level Box-Behnken design to obtain the optimum medium component concentrations (61.0 g/L maltose, 26.4 g/L CSL, and 13.8 g/L NaNO3). The greatest AAO activity achieved was 1021 U/L with a protein concentration of 0.75 g/L.
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Affiliation(s)
- Enshi Liu
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Mengxing Li
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Department of Statistics, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Asmaa Abdella
- Department of Industrial Biotechnology, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City 22857, Egypt; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Mark R Wilkins
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
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Melnichuk N, Braia MJ, Anselmi PA, Meini MR, Romanini D. Valorization of two agroindustrial wastes to produce alpha-amylase enzyme from Aspergillus oryzae by solid-state fermentation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 106:155-161. [PMID: 32220823 DOI: 10.1016/j.wasman.2020.03.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 06/10/2023]
Abstract
The global amount of soybean and wheat produced is about 350 and 750 million metric tons every year, respectively. In consequence, huge amounts of waste are produced from them. The aim of this work was to employ two wastes -soybean husk and flour mill waste- to produce high quantities of alpha-amylase enzyme. The substrate composition and the culture conditions were assayed to improve alpha-amylase production by solid-state fermentation employing the fungus Aspergillus oryzae. The maximum productivity of the enzyme was achieved using a culture substrate composed of the two wastes, at 45% soybean husk and 55% flour mill by-product, without pre-treatment, at an incubation temperature of 30 °C. The optimal incubation time (6 days), yielded a very high alpha-amylase activity (47,000 U/g dry substrate) at low-cost. The enzymatic extract obtained was characterized by LC-MS, providing a complete profile of the proteins produced during the solid-state fermentation on these two wastes. Then, the extract was purified in a single-step by size-exclusion chromatography and the recovery and the purification factor of alpha-amylase enzyme were about 83% and 6, respectively. The system was scaled up 50 times and yielded a similar enzymatic activity (45,900 U/g of dry substrate).
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Affiliation(s)
- Natasha Melnichuk
- Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario, Argentina; Departamento de Tecnología, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario, Argentina
| | - Mauricio J Braia
- Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario, Argentina; Departamento de Tecnología, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario, Argentina
| | - Pablo A Anselmi
- Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - María-Rocío Meini
- Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario, Argentina; Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario, Argentina
| | - Diana Romanini
- Instituto de Procesos Biotecnológicos y Químicos (IPROBYQ), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario, Argentina; Departamento de Tecnología, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Rosario, Argentina.
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Abdella A, Segato F, Wilkins MR. Optimization of nutrient medium components for production of a client endo-β-1,4-xylanase from Aspergillus fumigatus var. niveus using a recombinant Aspergillus nidulans strain. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101267] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Li M, Eskridge K, Liu E, Wilkins M. Enhancement of polyhydroxybutyrate (PHB) production by 10-fold from alkaline pretreatment liquor with an oxidative enzyme-mediator-surfactant system under Plackett-Burman and central composite designs. BIORESOURCE TECHNOLOGY 2019; 281:99-106. [PMID: 30807996 DOI: 10.1016/j.biortech.2019.02.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 06/09/2023]
Abstract
In this study, Plackett-Burman and central composite designs were applied to improve polyhydroxybutyrate (PHB) production from alkaline pretreatment liquor (APL) by Cupriavidus necator DSM 545 using a supplement system consisting of oxidative enzymes (laccase, aryl alcohol oxidase (AAO)), mediators (ABTS, HOBT), DMSO, silica nanoparticle Aerosol R816 and surfactant Tween 80. First, screening experiments under Plackett-Burman design showed R816, ABTS and Tween 80 could significantly enhance PHB production. Additional experiments showed that HOBT and DMSO could be removed, and laccase and AAO were needed to remain in the system. Second, a central composite design was applied to obtain the optimum supplemental levels of R816, ABTS and Tween 80. Under optimum conditions, theoretical maximum PHB production (1.9 g/L) was close to experimental PHB production (2.1 g/L). With the supplement system, a 10-fold increase was achieved compared to PHB production (0.2 g/L) without any supplements.
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Affiliation(s)
- Mengxing Li
- Department of Biological Systems Engineering, The University of Nebraska-Lincoln, Lincoln 68583, USA; Department of Statistics, The University of Nebraska-Lincoln, Lincoln 68583, USA
| | - Kent Eskridge
- Department of Statistics, The University of Nebraska-Lincoln, Lincoln 68583, USA
| | - Enshi Liu
- Department of Biological Systems Engineering, The University of Nebraska-Lincoln, Lincoln 68583, USA
| | - Mark Wilkins
- Department of Biological Systems Engineering, The University of Nebraska-Lincoln, Lincoln 68583, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln 68588, USA; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln 68583, USA.
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Pardo-Planas O, Atiyeh HK, Prade RA, Müller M, Wilkins MR. Continuous aryl alcohol oxidase production under growth-limited conditions using a trickle bed reactor. BIORESOURCE TECHNOLOGY 2018; 255:149-155. [PMID: 29414160 DOI: 10.1016/j.biortech.2018.01.098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/19/2018] [Accepted: 01/20/2018] [Indexed: 06/08/2023]
Abstract
An A. nidulans strain with a pyridoxine marker was used for continuous production of aryl alcohol oxidase (AAO) in a trickle bed reactor (TBR). Modified medium with reduced zinc, no copper, and 5 g/L ascorbic acid that reduced melanin production and increased AAO productivity under growth limited conditions was used. Two air flow rates, 0.11 L/min (0.1 vvm) and 1.1 L/min (1.0 vvm) were tested. More melanin formation and reduced protein productivity were observed with air flow rate of 1.1 L/min. Three random packings were used as support for the fungus inside the TBR column, two of which were hydrophobic and one which was hydrophilic, and three different dilution rates were tested. The use of GEA BCN 030 hydrophobic packing resulted in greater AAO yield and productivity than the other packings. Increasing dilution rates favored melanin formation and citric, lactic and succinic acid accumulation, which decreased AAO yield and productivity.
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Affiliation(s)
- Oscar Pardo-Planas
- Department of Biosystems and Agricultural Engineering, 111 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, USA
| | - Hasan K Atiyeh
- Department of Biosystems and Agricultural Engineering, 111 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, USA
| | - Rolf A Prade
- Department of Microbiology and Molecular Genetics, 307 Life Sciences East, Oklahoma State University, Stillwater, OK 74078, USA
| | - Michael Müller
- Prüf-und-Forschungsinstitut Pirmasens, Marie-Curie-Straβe 19, 66953 Pirmasens, Germany
| | - Mark R Wilkins
- Department of Biosystems and Agricultural Engineering, 111 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, USA.
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Pardo-Planas O, Prade RA, Müller M, Atiyeh HK, Wilkins MR. Prevention of melanin formation during aryl alcohol oxidase production under growth-limited conditions using an Aspergillus nidulans cell factory. BIORESOURCE TECHNOLOGY 2017; 243:874-882. [PMID: 28738504 DOI: 10.1016/j.biortech.2017.06.183] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
An Aspergillus nidulans cell factory was genetically engineered to produce an aryl alcohol oxidase (AAO). The cell factory initiated production of melanin when growth-limited conditions were established using stationary plates and shaken flasks. This phenomenon was more pronounced when the strain was cultured in a trickle bed reactor (TBR). This study investigated different approaches to reduce melanin formation in fungal mycelia and liquid medium in order to increase the enzyme production yield. Removal of copper from the medium recipe reduced melanin formation in agar cultures and increased enzyme activities by 48% in agitated liquid cultures. Copper has been reported as a key element for tyrosinase, an enzyme responsible for melanin production. Ascorbic acid (0.44g/L) stopped melanin accumulation, did not affect growth parameters and resulted in AAO activity that was more than two-fold greater than a control treatment with no ascorbic acid.
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Affiliation(s)
- Oscar Pardo-Planas
- Department of Biosystems and Agricultural Engineering, 111 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, USA
| | - Rolf A Prade
- Department of Microbiology and Molecular Genetics, 307 Life Sciences East, Oklahoma State University, Stillwater, OK 74078, USA
| | - Michael Müller
- Prüf- und Forschungsinstitut Pirmasens e.V, Marie-Curie-Strasse 19, 66953 Pirmasens, Germany
| | - Hasan K Atiyeh
- Department of Biosystems and Agricultural Engineering, 111 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, USA
| | - Mark R Wilkins
- Department of Biosystems and Agricultural Engineering, 111 Agriculture Hall, Oklahoma State University, Stillwater, OK 74078, USA.
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