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Hoang H, Liu W, Zhan W, Zou S, Xu L, Zhan Y, Cheng H, Chen Z, Zhou H, Wang Y. Reductant-independent oxidative cleavage of cellulose by a novel marine fungal lytic polysaccharide monooxygenase. Int J Biol Macromol 2024; 276:133929. [PMID: 39025178 DOI: 10.1016/j.ijbiomac.2024.133929] [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: 06/01/2024] [Revised: 07/12/2024] [Accepted: 07/15/2024] [Indexed: 07/20/2024]
Abstract
Among the enzymes derived from fungus that act on polysaccharides, lytic polysaccharide monooxygenase (LPMOs) has emerged as a new member with complex reaction mechanisms and high efficiency in dealing with recalcitrant crystalline polysaccharides. This study reported the characteristics, structure, and biochemical properties of a novel LPMO from Talaromyces sedimenticola (namely MaLPMO9K) obtained from the Mariana Trench. MaLPMO9K was a multi-domain protein combined with main body and a carbohydrate-binding module. It was heterologously expressed in E. coli for analyzing peroxidase activity in reactions with the substrate 2,6-DMP, where H2O2 serves as a co-substrate. Optimal peroxidase activity for MaLPMO9K was observed at pH 8 and 25 °C, achieving the best Vmax value of 265.2 U·g-1. In addition, MaLPMO9K also demonstrated the ability to treat cellulose derivatives, and cellobiose substrates without the presence of reducing agents.
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Affiliation(s)
- Honghanh Hoang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Wenxian Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Wenhao Zhan
- National Key Laboratory of Human Factors Engineering, China Astronauts Research and Training Center, Beijing 100094, China
| | - Sini Zou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Liting Xu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Yuran Zhan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Haina Cheng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Zhu Chen
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Hongbo Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Yuguang Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
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2
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Berhe MH, Song X, Yao L. Improving the Enzymatic Activity and Stability of a Lytic Polysaccharide Monooxygenase. Int J Mol Sci 2023; 24:ijms24108963. [PMID: 37240310 DOI: 10.3390/ijms24108963] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Lytic Polysaccharide Monooxygenases (LPMOs) are copper-dependent enzymes that play a pivotal role in the enzymatic conversion of the most recalcitrant polysaccharides, such as cellulose and chitin. Hence, protein engineering is highly required to enhance their catalytic efficiencies. To this effect, we optimized the protein sequence encoding for an LPMO from Bacillus amyloliquefaciens (BaLPMO10A) using the sequence consensus method. Enzyme activity was determined using the chromogenic substrate 2,6-Dimethoxyphenol (2,6-DMP). Compared with the wild type (WT), the variants exhibit up to a 93.7% increase in activity against 2,6-DMP. We also showed that BaLPMO10A can hydrolyze p-nitrophenyl-β-D-cellobioside (PNPC), carboxymethylcellulose (CMC), and phosphoric acid-swollen cellulose (PASC). In addition to this, we investigated the degradation potential of BaLPMO10A against various substrates such as PASC, filter paper (FP), and Avicel, in synergy with the commercial cellulase, and it showed up to 2.7-, 2.0- and 1.9-fold increases in production with the substrates PASC, FP, and Avicel, respectively, compared to cellulase alone. Moreover, we examined the thermostability of BaLPMO10A. The mutants exhibited enhanced thermostability with an apparent melting temperature increase of up to 7.5 °C compared to the WT. The engineered BaLPMO10A with higher activity and thermal stability provides a better tool for cellulose depolymerization.
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Affiliation(s)
- Miesho Hadush Berhe
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Department of Biotechnology, College of Natural and Computational Sciences, Aksum University, Axum 1010, Ethiopia
| | - Xiangfei Song
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
| | - Lishan Yao
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
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3
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Sun XB, Gao DY, Cao JW, Liu Y, Rong ZT, Wang JK, Wang Q. BsLPMO10A from Bacillus subtilis boosts the depolymerization of diverse polysaccharides linked via β-1,4-glycosidic bonds. Int J Biol Macromol 2023; 230:123133. [PMID: 36621733 DOI: 10.1016/j.ijbiomac.2023.123133] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/24/2022] [Accepted: 01/01/2023] [Indexed: 01/07/2023]
Abstract
Lytic polysaccharide monooxygenase (LPMO) is known as an oxidatively cleaving enzyme in recalcitrant polysaccharide deconstruction. Herein, we report a novel AA10 LPMO derived from Bacillus subtilis (BsLPMO10A). A substrate specificity study revealed that the enzyme exhibited an extensive active-substrate spectrum, particularly for polysaccharides linked via β-1,4 glycosidic bonds, such as β-(Man1 → 4Man), β-(Glc1 → 4Glc) and β-(Xyl1 → 4Xyl). HPAEC-PAD and MALDI-TOF-MS analyses indicated that BsLPMO10A dominantly liberated native oligosaccharides with a degree of polymerization (DP) of 3-6 and C1-oxidized oligosaccharides ranging from DP3ox to DP6ox from mixed linkage glucans and beechwood xylan. Due to its synergistic action with a variety of glycoside hydrolases, including glucanase IDSGLUC5-38, xylanase TfXYN11-1, cellulase IDSGLUC5-11 and chitinase BtCHI18-1, BsLPMO10A dramatically accelerated glucan, xylan, cellulose and chitin saccharification. After co-reaction for 72 h, the reducing sugars in Icelandic moss lichenan, beechwood xylan, phosphoric acid swollen cellulose and chitin yielded 3176 ± 97, 7436 ± 165, 649 ± 44, and 2604 ± 130 μmol/L, which were 1.47-, 1.56-, 1.44- and 1.25-fold higher than those in the GHs alone groups, respectively (P < 0.001). In addition, the synergy of BsLPMO10A and GHs was further validated by the degradation of natural feedstuffs, the co-operation of BsLPMO10A and GHs released 3266 ± 182 and 1725 ± 107 μmol/L of reducing sugars from Oryza sativa L. and Arachis hypogaea L. straws, respectively, which were significantly higher than those produced by GHs alone (P < 0.001). Furthermore, BsLPMO10A also accelerated the liberation of reducing sugars from Celluclast® 1.5 L, a commercial cellulase cocktail, on filter paper, A. hypogaea L. and O. sativa L. straws by 49.58 % (P < 0.05), 72.19 % (P < 0.001) and 54.36 % (P < 0.05), respectively. This work has characterized BsLPMO10A with a broad active-substrate scope, providing a promising candidate for lignocellulosic biomass biorefinery.
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Affiliation(s)
- Xiao-Bao Sun
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Zhejiang University, Hangzhou 310058, China; Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - De-Ying Gao
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Zhejiang University, Hangzhou 310058, China; Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jia-Wen Cao
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Zhejiang University, Hangzhou 310058, China; Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310058, China
| | - Yu Liu
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhou-Ting Rong
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
| | - Jia-Kun Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Zhejiang University, Hangzhou 310058, China; Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Qian Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Zhejiang University, Hangzhou 310058, China; Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
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Schwaiger L, Zenone A, Csarman F, Ludwig R. Continuous photometric activity assays for lytic polysaccharide monooxygenase-Critical assessment and practical considerations. Methods Enzymol 2022; 679:381-404. [PMID: 36682872 DOI: 10.1016/bs.mie.2022.08.054] [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] [Indexed: 12/31/2022]
Abstract
Lytic polysaccharide monooxygenase (LPMO) is a monocopper-dependent enzyme that cleaves glycosidic bonds by using an oxidative mechanism. In nature, they act in concert with cellobiohydrolases to facilitate the efficient degradation of lignocellulosic biomass. After more than a decade of LPMO research, it has become evident that LPMOs are abundant in all domains of life and fulfill a diverse range of biological functions. Independent of their biological function and the preferred polysaccharide substrate, studying and characterizing LPMOs is tedious and so far mostly relied on the discontinuous analysis of the solubilized reaction products by HPLC/MS-based methods. In the absence of appropriate substrates, LPMOs can engage in two off-pathway reactions, i.e., an oxidase and a peroxidase-like activity. These futile reactions have been exploited to set up easy-to-use continuous spectroscopic assays. As the natural substrates of newly discovered LPMOs are often unknown, widely applicable, simple, reliable, and robust spectroscopic assays are required to monitor LPMO expression and to perform initial biochemical characterizations, e.g., thermal stability measurements. Here we provide detailed descriptions and practical protocols to perform continuous photometric assays using either 2,6-dimethoxyphenol (2,6-DMP) or hydrocoerulignone as colorimetric substrates as a broadly applicable assay for a range of LPMOs. In addition, a turbidimetric measurement is described as the currently only method available to continuously monitor LPMOs acting on amorphous cellulose.
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Affiliation(s)
- Lorenz Schwaiger
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Alice Zenone
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Florian Csarman
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria.
| | - Roland Ludwig
- Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Vienna, Austria
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5
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Li F, Liu Y, Liu Y, Li Y, Yu H. Heterologous expression and characterization of a novel lytic polysaccharide monooxygenase from Natrialbaceae archaeon and its application for chitin biodegradation. BIORESOURCE TECHNOLOGY 2022; 354:127174. [PMID: 35436543 DOI: 10.1016/j.biortech.2022.127174] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Lytic polysaccharide monooxygenases could enhance the enzymatic conversion of recalcitrant polysaccharides by glycoside hydrolases. This study reports the expression and identification of a novel AA10 LPMO from Natrialbaceae archaeon, named NaLPMO10A, as a C1 oxidizer of chitin. The optimal temperature and pH for NaLPMO10A activity were 40 °C and 9.0, respectively, and NaLPMO10A exhibited high thermostability and pH stability under alkaline conditions. NaLPMO10A was also highly tolerant and stable when treated with high concentration of metal ions (1 M). Moreover, metal ions (Na+, K+, Ca2+ and Mg2+) significantly promoted NaLPMO10A activity and improved the saccharification efficiency of chitin by 22.6%, 45.9%, 36.7% and 53.9%, respectively, compared to commercial chitinase alone. Together, the findings of this study fill a gap in archaeal LPMO research, and for the first time demonstrate that archaeal NaLPMO10A could be a promising enzyme for improving saccharification under extreme condition, with potential applications in biorefineries.
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Affiliation(s)
- Fei Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yuxin Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yang Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yanjun Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hongbo Yu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
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Méndez-Líter JA, Ayuso-Fernández I, Csarman F, de Eugenio LI, Míguez N, Plou FJ, Prieto A, Ludwig R, Martínez MJ. Lytic Polysaccharide Monooxygenase from Talaromyces amestolkiae with an Enigmatic Linker-like Region: The Role of This Enzyme on Cellulose Saccharification. Int J Mol Sci 2021; 22:13611. [PMID: 34948409 PMCID: PMC8703934 DOI: 10.3390/ijms222413611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 11/30/2022] Open
Abstract
The first lytic polysaccharide monooxygenase (LPMO) detected in the genome of the widespread ascomycete Talaromyces amestolkiae (TamAA9A) has been successfully expressed in Pichia pastoris and characterized. Molecular modeling of TamAA9A showed a structure similar to those from other AA9 LPMOs. Although fungal LPMOs belonging to the genera Penicillium or Talaromyces have not been analyzed in terms of regioselectivity, phylogenetic analyses suggested C1/C4 oxidation which was confirmed by HPAEC. To ascertain the function of a C-terminal linker-like region present in the wild-type sequence of the LPMO, two variants of the wild-type enzyme, one without this sequence and one with an additional C-terminal carbohydrate binding domain (CBM), were designed. The three enzymes (native, without linker and chimeric variant with a CBM) were purified in two chromatographic steps and were thermostable and active in the presence of H2O2. The transition midpoint temperature of the wild-type LPMO (Tm = 67.7 °C) and its variant with only the catalytic domain (Tm = 67.6 °C) showed the highest thermostability, whereas the presence of a CBM reduced it (Tm = 57.8 °C) and indicates an adverse effect on the enzyme structure. Besides, the potential of the different T. amestolkiae LPMO variants for their application in the saccharification of cellulosic and lignocellulosic materials was corroborated.
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Affiliation(s)
- Juan Antonio Méndez-Líter
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
| | - Iván Ayuso-Fernández
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1462 Ås, Norway;
| | - Florian Csarman
- Department of Food Science and Technology, BOKU–University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria; (F.C.); (R.L.)
| | - Laura Isabel de Eugenio
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
| | - Noa Míguez
- Instituto de Catálisis y Petroleoquímica, Spanish National Research Council (CSIC), Marie Curie 2, 28049 Madrid, Spain; (N.M.); (F.J.P.)
| | - Francisco J. Plou
- Instituto de Catálisis y Petroleoquímica, Spanish National Research Council (CSIC), Marie Curie 2, 28049 Madrid, Spain; (N.M.); (F.J.P.)
| | - Alicia Prieto
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
| | - Roland Ludwig
- Department of Food Science and Technology, BOKU–University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria; (F.C.); (R.L.)
| | - María Jesús Martínez
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas, Spanish National Research Council (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (J.A.M.-L.); (L.I.d.E.); (A.P.)
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Zhang X, Chen K, Long L, Ding S. Two C1-oxidizing AA9 lytic polysaccharide monooxygenases from Sordaria brevicollis differ in thermostability, activity, and synergy with cellulase. Appl Microbiol Biotechnol 2021; 105:8739-8759. [PMID: 34748039 DOI: 10.1007/s00253-021-11677-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 11/24/2022]
Abstract
Cellulolytic fungi usually have multiple genes for C1-oxidizing auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) in their genomes, but their potential functional differences are less understood. In this study, two C1-oxidizing AA9 LPMOs, SbLPMO9A and SbLPMO9B, were identified from Sordaria brevicollis, and their differences, particularly in terms of thermostability, reducing agent specificity, and synergy with cellulase, were explored. The two enzymes exhibited weak binding to cellulose and intolerance to hydrogen peroxide. Their oxidative activity was influenced by cellulose crystallinity and surface morphology, and both enzymes tended to oxidize celluloses of lower crystallinity and high surface area. Comparably, SbLPMO9A had much better thermostability than SbLPMO9B, which may be attributed to the presence of a carbohydrate binding module 1 (CBM1)-like sequence at its C-terminus. In addition, the two enzymes exhibited different specificities and responsivities toward electron donors. SbLPMO9A and SbLPMO9B were able to boost the catalytic efficiency of endoglucanase I (EGI) on physically and chemically pretreated substrates but with different degrees of synergy. Substrate- and enzyme-specific synergism was observed by comparing the synergistic action of SbLPMO9A or SbLPMO9B with commercial Celluclast 1.5L on three kinds of cellulosic substrates. On regenerated amorphous cellulose and PFI (Papirindustriens Forskningsinstitut)-fibrillated bleached eucalyptus pulp, SbLPMO9B showed a higher synergistic effect than SbLPMO9A, while on delignified wheat straw, the synergistic effect of SbLPMO9A was higher than that of SbLPMO9B. On account of its excellent thermostability and boosting effect on the enzymatic hydrolysis of delignified wheat straw, SbLPMO9A may have high application potential in biorefineries for lignocellulosic biomass. KEY POINTS: • C1-oxidizing SbLPMO9A displayed higher thermostability than SbLPMO9B, probably due to the presence of a CBM1-like module. • The oxidative activity of the two SbLPMO9s on celluloses increased with decreasing cellulose crystallinity or increasing beating degree. • The two SbLPMO9s boosted the catalytic efficiency of cellulase, but the synergistic effect was substrate- and enzyme-specific.
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Affiliation(s)
- Xi Zhang
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Kaixiang Chen
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Liangkun Long
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Shaojun Ding
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
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Semenova MV, Gusakov AV, Telitsin VD, Sinitsyn AP. Enzymatic Destruction of Cellulose: Characteristics of the Kinetic Interaction of Lytic Polysaccharide Monooxygenases and Individual Cellulases. APPL BIOCHEM MICRO+ 2021. [DOI: 10.1134/s0003683821050136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Thermostable cellulose saccharifying microbial enzymes: Characteristics, recent advances and biotechnological applications. Int J Biol Macromol 2021; 188:226-244. [PMID: 34371052 DOI: 10.1016/j.ijbiomac.2021.08.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/19/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022]
Abstract
Cellulases play a promising role in the bioconversion of renewable lignocellulosic biomass into fermentable sugars which are subsequently fermented to biofuels and other value-added chemicals. Besides biofuel industries, they are also in huge demand in textile, detergent, and paper and pulp industries. Low titres of cellulase production and processing are the main issues that contribute to high enzyme cost. The success of ethanol-based biorefinery depends on high production titres and the catalytic efficiency of cellulases functional at elevated temperatures with acid/alkali tolerance and the low cost. In view of their wider application in various industrial processes, stable cellulases that are active at elevated temperatures in the acidic-alkaline pH ranges, and organic solvents and salt tolerance would be useful. This review provides a recent update on the advances made in thermostable cellulases. Developments in their sources, characteristics and mechanisms are updated. Various methods such as rational design, directed evolution, synthetic & system biology and immobilization techniques adopted in evolving cellulases with ameliorated thermostability and characteristics are also discussed. The wide range of applications of thermostable cellulases in various industrial sectors is described.
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10
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Bhatia S, Yadav SK. Novel catalytic potential of a hyperthermostable mono‑copper oxidase (LPMO-AOAA17) for the oxidation of lignin monomers and depolymerisation of lignin dimer in aqueous media. Int J Biol Macromol 2021; 186:563-573. [PMID: 34273339 DOI: 10.1016/j.ijbiomac.2021.07.063] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/06/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
Abstract
Lytic polysaccharide monooxygenase (LPMO) are mono‑copper enzymes known for the oxidative cleavage of recalcitrant polysaccharides with their intriguing and unique catalytic chemistry. Such impeccable oxidation potential has made them highly valuable in the enzymatic consortia for the degradation of ligno-cellulosic biomass. Bioinformatic analysis has revealed an unannotated LPMO gene in the genome of A. oryzae. Multiple sequence alignment showed the presence of conserved "histidine brace" of LPMO in the amino acid sequence of the enzyme. The enzyme, named as LPMO-AOAA17 was recombinantly expressed in E. coli BL21 and characterised for its substrate specificity. Recombinant enzyme did not show any characteristic cleavage of polysaccharides. However, it was found to be oxidising broad range of phenolic and non-phenolic monomers of lignin. Biochemical study revealed the optimum activity of LPMO-AOAA17 at pH 7 and was highly stable and active at 100 °C. The enzyme LPMO-AOAA17 was also observed to be stable after autoclaving at 121 °C and 15 psi. Thermal stability of the LPMO-AOAA17 was further confirmed through differential scanning calorimetry. GC-MS analysis has confirmed the catalysis of LPMO-AOAA17 for the depolymerisation of lignin dimer, guaicyl glycerol β-guaicyl ether into guaiacol. This study has first time documented the identification of a hyperthermostable LPMO for oxidative cleavage of β-O-4 linkage of lignin compounds to form aromatic products in aqueous media.
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Affiliation(s)
- Simran Bhatia
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali 140306, Punjab, India
| | - Sudesh Kumar Yadav
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali 140306, Punjab, India.
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11
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Higasi PMR, Velasco JA, Pellegrini VOA, de Araújo EA, França BA, Keller MB, Labate CA, Blossom BM, Segato F, Polikarpov I. Light-stimulated T. thermophilus two-domain LPMO9H: Low-resolution SAXS model and synergy with cellulases. Carbohydr Polym 2021; 260:117814. [PMID: 33712158 DOI: 10.1016/j.carbpol.2021.117814] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 02/06/2021] [Accepted: 02/10/2021] [Indexed: 12/19/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs), monocopper enzymes that oxidatively cleave recalcitrant polysaccharides, have important biotechnological applications. Thermothelomyces thermophilus is a rich source of biomass-active enzymes, including many members from auxiliary activities family 9 LPMOs. Here, we report biochemical and structural characterization of recombinant TtLPMO9H which oxidizes cellulose at the C1 and C4 positions and shows enhanced activity in light-driven catalysis assays. TtLPMO9H also shows activity against xyloglucan. The addition of TtLPMO9H to endoglucanases from four different glucoside hydrolase families (GH5, GH12, GH45 and GH7) revealed that the product formation was remarkably increased when TtLPMO9H was combined with GH7 endoglucanase. Finally, we determind the first low resolution small-angle X-ray scattering model of the two-domain TtLPMO9H in solution that shows relative positions of its two functional domains and a conformation of the linker peptide, which can be relevant for the catalytic oxidation of cellulose and xyloglucan.
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Affiliation(s)
- Paula M R Higasi
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense 400, São Carlos, São Paulo, Brazil
| | - Josman A Velasco
- Lorena School of Engineering, University of São Paulo, Estrada Municipal do Campinho s/n, Lorena, São Paulo, Brazil
| | - Vanessa O A Pellegrini
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense 400, São Carlos, São Paulo, Brazil
| | - Evandro A de Araújo
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense 400, São Carlos, São Paulo, Brazil
| | - Bruno Alves França
- Lorena School of Engineering, University of São Paulo, Estrada Municipal do Campinho s/n, Lorena, São Paulo, Brazil
| | - Malene B Keller
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - Carlos A Labate
- Luiz de Queiroz College of Agriculture, University of São Paulo, Av. Pádua Dias 11, Piracicaba, São Paulo, Brazil
| | - Benedikt M Blossom
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - Fernando Segato
- Lorena School of Engineering, University of São Paulo, Estrada Municipal do Campinho s/n, Lorena, São Paulo, Brazil
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo, Av. Trabalhador São-carlense 400, São Carlos, São Paulo, Brazil.
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12
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Méndez-Líter JA, de Eugenio LI, Nieto-Domínguez M, Prieto A, Martínez MJ. Hemicellulases from Penicillium and Talaromyces for lignocellulosic biomass valorization: A review. BIORESOURCE TECHNOLOGY 2021; 324:124623. [PMID: 33434871 DOI: 10.1016/j.biortech.2020.124623] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 05/26/2023]
Abstract
The term hemicellulose groups different polysaccharides with heterogeneous structures, mannans, xyloglucans, mixed-linkage β-glucans and xylans, which differ in their backbone and branches, and in the type and distribution of glycosidic linkages. The enzymatic degradation of these complex polymers requires the concerted action of multiple hemicellulases and auxiliary enzymes. Most commercial enzymes are produced by Trichoderma and Aspergillus species, but recent studies have disclosed Penicillium and Talaromyces as promising sources of hemicellulases. In this review, we summarize the current knowledge on the hemicellulolytic system of these genera, and the role of hemicellulases in the disruption and synthesis of glycosidic bonds. In both cases, the enzymes from Penicillium and Talaromyces represent an interesting alternative for valorization of lignocellulosic biomass in the current framework of circular economy.
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Affiliation(s)
- Juan A Méndez-Líter
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Laura I de Eugenio
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Manuel Nieto-Domínguez
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Alicia Prieto
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - María Jesús Martínez
- Biotechnology for Lignocellulosic Biomass Group, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), c/ Ramiro de Maeztu 9, 28040 Madrid, Spain.
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13
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Velasco J, de Oliveira Arnoldi Pellegrini V, Sepulchro AGV, Kadowaki MAS, Santo MCE, Polikarpov I, Segato F. Comparative analysis of two recombinant LPMOs from Aspergillus fumigatus and their effects on sugarcane bagasse saccharification. Enzyme Microb Technol 2021; 144:109746. [PMID: 33541573 DOI: 10.1016/j.enzmictec.2021.109746] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/11/2020] [Accepted: 12/30/2020] [Indexed: 01/19/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) have been introduced into industrial cocktails used for biomass saccharification due to their capacity to boost enzymatic conversion of recalcitrant cellulose. The genome of the thermotolerant ascomycete Aspergillus fumigatus encodes 7 genes for LPMOs that belong to auxiliary activity family 9 (AA9). Here, we cloned, successfully expressed and performed biochemical evaluation of two CBM-less A. fumigatus LPMOs (AfAA9A and AfAA9B). A high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) analysis demonstrated that AfAA9A and AfAA9B are able to oxide cellulose at C1 and C1/C4 positions, respectively. Synergic effects of LPMOs (separately and in combination) with cellulases were investigated. Supplementation of Celluclast 1.5 L with a low concentration of AfAA9B improved in 20 % the saccharification of sugarcane bagasse pretreated by steam explosion (SEB), while AfAA9A did not improvethe saccharification. Analysis of the hydrolyzed biomass by confocal laser scanning microscopy (CLSM) showed the LPMOs are promoting lignin oxidation in the lignocellulosic material. This study complements the available results concerning the utilization of LPMOs in the enzymatic saccharification of lignocellulosic biomass.
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Affiliation(s)
- Josman Velasco
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | | | | | | | | | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil.
| | - Fernando Segato
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil.
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14
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Tuveng TR, Jensen MS, Fredriksen L, Vaaje-Kolstad G, Eijsink VGH, Forsberg Z. A thermostable bacterial lytic polysaccharide monooxygenase with high operational stability in a wide temperature range. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:194. [PMID: 33292445 PMCID: PMC7708162 DOI: 10.1186/s13068-020-01834-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
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.
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Affiliation(s)
- Tina Rise Tuveng
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Marianne Slang Jensen
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Lasse Fredriksen
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway.
| | - Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway.
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15
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Gaber Y, Rashad B, Hussein R, Abdelgawad M, Ali NS, Dishisha T, Várnai A. Heterologous expression of lytic polysaccharide monooxygenases (LPMOs). Biotechnol Adv 2020; 43:107583. [DOI: 10.1016/j.biotechadv.2020.107583] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/20/2022]
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16
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Zhang R. Functional characterization of cellulose-degrading AA9 lytic polysaccharide monooxygenases and their potential exploitation. Appl Microbiol Biotechnol 2020; 104:3229-3243. [PMID: 32076777 DOI: 10.1007/s00253-020-10467-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 12/25/2019] [Accepted: 02/12/2020] [Indexed: 01/05/2023]
Abstract
Cellulose-degrading auxiliary activity family 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) are known to be widely distributed among filamentous fungi and participate in the degradation of lignocellulose via the oxidative cleavage of celluloses, cello-oligosaccharides, or hemicelluloses. AA9 LPMOs have been reported to have extensive interactions with not only cellulases but also oxidases. The addition of AA9 LPMOs can greatly reduce the amount of cellulase needed for saccharification and increase the yield of glucose. The discovery of AA9 LPMOs has greatly changed our understanding of how fungi degrade cellulose. In this review, apart from summarizing the recent discoveries related to their catalytic reaction, functional diversity, and practical applications, the stability, expression system, and protein engineering of AA9 LPMOs are reviewed for the first time. This review may provide a reference value to further broaden the substrate range of AA9 LPMOs, expand the scope of their practical applications, and realize their customization for industrial utilization.Key Points• The stability and expression system of AA9 LPMOs are reviewed for the first time.• The protein engineering of AA9 LPMOs is systematically summarized for the first time.• The latest research results on the catalytic mechanism of AA9 LPMOs are summarized.• The application of AA9 LPMOs and their relationship with other enzymes are reviewed.
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Affiliation(s)
- Ruiqin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, China.
- Department of Bioengineering, Huainan Normal University, No. 278 Xueyuannan Road, Huainan, 232038, China.
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17
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Breslmayr E, Daly S, Požgajčić A, Chang H, Rezić T, Oostenbrink C, Ludwig R. Improved spectrophotometric assay for lytic polysaccharide monooxygenase. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:283. [PMID: 31827611 PMCID: PMC6894463 DOI: 10.1186/s13068-019-1624-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/28/2019] [Indexed: 05/31/2023]
Abstract
BACKGROUND The availability of a sensitive and robust activity assay is a prerequisite for efficient enzyme production, purification, and characterization. Here we report on a spectrophotometric assay for lytic polysaccharide monooxygenase (LPMO), which is an advancement of the previously published 2,6-dimethoxyphenol (2,6-DMP)-based LPMO assay. The new assay is based on hydrocoerulignone as substrate and hydrogen peroxide as cosubstrate and aims toward a higher sensitivity at acidic pH and a more reliable detection of LPMO in complex matrices like culture media. RESULTS An LPMO activity assay following the colorimetric oxidation of hydrocoerulignone to coerulignone was developed. This peroxidase activity of LPMO in the presence of hydrogen peroxide can be detected in various buffers between pH 4-8. By reducing the substrate and cosubstrate concentration, the assay has been optimized for minimal autoxidation and enzyme deactivation while maintaining sensitivity. Finally, the optimized and validated LPMO assay was used to follow the recombinant expression of an LPMO in Pichia pastoris and to screen for interfering substances in fermentation media suppressing the assayed reaction. CONCLUSIONS The biphenol hydrocoerulignone is a better substrate for LPMO than the monophenol 2,6-DMP, because of a ~ 30 times lower apparent K M value and a 160 mV lower oxidation potential. This greatly increases the measured LPMO activity when using hydrocoerulignone instead of 2,6-DMP under otherwise similar assay conditions. The improved activity allows the adaptation of the LPMO assay toward a higher sensitivity, different buffers and pH values, more stable assay conditions or to overcome low concentrations of inhibiting substances. The developed assay protocol and optimization guidelines increase the adaptability and applicability of the hydrocoerulignone assay for the production, purification, and characterization of LPMOs.
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Affiliation(s)
- Erik Breslmayr
- Biocatalysis and Biosensor Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
- Institute of Molecular Modeling and Simulation, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Sarah Daly
- Biocatalysis and Biosensor Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Alen Požgajčić
- Biocatalysis and Biosensor Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
- Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Hucheng Chang
- Biocatalysis and Biosensor Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Tonči Rezić
- Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
| | - Chris Oostenbrink
- Institute of Molecular Modeling and Simulation, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- Biocatalysis and Biosensor Laboratory, Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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