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Mubayi V, Ahern CB, Calusinska M, O’Malley MA. Toward a Circular Bioeconomy: Designing Microbes and Polymers for Biodegradation. ACS Synth Biol 2024; 13:1978-1993. [PMID: 38918080 PMCID: PMC11264326 DOI: 10.1021/acssynbio.4c00077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/27/2024]
Abstract
Polymer production is rapidly increasing, but there are no large-scale technologies available to effectively mitigate the massive accumulation of these recalcitrant materials. One potential solution is the development of a carbon-neutral polymer life cycle, where microorganisms convert plant biomass to chemicals, which are used to synthesize biodegradable materials that ultimately contribute to the growth of new plants. Realizing a circular carbon life cycle requires the integration of knowledge across microbiology, bioengineering, materials science, and organic chemistry, which itself has hindered large-scale industrial advances. This review addresses the biodegradation status of common synthetic polymers, identifying novel microbes and enzymes capable of metabolizing these recalcitrant materials and engineering approaches to enhance their biodegradation pathways. Design considerations for the next generation of biodegradable polymers are also reviewed, and finally, opportunities to apply findings from lignocellulosic biodegradation to the design and biodegradation of similarly recalcitrant synthetic polymers are discussed.
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Affiliation(s)
- Vikram Mubayi
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Colleen B. Ahern
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Magdalena Calusinska
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Environmental
Research and Innovation Department, Luxembourg
Institute of Science and Technology, L-4422 Belvaux, Luxembourg
| | - Michelle A. O’Malley
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Department
of Bioengineering, University of California, Santa Barbara, California 93106, United States
- Joint
BioEnergy Institute (JBEI), Emeryville, California 94608, United States
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2
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Bleem AC, Kuatsjah E, Johnsen J, Mohamed ET, Alexander WG, Kellermyer ZA, Carroll AL, Rossi R, Schlander IB, Peabody V GL, Guss AM, Feist AM, Beckham GT. Evolution and engineering of pathways for aromatic O-demethylation in Pseudomonas putida KT2440. Metab Eng 2024; 84:145-157. [PMID: 38936762 DOI: 10.1016/j.ymben.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
Biological conversion of lignin from biomass offers a promising strategy for sustainable production of fuels and chemicals. However, aromatic compounds derived from lignin commonly contain methoxy groups, and O-demethylation of these substrates is often a rate-limiting reaction that influences catabolic efficiency. Several enzyme families catalyze aromatic O-demethylation, but they are rarely compared in vivo to determine an optimal biocatalytic strategy. Here, two pathways for aromatic O-demethylation were compared in Pseudomonas putida KT2440. The native Rieske non-heme iron monooxygenase (VanAB) and, separately, a heterologous tetrahydrofolate-dependent demethylase (LigM) were constitutively expressed in P. putida, and the strains were optimized via adaptive laboratory evolution (ALE) with vanillate as a model substrate. All evolved strains displayed improved growth phenotypes, with the evolved strains harboring the native VanAB pathway exhibiting growth rates ∼1.8x faster than those harboring the heterologous LigM pathway. Enzyme kinetics and transcriptomics studies investigated the contribution of selected mutations toward enhanced utilization of vanillate. The VanAB-overexpressing strains contained the most impactful mutations, including those in VanB, the reductase for vanillate O-demethylase, PP_3494, a global regulator of vanillate catabolism, and fghA, involved in formaldehyde detoxification. These three mutations were combined into a single strain, which exhibited approximately 5x faster vanillate consumption than the wild-type strain in the first 8 h of cultivation. Overall, this study illuminates the details of vanillate catabolism in the context of two distinct enzymatic mechanisms, yielding a platform strain for efficient O-demethylation of lignin-related aromatic compounds to value-added products.
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Affiliation(s)
- Alissa C Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Eugene Kuatsjah
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Josefin Johnsen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Elsayed T Mohamed
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - William G Alexander
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biosciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, USA
| | - Zoe A Kellermyer
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Austin L Carroll
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biosciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, USA
| | - Riccardo Rossi
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark; Department of Bioengineering, University of California, San Diego, CA, USA
| | - Ian B Schlander
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - George L Peabody V
- Biosciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, USA
| | - Adam M Guss
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biosciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN, USA
| | - Adam M Feist
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark; Joint BioEnergy Institute, Emeryville, CA, USA; Department of Bioengineering, University of California, San Diego, CA, USA.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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3
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Meriläinen E, Efimova E, Santala V, Santala S. Carbon-wise utilization of lignin-related compounds by synergistically employing anaerobic and aerobic bacteria. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:78. [PMID: 38851749 PMCID: PMC11161944 DOI: 10.1186/s13068-024-02526-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
BACKGROUND Lignin is a highly abundant but strongly underutilized natural resource that could serve as a sustainable feedstock for producing chemicals by microbial cell factories. Because of the heterogeneous nature of the lignin feedstocks, the biological upgrading of lignin relying on the metabolic routes of aerobic bacteria is currently considered as the most promising approach. However, the limited substrate range and the inefficient catabolism of the production hosts hinder the upgrading of lignin-related aromatics. Particularly, the aerobic O-demethylation of the methoxyl groups in aromatic substrates is energy-limited, inhibits growth, and results in carbon loss in the form of CO2. RESULTS In this study, we present a novel approach for carbon-wise utilization of lignin-related aromatics by the integration of anaerobic and aerobic metabolisms. In practice, we employed an acetogenic bacterium Acetobacterium woodii for anaerobic O-demethylation of aromatic compounds, which distinctively differs from the aerobic O-demethylation; in the process, the carbon from the methoxyl groups is fixed together with CO2 to form acetate, while the aromatic ring remains unchanged. These accessible end-metabolites were then utilized by an aerobic bacterium Acinetobacter baylyi ADP1. By utilizing this cocultivation approach, we demonstrated an upgrading of guaiacol, an abundant but inaccessible substrate to most microbes, into a plastic precursor muconate, with a nearly equimolar yields (0.9 mol/mol in a small-scale cultivation and 1.0 mol/mol in a one-pot bioreactor cultivation). The process required only a minor genetic engineering, namely a single gene knock-out. Noticeably, by employing a metabolic integration of the two bacteria, it was possible to produce biomass and muconate by utilizing only CO2 and guaiacol as carbon sources. CONCLUSIONS By the novel approach, we were able to overcome the issues related to aerobic O-demethylation of methoxylated aromatic substrates and demonstrated carbon-wise conversion of lignin-related aromatics to products with yields unattainable by aerobic processes. This study highlights the power of synergistic integration of distinctive metabolic features of bacteria, thus unlocking new opportunities for harnessing microbial cocultures in upgrading challenging feedstocks.
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Affiliation(s)
- Ella Meriläinen
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland.
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4
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Sun C, Cao F, Xu Y, Feng J, Wang K, Fang Z, Wen Y. Carboxymethylated Lignin Reinforcement of SPI Adhesive: Enhancing Strength, Antimicrobial, and Flame-Retardant Properties without Excessive Alkali Introduction. ACS OMEGA 2024; 9:22703-22710. [PMID: 38826563 PMCID: PMC11137684 DOI: 10.1021/acsomega.4c00452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 04/10/2024] [Accepted: 04/22/2024] [Indexed: 06/04/2024]
Abstract
To address the challenges associated with formaldehyde emissions in engineered wood adhesives and simultaneously enhance adhesive properties related to water resistance, fire resistance, and mold resistance, a novel environmentally sustainable biomass-based adhesive was formulated. In this work, kraft lignin was carboxymethylated and then blended with the soy protein isolate (SPI)-based adhesive, the dry and wet shear strength of the plywood bonded by the resultant adhesive was enhanced from 1.10 and 0.63 MPa to 1.73 and 1.23 MPa, respectively, resulting in improvements of 157% and 195%. Carboxymethylated lignin (CML) significantly improved the mold resistance and flame-resistance residual rate of the adhesive and decreased the water absorption rate from 190% to 108%. Furthermore, the adhesive exhibits outstanding flame-retardancy, with self-extinguishing capability rendering it suitable for industrial production. In addition, we also evaluated the performances of resulting adhesives cured with different diepoxides and triepoxides, and the comparisons of the adhesive in this work to commercial urea glue and soy protein-based adhesives were conducted. To our delight, the SPI-10CML adhesive presented comparable or even improved performances, showing its promising practical applications such as for fire doors.
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Affiliation(s)
- Changjiang Sun
- Tianjin
Key Laboratory of Pulp and Paper, Tianjin
University of Science & Technology, No. 29, 13th Avenue, Tianjin Economic and Technological
Development Area, Tianjin 300457, China
- Shandong
Laboratory of Yantai Advanced Material and Green Manufacture, Yantai 264006, China
| | - Fengxiang Cao
- Shandong
Laboratory of Yantai Advanced Material and Green Manufacture, Yantai 264006, China
| | - Yecheng Xu
- Shandong
Laboratory of Yantai Advanced Material and Green Manufacture, Yantai 264006, China
| | - Jiao Feng
- Tianjin
Key Laboratory of Pulp and Paper, Tianjin
University of Science & Technology, No. 29, 13th Avenue, Tianjin Economic and Technological
Development Area, Tianjin 300457, China
- Shandong
Laboratory of Yantai Advanced Material and Green Manufacture, Yantai 264006, China
| | - Keyan Wang
- Tianjin
Key Laboratory of Pulp and Paper, Tianjin
University of Science & Technology, No. 29, 13th Avenue, Tianjin Economic and Technological
Development Area, Tianjin 300457, China
| | - Zhen Fang
- Shandong
Laboratory of Yantai Advanced Material and Green Manufacture, Yantai 264006, China
- International
Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China
| | - Yangbing Wen
- Tianjin
Key Laboratory of Pulp and Paper, Tianjin
University of Science & Technology, No. 29, 13th Avenue, Tianjin Economic and Technological
Development Area, Tianjin 300457, China
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5
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Jin X, Li X, Zou L, Zheng Z, Ouyang J. Biological Valorization of Lignin-Derived Aromatics in Hydrolysate to Protocatechuic Acid by Engineered Pseudomonas putida KT2440. Molecules 2024; 29:1555. [PMID: 38611834 PMCID: PMC11013400 DOI: 10.3390/molecules29071555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Alongside fermentable sugars, weak acids, and furan derivatives, lignocellulosic hydrolysates contain non-negligible amounts of lignin-derived aromatic compounds. The biological funnel of lignin offers a new strategy for the "natural" production of protocatechuic acid (PCA). Herein, Pseudomonas putida KT2440 was engineered to produce PCA from lignin-derived monomers in hydrolysates by knocking out protocatechuate 3,4-dioxygenase and overexpressing vanillate-O-demethylase endogenously, while acetic acid was used for cell growth. The sugar catabolism was further blocked to prevent the loss of fermentable sugar. Using the engineered strain, a total of 253.88 mg/L of PCA was obtained with a yield of 70.85% from corncob hydrolysate 1. The highest titer of 433.72 mg/L of PCA was achieved using corncob hydrolysate 2 without any additional nutrients. This study highlights the potential ability of engineered strains to address the challenges of PCA production from lignocellulosic hydrolysate, providing novel insights into the utilization of hydrolysates.
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Affiliation(s)
| | | | | | | | - Jia Ouyang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; (X.J.); (X.L.); (L.Z.); (Z.Z.)
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6
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Wolf ME, Lalande AT, Newman BL, Bleem AC, Palumbo CT, Beckham GT, Eltis LD. The catabolism of lignin-derived p-methoxylated aromatic compounds by Rhodococcus jostii RHA1. Appl Environ Microbiol 2024; 90:e0215523. [PMID: 38380926 PMCID: PMC10952524 DOI: 10.1128/aem.02155-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/23/2024] [Indexed: 02/22/2024] Open
Abstract
Emergent strategies to valorize lignin, an abundant but underutilized aromatic biopolymer, include tandem processes that integrate chemical depolymerization and biological catalysis. To date, aromatic monomers from C-O bond cleavage of lignin have been converted to bioproducts, but the presence of recalcitrant C-C bonds in lignin limits the product yield. A promising chemocatalytic strategy that overcomes this limitation involves phenol methyl protection and autoxidation. Incorporating this into a tandem process requires microbial cell factories able to transform the p-methoxylated products in the resulting methylated lignin stream. In this study, we assessed the ability of Rhodococcus jostii RHA1 to catabolize the major aromatic products in a methylated lignin stream and elucidated the pathways responsible for this catabolism. RHA1 grew on a methylated pine lignin stream, catabolizing the major aromatic monomers: p-methoxybenzoate (p-MBA), veratrate, and veratraldehyde. Bioinformatic analyses suggested that a cytochrome P450, PbdA, and its cognate reductase, PbdB, are involved in p-MBA catabolism. Gene deletion studies established that both pbdA and pbdB are essential for growth on p-MBA and several derivatives. Furthermore, a deletion mutant of a candidate p-hydroxybenzoate (p-HBA) hydroxylase, ΔpobA, did not grow on p-HBA. Veratraldehyde and veratrate catabolism required both vanillin dehydrogenase (Vdh) and vanillate O-demethylase (VanAB), revealing previously unknown roles of these enzymes. Finally, a ΔpcaL strain grew on neither p-MBA nor veratrate, indicating they are catabolized through the β-ketoadipate pathway. This study expands our understanding of the bacterial catabolism of aromatic compounds and facilitates the development of biocatalysts for lignin valorization.IMPORTANCELignin, an abundant aromatic polymer found in plant biomass, is a promising renewable replacement for fossil fuels as a feedstock for the chemical industry. Strategies for upgrading lignin include processes that couple the catalytic fractionation of biomass and biocatalytic transformation of the resulting aromatic compounds with a microbial cell factory. Engineering microbial cell factories for this biocatalysis requires characterization of bacterial pathways involved in catabolizing lignin-derived aromatic compounds. This study identifies new pathways for lignin-derived aromatic degradation in Rhodococcus, a genus of bacteria well suited for biocatalysis. Additionally, we describe previously unknown activities of characterized enzymes on lignin-derived compounds, expanding their utility. This work advances the development of strategies to replace fossil fuel-based feedstocks with sustainable alternatives.
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Affiliation(s)
- Megan E. Wolf
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, Canada
| | - Anne T. Lalande
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, Canada
| | - Brianne L. Newman
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, Canada
| | - Alissa C. Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Chad T. Palumbo
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Gregg T. Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Lindsay D. Eltis
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, Canada
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7
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Borchert AJ, Bleem AC, Lim HG, Rychel K, Dooley KD, Kellermyer ZA, Hodges TL, Palsson BO, Beckham GT. Machine learning analysis of RB-TnSeq fitness data predicts functional gene modules in Pseudomonas putida KT2440. mSystems 2024; 9:e0094223. [PMID: 38323821 PMCID: PMC10949508 DOI: 10.1128/msystems.00942-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 01/07/2024] [Indexed: 02/08/2024] Open
Abstract
There is growing interest in engineering Pseudomonas putida KT2440 as a microbial chassis for the conversion of renewable and waste-based feedstocks, and metabolic engineering of P. putida relies on the understanding of the functional relationships between genes. In this work, independent component analysis (ICA) was applied to a compendium of existing fitness data from randomly barcoded transposon insertion sequencing (RB-TnSeq) of P. putida KT2440 grown in 179 unique experimental conditions. ICA identified 84 independent groups of genes, which we call fModules ("functional modules"), where gene members displayed shared functional influence in a specific cellular process. This machine learning-based approach both successfully recapitulated previously characterized functional relationships and established hitherto unknown associations between genes. Selected gene members from fModules for hydroxycinnamate metabolism and stress resistance, acetyl coenzyme A assimilation, and nitrogen metabolism were validated with engineered mutants of P. putida. Additionally, functional gene clusters from ICA of RB-TnSeq data sets were compared with regulatory gene clusters from prior ICA of RNAseq data sets to draw connections between gene regulation and function. Because ICA profiles the functional role of several distinct gene networks simultaneously, it can reduce the time required to annotate gene function relative to manual curation of RB-TnSeq data sets. IMPORTANCE This study demonstrates a rapid, automated approach for elucidating functional modules within complex genetic networks. While Pseudomonas putida randomly barcoded transposon insertion sequencing data were used as a proof of concept, this approach is applicable to any organism with existing functional genomics data sets and may serve as a useful tool for many valuable applications, such as guiding metabolic engineering efforts in other microbes or understanding functional relationships between virulence-associated genes in pathogenic microbes. Furthermore, this work demonstrates that comparison of data obtained from independent component analysis of transcriptomics and gene fitness datasets can elucidate regulatory-functional relationships between genes, which may have utility in a variety of applications, such as metabolic modeling, strain engineering, or identification of antimicrobial drug targets.
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Affiliation(s)
- Andrew J. Borchert
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Alissa C. Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Agile BioFoundry, Emeryville, California, USA
| | - Hyun Gyu Lim
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
- Joint BioEnergy Institute, Emeryville, California, USA
- Department of Biological Engineering, Inha University, Incheon, Korea
| | - Kevin Rychel
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Keven D. Dooley
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
- Agile BioFoundry, Emeryville, California, USA
| | - Zoe A. Kellermyer
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Tracy L. Hodges
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
- Agile BioFoundry, Emeryville, California, USA
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
- Joint BioEnergy Institute, Emeryville, California, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
- Department of Pediatrics, University of California, San Diego, California, USA
| | - Gregg T. Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Agile BioFoundry, Emeryville, California, USA
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8
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Banerjee D, Yunus IS, Wang X, Kim J, Srinivasan A, Menchavez R, Chen Y, Gin JW, Petzold CJ, Martin HG, Magnuson JK, Adams PD, Simmons BA, Mukhopadhyay A, Kim J, Lee TS. Genome-scale and pathway engineering for the sustainable aviation fuel precursor isoprenol production in Pseudomonas putida. Metab Eng 2024; 82:157-170. [PMID: 38369052 DOI: 10.1016/j.ymben.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 01/10/2024] [Accepted: 02/10/2024] [Indexed: 02/20/2024]
Abstract
Sustainable aviation fuel (SAF) will significantly impact global warming in the aviation sector, and important SAF targets are emerging. Isoprenol is a precursor for a promising SAF compound DMCO (1,4-dimethylcyclooctane) and has been produced in several engineered microorganisms. Recently, Pseudomonas putida has gained interest as a future host for isoprenol bioproduction as it can utilize carbon sources from inexpensive plant biomass. Here, we engineer metabolically versatile host P. putida for isoprenol production. We employ two computational modeling approaches (Bilevel optimization and Constrained Minimal Cut Sets) to predict gene knockout targets and optimize the "IPP-bypass" pathway in P. putida to maximize isoprenol production. Altogether, the highest isoprenol production titer from P. putida was achieved at 3.5 g/L under fed-batch conditions. This combination of computational modeling and strain engineering on P. putida for an advanced biofuels production has vital significance in enabling a bioproduction process that can use renewable carbon streams.
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Affiliation(s)
- Deepanwita Banerjee
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ian S Yunus
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Xi Wang
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jinho Kim
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Aparajitha Srinivasan
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Russel Menchavez
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yan Chen
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jennifer W Gin
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Christopher J Petzold
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Hector Garcia Martin
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jon K Magnuson
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Energy Processes & Materials Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Paul D Adams
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Blake A Simmons
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Joonhoon Kim
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Energy Processes & Materials Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
| | - Taek Soon Lee
- Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA; Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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9
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Liu S, He Y, Zhang W, Fu T, Wang L, Zhang Y, Xu Y, Sun H, Zhao H. Self-Cascade Ce-MOF-818 Nanozyme for Sequential Hydrolysis and Oxidation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306522. [PMID: 37884468 DOI: 10.1002/smll.202306522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/24/2023] [Indexed: 10/28/2023]
Abstract
Mimicking efficient biocatalytic cascades using nanozymes has gained enormous attention in catalytic chemistry, but it remains challenging to develop a nanozyme-based cascade system to sequentially perform the desired reactions. Particularly, the integration of sequential hydrolysis and oxidation reactions into nanozyme-based cascade systems has not yet been achieved, despite their significant roles in various domains. Herein, a self-cascade Ce-MOF-818 nanozyme for sequential hydrolysis and oxidation reactions is developed. Ce-MOF-818 is the first Ce(IV)-based heterometallic metal-organic framework constructed through the coordination of Ce and Cu to distinct groups. It is successfully synthesized using an improved solvothermal method, overcoming the challenge posed by the significant difference in the binding speeds of Ce and Cu to ligands. With excellent organophosphate hydrolase-like (Km = 42.3 µM, Kcat = 0.0208 min-1 ) and catechol oxidase-like (Km = 2589 µM, Kcat = 1.25 s-1 ) activities attributed to its bimetallic active centers, Ce-MOF-818 serves as a promising self-cascade platform for sequential hydrolysis and oxidation. Notably, its catalytic efficiency surpasses that of physically mixed nanozymes by approximately fourfold, owning to the close integration of active sites. The developed hydrolysis-oxidation self-cascade nanozyme has promising potential applications in catalytic chemistry and provides valuable insights into the rational design of nanozyme-based cascade systems.
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Affiliation(s)
- Sheng Liu
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Yang He
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Weikun Zhang
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Tao Fu
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Liangjie Wang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Yixin Zhang
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
- Department of Chemistry, Imperial College London, London, SW7 2AZ, UK
| | - Yi Xu
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Hao Sun
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Huazhang Zhao
- The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
- Shanxi Laboratory for Yellow River, College of Environmental & Resource Sciences, Shanxi University, Taiyuan, 030006, China
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10
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Zhu R, Mao C, Gao F, Guo Z, Li M, Xin Y, Gu Z, Zhang L. Catalytic Cleavage of the C-O Bonds in Lignin and Lignin Model Compounds by Metal Triflate Catalysts. CHEMSUSCHEM 2024; 17:e202301743. [PMID: 38206879 DOI: 10.1002/cssc.202301743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 01/13/2024]
Abstract
The effective cleavage of C-O bonds in linkages of lignin was one of the significant strategies promoting lignin valorization. Herein, the strategy of C-O bonds cleavage of lignin using metal triflate as the catalyst was developed. The carboxylic acid or alcohol could be used as the nucleophile to stabilize the reactive intermediates formed during the depolymerization of lignin, and the corresponding ester/ether compounds could be obtained. This catalytic system was suitable for the C-O bond cleavage in α-O-4 and β-O-4 linkages with excellent efficiency. Additionally, reaction conditions were optimized. The reaction mixture was detected by 1 H NMR, and no other byproducts were found. As for treated lignin samples, the cleavage of C-O bonds in linkages was determined by 2D HSQC NMR, the increased content of the phenol hydroxyl group was proved by FT-IR, and the reduced molecular weight was investigated by GPC. Furthermore, multiple phenolic compounds were detected by GC-MS in the reaction mixtures.
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Affiliation(s)
- Rui Zhu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, P. R. China
| | - Changtao Mao
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
| | - Fang Gao
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
| | - Zhongpeng Guo
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, P. R. China
| | - Moying Li
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, P. R. China
| | - Yu Xin
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, P. R. China
| | - Zhenghua Gu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, P. R. China
- JITRI Future Food Technology Research Institute Co., Ltd, Yixing, 214200, P. R. China
| | - Liang Zhang
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, 214122, P. R. China
- Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, P. R. China
- JITRI Future Food Technology Research Institute Co., Ltd, Yixing, 214200, P. R. China
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11
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Martínez-García E, de Lorenzo V. Pseudomonas putida as a synthetic biology chassis and a metabolic engineering platform. Curr Opin Biotechnol 2024; 85:103025. [PMID: 38061264 DOI: 10.1016/j.copbio.2023.103025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 02/09/2024]
Abstract
The soil bacterium Pseudomonas putida, especially the KT2440 strain, is increasingly being utilized as a host for biotransformations of both industrial and environmental interest. The foundations of such performance include its robust redox metabolism, ability to tolerate a wide range of physicochemical stresses, rapid growth, versatile metabolism, nonpathogenic nature, and the availability of molecular tools for advanced genetic programming. These attributes have been leveraged for hosting engineered pathways for production of valuable chemicals or degradation/valorization of environmental pollutants. This has in turn pushed the boundaries of conventional enzymology toward previously unexplored reactions in nature. Furthermore, modifications to the physical properties of the cells have been made to enhance their catalytic performance. These advancements establish P. putida as bona fide chassis for synthetic biology, on par with more traditional metabolic engineering platforms.
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Affiliation(s)
- Esteban Martínez-García
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Calle Darwin 3, 28049 Madrid, Spain
| | - Víctor de Lorenzo
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Calle Darwin 3, 28049 Madrid, Spain.
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12
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Fan S, Cong Z. Emerging Strategies for Modifying Cytochrome P450 Monooxygenases into Peroxizymes. Acc Chem Res 2024. [PMID: 38293787 DOI: 10.1021/acs.accounts.3c00746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
ConspectusCytochrome P450 monooxygenase is a versatile oxidizing enzyme with great potential in synthetic chemistry and biology. However, the dependence of its catalytic function on the nicotinamide cofactor NAD(P)H and redox partner proteins limits the practical catalytic application of P450 in vitro. An alternative to expensive cofactors is low-cost H2O2, which can be used directly to exploit the catalytic potential of P450s. However, the peroxide shunt pathway is generally inefficient at driving P450 catalysis compared to normal NAD(P)H-dependent activity. Over the last few decades, the scientific community has made continuous efforts to use directed evolution or site-directed mutagenesis to modify P450 monooxygenases into their peroxizyme modes─peroxygenase and peroxidase. Despite significant progress, obtaining efficient P450 peroxizymes remains a huge challenge. Here, we summarize our efforts to modulate peroxizyme activity in P450 monooxygenases and exploit their catalytic applications in challenging selective C-H oxidation, oxygenation, and oxyfunctionalization over the past seven years. We first developed a dual-functional small molecule (DFSM) strategy for transforming P450BM3 monooxygenase into peroxygenase. In this strategy, the typical DFSM, such as N-(ω-imidazolyl)-hexanoyl-l-phenylalanine (Im-C6-Phe), binds to the P450BM3 protein with an anchoring group at one end and plays a general acid-base catalytic role in the activation of H2O2 with an imidazolyl group at the other end. Compared with the O-O homolysis mechanism in the absence of DFSM, the addition of DFSM efficiently enables the heterolytic O-O cleavage of the adduct Fe-O-OH, thus being favored for the formation of active species compound I, which has been demonstrated by combining crystallographic and theoretical calculations. Furthermore, protein engineering showed the unique catalytic performance of DFSM-facilitated P450 peroxygenase for the highly difficult selective oxidation of C-H bonds. This catalytic performance was demonstrated during the chemoselective hydroxylation of gaseous alkanes, regioselective O-demethylation of aryl ethers, highly (R)-enantioselective epoxidation of styrene, and regio- and enantiomerically diverse hydroxylation of alkylbenzenes. Second, we demonstrated that DFSM-facilitated P450BM3 peroxygenase could be effectively switched to an efficient peroxidase mode through mechanism-guided protein engineering of redox-sensitive residues. Utilizing the peroxidase function of P450 enabled the direct nitration of unsaturated hydrocarbons including phenols, aromatic amines, and styrene derivatives, which was not only the P450-catalyzed direct nitration of phenols and aromatic amines for the first time but also the first example of the direct biological nitration of olefins. Finally, we report an H2O2 tunnel engineering strategy to enable peroxygenase activity in several different P450 monooxygenases for the first time, providing a general approach for accessing engineered P450 peroxygenases. In this Account, we highlight the emerging strategies we have developed for producing practical P450 peroxizyme biocatalysts. Although the DFSM strategy is primarily applied to P450BM3 to date, both strategies of redox-sensitive residue engineering and H2O2 tunnel engineering show great potential to extend to other P450s. These strategies have expanded the scope of applications of P450 chemistry and catalysis. Additionally, they provide a unique solution to the challenging selective oxidation of inert C-H bonds in synthetic chemistry.
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Affiliation(s)
- Shengxian Fan
- CAS Key Laboratory of Biofuels and Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiqi Cong
- CAS Key Laboratory of Biofuels and Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Shandong Energy Institute, Qingdao, Shandong 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, Shandong 266101, China
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13
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Palumbo CT, Gu NX, Bleem AC, Sullivan KP, Katahira R, Stanley LM, Kenny JK, Ingraham MA, Ramirez KJ, Haugen SJ, Amendola CR, Stahl SS, Beckham GT. Catalytic carbon-carbon bond cleavage in lignin via manganese-zirconium-mediated autoxidation. Nat Commun 2024; 15:862. [PMID: 38286984 PMCID: PMC10825196 DOI: 10.1038/s41467-024-45038-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 01/09/2024] [Indexed: 01/31/2024] Open
Abstract
Efforts to produce aromatic monomers through catalytic lignin depolymerization have historically focused on aryl-ether bond cleavage. A large fraction of aromatic monomers in lignin, however, are linked by various carbon-carbon (C-C) bonds that are more challenging to cleave and limit the yields of aromatic monomers from lignin depolymerization. Here, we report a catalytic autoxidation method to cleave C-C bonds in lignin-derived dimers and oligomers from pine and poplar. The method uses manganese and zirconium salts as catalysts in acetic acid and produces aromatic carboxylic acids as primary products. The mixtures of the oxygenated monomers are efficiently converted to cis,cis-muconic acid in an engineered strain of Pseudomonas putida KT2440 that conducts aromatic O-demethylation reactions at the 4-position. This work demonstrates that autoxidation of lignin with Mn and Zr offers a catalytic strategy to increase the yield of valuable aromatic monomers from lignin.
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Affiliation(s)
- Chad T Palumbo
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Nina X Gu
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Alissa C Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Kevin P Sullivan
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Rui Katahira
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Lisa M Stanley
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Jacob K Kenny
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, 80303, CO, USA
| | - Morgan A Ingraham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Kelsey J Ramirez
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Stefan J Haugen
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Caroline R Amendola
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Shannon S Stahl
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
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14
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Bijukumar S, Murugesan T, Dhanapal AR, Mubarak SJ, Vedagiri H, Jayaraman A. Construing recombinant ZFP160 from Aspergillus terreus as pterin deaminase enzyme. Biotechnol Appl Biochem 2023; 70:2150-2162. [PMID: 37766485 DOI: 10.1002/bab.2515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 09/09/2023] [Indexed: 09/29/2023]
Abstract
Pterin deaminase stands as a metalloenzyme and exhibits both antitumor and anticancer activities. Therefore, this study aimed to explore the molecular function of zinc finger protein-160 (zfp160) from Aspergillus terreus with its enzyme mechanism in detail. Subsequently, preliminary molecular docking studies on zfp160 from A. terreus were done. Next, the cloning and expression of zfp160 protein were carried out. Following, protein expression was induced and purified through nickel NTA column with imidazole gradient elution. Through the Mascot search engine tool, the expressed protein of MALDI-TOF was confirmed by 32 kDa bands of SDS-PAGE. Furthermore, its enzymatic characterization and biochemical categorization were also explored. The optimum conditions for enzyme were determined to be pH 8, temperature 35°C, km 50 μm with folic acid as substrate, and Vmax of 24.16 (IU/mL). Further, in silico analysis tried to explore the interactions and binding affinity of various substrates to the modeled pterin deaminase from A. terreus. Our results revealed the binding mode of different substrate molecules with pterin deaminase using the approximate scoring functions that possibly correlate with actual experimental binding affinities. Following this, molecular dynamic simulations provided the in-depth knowledge on deciphering functional mechanisms of pterin deaminase over other drugs.
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Affiliation(s)
- Sajitha Bijukumar
- Cancer Therapeutics Laboratory, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Thandeeswaran Murugesan
- Bharathiar Cancer Theranostics Research Centre (BCTRC), RUSA2.0, Bharathiar University, Coimbatore, India
| | - Anand Raj Dhanapal
- Chemistry and Bioprospecting Division, Institute of Forest Genetics and Tree Breeding (IFGTB), Indian Council of Forestry Research and Education (ICFRE), Coimbatore, Tamil Nadu, India
| | - Shoufia Jabeen Mubarak
- Medical Genomics Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Hemamalini Vedagiri
- Medical Genomics Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, Tamil Nadu, India
| | - Angayarkanni Jayaraman
- Cancer Therapeutics Laboratory, Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, India
- Bharathiar Cancer Theranostics Research Centre (BCTRC), RUSA2.0, Bharathiar University, Coimbatore, India
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15
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Li X, Gluth A, Feng S, Qian WJ, Yang B. Harnessing redox proteomics to study metabolic regulation and stress response in lignin-fed Rhodococci. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:180. [PMID: 37986172 PMCID: PMC10662689 DOI: 10.1186/s13068-023-02424-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 11/02/2023] [Indexed: 11/22/2023]
Abstract
BACKGROUND Rhodococci are studied for their bacterial ligninolytic capabilities and proclivity to accumulate lipids. Lignin utilization is a resource intensive process requiring a variety of redox active enzymes and cofactors for degradation as well as defense against the resulting toxic byproducts and oxidative conditions. Studying enzyme expression and regulation between carbon sources will help decode the metabolic rewiring that stymies lignin to lipid conversion in these bacteria. Herein, a redox proteomics approach was applied to investigate a fundamental driver of carbon catabolism and lipid anabolism: redox balance. RESULTS A consortium of Rhodococcus strains was employed in this study given its higher capacity for lignin degradation compared to monocultures. This consortium was grown on glucose vs. lignin under nitrogen limitation to study the importance of redox balance as it relates to nutrient availability. A modified bottom-up proteomics workflow was harnessed to acquire a general relationship between protein abundance and protein redox states. Global proteomics results affirm differential expression of enzymes involved in sugar metabolism vs. those involved in lignin degradation and aromatics metabolism. As reported previously, several enzymes in the lipid biosynthetic pathways were downregulated, whereas many involved in β-oxidation were upregulated. Interestingly, proteins involved in oxidative stress response were also upregulated perhaps in response to lignin degradation and aromatics catabolism, which require oxygen and reactive oxygen species and generate toxic byproducts. Enzymes displaying little-to-no change in abundance but differences in redox state were observed in various pathways for carbon utilization (e.g., β‑ketoadipate pathway), lipid metabolism, as well as nitrogen metabolism (e.g., purine scavenging/synthesis), suggesting potential mechanisms of redox-dependent regulation of metabolism. CONCLUSIONS Efficient lipid production requires a steady carbon and energy flux while balancing fundamental requirements for enzyme production and cell maintenance. For lignin, we theorize that this balance is difficult to establish due to resource expenditure for enzyme production and stress response. This is supported by significant changes to protein abundances and protein cysteine oxidation in various metabolic pathways and redox processes.
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Affiliation(s)
- Xiaolu Li
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Austin Gluth
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA
| | - Song Feng
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Bin Yang
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA.
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
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16
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Xue L, Zhao Y, Li L, Rao X, Chen X, Ma F, Yu H, Xie S. A key O-demethylase in the degradation of guaiacol by Rhodococcus opacus PD630. Appl Environ Microbiol 2023; 89:e0052223. [PMID: 37800939 PMCID: PMC10617553 DOI: 10.1128/aem.00522-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/24/2023] [Indexed: 10/07/2023] Open
Abstract
Rhodococcus opacus PD630 is a high oil-producing strain with the ability to convert lignin-derived aromatics to high values, but limited research has been done to elucidate its conversion pathway, especially the upper pathways. In this study, we focused on the upper pathways and demethylation mechanism of lignin-derived aromatics metabolism by R. opacus PD630. The results of the aromatic carbon resource utilization screening showed that R. opacus PD630 had a strong degradation capacity to the lignin-derived methoxy-containing aromatics, such as guaiacol, 3,4-veratric acid, anisic acid, isovanillic acid, and vanillic acid. The gene of gcoAR, which encodes cytochrome P450, showed significant up-regulation when R. opacus PD630 grew on diverse aromatics. Deletion mutants of gcoAR and its partner protein gcoBR resulted in the strain losing the ability to grow on guaiacol, but no significant difference to the other aromatics. Only co-complementation alone of gcoAR and gcoBR restored the strain's ability to utilize guaiacol, demonstrating that both genes were equally important in the utilization of guaiacol. In vitro assays further revealed that GcoAR could convert guaiacol and anisole to catechol and phenol, respectively, with the production of formaldehyde as a by-product. The study provided robust evidence to reveal the molecular mechanism of R. opacus PD630 on guaiacol metabolism and offered a promising study model for dissecting the demethylation process of lignin-derived aromatics in microbes.IMPORTANCEAryl-O-demethylation is believed to be the key rate-limiting step in the catabolism of heterogeneous lignin-derived aromatics in both native and engineered microbes. However, the mechanisms of O-demethylation in lignin-derived aromatic catabolism remain unclear. Notably, guaiacol, the primary component unit of lignin, lacks in situ demonstration and illustration of the molecular mechanism of guaiacol O-demethylation in lignin-degrading bacteria. This is the first study to illustrate the mechanism of guaiacol metabolism by R. opacus PD630 in situ as well as characterize the purified key O-demethylase in vitro. This study provided further insight into the lignin metabolic pathway of R. opacus PD630 and could guide the design of an efficient biocatalytic system for lignin valorization.
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Affiliation(s)
- Le Xue
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yiquan Zhao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ling Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xinran Rao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xinjie Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fuying Ma
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hongbo Yu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shangxian Xie
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
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17
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Kumagawa E, Katsumata M, Ohta Y. Catalytic and molecular properties of alkaliphilic and thermotolerant β-etherase from Altererythrobacter sp. B11. Biosci Biotechnol Biochem 2023; 87:1183-1192. [PMID: 37403406 DOI: 10.1093/bbb/zbad091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023]
Abstract
Phenylpropanone monomers, including guaiacyl hydroxypropanone, are important precursors for the synthesis of various chemicals. The monomers are obtained in a three-step cascade reaction catalyzed by a group of enzymes in the β-etherase system that cleaves the β-O-4 bond, the major bond in lignin. In this study, one of the β-etherase of the glutathione-S-transferase superfamily, AbLigF2, was discovered in genus Altererythrobacter, and the recombinant etherase was characterized. The enzyme showed maximal activity at 45 °C, maintained 30% of its activity after 2 h at 50 °C, and was the most thermostable among the previously reported enzymes. Moreover, N13, S14, and S115, located near the thiol group of glutathione, had a significant effect on the maximum reaction rate of enzyme activity. This study suggests that AbLigF2 has the potential to serve as a thermostable enzyme for lignin utilization and provides insights into its catalytic mechanism.
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Affiliation(s)
- Eri Kumagawa
- Graduate School of Science and Technology, Gunma University, Gunma, Japan
| | - Madoka Katsumata
- Gunma University Center for Food Science and Wellness, Gunma, Japan
| | - Yukari Ohta
- Gunma University Center for Food Science and Wellness, Gunma, Japan
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18
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Werner AZ, Cordell WT, Lahive CW, Klein BC, Singer CA, Tan EC, Ingraham MA, Ramirez KJ, Kim DH, Pedersen JN, Johnson CW, Pfleger BF, Beckham GT, Salvachúa D. Lignin conversion to β-ketoadipic acid by Pseudomonas putida via metabolic engineering and bioprocess development. SCIENCE ADVANCES 2023; 9:eadj0053. [PMID: 37672573 PMCID: PMC10482344 DOI: 10.1126/sciadv.adj0053] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/04/2023] [Indexed: 09/08/2023]
Abstract
Bioconversion of a heterogeneous mixture of lignin-related aromatic compounds (LRCs) to a single product via microbial biocatalysts is a promising approach to valorize lignin. Here, Pseudomonas putida KT2440 was engineered to convert mixed p-coumaroyl- and coniferyl-type LRCs to β-ketoadipic acid, a precursor for performance-advantaged polymers. Expression of enzymes mediating aromatic O-demethylation, hydroxylation, and ring-opening steps was tuned, and a global regulator was deleted. β-ketoadipate titers of 44.5 and 25 grams per liter and productivities of 1.15 and 0.66 grams per liter per hour were achieved from model LRCs and corn stover-derived LRCs, respectively, the latter representing an overall yield of 0.10 grams per gram corn stover-derived lignin. Technoeconomic analysis of the bioprocess and downstream processing predicted a β-ketoadipate minimum selling price of $2.01 per kilogram, which is cost competitive with fossil carbon-derived adipic acid ($1.10 to 1.80 per kilogram). Overall, this work achieved bioproduction metrics with economic relevance for conversion of lignin-derived streams into a performance-advantaged bioproduct.
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Affiliation(s)
- Allison Z. Werner
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - William T. Cordell
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Ciaran W. Lahive
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Bruno C. Klein
- Catalytic Carbon Transformation and Scale-Up Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Christine A. Singer
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Eric C. D. Tan
- Catalytic Carbon Transformation and Scale-Up Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Morgan A. Ingraham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Kelsey J. Ramirez
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Dong Hyun Kim
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Jacob Nedergaard Pedersen
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Christopher W. Johnson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Gregg T. Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Davinia Salvachúa
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
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Bleem A, Kato R, Kellermyer ZA, Katahira R, Miyamoto M, Niinuma K, Kamimura N, Masai E, Beckham GT. Multiplexed fitness profiling by RB-TnSeq elucidates pathways for lignin-related aromatic catabolism in Sphingobium sp. SYK-6. Cell Rep 2023; 42:112847. [PMID: 37515767 DOI: 10.1016/j.celrep.2023.112847] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 05/21/2023] [Accepted: 07/07/2023] [Indexed: 07/31/2023] Open
Abstract
Bioconversion of lignin-related aromatic compounds relies on robust catabolic pathways in microbes. Sphingobium sp. SYK-6 (SYK-6) is a well-characterized aromatic catabolic organism that has served as a model for microbial lignin conversion, and its utility as a biocatalyst could potentially be further improved by genome-wide metabolic analyses. To this end, we generate a randomly barcoded transposon insertion mutant (RB-TnSeq) library to study gene function in SYK-6. The library is enriched under dozens of enrichment conditions to quantify gene fitness. Several known aromatic catabolic pathways are confirmed, and RB-TnSeq affords additional detail on the genome-wide effects of each enrichment condition. Selected genes are further examined in SYK-6 or Pseudomonas putida KT2440, leading to the identification of new gene functions. The findings from this study further elucidate the metabolism of SYK-6, while also providing targets for future metabolic engineering in this organism or other hosts for the biological valorization of lignin.
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Affiliation(s)
- Alissa Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Ryo Kato
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan
| | - Zoe A Kellermyer
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Rui Katahira
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Masahiro Miyamoto
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan
| | - Koh Niinuma
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan
| | - Naofumi Kamimura
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan
| | - Eiji Masai
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
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20
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Kato R, Maekawa K, Kobayashi S, Hishiyama S, Katahira R, Nambo M, Higuchi Y, Kuatsjah E, Beckham GT, Kamimura N, Masai E. Stereoinversion via Alcohol Dehydrogenases Enables Complete Catabolism of β-1-Type Lignin-Derived Aromatic Isomers. Appl Environ Microbiol 2023; 89:e0017123. [PMID: 37184397 PMCID: PMC10304671 DOI: 10.1128/aem.00171-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/24/2023] [Indexed: 05/16/2023] Open
Abstract
Sphingobium sp. strain SYK-6 is an efficient aromatic catabolic bacterium that can consume all four stereoisomers of 1,2-diguaiacylpropane-1,3-diol (DGPD), which is a ring-opened β-1-type dimer. Recently, LdpA-mediated catabolism of erythro-DGPD was reported in SYK-6, but the catabolic pathway for threo-DGPD was as yet unknown. Here, we elucidated the catabolism of threo-DGPD, which proceeds through conversion to erythro-DGPD. When threo-DGPD was incubated with SYK-6, the Cα hydroxy groups of threo-DGPD (DGPD I and II) were initially oxidized to produce the Cα carbonyl form (DGPD-keto I and II). This initial oxidation step is catalyzed by Cα-dehydrogenases, which belong to the short-chain dehydrogenase/reductase (SDR) family and are involved in the catabolism of β-O-4-type dimers. Analysis of seven candidate genes revealed that NAD+-dependent LigD and LigL are mainly involved in the conversion of DGPD I and II, respectively. Next, we found that DGPD-keto I and II were reduced to erythro-DGPD (DGPD III and IV) in the presence of NADPH. Genes involved in this reduction were sought from Cα-dehydrogenase and ldpA-neighboring SDR genes. The gene products of SLG_12690 (ldpC) and SLG_12640 (ldpB) catalyzed the NADPH-dependent conversion of DGPD-keto I to DGPD III and DGPD-keto II to DGPD IV, respectively. Mutational analysis further indicated that ldpC and ldpB are predominantly involved in the reduction of DGPD-keto. Together, these results demonstrate that SYK-6 harbors a comprehensive catabolic enzyme system to utilize all four β-1-type stereoisomers through successive oxidation and reduction reactions of the Cα hydroxy group of threo-DGPD with a net stereoinversion using multiple dehydrogenases. IMPORTANCE In many catalytic depolymerization processes of lignin polymers, aryl-ether bonds are selectively cleaved, leaving carbon-carbon bonds between aromatic units intact, including dimers and oligomers with β-1 linkages. Therefore, elucidating the catabolic system of β-1-type lignin-derived compounds will aid in the establishment of biological funneling of heterologous lignin-derived aromatic compounds to value-added products. Here, we found that threo-DGPD was converted by successive stereoselective oxidation and reduction at the Cα position by multiple alcohol dehydrogenases to erythro-DGPD, which is further catabolized. This system is very similar to that developed to obtain enantiopure alcohols from racemic alcohols by artificially combining two enantiocomplementary alcohol dehydrogenases. The results presented here demonstrate that SYK-6 has evolved to catabolize all four stereoisomers of DGPD by incorporating this stereoinversion system into its native β-1-type dimer catabolic system.
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Affiliation(s)
- Ryo Kato
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Kodai Maekawa
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Shota Kobayashi
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Shojiro Hishiyama
- Department of Forest Resource Chemistry, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, Japan
| | - Rui Katahira
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Miki Nambo
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Yudai Higuchi
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Eugene Kuatsjah
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Gregg T. Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Naofumi Kamimura
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Eiji Masai
- Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
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21
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Ley Y, Cheng XY, Ying ZY, Zhou NY, Xu Y. Characterization of Two Marine Lignin-Degrading Consortia and the Potential Microbial Lignin Degradation Network in Nearshore Regions. Microbiol Spectr 2023; 11:e0442422. [PMID: 37042774 PMCID: PMC10269927 DOI: 10.1128/spectrum.04424-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/27/2023] [Indexed: 04/13/2023] Open
Abstract
Terrestrial organic carbon such as lignin is an important component of the global marine carbon. However, the structural complexity and recalcitrant nature of lignin are deemed challenging for biodegradation. It has been speculated that bacteria play important roles in lignin degradation in the marine system. However, the extent of the involvement of marine microorganisms in lignin degradation and their contribution to the oceanic carbon cycle remains elusive. In this study, two bacterial consortia capable of degrading alkali lignin (a model compound of lignin), designated LIG-B and LIG-S, were enriched from the nearshore sediments of the East and South China Seas. Consortia LIG-B and LIG-S mainly comprised of the Proteobacteria phylum with Nitratireductor sp. (71.6%) and Halomonas sp. (91.6%), respectively. Lignin degradation was found more favorable in consortium LIG-B (max 57%) than in LIG-S (max 18%). Ligninolytic enzymes laccase (Lac), manganese peroxidase (MnP), and lignin peroxidase (LiP) capable of decomposing lignin into smaller fragments were all active in both consortia. The newly emerged low-molecular-weight aromatics, organic acids, and other lignin-derived compounds in biotreated alkali lignin also evidently showed the depolymerization of lignin by both consortia. The lignin degradation pathways reconstructed from consortium LIG-S were found to be more comprehensive compared to consortium LIG-B. It was further revealed that catabolic genes, involved in the degradation of lignin and its derivatives through multiple pathways via protocatechuate and catechol, are present not only in lignin-degrading consortia LIG-B and LIG-S but also in 783 publicly available metagenomic-assembled genomes from nine nearshore regions. IMPORTANCE Numerous terrigenous lignin-containing plant materials are constantly discharged from rivers and estuaries into the marine system. However, only low levels of terrigenous organic carbon, especially lignin, are detected in the global marine system due to the abundance of active heterotrophic microorganisms driving the carbon cycle. Simultaneously, the lack of knowledge on lignin biodegradation has hindered our understanding of the oceanic carbon cycle. Moreover, bacteria have been speculated to play important roles in the marine lignin biodegradation. Here, we enriched two bacterial consortia from nearshore sediments capable of utilizing alkali lignin for cell growth while degrading it into smaller molecules and reconstructed the lignin degradation network. In particular, this study highlights that marine microorganisms in nearshore regions mostly undergo similar pathways using protocatechuate and catechol as ring-cleavage substrates to drive lignin degradation as part of the oceanic carbon cycle, regardless of whether they are in sediments or water column.
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Affiliation(s)
- Yvette Ley
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiao-Yu Cheng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhi-Yue Ying
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ying Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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22
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Liu J, Sun K, Zhu R, Wang X, Waigi MG, Li S. Biotransformation of bisphenol A in vivo and in vitro by laccase-producing Trametes hirsuta La-7: Kinetics, products, and mechanisms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 321:121155. [PMID: 36709035 DOI: 10.1016/j.envpol.2023.121155] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/13/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Bisphenol A (BPA) is a ubiquitous endocrine disruptor that poses adverse human health risks. Herein, biotransformation kinetics, products, and mechanisms of BPA undergoing a laccase-producing Trametes hirsuta La-7 metabolism were for the first time reported. Strain La-7 could completely biotransform ≤0.5 mmol·L-1 BPA within 6 d in vivo. Notably, its extracellular crude laccase solution (ECLS) and intracellular homogenized mycelium (HM) only required 6 h to convert 85.71% and 84.24% of 0.5 mmol·L-1 BPA in vitro, respectively. The removal of BPA was noticeably hampered by adding a cytochrome P-450 inhibitor (piperonyl butoxide) in HM, disclosing that cytochrome P-450 monooxygenase participated in BPA oxidation and metabolism. BPA intermediates were elaborately identified by high-resolution mass spectrometry (HRMS) combined with 13C stable isotope ratios (BPA: 13C12-BPA = 0.25: 0.25, molar concentration). Based on the accurate molecular mass, isotope labeling difference, and relative intensity ratio of product peaks, 6 versatile metabolic mechanisms of BPA, including polymerization, hydroxylation, dehydration, bond cleavage, dehydrogenation, and carboxylation in vivo and in vitro, were confirmed. Germination index values revealed that inoculating strain La-7 in a BPA-contaminated medium presented no phytotoxicity to the germinated radish (Raphanus sativus L.) seeds. In vivo, Mg2+, Fe2+, Fe3+, and Mn2+ were conducive to BPA removal, but Cd2+ and Hg2+ significantly obstructed BPA elimination. Additionally, strain La-7 also exhibited high-efficiency metabolic ability toward estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2), with more than 96.13%, 96.65%, and 100% of E1, E2, and EE2 having been converted, respectively. Our findings provide an environmentally powerful laccase-producing fungus to decontaminate endocrine disruptor-contaminated water matrices by radical polymerization and oxidative decomposition.
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Affiliation(s)
- Jie Liu
- Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Kai Sun
- Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei, 230036, Anhui, China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, 230026, Anhui, China.
| | - Rui Zhu
- Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Xun Wang
- Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Michael Gatheru Waigi
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Shunyao Li
- Laboratory of Wetland Protection and Ecological Restoration, Anhui University, Hefei, 230601, Anhui, China
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23
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Werner AZ, Eltis LD. Tandem chemocatalysis and biological funneling to valorize lignin. Trends Biotechnol 2023; 41:270-272. [PMID: 36535815 DOI: 10.1016/j.tibtech.2022.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
In 2014, Linger et al. presented a tandem process for lignin valorization by integrating chemical and biological catalysis. Chemical pretreatment of corn stover generated mixed lignocellulose-derived monomers that were converted to a single product, polyhydroxyalkanoates, by Pseudomonas putida. Tandem processes have since been developed for diverse feedstocks to support the bioeconomy.
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Affiliation(s)
- Allison Z Werner
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA.
| | - Lindsay D Eltis
- Department of Microbiology and Immunology, Life Sciences Institute, BioProducts Institute, The University of British Columbia, Vancouver, BC, Canada.
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24
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Grimm C, Pompei S, Egger K, Fuchs M, Kroutil W. Anaerobic demethylation of guaiacyl-derived monolignols enabled by a designed artificial cobalamin methyltransferase fusion enzyme. RSC Adv 2023; 13:5770-5777. [PMID: 36816070 PMCID: PMC9930637 DOI: 10.1039/d2ra08005b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/06/2023] [Indexed: 02/17/2023] Open
Abstract
Lignin-derived aryl methyl ethers (e.g. coniferyl alcohol, ferulic acid) are expected to be a future carbon source for chemistry. The well-known P450 dependent biocatalytic O-demethylation of these aryl methyl ethers is prone to side product formation especially for the oxidation sensitive catechol products which get easily oxidized in the presence of O2. Alternatively, biocatalytic demethylation using cobalamin dependent enzymes may be used under anaerobic conditions, whereby two proteins, namely a methyltransferase and a carrier protein are required. To make this approach applicable for preparative transformations, fusion proteins were designed connecting the cobalamin-dependent methyltransferase (MT) with the corrinoid-binding protein (CP) from Desulfitobacterium hafniense by variable glycine linkers. From the proteins created, the fusion enzyme MT-L5-CP with the shortest linker performed best of all fusion enzymes investigated showing comparable and, in some aspects, even better performance than the separated proteins. The fusion enzymes provided several advantages like that the cobalamin cofactor loading step required originally for the CP could be skipped enabling a significantly simpler protocol. Consequently, the biocatalytic demethylation was performed using Schlenk conditions allowing the O-demethylation e.g. of the monolignol coniferyl alcohol on a 25 mL scale leading to 75% conversion. The fusion enzyme represents a promising starting point to be evolved for alternative demethylation reactions to diversify natural products and to valorize lignin.
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Affiliation(s)
- Christopher Grimm
- Institute of Chemistry, University of Graz, NAWI Graz Heinrichstraße 28 8010 Graz Austria
| | - Simona Pompei
- Institute of Chemistry, University of Graz, NAWI Graz Heinrichstraße 28 8010 Graz Austria
| | - Kristina Egger
- Institute of Chemistry, University of Graz, NAWI Graz Heinrichstraße 28 8010 Graz Austria
| | - Michael Fuchs
- Institute of Chemistry, University of Graz, NAWI Graz Heinrichstraße 28 8010 Graz Austria
| | - Wolfgang Kroutil
- Institute of Chemistry, University of Graz, NAWI Graz Heinrichstraße 28 8010 Graz Austria .,BioTechMed Graz 8010 Graz Austria.,Field of Excellence BioHealth, University of Graz 8010 Graz Austria
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25
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Rogers MS, Gordon AM, Rappe TM, Goodpaster JD, Lipscomb JD. Contrasting Mechanisms of Aromatic and Aryl-Methyl Substituent Hydroxylation by the Rieske Monooxygenase Salicylate 5-Hydroxylase. Biochemistry 2023; 62:507-523. [PMID: 36583545 PMCID: PMC9854337 DOI: 10.1021/acs.biochem.2c00610] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hydroxylase component (S5HH) of salicylate-5-hydroxylase catalyzes C5 ring hydroxylation of salicylate but switches to methyl hydroxylation when a C5 methyl substituent is present. The use of 18O2 reveals that both aromatic and aryl-methyl hydroxylations result from monooxygenase chemistry. The functional unit of S5HH comprises a nonheme Fe(II) site located 12 Å across a subunit boundary from a one-electron reduced Rieske-type iron-sulfur cluster. Past studies determined that substrates bind near the Fe(II), followed by O2 binding to the iron to initiate catalysis. Stopped-flow-single-turnover reactions (STOs) demonstrated that the Rieske cluster transfers an electron to the iron site during catalysis. It is shown here that fluorine ring substituents decrease the rate constant for Rieske electron transfer, implying a prior reaction of an Fe(III)-superoxo intermediate with a substrate. We propose that the iron becomes fully oxidized in the resulting Fe(III)-peroxo-substrate-radical intermediate, allowing Rieske electron transfer to occur. STO using 5-CD3-salicylate-d8 occurs with an inverse kinetic isotope effect (KIE). In contrast, STO of a 1:1 mixture of unlabeled and 5-CD3-salicylate-d8 yields a normal product isotope effect. It is proposed that aromatic and aryl-methyl hydroxylation reactions both begin with the Fe(III)-superoxo reaction with a ring carbon, yielding the inverse KIE due to sp2 → sp3 carbon hybridization. After Rieske electron transfer, the resulting Fe(III)-peroxo-salicylate intermediate can continue to aromatic hydroxylation, whereas the equivalent aryl-methyl intermediate formation must be reversible to allow the substrate exchange necessary to yield a normal product isotope effect. The resulting Fe(III)-(hydro)peroxo intermediate may be reactive or evolve through a high-valent iron intermediate to complete the aryl-methyl hydroxylation.
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Affiliation(s)
- Melanie S. Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Adrian M. Gordon
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Todd M. Rappe
- Minnesota NMR Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jason D. Goodpaster
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
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26
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Systems metabolic engineering upgrades Corynebacterium glutamicum to high-efficiency cis, cis-muconic acid production from lignin-based aromatics. Metab Eng 2023; 75:153-169. [PMID: 36563956 DOI: 10.1016/j.ymben.2022.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/14/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022]
Abstract
Lignin displays a highly challenging renewable. To date, massive amounts of lignin, generated in lignocellulosic processing facilities, are for the most part merely burned due to lacking value-added alternatives. Aromatic lignin monomers of recognized relevance are in particular vanillin, and to a lesser extent vanillate, because they are accessible at high yield from softwood-lignin using industrially operated alkaline oxidative depolymerization. Here, we metabolically engineered C. glutamicum towards cis, cis-muconate (MA) production from these key aromatics. Starting from the previously created catechol-based producer C. glutamicum MA-2, systems metabolic engineering first discovered an unspecific aromatic aldehyde reductase that formed aromatic alcohols from vanillin, protocatechualdehyde, and p- hydroxybenzaldehyde, and was responsible for the conversion up to 57% of vanillin into vanillyl alcohol. The alcohol was not re-consumed by the microbe later, posing a strong drawback on the producer. The identification and subsequent elimination of the encoding fudC gene completely abolished vanillyl alcohol formation. Second, the initially weak flux through the native vanillin and vanillate metabolism was enhanced up to 2.9-fold by implementing synthetic pathway modules. Third, the most efficient protocatechuate decarboxylase AroY for conversion of the midstream pathway intermediate protocatechuate into catechol was identified out of several variants in native and codon optimized form and expressed together with the respective helper proteins. Fourth, the streamlined modules were all genomically combined which yielded the final strain MA-9. MA-9 produced bio-based MA from vanillin, vanillate, and seven structurally related aromatics at maximum selectivity. In addition, MA production from softwood-based vanillin, obtained through alkaline depolymerization, was demonstrated.
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27
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Li F, Zhao Y, Xue L, Ma F, Dai SY, Xie S. Microbial lignin valorization through depolymerization to aromatics conversion. Trends Biotechnol 2022; 40:1469-1487. [PMID: 36307230 DOI: 10.1016/j.tibtech.2022.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/17/2022] [Accepted: 09/19/2022] [Indexed: 11/05/2022]
Abstract
Lignin is the most abundant source of renewable aromatic biopolymers and its valorization presents significant value for biorefinery sustainability, which promotes the utilization of renewable resources. However, it is challenging to fully convert the structurally complex, heterogeneous, and recalcitrant lignin into high-value products. The in-depth research on the lignin degradation mechanism, microbial metabolic pathways, and rational design of new systems using synthetic biology have significantly accelerated the development of lignin valorization. This review summarizes the key enzymes involved in lignin depolymerization, the mechanisms of microbial lignin conversion, and the lignin valorization application with integrated systems and synthetic biology. Current challenges and future strategies to further study lignin biodegradation and the trends of lignin valorization are also discussed.
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Affiliation(s)
- Fei Li
- Department of Biotechnology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yiquan Zhao
- Department of Biotechnology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Le Xue
- Department of Biotechnology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Fuying Ma
- Department of Biotechnology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Susie Y Dai
- Department of Plant Pathology and Microbiology, Texas A&M University, College station, TX 77843, USA.
| | - Shangxian Xie
- Department of Biotechnology, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
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28
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Liu ZH, Li BZ, Yuan JS, Yuan YJ. Creative biological lignin conversion routes toward lignin valorization. Trends Biotechnol 2022; 40:1550-1566. [PMID: 36270902 DOI: 10.1016/j.tibtech.2022.09.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/18/2022] [Accepted: 09/22/2022] [Indexed: 11/05/2022]
Abstract
Lignin, the largest renewable aromatic resource, is a promising alternative feedstock for the sustainable production of various chemicals, fuels, and materials. Despite this potential, lignin is characterized by heterogeneous and macromolecular structures that must be addressed. In this review, we present biological lignin conversion routes (BLCRs) that offer opportunities for overcoming these challenges, making lignin valorization feasible. Funneling heterogeneous aromatics via a 'biological funnel' offers a high-specificity bioconversion route for aromatic platform chemicals. The inherent aromaticity of lignin drives atom-economic functionalization routes toward aromatic natural product generation. By harnessing the ligninolytic capacities of specific microbial systems, powerful aromatic ring-opening routes can be developed to generate various value-added products. Thus, BLCRs hold the promise to make lignin valorization feasible and enable a lignocellulose-based bioeconomy.
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Affiliation(s)
- Zhi-Hua Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Bing-Zhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
| | - Joshua S Yuan
- Department of Energy, Environmental, and Chemical Engineering, The McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
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29
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Xu Z, Peng B, Kitata RB, Nicora CD, Weitz KK, Pu Y, Shi T, Cort JR, Ragauskas AJ, Yang B. Understanding of bacterial lignin extracellular degradation mechanisms by Pseudomonas putida KT2440 via secretomic analysis. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:117. [PMID: 36316752 PMCID: PMC9620641 DOI: 10.1186/s13068-022-02214-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 10/12/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Bacterial lignin degradation is believed to be primarily achieved by a secreted enzyme system. Effects of such extracellular enzyme systems on lignin structural changes and degradation pathways are still not clearly understood, which remains as a bottleneck in the bacterial lignin bioconversion process. RESULTS This study investigated lignin degradation using an isolated secretome secreted by Pseudomonas putida KT2440 that grew on glucose as the only carbon source. Enzyme assays revealed that the secretome harbored oxidase and peroxidase/Mn2+-peroxidase capacity and reached the highest activity at 120 h of the fermentation time. The degradation rate of alkali lignin was found to be only 8.1% by oxidases, but increased to 14.5% with the activation of peroxidase/Mn2+-peroxidase. Gas chromatography-mass spectrometry (GC-MS) and two-dimensional 1H-13C heteronuclear single-quantum coherence (HSQC) NMR analysis revealed that the oxidases exhibited strong C-C bond (β-β, β-5, and β-1) cleavage. The activation of peroxidases enhanced lignin degradation by stimulating C-O bond (β-O-4) cleavage, resulting in increased yields of aromatic monomers and dimers. Further mass spectrometry-based quantitative proteomics measurements comprehensively identified different groups of enzymes particularly oxidoreductases in P. putida secretome, including reductases, peroxidases, monooxygenases, dioxygenases, oxidases, and dehydrogenases, potentially contributed to the lignin degradation process. CONCLUSIONS Overall, we discovered that bacterial extracellular degradation of alkali lignin to vanillin, vanillic acid, and other lignin-derived aromatics involved a series of oxidative cleavage, catalyzed by active DyP-type peroxidase, multicopper oxidase, and other accessory enzymes. These results will guide further metabolic engineering design to improve the efficiency of lignin bioconversion.
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Affiliation(s)
- Zhangyang Xu
- grid.451303.00000 0001 2218 3491Bioproducts, Sciences & Engineering Laboratory, Department of Biological Systems Engineering, ashington State University Tri-Cities, Joint Appointment: Pacific Northwest National Laboratory, 2710 Crimson Way, Richland, WA 99354 USA
| | - Bo Peng
- grid.451303.00000 0001 2218 3491Bioproducts, Sciences & Engineering Laboratory, Department of Biological Systems Engineering, ashington State University Tri-Cities, Joint Appointment: Pacific Northwest National Laboratory, 2710 Crimson Way, Richland, WA 99354 USA
| | - Reta Birhanu Kitata
- grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 USA
| | - Carrie D. Nicora
- grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 USA
| | - Karl K. Weitz
- grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 USA
| | - Yunqiao Pu
- grid.135519.a0000 0004 0446 2659Joint Institute for Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Tujin Shi
- grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 USA
| | - John R. Cort
- grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 USA
| | - Arthur J. Ragauskas
- grid.135519.a0000 0004 0446 2659Joint Institute for Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA ,grid.411461.70000 0001 2315 1184Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996 USA ,grid.411461.70000 0001 2315 1184Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, University of Tennessee Institute of Agriculture, Knoxville, TN 37996 USA
| | - Bin Yang
- grid.451303.00000 0001 2218 3491Bioproducts, Sciences & Engineering Laboratory, Department of Biological Systems Engineering, ashington State University Tri-Cities, Joint Appointment: Pacific Northwest National Laboratory, 2710 Crimson Way, Richland, WA 99354 USA ,grid.451303.00000 0001 2218 3491Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352 USA
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30
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Vermaas JV, Crowley MF, Beckham GT. Molecular simulation of lignin-related aromatic compound permeation through gram-negative bacterial outer membranes. J Biol Chem 2022; 298:102627. [PMID: 36273587 PMCID: PMC9720347 DOI: 10.1016/j.jbc.2022.102627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 12/12/2022] Open
Abstract
Lignin, an abundant aromatic heteropolymer in secondary plant cell walls, is the single largest source of renewable aromatics in the biosphere. Leveraging this resource for renewable bioproducts through targeted microbial action depends on lignin fragment uptake by microbial hosts and subsequent enzymatic action to obtain the desired product. Recent computational work has emphasized that bacterial inner membranes are permeable to many aromatic compounds expected from lignin depolymerization processes. In this study, we expand on these findings through simulations for 42 lignin-related compounds across a gram-negative bacterial outer membrane model. Unbiased simulation trajectories indicate that spontaneous crossing for the full outer membrane is relatively rare at molecular simulation timescales, primarily due to preferential membrane partitioning and slow diffusion within the lipopolysaccharide layer within the outer membrane. Membrane partitioning and permeability coefficients were determined through replica exchange umbrella sampling simulations to overcome sampling limitations. We find that the glycosylated lipopolysaccharides found in the outer membrane increase the permeation barrier to many lignin-related compounds, particularly the most hydrophobic compounds. However, the effect is relatively modest; at industrially relevant concentrations, uncharged lignin-related compounds will readily diffuse across the outer membrane without the need for specific porins. Together, our results provide insight into the permeability of the bacterial outer membrane for assessing lignin fragment uptake and the future production of renewable bioproducts.
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Affiliation(s)
- Josh V. Vermaas
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA,National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA,MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA,For correspondence: Josh V. Vermaas; Michael F. Crowley; Gregg T. Beckham
| | - Michael F. Crowley
- Renewable Resources and Enabling Sciences Center, National Renewable Energy, Laboratory, Golden, Colorado, USA,For correspondence: Josh V. Vermaas; Michael F. Crowley; Gregg T. Beckham
| | - Gregg T. Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy, Laboratory, Golden, Colorado, USA,For correspondence: Josh V. Vermaas; Michael F. Crowley; Gregg T. Beckham
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31
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Recent Advancements and Challenges in Lignin Valorization: Green Routes towards Sustainable Bioproducts. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27186055. [PMID: 36144795 PMCID: PMC9500909 DOI: 10.3390/molecules27186055] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/10/2022] [Accepted: 09/13/2022] [Indexed: 11/27/2022]
Abstract
The aromatic hetero-polymer lignin is industrially processed in the paper/pulp and lignocellulose biorefinery, acting as a major energy source. It has been proven to be a natural resource for useful bioproducts; however, its depolymerization and conversion into high-value-added chemicals is the major challenge due to the complicated structure and heterogeneity. Conversely, the various pre-treatments techniques and valorization strategies offers a potential solution for developing a biomass-based biorefinery. Thus, the current review focus on the new isolation techniques for lignin, various pre-treatment approaches and biocatalytic methods for the synthesis of sustainable value-added products. Meanwhile, the challenges and prospective for the green synthesis of various biomolecules via utilizing the complicated hetero-polymer lignin are also discussed.
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32
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Sohn YJ, Son J, Lim HJ, Lim SH, Park SJ. Valorization of lignocellulosic biomass for polyhydroxyalkanoate production: Status and perspectives. BIORESOURCE TECHNOLOGY 2022; 360:127575. [PMID: 35792330 DOI: 10.1016/j.biortech.2022.127575] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
With the increasing concerns regarding climate, energy, and plastic crises, bio-based production of biodegradable polymers has become a dire necessity. Significant progress has been made in biotechnology for the production of biodegradable polymers from renewable resources to achieve the goal of zero plastic waste and a net-zero carbon bioeconomy. In this review, an overview of polyhydroxyalkanoate (PHA) production from lignocellulosic biomass (LCB) was presented. Having established LCB-based biorefinery with proper pretreatment techniques, various PHAs could be produced from LCB-derived sugars, hydrolysates, and/or aromatic mixtures employing microorganisms. This provides a clue for addressing the current environmental crises because "biodegradable polymers" could be produced from one of the most abundant resources that are renewable and sustainable in a "carbon-neutral process". Furthermore, the potential future of LCB-to-non-natural PHA production was discussed with particular reference to non-natural PHA biosynthesis methods and LCB-derived aromatic mixture biofunnelling systems.
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Affiliation(s)
- Yu Jung Sohn
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jina Son
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hye Jin Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Seo Hyun Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea.
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33
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Cai C, Xu Z, Li J, Zhou H, Jin M. Developing
Rhodococcus opacus
and
Sphingobium
sp. co‐culture systems for valorization of lignin‐derived dimers. Biotechnol Bioeng 2022; 119:3162-3177. [DOI: 10.1002/bit.28215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/17/2022] [Accepted: 08/21/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Chenggu Cai
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
| | - Zhaoxian Xu
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
| | - Jie Li
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
| | - Huarong Zhou
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
| | - Mingjie Jin
- School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing210094China
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34
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Xu T, Zong QJ, Liu H, Wang L, Liu ZH, Li BZ, Yuan YJ. Identifying ligninolytic bacteria for lignin valorization to bioplastics. BIORESOURCE TECHNOLOGY 2022; 358:127383. [PMID: 35644455 DOI: 10.1016/j.biortech.2022.127383] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Biological valorization of lignin to bioplastics is a promising route to improve biorefinery efficiency and address environmental challenges. A two-stage screening procedure had been designed to successfully identify four ligninolytic bacteria from soil samples. The isolated bacteria displayed substrate preference of guaiacyl- and hydroxyphenyl-based aromatics, but they effectively synthesized polyhydroxyalkanoates (PHAs). B. cepacia B1-2 and P. putida KT3-1 accumulated 27.3% and 20.9% PHA in cells and achieved a titer of 280.9 and 204.1 mg/L, respectively, from p-hydroxybenzoic acid. The isolated bacteria exhibited good ligninolytic performance indicated by the degradation of β-O-4 linkage and small molecules. B. cepacia B1-2 grew well on actual lignin substrate and yielded a PHA titer of 87.2 mg/L. With the design of fed-batch mode, B. cepacia B1-2 produced the highest PHA titer of 1420 mg/L from lignin-derived aromatics. Overall, isolated ligninolytic bacteria show good PHA accumulation capacity, which are the promising host strains for lignin valorization.
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Affiliation(s)
- Tao Xu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Qiu-Jin Zong
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - He Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Li Wang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Zhi-Hua Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
| | - Bing-Zhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China
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35
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Luo H, Liu X, Yu D, Yuan J, Tan J, Li H. Research Progress on Lignocellulosic Biomass Degradation Catalyzed by Enzymatic Nanomaterials. Chem Asian J 2022; 17:e202200566. [PMID: 35862657 DOI: 10.1002/asia.202200566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/21/2022] [Indexed: 11/11/2022]
Abstract
Lignocellulose biomass (LCB) has extensive applications in many fields such as bioenergy, food, medicines, and raw materials for producing value-added products. One of the keys to efficient utilization of LCB is to obtain directly available oligo- and monomers (e.g., glucose). With the characteristics of easy recovery and separation, high efficiency, economy, and environmental protection, immobilized enzymes have been developed as heterogeneous catalysts to degrade LCB effectively. In this review, applications and mechanisms of LCB-degrading enzymes are discussed, and the nanomaterials and methods used to immobilize enzymes are also discussed. Finally, the research progress of lignocellulose biodegradation catalyzed by nano-enzymes was discussed.
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Affiliation(s)
- Hangyu Luo
- Guiyang University, College of Biology and Environmental Engineering, CHINA
| | - Xiaofang Liu
- Guiyang University, College of Biology and Environmental Engineering, CHINA
| | - Dayong Yu
- Guiyang University, College of Biology and Environmental Engineering, CHINA
| | - Junfa Yuan
- Guizhou University, Center for R&D of Fine Chemicals, CHINA
| | - Jinyu Tan
- Guizhou University, Center for R&D of Fine Chemicals, CHINA
| | - Hu Li
- Guizhou University, Center for R&D of Fine Chemicals, Huaxi Street, 550025, Guiyang, CHINA
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36
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Zhou H, Wang Y, Ren Y, Li Z, Kong X, Shao M, Duan H. Plastic Waste Valorization by Leveraging Multidisciplinary Catalytic Technologies. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Hua Zhou
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Ye Wang
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yue Ren
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhenhua Li
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xianggui Kong
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Mingfei Shao
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
| | - Haohong Duan
- Department of Chemistry, Tsinghua University, Beijing 100084, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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37
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Jayasekara S, Dissanayake L, Jayakody LN. Opportunities in the microbial valorization of sugar industrial organic waste to biodegradable smart food packaging materials. Int J Food Microbiol 2022; 377:109785. [PMID: 35752069 DOI: 10.1016/j.ijfoodmicro.2022.109785] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/12/2022] [Accepted: 06/07/2022] [Indexed: 12/20/2022]
Abstract
Many petroleum-derived plastics, including food packaging materials are non-biodegradable and designed for single-use applications. Annually, around 175 Mt. of plastic enters the land and ocean ecosystems due to mismanagement and lack of techno economically feasible plastic waste recycling technologies. Renewable sourced, biodegradable polymer-based food packaging materials can reduce this environmental pollution. Sugar production from sugarcane or sugar beet generates organic waste streams that contain fermentable substrates, including sugars, acids, and aromatics. Microbial metabolism can be leveraged to funnel those molecules to platform chemicals or biopolymers to generate biodegradable food packaging materials that have active or sensing molecules embedded in biopolymer matrices. The smart package can real-time monitor food quality, assure health safety, and provide economic and environmental benefits. Active packaging materials display functional properties such as antimicrobial, antioxidant, and light or gas barrier. This article provides an overview of potential biodegradable smart/active polymer packages for food applications by valorizing sugar industry-generated organic waste. We highlight the potential microbial pathways and metabolic engineering strategies to biofunnel the waste carbon efficiently into the targeted platform chemicals such as lactic, succinate, muconate, and biopolymers, including polyhydroxyalkanoates, and bacterial cellulose. The obtained platform chemicals can be used to produce biodegradable polymers such as poly (butylene adipate-co-terephthalate) (PBAT) that could replace incumbent polyethylene and polypropylene food packaging materials. When nanomaterials are added, these polymers can be active/smart. The process can remarkably lower the greenhouse gas emission and energy used to produce food-packaging material via sugar industrial waste carbon relative to the petroleum-based production. The proposed green routes enable the valorization of sugar processing organic waste into biodegradable materials and enable the circular economy.
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Affiliation(s)
- Sandhya Jayasekara
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Lakshika Dissanayake
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Lahiru N Jayakody
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA; Fermentation Science Institute, Southern Illinois University Carbondale, Carbondale, IL, USA.
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38
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Zong QJ, Xu T, Liu H, Xu L, Zhang RK, Li BZ, Liu ZH, Yuan YJ. Microbial Valorization of Lignin to Bioplastic by Genome-Reduced Pseudomonas putida. Front Microbiol 2022; 13:923664. [PMID: 35707171 PMCID: PMC9189415 DOI: 10.3389/fmicb.2022.923664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 05/09/2022] [Indexed: 11/13/2022] Open
Abstract
As the most abundant natural aromatic resource, lignin valorization will contribute to a feasible biobased economy. Recently, biological lignin valorization has been advocated since ligninolytic microbes possess proficient funneling pathways of lignin to valuable products. In the present study, the potential to convert an actual lignin stream into polyhydroxyalkanoates (PHAs) had been evaluated using ligninolytic genome-reduced Pseudomonas putida. The results showed that the genome-reduced P. putida can grow well on an actual lignin stream to successfully yield a high PHA content and titer. The designed fermentation strategy almost eliminated the substrate effects of lignin on PHA accumulation. Employing a fed-batch strategy produced the comparable PHA contents and titers of 0.35 g/g dried cells and 1.4 g/L, respectively. The molecular mechanism analysis unveiled that P. putida consumed more small and hydrophilic lignin molecules to stimulate cell growth and PHA accumulation. Overall, the genome-reduced P. putida exhibited a superior capacity of lignin bioconversion and promote PHA accumulation, providing a promising route for sustainable lignin valorization.
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39
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Harlington AC, Shearwin KE, Bell SG, Whelan F. Efficient O-demethylation of lignin monoaromatics using the peroxygenase activity of cytochrome P450 enzymes. Chem Commun (Camb) 2022; 58:13321-13324. [DOI: 10.1039/d2cc04698a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Selective O-demethylation of the lignin monoaromatics, syringol and guaiacol, using the peroxygenase activity of two distinct cytochrome P450 enzymes.
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Affiliation(s)
- Alix C. Harlington
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Keith E. Shearwin
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Stephen G. Bell
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia
| | - Fiona Whelan
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
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