scholarly journals Combining pieces: a thorough analysis of light activation boosting power and co-substrate preferences for the catalytic efficiency of lytic polysaccharide monooxygenase MtLPMO9A

2021 ◽  
Vol 8 (3) ◽  
pp. 1454-1464
Author(s):  
Ana Gabriela V. Sepulchro ◽  
Vanessa O.A. Pellegrini ◽  
Lucas D. Dias ◽  
Marco A.S. Kadowaki ◽  
David Cannella ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Biomass Conversion ◽  
Direct Electron Transfer ◽  
Catalytic Efficiency ◽  
Reaction Products ◽  
Lytic Polysaccharide Monooxygenase ◽  
Substrate Preferences ◽  
Polysaccharide Monooxygenases ◽  
Significant Release ◽  
Cost Efficient

Cost-efficient plant biomass conversion using biochemical and/or chemical routes is essential for transitioning to sustainable chemical technologies and renewable biofuels. Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that make part of modern hydrolytic cocktails destined for plant biomass degradation. Here, we characterized MtLPMO9A from Thermothelomyces thermophilus M77 (formerly Myceliophthora thermophila) and demonstrated that it could be efficiently driven by chlorophyllin excited by light in the presence of a reductant agent. However, in the absence of chemical reductant, chlorophyllin and light alone do not lead to a significant release of the reaction products by the LPMO, indicating a low capacity of MtLPMO9A reduction (either via direct electron transfer or via superoxide ion, O2•-). We showed that photocatalysis could significantly increase the LPMO activity against highly crystalline and recalcitrant cellulosic substrates, which are poorly degraded in the absence of chlorophyllin and light. We also evaluated the use of co-substrates by MtLPMO9A, revealing that the enzyme can use both hydrogen peroxide (H2O2) and molecular oxygen (O2) as co-substrates for cellulose catalytic oxidation.

scholarly journals Recent Advances in Screening Methods for the Functional Investigation of Lytic Polysaccharide Monooxygenases

2021 ◽  
Vol 9 ◽  
Author(s):  
Damao Wang ◽  
Yanping Li ◽  
Yuting Zheng ◽  
Yves S. Y. Hsieh
Keyword(s):  
Copper Ions ◽  
Biomass Conversion ◽  
Screening Methods ◽  
Lytic Polysaccharide Monooxygenase ◽  
Indirect Measurements ◽  
Glycosidic Bonds ◽  
Lytic Polysaccharide Monooxygenases ◽  
Polysaccharide Monooxygenases ◽  
Functional Investigation ◽  
Polysaccharide Monooxygenase

Lytic polysaccharide monooxygenase (LPMO) is a newly discovered and widely studied enzyme in recent years. These enzymes play a key role in the depolymerization of sugar-based biopolymers (including cellulose, hemicellulose, chitin and starch), and have a positive significance for biomass conversion. LPMO is a copper-dependent enzyme that can oxidize and cleave glycosidic bonds in cellulose and other polysaccharides. Their mechanism of action depends on the correct coordination of copper ions in the active site. There are still difficulties in the analysis of LPMO activity, which often requires multiple methods to be used in concert. In this review, we discussed various LPMO activity analysis methods reported so far, including mature mass spectrometry, chromatography, labeling, and indirect measurements, and summarized the advantages, disadvantages and applicability of different methods.

scholarly journals Water-soluble chlorophyll-binding proteins from Brassica oleracea allow for stable photobiocatalytic oxidation of cellulose by a lytic polysaccharide monooxygenase

2020 ◽  
Author(s):  
N. Dodge ◽  
D. A. Russo ◽  
B.M. Blossom ◽  
R.K. Singh ◽  
B. van Oort ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Plant Biomass ◽  
Light Exposure ◽  
Water Soluble ◽  
Lytic Polysaccharide Monooxygenase ◽  
Cellulose Oxidation ◽  
Biomass Processing ◽  
Polysaccharide Monooxygenases ◽  
Cellulose Depolymerization

Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are indispensable redox enzymes used in industry for the saccharification of plant biomass. LPMO-driven cellulose oxidation can be enhanced considerably through photobiocatalysis using chlorophyll derivatives and light. Water soluble chlorophyll binding proteins (WSCPs) make it is possible to stabilize and solubilize chlorophyll in aqueous solution, allowing for in vitro studies on photostability and ROS production. Here we aim apply a WSCP-Chl a as a photosensitizing complex for photobiocatalysis with the LPMO, TtAA9. Results We have in this study demonstrated how WSCP reconstituted with chlorophyll a (WSCP-Chl a) can create a stable photosensitizing complex which produces controlled amounts of H2O2 in the presence of ascorbic acid and light. WSCP-Chl a is highly reactive and allows for tightly controlled formation of H2O2 by regulating light intensity. TtAA9 together with WSCP-Chl a shows increased cellulose oxidation under low light conditions, and the WSCP-Chl a complex remains stable after 24 hours of light exposure. Additionally, the WSCP-Chl a complex demonstrates stability over a range of temperatures and pH conditions relevant for enzyme activity in industrial settings. Conclusion With WSCP-Chl a as the photosensitizer, the need to replenish Chl is greatly reduced, enhancing the catalytic lifetime of light-driven LPMOs and increasing the efficiency of cellulose depolymerization. WSCP-Chl a allows for stable photobiocatalysis providing a sustainable solution for biomass processing.

scholarly journals Water-soluble chlorophyll-binding proteins from Brassica oleracea allow for stable photobiocatalytic oxidation of cellulose by a lytic polysaccharide monooxygenase

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
N. Dodge ◽  
D. A. Russo ◽  
B. M. Blossom ◽  
R. K. Singh ◽  
B. van Oort ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Plant Biomass ◽  
Light Exposure ◽  
Water Soluble ◽  
Lytic Polysaccharide Monooxygenase ◽  
Cellulose Oxidation ◽  
Biomass Processing ◽  
Polysaccharide Monooxygenases ◽  
Cellulose Depolymerization

Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are indispensable redox enzymes used in industry for the saccharification of plant biomass. LPMO-driven cellulose oxidation can be enhanced considerably through photobiocatalysis using chlorophyll derivatives and light. Water soluble chlorophyll binding proteins (WSCPs) make it is possible to stabilize and solubilize chlorophyll in aqueous solution, allowing for in vitro studies on photostability and ROS production. Here we aim to apply WSCP–Chl a as a photosensitizing complex for photobiocatalysis with the LPMO, TtAA9. Results We have in this study demonstrated how WSCP reconstituted with chlorophyll a (WSCP–Chl a) can create a stable photosensitizing complex which produces controlled amounts of H2O2 in the presence of ascorbic acid and light. WSCP–Chl a is highly reactive and allows for tightly controlled formation of H2O2 by regulating light intensity. TtAA9 together with WSCP–Chl a shows increased cellulose oxidation under low light conditions, and the WSCP–Chl a complex remains stable after 24 h of light exposure. Additionally, the WSCP–Chl a complex demonstrates stability over a range of temperatures and pH conditions relevant for enzyme activity in industrial settings. Conclusion With WSCP–Chl a as the photosensitizer, the need to replenish Chl is greatly reduced, enhancing the catalytic lifetime of light-driven LPMOs and increasing the efficiency of cellulose depolymerization. WSCP–Chl a allows for stable photobiocatalysis providing a sustainable solution for biomass processing.

scholarly journals Synthesis of Glycoconjugates Utilizing the Regioselectivity of a Lytic Polysaccharide Monooxygenase

2020 ◽  
Author(s):  
Bjørge Westereng ◽  
Stjepan K. Kračun ◽  
Shaun Leivers ◽  
Magnus Ø. Arntzen ◽  
Finn L. Aachmann ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulose Degradation ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Lytic Polysaccharide Monooxygenase ◽  
Renewable Chemicals ◽  
Polysaccharide Monooxygenases ◽  
Chemical Coupling ◽  
Potential Biodegradability ◽  
Polysaccharide Monooxygenase

ABSTRACTPolysaccharides from plant biomass are the most abundant renewable chemicals on Earth and can potentially be converted to a wide variety of useful glycoconjugates. While anomeric hydroxyl groups of carbohydrates are amenable to a variety of useful chemical modifications, selective cross-coupling to non-reducing ends has remained challenging. Several lytic polysaccharide monooxygenases (LPMOs), powerful enzymes known for their application in cellulose degradation, specifically oxidize non-reducing ends, introducing carbonyl groups that can be utilized for chemical coupling. This study provides a simple and highly specific approach to produce oxime-based glycoconjugates from LPMO-functionalized oligosaccharides. The products are evaluated by HPLC, mass spectrometry and NMR. Furthermore, we demonstrate potential biodegradability of these glycoconjugates using selective enzymes.

scholarly journals Water-soluble chlorophyll-binding proteins from Brassica oleracea allow for stable photobiocatalytic oxidation of cellulose by a lytic polysaccharide monooxygenase.

2020 ◽  
Author(s):  
N. Dodge ◽  
D. A. Russo ◽  
B.M. Blossom ◽  
R.K. Singh ◽  
B. van Oort ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Plant Biomass ◽  
Light Exposure ◽  
Water Soluble ◽  
Lytic Polysaccharide Monooxygenase ◽  
Cellulose Oxidation ◽  
Biomass Processing ◽  
Polysaccharide Monooxygenases ◽  
Cellulose Depolymerization

Abstract Background: Lytic polysaccharide monooxygenases (LPMOs) are indispensable redox enzymes used in industry for the saccharification of plant biomass. LPMO-driven cellulose oxidation can be enhanced considerably through photobiocatalysis using chlorophyll derivatives and light. Water soluble chlorophyll binding proteins (WSCPs) make it is possible to stabilize and solubilize chlorophyll in aqueous solution, allowing for in vitro studies on photostability and ROS production. Here we aim apply a WSCP-Chl α as a photosensitizing complex for photobiocatalysis with the LPMO, TtAA9. Results: We have in this study demonstrated how WSCP reconstituted with chlorophyll a (WSCP-Chl α) can create a stable photosensitizing complex which produces controlled amounts of H2O2 in the presence of ascorbic acid and light. WSCP-Chl α is highly reactive and allows for tightly controlled formation of H2O2 by regulating light intensity. TtAA9 together with WSCP-Chl α shows increased cellulose oxidation under low light conditions, and the WSCP-Chl α complex remains stable after 24 hours of light exposure. Additionally, the WSCP-Chl α complex demonstrates stability over a range of temperatures and pH conditions relevant for enzyme activity in industrial settings.Conclusion: With WSCP-Chl α as the photosensitizer, the need to replenish Chl is greatly reduced, enhancing the catalytic lifetime of light-driven LPMOs and increasing the efficiency of cellulose depolymerization. WSCP-Chl α allows for stable photobiocatalysis providing a sustainable solution for biomass processing.

scholarly journals Structure of a C1/C4-oxidizing AA9 lytic polysaccharide monooxygenase from the thermophilic fungus Malbranchea cinnamomea

2021 ◽  
Vol 77 (8) ◽  
Author(s):  
Scott Mazurkewich ◽  
Andrea Seveso ◽  
Silvia Hüttner ◽  
Gisela Brändén ◽  
Johan Larsbrink
Keyword(s):  
Plant Cell Wall ◽  
Plant Biomass ◽  
Industrial Applications ◽  
Thermophilic Fungus ◽  
Lytic Polysaccharide Monooxygenase ◽  
Large Loop ◽  
Small Loop ◽  
Polysaccharide Monooxygenases ◽  
Equivalent Residue ◽  
Residue Substitution

The thermophilic fungus Malbranchea cinnamomea contains a host of enzymes that enable its ability as an efficient degrader of plant biomass and that could be mined for industrial applications. This thermophilic fungus has been studied and found to encode eight lytic polysaccharide monooxygenases (LPMOs) from auxiliary activity family 9 (AA9), which collectively possess different substrate specificities for a range of plant cell-wall-related polysaccharides and oligosaccharides. To gain greater insight into the molecular determinants defining the different specificities, structural studies were pursued and the structure of McAA9F was determined. The enzyme contains the immunoglobulin-like fold typical of previously solved AA9 LPMO structures, but contains prominent differences in the loop regions found on the surface of the substrate-binding site. Most significantly, McAA9F has a broad substrate specificity, with activity on both crystalline and soluble polysaccharides. Moreover, it contains a small loop in a region where a large loop has been proposed to govern specificity towards oligosaccharides. The presence of the small loop leads to a considerably flatter and more open surface that is likely to enable the broad specificity of the enzyme. The enzyme contains a succinimide residue substitution, arising from intramolecular cyclization of Asp10, at a position where several homologous members contain an equivalent residue but cyclization has not previously been observed. This first structure of an AA9 LPMO from M. cinnamomea aids both the understanding of this family of enzymes and the exploration of the repertoire of industrially relevant lignocellulolytic enzymes from this fungus.

scholarly journals A thermostable bacterial lytic polysaccharide monooxygenase with high operational stability in a wide temperature range

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Tina Rise Tuveng ◽  
Marianne Slang Jensen ◽  
Lasse Fredriksen ◽  
Gustav Vaaje-Kolstad ◽  
Vincent G. H. Eijsink ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
Plant Biomass ◽  
Thermostable Enzyme ◽  
Operational Stability ◽  
Lytic Polysaccharide Monooxygenase ◽  
Temperature Range ◽  
Catalytically Active ◽  
Polysaccharide Monooxygenases ◽  
Interesting Candidate ◽  
A Minor

Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are oxidative, copper-dependent enzymes that function as powerful tools in the turnover of various biomasses, including lignocellulosic plant biomass. While LPMOs are considered to be of great importance for biorefineries, little is known about industrial relevant properties such as the ability to operate at high temperatures. Here, we describe a thermostable, cellulose-active LPMO from a high-temperature compost metagenome (called mgLPMO10). Results MgLPMO10 was found to have the highest apparent melting temperature (83 °C) reported for an LPMO to date, and is catalytically active up to temperatures of at least 80 °C. Generally, mgLPMO10 showed good activity and operational stability over a wide temperature range. The LPMO boosted cellulose saccharification by recombinantly produced GH48 and GH6 cellobiohydrolases derived from the same metagenome, albeit to a minor extent. Cellulose saccharification studies with a commercial cellulase cocktail (Celluclast®) showed that the performance of this thermostable bacterial LPMO is comparable with that of a frequently utilized fungal LPMO from Thermoascus aurantiacus (TaLPMO9A). Conclusions The high activity and operational stability of mgLPMO10 are of both fundamental and applied interest. The ability of mgLPMO10 to perform oxidative cleavage of cellulose at 80 °C and the clear synergy with Celluclast® make this enzyme an interesting candidate in the development of thermostable enzyme cocktails for use in lignocellulosic biorefineries.

scholarly journals Dissecting cellobiose metabolic pathway and its application in biorefinery through consolidated bioprocessing in Myceliophthora thermophila

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Jingen Li ◽  
Shuying Gu ◽  
Zhen Zhao ◽  
Bingchen Chen ◽  
Qian Liu ◽  
...  
Keyword(s):  
Malic Acid ◽  
Plant Biomass ◽  
Consolidated Bioprocessing ◽  
Cellulase Activity ◽  
Industrial Applications ◽  
Efficient Production ◽  
Myceliophthora Thermophila ◽  
Final Strain ◽  
Cellobiose Metabolism ◽  
Cost Efficient

Abstract Background Lignocellulosic biomass has long been recognized as a potential sustainable source for industrial applications. The costs associated with conversion of plant biomass to fermentable sugar represent a significant barrier to the production of cost-competitive biochemicals. Consolidated bioprocessing (CBP) is considered a potential breakthrough for achieving cost-efficient production of biomass-based fuels and commodity chemicals. During the degradation of cellulose, cellobiose (major end-product of cellulase activity) is catabolized by hydrolytic and phosphorolytic pathways in cellulolytic organisms. However, the details of the two intracellular cellobiose metabolism pathways in cellulolytic fungi remain to be uncovered. Results Using the engineered malic acid production fungal strain JG207, we demonstrated that the hydrolytic pathway by β-glucosidase and the phosphorolytic pathway by phosphorylase are both used for intracellular cellobiose metabolism in Myceliophthora thermophila, and the yield of malic acid can benefit from the energy advantages of phosphorolytic cleavage. There were obvious differences in regulation of the two cellobiose catabolic pathways depending on whether M. thermophila JG207 was grown on cellobiose or Avicel. Disruption of Mtcpp in strain JG207 led to decreased production of malic acid under cellobiose conditions, while expression levels of all three intracellular β-glucosidase genes were significantly up-regulated to rescue the impairment of the phosphorolytic pathway under Avicel conditions. When the flux of the hydrolytic pathway was reduced, we found that β-glucosidase encoded by bgl1 was the dominant enzyme in the hydrolytic pathway and deletion of bgl1 resulted in significant enhancement of protein secretion but reduction of malate production. Combining comprehensive manipulation of both cellobiose utilization pathways and enhancement of cellobiose uptake by overexpression of a cellobiose transporter, the final strain JG412Δbgl2Δbgl3 produced up to 101.2 g/L and 77.4 g/L malic acid from cellobiose and Avicel, respectively, which corresponded to respective yields of 1.35 g/g and 1.03 g/g, representing significant improvement over the starting strain JG207. Conclusions This is the first report of detailed investigation of intracellular cellobiose catabolism in cellulolytic fungus M. thermophila. These results provide insights that can be applied to industrial fungi for production of biofuels and biochemicals from cellobiose and cellulose.

scholarly journals Novel molecular biological tools for the efficient expression of fungal lytic polysaccharide monooxygenases in Pichia pastoris

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lukas Rieder ◽  
Katharina Ebner ◽  
Anton Glieder ◽  
Morten Sørlie
Keyword(s):  
Pichia Pastoris ◽  
Biomass Conversion ◽  
Single Step ◽  
Additional Advantage ◽  
Lytic Polysaccharide Monooxygenases ◽  
Expression Host ◽  
Shake Flask Cultivation ◽  
Polysaccharide Monooxygenases ◽  
Efficient Expression ◽  
High Yields

Abstract Background Lytic polysaccharide monooxygenases (LPMOs) are attracting large attention due their ability to degrade recalcitrant polysaccharides in biomass conversion and to perform powerful redox chemistry. Results We have established a universal Pichia pastoris platform for the expression of fungal LPMOs using state-of-the-art recombination cloning and modern molecular biological tools to achieve high yields from shake-flask cultivation and simple tag-less single-step purification. Yields are very favorable with up to 42 mg per liter medium for four different LPMOs spanning three different families. Moreover, we report for the first time of a yeast-originating signal peptide from the dolichyl-diphosphooligosaccharide-protein glycosyltransferase subunit 1 (OST1) form S. cerevisiae efficiently secreting and successfully processes the N-terminus of LPMOs yielding in fully functional enzymes. Conclusion The work demonstrates that the industrially most relevant expression host P. pastoris can be used to express fungal LPMOs from different families in high yields and inherent purity. The presented protocols are standardized and require little equipment with an additional advantage with short cultivation periods.

scholarly journals Amperometric Biosensors Based on Direct Electron Transfer Enzymes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4525
Author(s):  
Franziska Schachinger ◽  
Hucheng Chang ◽  
Stefan Scheiblbrandner ◽  
Roland Ludwig
Keyword(s):  
Electron Transfer ◽  
Electrode Materials ◽  
Direct Electron Transfer ◽  
Accurate Determination ◽  
Direct Electrochemistry ◽  
Product Analysis ◽  
Amperometric Biosensors ◽  
Chemical Surface ◽  
Fusion Enzymes ◽  
Cost Efficient

The accurate determination of analyte concentrations with selective, fast, and robust methods is the key for process control, product analysis, environmental compliance, and medical applications. Enzyme-based biosensors meet these requirements to a high degree and can be operated with simple, cost efficient, and easy to use devices. This review focuses on enzymes capable of direct electron transfer (DET) to electrodes and also the electrode materials which can enable or enhance the DET type bioelectrocatalysis. It presents amperometric biosensors for the quantification of important medical, technical, and environmental analytes and it carves out the requirements for enzymes and electrode materials in DET-based third generation biosensors. This review critically surveys enzymes and biosensors for which DET has been reported. Single- or multi-cofactor enzymes featuring copper centers, hemes, FAD, FMN, or PQQ as prosthetic groups as well as fusion enzymes are presented. Nanomaterials, nanostructured electrodes, chemical surface modifications, and protein immobilization strategies are reviewed for their ability to support direct electrochemistry of enzymes. The combination of both biosensor elements—enzymes and electrodes—is evaluated by comparison of substrate specificity, current density, sensitivity, and the range of detection.

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