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Miller ML, Nagarajan R, Thauland TJ, Butte MJ. Enhancing tumor-infiltrating T cells with an exclusive fuel source. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.20.595053. [PMID: 38826342 PMCID: PMC11142041 DOI: 10.1101/2024.05.20.595053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Solid tumors harbor immunosuppressive microenvironments that inhibit tumor infiltrating lymphocytes (TILs) through the voracious consumption of glucose. We sought to restore TIL function by providing them with an exclusive fuel source. The glucose disaccharide cellobiose, which is a building block of cellulose, contains a β-1,4-glycosidic bond that cannot be hydrolyzed by animals (or their tumors), but fungal and bacterial organisms have evolved enzymes to catabolize cellobiose and use the resulting glucose. By equipping T cells with two proteins that enable import and hydrolysis of cellobiose, we demonstrate that supplementation of cellobiose during glucose withdrawal restores T cell cytokine production and cellular proliferation. Murine tumor growth is suppressed and survival is prolonged. Offering exclusive access to a natural disaccharide is a new tool that augments cancer immunotherapies. Beyond cancer, this approach could be used to answer questions about the regulation of glucose metabolism across many cell types, biological processes, and diseases.
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2
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Ye Y, Liu H, Wang Z, Qi Q, Du J, Tian S. A cellulosomal yeast reaction system of lignin-degrading enzymes for cellulosic ethanol fermentation. Biotechnol Lett 2024:10.1007/s10529-024-03485-0. [PMID: 38607604 DOI: 10.1007/s10529-024-03485-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/01/2024] [Accepted: 03/25/2024] [Indexed: 04/13/2024]
Abstract
Biofuel production from lignocellulose feedstocks is sustainable and environmentally friendly. However, the lignocellulosic pretreatment could produce fermentation inhibitors causing multiple stresses and low yield. Therefore, the engineering construction of highly resistant microorganisms is greatly significant. In this study, a composite functional chimeric cellulosome equipped with laccase, versatile peroxidase, and lytic polysaccharide monooxygenase was riveted on the surface of Saccharomyces cerevisiae to construct a novel yeast strain YI/LVP for synergistic lignin degradation and cellulosic ethanol production. The assembly of cellulosome was assayed by immunofluorescence microscopy and flow cytometry. During the whole process of fermentation, the maximum ethanol concentration and cellulose conversion of engineering strain YI/LVP reached 8.68 g/L and 83.41%, respectively. The results proved the availability of artificial chimeric cellulosome containing lignin-degradation enzymes for cellulosic ethanol production. The purpose of the study was to improve the inhibitor tolerance and fermentation performance of S. cerevisiae through the construction and optimization of a synergistic lignin-degrading enzyme system based on cellulosome.
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Affiliation(s)
- Yutong Ye
- College of Life Science, Capital Normal University, Beijing, 100048, China
| | - Han Liu
- College of Life Science, Capital Normal University, Beijing, 100048, China
| | - Zhipeng Wang
- College of Life Science, Capital Normal University, Beijing, 100048, China
| | - Qi Qi
- Beijing Chaoyang Foreign Language School, Beijing, 100012, China
| | - Jiliang Du
- College of Life Science, Capital Normal University, Beijing, 100048, China
| | - Shen Tian
- College of Life Science, Capital Normal University, Beijing, 100048, China.
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3
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Raheja Y, Singh V, Sharma G, Tsang A, Chadha BS. A thermostable and inhibitor resistant β-glucosidase from Rasamsonia emersonii for efficient hydrolysis of lignocellulosics biomass. Bioprocess Biosyst Eng 2024; 47:567-582. [PMID: 38470501 DOI: 10.1007/s00449-024-02988-4] [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: 11/06/2023] [Accepted: 02/20/2024] [Indexed: 03/14/2024]
Abstract
The present study reports a highly thermostable β-glucosidase (GH3) from Rasamsonia emersonii that was heterologously expressed in Pichia pastoris. Extracellular β-glucosidase was purified to homogeneity using single step affinity chromatography with molecular weight of ~ 110 kDa. Intriguingly, the purified enzyme displayed high tolerance to inhibitors mainly acetic acid, formic acid, ferulic acid, vanillin and 5-hydroxymethyl furfural at concentrations exceeding those present in acid steam pretreated rice straw slurry used for hydrolysis and subsequent fermentation in 2G ethanol plants. Characteristics of purified β-glucosidase revealed the optimal activity at 80 °C, pH 5.0 and displayed high thermostability over broad range of temperature 50-70 °C with maximum half-life of ~ 60 h at 50 °C, pH 5.0. The putative transglycosylation activity of β-glucosidase was appreciably enhanced in the presence of methanol as an acceptor. Using the transglycosylation ability of β-glucosidase, the generated low cost mixed glucose disaccharides resulted in the increased induction of R. emersonii cellulase under submerged fermentation. Scaling up the recombinant protein production at fermenter level using temporal feeding approach resulted in maximal β-glucosidase titres of 134,660 units/L. Furthermore, a developed custom made enzyme cocktail consisting of cellulase from R. emersonii mutant M36 supplemented with recombinant β-glucosidase resulted in significantly enhanced hydrolysis of pretreated rice straw slurry from IOCL industries (India). Our results suggest multi-faceted β-glucosidase from R. emersonii can overcome obstacles mainly high cost associated enzyme production, inhibitors that impair the sugar yields and thermal inactivation of enzyme.
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Affiliation(s)
- Yashika Raheja
- Department of Microbiology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Varinder Singh
- Department of Microbiology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Gaurav Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
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4
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Teo KSK, Kondo K, Khattab SMR, Watanabe T, Nagata T, Katahira M. Enhancing Bioethanol Production from Rice Straw through Environmentally Friendly Delignification Using Versatile Peroxidase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:2657-2666. [PMID: 38288662 DOI: 10.1021/acs.jafc.3c07998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Rice straw (RS), an agricultural residue rich in carbohydrates, has substantial potential for bioethanol production. However, the presence of lignin impedes access to these carbohydrates, hindering efficient carbohydrate-to-bioethanol conversion. Here, we expressed versatile peroxidase (VP), a lignin-degrading enzyme, in Pichia pastoris and used it to delignify RS at 30 °C using a membrane bioreactor that continuously discarded the degraded lignin. Klason lignin analysis revealed that VP-treatment led to 35% delignification of RS. We then investigated the delignified RS by SEC, FTIR, and SEM. The results revealed the changes of RS caused by VP-mediated delignification. Additionally, we compared the saccharification and fermentation yields between RSs treated with and without VP, VP-RS, and Ctrl-RS, respectively. This examination unveiled an improvement in glucose and bioethanol production, VP-RS exhibiting up to 1.5-fold and 1.4-fold production, respectively. These findings underscore the potential of VP for delignifying RS and enhancing bioethanol production through an eco-friendly approach.
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Affiliation(s)
- Kenneth Sze Kai Teo
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Keiko Kondo
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Integrated Research Center for Carbon Negative Science, Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Biomass Product Tree Industry-Academia Collaborative Research Laboratory, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Sadat Mohamed Rezk Khattab
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Faculty of Science, Al-Azhar University, 2091110 Assiut, Egypt
| | - Takashi Watanabe
- Biomass Product Tree Industry-Academia Collaborative Research Laboratory, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Takashi Nagata
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Integrated Research Center for Carbon Negative Science, Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Masato Katahira
- Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Integrated Research Center for Carbon Negative Science, Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
- Biomass Product Tree Industry-Academia Collaborative Research Laboratory, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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5
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Bombardi L, Salini A, Aulitto M, Zuliani L, Andreolli M, Bordoli P, Coltro A, Vitulo N, Zaccone C, Lampis S, Fusco S. Lignocellulolytic Potential of Microbial Consortia Isolated from a Local Biogas Plant: The Case of Thermostable Xylanases Secreted by Mesophilic Bacteria. Int J Mol Sci 2024; 25:1090. [PMID: 38256164 PMCID: PMC10816813 DOI: 10.3390/ijms25021090] [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: 12/07/2023] [Revised: 01/05/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
Lignocellulose biomasses (LCB), including spent mushroom substrate (SMS), pose environmental challenges if not properly managed. At the same time, these renewable resources hold immense potential for biofuel and chemicals production. With the mushroom market growth expected to amplify SMS quantities, repurposing or disposal strategies are critical. This study explores the use of SMS for cultivating microbial communities to produce carbohydrate-active enzymes (CAZymes). Addressing a research gap in using anaerobic digesters for enriching microbiomes feeding on SMS, this study investigates microbial diversity and secreted CAZymes under varied temperatures (37 °C, 50 °C, and 70 °C) and substrates (SMS as well as pure carboxymethylcellulose, and xylan). Enriched microbiomes demonstrated temperature-dependent preferences for cellulose, hemicellulose, and lignin degradation, supported by thermal and elemental analyses. Enzyme assays confirmed lignocellulolytic enzyme secretion correlating with substrate degradation trends. Notably, thermogravimetric analysis (TGA), coupled with differential scanning calorimetry (TGA-DSC), emerged as a rapid approach for saccharification potential determination of LCB. Microbiomes isolated at mesophilic temperature secreted thermophilic hemicellulases exhibiting robust stability and superior enzymatic activity compared to commercial enzymes, aligning with biorefinery conditions. PCR-DGGE and metagenomic analyses showcased dynamic shifts in microbiome composition and functional potential based on environmental conditions, impacting CAZyme abundance and diversity. The meta-functional analysis emphasised the role of CAZymes in biomass transformation, indicating microbial strategies for lignocellulose degradation. Temperature and substrate specificity influenced the degradative potential, highlighting the complexity of environmental-microbial interactions. This study demonstrates a temperature-driven microbial selection for lignocellulose degradation, unveiling thermophilic xylanases with industrial promise. Insights gained contribute to optimizing enzyme production and formulating efficient biomass conversion strategies. Understanding microbial consortia responses to temperature and substrate variations elucidates bioconversion dynamics, emphasizing tailored strategies for harnessing their biotechnological potential.
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Affiliation(s)
- Luca Bombardi
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (L.B.); (A.S.); (L.Z.); (P.B.); (A.C.)
| | - Andrea Salini
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (L.B.); (A.S.); (L.Z.); (P.B.); (A.C.)
| | - Martina Aulitto
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy;
| | - Luca Zuliani
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (L.B.); (A.S.); (L.Z.); (P.B.); (A.C.)
| | - Marco Andreolli
- Lab of Environmental Microbiology & VUCC-DBT Verona University Culture Collection, Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (M.A.); (S.L.)
| | - Paola Bordoli
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (L.B.); (A.S.); (L.Z.); (P.B.); (A.C.)
| | - Annalaura Coltro
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (L.B.); (A.S.); (L.Z.); (P.B.); (A.C.)
| | - Nicola Vitulo
- Computational Genomics Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy;
| | - Claudio Zaccone
- Lab of Soil and Biomass Chemistry, Department of Biotechnology, University of Verona, 37134 Verona, Italy;
| | - Silvia Lampis
- Lab of Environmental Microbiology & VUCC-DBT Verona University Culture Collection, Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (M.A.); (S.L.)
| | - Salvatore Fusco
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy; (L.B.); (A.S.); (L.Z.); (P.B.); (A.C.)
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6
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Pepe M, Hesami M, de la Cerda KA, Perreault ML, Hsiang T, Jones AMP. A journey with psychedelic mushrooms: From historical relevance to biology, cultivation, medicinal uses, biotechnology, and beyond. Biotechnol Adv 2023; 69:108247. [PMID: 37659744 DOI: 10.1016/j.biotechadv.2023.108247] [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: 04/06/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/04/2023]
Abstract
Psychedelic mushrooms containing psilocybin and related tryptamines have long been used for ethnomycological purposes, but emerging evidence points to the potential therapeutic value of these mushrooms to address modern neurological, psychiatric health, and related disorders. As a result, psilocybin containing mushrooms represent a re-emerging frontier for mycological, biochemical, neuroscience, and pharmacology research. This work presents crucial information related to traditional use of psychedelic mushrooms, as well as research trends and knowledge gaps related to their diversity and distribution, technologies for quantification of tryptamines and other tryptophan-derived metabolites, as well as biosynthetic mechanisms for their production within mushrooms. In addition, we explore the current state of knowledge for how psilocybin and related tryptamines are metabolized in humans and their pharmacological effects, including beneficial and hazardous human health implications. Finally, we describe opportunities and challenges for investigating the production of psychedelic mushrooms and metabolic engineering approaches to alter secondary metabolite profiles using biotechnology integrated with machine learning. Ultimately, this critical review of all aspects related to psychedelic mushrooms represents a roadmap for future research efforts that will pave the way to new applications and refined protocols.
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Affiliation(s)
- Marco Pepe
- Department of Plant Agriculture, University of Guelph, Ontario N1G 2W1, Guelph, Canada
| | - Mohsen Hesami
- Department of Plant Agriculture, University of Guelph, Ontario N1G 2W1, Guelph, Canada
| | - Karla A de la Cerda
- School of Environmental Sciences, University of Guelph, Ontario N1G 2W1, Guelph, Canada
| | - Melissa L Perreault
- Departments of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Ontario N1G 2W1, Guelph, Canada
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7
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Dadwal A, Sharma S, Satyanarayana T. Biochemical characteristics of Myceliophthora thermophila recombinant β-glucosidase (MtBgl3c) applicable in cellulose bioconversion. Prep Biochem Biotechnol 2023; 53:1187-1198. [PMID: 36799667 DOI: 10.1080/10826068.2023.2177869] [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: 02/18/2023]
Abstract
The GH3 β-glucosidase gene of Myceliophthora thermophila (MtBgl3c) has been cloned and heterologously expressed in E. coli for the first time. This study highlights the important characteristics of recombinant MtBgl3c (rMtBgl3c) which make it a promising candidate in industrial applications. Optimization of the production of rMtBgl3c led to 28,000 U L-1. On purification, it has a molecular mass of ∼100 kDa. It is a broad substrate specific thermostable enzyme that exhibits pH and temperature optima at 5.0 and 55 °C, respectively. The amino acid residues Asp287 and Glu514 act as nucleophile and catalytic acid/base, respectively in the enzyme catalysis. Its low Km value (1.28 mM) indicates a high substrate affinity as compared to those previously reported. The rMtBgl3c displays a synergistic action with the commercial enzyme cocktail in the saccharification of sugarcane bagasse suggesting its utility in the cellulose bioconversion. Tolerance to solvents, detergents as well as glucose make this enzyme applicable in wine, detergent, paper and textile industries too.
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Affiliation(s)
- Anica Dadwal
- Department of Biological Sciences and Engineering, Netaji Subhas University of Technology, Azad Hind Fauj Marg, Dwarka, New Delhi, India
| | - Shilpa Sharma
- Department of Biological Sciences and Engineering, Netaji Subhas University of Technology, Azad Hind Fauj Marg, Dwarka, New Delhi, India
| | - Tulasi Satyanarayana
- Department of Biological Sciences and Engineering, Netaji Subhas University of Technology, Azad Hind Fauj Marg, Dwarka, New Delhi, India
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8
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Chen N, Yang S, You D, Shen J, Ruan B, Wu M, Zhang J, Luo X, Tang H. Systematic genetic modifications of cell wall biosynthesis enhanced the secretion and surface-display of polysaccharide degrading enzymes in Saccharomyces cerevisiae. Metab Eng 2023; 77:273-282. [PMID: 37100192 DOI: 10.1016/j.ymben.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/31/2023] [Accepted: 04/15/2023] [Indexed: 04/28/2023]
Abstract
Saccharomyces cerevisiae is a robust cell factory to secrete or surface-display cellulase and amylase for the conversion of agricultural residues into valuable chemicals. Engineering the secretory pathway is a well-known strategy for overproducing these enzymes. Although cell wall biosynthesis can be tightly linked to the secretory pathway by regulation of all involved processes, the effect of its modifications on protein production has not been extensively studied. In this study, we systematically studied the effect of engineering cell wall biosynthesis on the activity of cellulolytic enzyme β-glucosidase (BGL1) by comparing seventy-nine gene knockout S. cerevisiae strains and newly identified that inactivation of DFG5, YPK1, FYV5, CCW12 and KRE1 obviously improved BGL1 secretion and surface-display. Combinatorial modifications of these genes, particularly double deletion of FVY5 and CCW12, along with the use of rich medium, increased the activity of secreted and surface-displayed BGL1 by 6.13-fold and 7.99-fold, respectively. Additionally, we applied this strategy to improve the activity of the cellulolytic cellobiohydrolase and amylolytic α-amylase. Through proteomic analysis coupled with reverse engineering, we found that in addition to the secretory pathway, regulation of translation processes may also involve in improving enzyme activity by engineering cell wall biosynthesis. Our work provides new insight into the construction of a yeast cell factory for efficient production of polysaccharide degrading enzymes.
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Affiliation(s)
- Nanzhu Chen
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Shuo Yang
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China; State Key Laboratory of Biobased Material and Green Papermaking, School of Bioengineering, Key Laboratory of Shandong Microbial Engineering, Qilu University of Technology, 3501 Daxue Road, Jinan, 250353, China
| | - Dawei You
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Junfeng Shen
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Banlai Ruan
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Mei Wu
- Synceres Biosciences (Shenzhen) Co., Ltd, Nanshan Medical Device Industrial Park, Nanhai Avenue, Shenzhen, 518067, China
| | - Jianzhi Zhang
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xiaozhou Luo
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Hongting Tang
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
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Tamburino R, Castiglia D, Marcolongo L, Sannino L, Ionata E, Scotti N. Tobacco Plastid Transformation as Production Platform of Lytic Polysaccharide MonoOxygenase Auxiliary Enzymes. Int J Mol Sci 2022; 24:ijms24010309. [PMID: 36613758 PMCID: PMC9820616 DOI: 10.3390/ijms24010309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Plant biomass is the most abundant renewable resource in nature. In a circular economy perspective, the implementation of its bioconversion into fermentable sugars is of great relevance. Lytic Polysaccharide MonoOxygenases (LPMOs) are accessory enzymes able to break recalcitrant polysaccharides, boosting biomass conversion and subsequently reducing costs. Among them, auxiliary activity of family 9 (AA9) acts on cellulose in synergism with traditional cellulolytic enzymes. Here, we report for the first time, the production of the AA9 LPMOs from the mesophilic Trichoderma reesei (TrAA9B) and the thermophilic Thermoascus aurantiacus (TaAA9B) microorganisms in tobacco by plastid transformation with the aim to test this technology as cheap and sustainable manufacture platform. In order to optimize recombinant protein accumulation, two different N-terminal regulatory sequences were used: 5' untranslated region (5'-UTR) from T7g10 gene (DC41 and DC51 plants), and 5' translation control region (5'-TCR), containing the 5'-UTR and the first 14 amino acids (Downstream Box, DB) of the plastid atpB gene (DC40 and DC50 plants). Protein yields ranged between 0.5 and 5% of total soluble proteins (TSP). The phenotype was unaltered in all transplastomic plants, except for the DC50 line accumulating AA9 LPMO at the highest level, that showed retarded growth and a mild pale green phenotype. Oxidase activity was spectrophotometrically assayed and resulted higher for the recombinant proteins without the N-terminal fusion (DC41 and DC51), with a 3.9- and 3.4-fold increase compared to the fused proteins.
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Affiliation(s)
- Rachele Tamburino
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Portici, Italy
| | - Daniela Castiglia
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Portici, Italy
- CNR-ICB, Institute of Biomolecular Chemistry, 80078 Pozzuoli, Italy
| | | | - Lorenza Sannino
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Portici, Italy
| | - Elena Ionata
- CNR-IRET, Research Institute on Terrestrial Ecosystems, 80131 Naples, Italy
| | - Nunzia Scotti
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Portici, Italy
- Correspondence:
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10
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Tamburino R, Marcolongo L, Sannino L, Ionata E, Scotti N. Plastid Transformation: New Challenges in the Circular Economy Era. Int J Mol Sci 2022; 23:ijms232315254. [PMID: 36499577 PMCID: PMC9736159 DOI: 10.3390/ijms232315254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
In a circular economy era the transition towards renewable and sustainable materials is very urgent. The development of bio-based solutions, that can ensure technological circularity in many priority areas (e.g., agriculture, biotechnology, ecology, green industry, etc.), is very strategic. The agricultural and fishing industry wastes represent important feedstocks that require the development of sustainable and environmentally-friendly industrial processes to produce and recover biofuels, chemicals and bioactive molecules. In this context, the replacement, in industrial processes, of chemicals with enzyme-based catalysts assures great benefits to humans and the environment. In this review, we describe the potentiality of the plastid transformation technology as a sustainable and cheap platform for the production of recombinant industrial enzymes, summarize the current knowledge on the technology, and display examples of cellulolytic enzymes already produced. Further, we illustrate several types of bacterial auxiliary and chitinases/chitin deacetylases enzymes with high biotechnological value that could be manufactured by plastid transformation.
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Affiliation(s)
- Rachele Tamburino
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Naples, Italy
| | | | - Lorenza Sannino
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Naples, Italy
| | - Elena Ionata
- CNR-IRET, Research Institute on Terrestrial Ecosystems, 80131 Naples, Italy
| | - Nunzia Scotti
- CNR-IBBR, Institute of Biosciences and BioResources, 80055 Naples, Italy
- Correspondence:
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11
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Yuan H, Zhou Y, Lin Y, Tu R, Guo Y, Zhang Y, Wang Q. Microfluidic screening and genomic mutation identification for enhancing cellulase production in Pichia pastoris. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:50. [PMID: 35568955 PMCID: PMC9107654 DOI: 10.1186/s13068-022-02150-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 05/05/2022] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Pichia pastoris is a widely used host organism for heterologous production of industrial proteins, such as cellulases. Although great progress has been achieved in improving protein expression in P. pastoris, the potential of the P. pastoris expression system has not been fully explored due to unknown genomic impact factors. Recently, whole-cell directed evolution, employing iterative rounds of genome-wide diversity generation and high-throughput screening (HTS), has been considered to be a promising strategy in strain improvement at the genome level.
Results
In this study, whole-cell directed evolution of P. pastoris, employing atmospheric and room temperature plasma (ARTP) mutagenesis and droplet-based microfluidic HTS, was developed to improve heterogenous cellulase production. The droplet-based microfluidic platform based on a cellulase-catalyzed reaction of releasing fluorescence was established to be suitable for methanol-grown P. pastoris. The validation experiment showed a positive sorting efficiency of 94.4% at a sorting rate of 300 droplets per second. After five rounds of iterative ARTP mutagenesis and microfluidic screening, the best mutant strain was obtained and exhibited the cellulase activity of 11,110 ± 523 U/mL, an approximately twofold increase compared to the starting strain. Whole-genome resequencing analysis further uncovered three accumulated genomic alterations in coding region. The effects of point mutations and mutant genes on cellulase production were verified using reconstruction of point mutations and gene deletions. Intriguingly, the point mutation Rsc1G22V was observed in all the top-performing producers selected from each round, and gene deletion analysis confirmed that Rsc1, a component of the RSC chromatin remodeling complex, might play an important role in cellulase production.
Conclusions
We established a droplet-based microfluidic HTS system, thereby facilitating whole-cell directed evolution of P. pastoris for enhancing cellulase production, and meanwhile identified genomic alterations by whole-genome resequencing and genetic validation. Our approaches and findings would provide guides to accelerate whole-cell directed evolution of host strains and enzymes of high industrial interest.
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12
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Wang L, Lin X, Zhou Y, Chen H. Porous inert material as promising carrier enhanced cellulase production from Trichoderma reesei in solid-state fermentation. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Baptista M, Domingues L. Kluyveromyces marxianus as a microbial cell factory for lignocellulosic biomass valorisation. Biotechnol Adv 2022; 60:108027. [PMID: 35952960 DOI: 10.1016/j.biotechadv.2022.108027] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 11/02/2022]
Abstract
The non-conventional yeast Kluyveromyces marxianus is widely used for several biotechnological applications, mainly due to its thermotolerance, high growth rate, and ability to metabolise a wide range of sugars. These cell traits are strategic for lignocellulosic biomass valorisation and strain diversity prompts the development of robust chassis, either with improved tolerance to lignocellulosic inhibitors or ethanol. This review summarises bioethanol and value-added chemicals production by K. marxianus from different lignocellulosic biomasses. Moreover, metabolic engineering and process optimization strategies developed to expand K. marxianus potential are also compiled, as well as studies reporting cell mechanisms to cope with lignocellulosic-derived inhibitors. The main lignocellulosic-based products are bioethanol, representing 71% of the reports, and xylitol, representing 17% of the reports. K. marxianus also proved to be a good chassis for lactic acid and volatile compounds production from lignocellulosic biomass, although the literature on this matter is still scarce. The increasing advances in genome editing tools and process optimization strategies will widen the K. marxianus-based portfolio products.
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Affiliation(s)
- Marlene Baptista
- CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; LABBELS -Associate Laboratory, Braga/Guimarães, Portugal
| | - Lucília Domingues
- CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; LABBELS -Associate Laboratory, Braga/Guimarães, Portugal.
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14
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Kurniati A, Puspaningsih NNT, Putri KDA, Damayanti M, Purwani NN, Rahmah SA, Purkan, Fujiyama K, Sakka M, Sakka K, Kimura T, Rohman A, Baktir A, Sanjaya RE. Heterologous fusion gene expression and characterization of a novel carbohydrate binding module (Cbm36) to laccase (Lcc2). BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Metagenomic mining and structure-function studies of a hyper-thermostable cellobiohydrolase from hot spring sediment. Commun Biol 2022; 5:247. [PMID: 35318423 PMCID: PMC8940973 DOI: 10.1038/s42003-022-03195-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/25/2022] [Indexed: 11/09/2022] Open
Abstract
Enzymatic breakdown is an attractive cellulose utilisation method with a low environmental load. Its high temperature operation could promote saccharification and lower contamination risk. Here we report a hyper-thermostable cellobiohydrolase (CBH), named HmCel6A and its variant HmCel6A-3SNP that were isolated metagenomically from hot spring sediments and expressed in Escherichia coli. They are classified into glycoside hydrolases family 6 (GH6). HmCel6A-3SNP had three amino acid replacements to HmCel6A (P88S/L230F/F414S) and the optimum temperature at 95 °C, while HmCel6A did it at 75 °C. Crystal structure showed conserved features among GH6, a (β/α)8-barrel core and catalytic residues, and resembles TfCel6B, a bacterial CBH II of Thermobifida fusca, that had optimum temperature at 60 °C. From structure-function studies, we discuss unique structural features that allow the enzyme to reach its high thermostability level, such as abundance of hydrophobic and charge-charge interactions, characteristic metal bindings and disulphide bonds. Moreover, structure and surface plasmon resonance analysis with oligosaccharides suggested that the contribution of an additional tryptophan located at the tunnel entrance could aid in substrate recognition and thermostability. These results may help to design efficient enzymes and saccharification methods for cellulose working at high temperatures. Bacteria from hot springs are known for highly thermostable enzymes, which may have industrial potential. Here, a unique thermostable cellobiohydrolase is reported that can breakdown cellulose at temperature up to 95 degrees Celsius.
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Structural and Biochemical Characterization of Endo-β-1,4-glucanase from Dictyoglomus thermophilum, a Hyperthermostable and Halotolerant Cellulase. Catalysts 2022. [DOI: 10.3390/catal12030302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Enzymatic conversion of polysaccharides in the lignocellulosic biomass is currently the subject of intensive research and will be a key technology in future biorefineries. Using a bioinformatics approach, we previously identified a putative endo-β-1,4-glucanase (DtCel5A) from Dictyoglomus thermophilum, a chemoorganotrophic and thermophilic bacterium. Here, we structurally and functionally characterize DtCel5A and show that it is endowed with remarkable thermal and chemical stability. The structural features of DtCel5A and of its complex with cellobiose have been investigated by combining X-ray crystallography and other biophysical studies. Importantly, biochemical assays show that DtCel5A retains its activity on cellulose at high temperatures and at elevated salt concentrations. These features make DtCel5A an enzyme with interesting biotechnological applications for biomass degradation.
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Sharma A, Balda S, Capalash N, Sharma P. Engineering multifunctional enzymes for agro-biomass utilization. BIORESOURCE TECHNOLOGY 2022; 347:126706. [PMID: 35033642 DOI: 10.1016/j.biortech.2022.126706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
Lignocellulosic biomass is a plentiful renewable resource that can be converted into a wide range of high-value-added industrial products. However, the complexity of its structural integrity is one of the major constraints and requires combinations of different fibrolytic enzymes for the cost-effective, industrially and environmentally feasible transformation. An interesting approach is constructing multifunctional enzymes, either in a single polypeptide or by joining multiple domains with linkers and performing diverse reactions simultaneously, in a single host. The production of such chimera proteins multiplies the advantages of different enzymatic reactions in a single setup, in lesser time, at lower production cost and with desirable and improved catalytic activities. This review embodies the various domain-tailoring and extracellular secretion strategies, possible solutions to their challenges, and efforts to experimentally connect different catalytic activities in a single host, as well as their applications.
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Affiliation(s)
- Aarjoo Sharma
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Sanjeev Balda
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Prince Sharma
- Department of Microbiology, Panjab University, Chandigarh, India.
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18
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Dadwal A, Sharma S, Satyanarayana T. Recombinant cellobiohydrolase of Myceliophthora thermophila: characterization and applicability in cellulose saccharification. AMB Express 2021; 11:148. [PMID: 34735642 PMCID: PMC8568750 DOI: 10.1186/s13568-021-01311-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 10/29/2021] [Indexed: 12/31/2022] Open
Abstract
A codon optimized cellobiohydrolase (CBH) encoding synthetic gene of 1188 bp from a thermophilic mold Myceliophthora thermophila (MtCel6A) was cloned and heterologously expressed in Escherichia coli for the first time. In silico analysis suggested that MtCel6A is a GH6 CBH and belongs to CBHII family, which is structurally similar to Cel6A of Humicola insolens. The recombinant MtCel6A is expressed as active inclusion bodies, and the molecular mass of the purified enzyme is ~ 45 kDa. The rMtCel6A is active in a wide range of pH (4-12) and temperatures (40-100 °C) with optima at pH 10.0 and 60 °C. It exhibits T1/2 of 6.0 and 1.0 h at 60 and 90 °C, respectively. The rMtCel6A is an extremozyme with organic solvent, salt and alkali tolerance. The Km, Vmax, kcat and kcat/Km values of the enzyme are 3.2 mg mL-1, 222.2 μmol mg-1 min-1, 2492 s-1 and 778.7 s-1 mg-1 mL-1, respectively. The product analysis of rMtCel6A confirmed that it is an exoenzyme that acts from the non-reducing end of cellulose. The addition of rMtCel6A to the commercial cellulase mix (Cellic CTec2) led to 1.9-fold increase in saccharification of the pre-treated sugarcane bagasse. The rMtCel6A is a potential CBH that finds utility in industrial processes such as in bioethanol, paper pulp and textile industries.
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Affiliation(s)
- Anica Dadwal
- Department of Biological Sciences & Engineering, Netaji Subhas Institute of Technology (University of Delhi), Azad Hind Fauj Marg, Sector-3 Dwarka, New Delhi, 110078, India
| | - Shilpa Sharma
- Department of Biological Sciences & Engineering, Netaji Subhas Institute of Technology (University of Delhi), Azad Hind Fauj Marg, Sector-3 Dwarka, New Delhi, 110078, India
- Department of Biological Sciences & Engineering, Netaji Subhas University of Technology, Azad Hind Fauj Marg, Sector-3 Dwarka, New Delhi, 110078, India
| | - Tulasi Satyanarayana
- Department of Biological Sciences & Engineering, Netaji Subhas Institute of Technology (University of Delhi), Azad Hind Fauj Marg, Sector-3 Dwarka, New Delhi, 110078, India.
- Department of Biological Sciences & Engineering, Netaji Subhas University of Technology, Azad Hind Fauj Marg, Sector-3 Dwarka, New Delhi, 110078, India.
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19
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Cutolo E, Tosoni M, Barera S, Herrera-Estrella L, Dall'Osto L, Bassi R. A chimeric hydrolase-PTXD transgene enables chloroplast-based heterologous protein expression and non-sterile cultivation of Chlamydomonas reinhardtii. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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20
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Current Progress in Production of Building-Block Organic Acids by Consolidated Bioprocessing of Lignocellulose. FERMENTATION-BASEL 2021. [DOI: 10.3390/fermentation7040248] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Several organic acids have been indicated among the top value chemicals from biomass. Lignocellulose is among the most attractive feedstocks for biorefining processes owing to its high abundance and low cost. However, its highly complex nature and recalcitrance to biodegradation hinder development of cost-competitive fermentation processes. Here, current progress in development of single-pot fermentation (i.e., consolidated bioprocessing, CBP) of lignocellulosic biomass to high value organic acids will be examined, based on the potential of this approach to dramatically reduce process costs. Different strategies for CBP development will be considered such as: (i) design of microbial consortia consisting of (hemi)cellulolytic and valuable-compound producing strains; (ii) engineering of microorganisms that combine biomass-degrading and high-value compound-producing properties in a single strain. The present review will mainly focus on production of organic acids with application as building block chemicals (e.g., adipic, cis,cis-muconic, fumaric, itaconic, lactic, malic, and succinic acid) since polymer synthesis constitutes the largest sector in the chemical industry. Current research advances will be illustrated together with challenges and perspectives for future investigations. In addition, attention will be dedicated to development of acid tolerant microorganisms, an essential feature for improving titer and productivity of fermentative production of acids.
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21
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den Haan R, Rose SH, Cripwell RA, Trollope KM, Myburgh MW, Viljoen-Bloom M, van Zyl WH. Heterologous production of cellulose- and starch-degrading hydrolases to expand Saccharomyces cerevisiae substrate utilization: Lessons learnt. Biotechnol Adv 2021; 53:107859. [PMID: 34678441 DOI: 10.1016/j.biotechadv.2021.107859] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
Selected strains of Saccharomyces cerevisiae are used for commercial bioethanol production from cellulose and starch, but the high cost of exogenous enzymes for substrate hydrolysis remains a challenge. This can be addressed through consolidated bioprocessing (CBP) where S. cerevisiae strains are engineered to express recombinant glycoside hydrolases during fermentation. Looking back at numerous strategies undertaken over the past four decades to improve recombinant protein production in S. cerevisiae, it is evident that various steps in the protein production "pipeline" can be manipulated depending on the protein of interest and its anticipated application. In this review, we briefly introduce some of the strategies and highlight lessons learned with regards to improved transcription, translation, post-translational modification and protein secretion of heterologous hydrolases. We examine how host strain selection and modification, as well as enzyme compatibility, are crucial determinants for overall success. Finally, we discuss how lessons from heterologous hydrolase expression can inform modern synthetic biology and genome editing tools to provide process-ready yeast strains in future. However, it is clear that the successful expression of any particular enzyme is still unpredictable and requires a trial-and-error approach.
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Affiliation(s)
- Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Kim M Trollope
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Marthinus W Myburgh
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | | | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa.
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22
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Clostridium thermocellum as a Promising Source of Genetic Material for Designer Cellulosomes: An Overview. Catalysts 2021. [DOI: 10.3390/catal11080996] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Plant biomass-based biofuels have gradually substituted for conventional energy sources thanks to their obvious advantages, such as renewability, huge quantity, wide availability, economic feasibility, and sustainability. However, to make use of the large amount of carbon sources stored in the plant cell wall, robust cellulolytic microorganisms are highly demanded to efficiently disintegrate the recalcitrant intertwined cellulose fibers to release fermentable sugars for microbial conversion. The Gram-positive, thermophilic, cellulolytic bacterium Clostridium thermocellum possesses a cellulolytic multienzyme complex termed the cellulosome, which has been widely considered to be nature’s finest cellulolytic machinery, fascinating scientists as an auspicious source of saccharolytic enzymes for biomass-based biofuel production. Owing to the supra-modular characteristics of the C. thermocellum cellulosome architecture, the cellulosomal components, including cohesin, dockerin, scaffoldin protein, and the plentiful cellulolytic and hemicellulolytic enzymes have been widely used for constructing artificial cellulosomes for basic studies and industrial applications. In addition, as the well-known microbial workhorses are naïve to biomass deconstruction, several research groups have sought to transform them from non-cellulolytic microbes into consolidated bioprocessing-enabling microbes. This review aims to update and discuss the current progress in these mentioned issues, point out their limitations, and suggest some future directions.
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23
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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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24
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25
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Advances in enzymatic oxyfunctionalization of aliphatic compounds. Biotechnol Adv 2021; 51:107703. [PMID: 33545329 DOI: 10.1016/j.biotechadv.2021.107703] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/17/2021] [Accepted: 01/25/2021] [Indexed: 12/27/2022]
Abstract
Selective oxyfunctionalizations of aliphatic compounds are difficult chemical reactions, where enzymes can play an important role due to their stereo- and regio-selectivity and operation under mild reaction conditions. P450 monooxygenases are well-known biocatalysts that mediate oxyfunctionalization reactions in different living organisms (from bacteria to humans). Unspecific peroxygenases (UPOs), discovered in fungi, have arisen as "dream biocatalysts" of great biotechnological interest because they catalyze the oxyfunctionalization of aliphatic and aromatic compounds, avoiding the necessity of expensive cofactors and regeneration systems, and only depending on H2O2 for their catalysis. Here, we summarize recent advances in aliphatic oxyfunctionalization reactions by UPOs, as well as the molecular determinants of the enzyme structures responsible for their activities, emphasizing the differences found between well-known P450s and the novel fungal peroxygenases.
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26
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Lopes AMM, Martins M, Goldbeck R. Heterologous Expression of Lignocellulose-Modifying Enzymes in Microorganisms: Current Status. Mol Biotechnol 2021; 63:184-199. [PMID: 33484441 DOI: 10.1007/s12033-020-00288-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 02/06/2023]
Abstract
Heterologous expression of the carbohydrate-active enzymes in microorganisms is a promising approach to produce bio-based compounds, such as fuels, nutraceuticals and other value-added products from sustainable lignocellulosic sources. Several microorganisms, including Saccharomyces cerevisiae, Escherichia coli, and the filamentous fungi Aspergillus nidulans, have unique characteristics desirable for a biorefinery production approach like well-known genetic tools, thermotolerance, high fermentative capacity and product tolerance, and high amount of recombinant enzyme secretion. These microbial factories are already stablished in the heterologous production of the carbohydrate-active enzymes to produce, among others, ethanol, xylooligosaccharides and the valuable coniferol. A complete biocatalyst able to heterologous express the CAZymes of glycoside hydrolases, carbohydrate esterases and auxiliary activities families could release these compounds faster, with higher yield and specificity. Recent advances in the synthetic biology tools could expand the number and diversity of enzymes integrated in these microorganisms, and also modify those already integrated. This review outlines the heterologous expression of carbohydrate-active enzymes in microorganisms, as well as recent updates in synthetic biology.
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Affiliation(s)
- Alberto Moura Mendes Lopes
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas (UNICAMP), Rua Monteiro Lobato no 80, Cidade Universitária, Campinas, São Paulo, 13083-862, Brazil
| | - Manoela Martins
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas (UNICAMP), Rua Monteiro Lobato no 80, Cidade Universitária, Campinas, São Paulo, 13083-862, Brazil
| | - Rosana Goldbeck
- Bioprocess and Metabolic Engineering Laboratory, School of Food Engineering, University of Campinas (UNICAMP), Rua Monteiro Lobato no 80, Cidade Universitária, Campinas, São Paulo, 13083-862, Brazil.
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27
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Alahuhta M, Xu Q, Knoshaug EP, Wang W, Wei H, Amore A, Baker JO, Vander Wall T, Himmel ME, Zhang M. Chimeric cellobiohydrolase I expression, activity, and biochemical properties in three oleaginous yeast. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:6. [PMID: 33407766 PMCID: PMC7789491 DOI: 10.1186/s13068-020-01856-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/10/2020] [Indexed: 05/16/2023]
Abstract
Consolidated bioprocessing using oleaginous yeast is a promising modality for the economic conversion of plant biomass to fuels and chemicals. However, yeast are not known to produce effective biomass degrading enzymes naturally and this trait is essential for efficient consolidated bioprocessing. We expressed a chimeric cellobiohydrolase I gene in three different oleaginous, industrially relevant yeast: Yarrowia lipolytica, Lipomyces starkeyi, and Saccharomyces cerevisiae to study the biochemical and catalytic properties and biomass deconstruction potential of these recombinant enzymes. Our results showed differences in glycosylation, surface charge, thermal and proteolytic stability, and efficacy of biomass digestion. L. starkeyi was shown to be an inferior active cellulase producer compared to both the Y. lipolytica and S. cerevisiae enzymes, whereas the cellulase expressed in S. cerevisiae displayed the lowest activity against dilute-acid-pretreated corn stover. Comparatively, the chimeric cellobiohydrolase I enzyme expressed in Y. lipolytica was found to have a lower extent of glycosylation, better protease stability, and higher activity against dilute-acid-pretreated corn stover.
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Affiliation(s)
- Markus Alahuhta
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - Qi Xu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Eric P Knoshaug
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Wei Wang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Antonella Amore
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - John O Baker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Todd Vander Wall
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Michael E Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Min Zhang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
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28
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Geem KR, Song Y, Hwang I, Bae HJ, Lee DW. Production of Gloeophyllum trabeum Endoglucanase Cel12A in Nicotiana benthamiana for Cellulose Degradation. FRONTIERS IN PLANT SCIENCE 2021; 12:696199. [PMID: 34262588 PMCID: PMC8273430 DOI: 10.3389/fpls.2021.696199] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/02/2021] [Indexed: 05/06/2023]
Abstract
Lignocellulosic biomass from plants has been used as a biofuel source and the potent acidic endoglucanase GtCel12A has been isolated from Gloeophyllum trabeum, a filamentous fungus. In this study, we established a plant-based platform for the production of active GtCel12A fused to family 3 cellulose-binding module (CBM3). We used the signal sequence of binding immunoglobulin protein (BiP) and the endoplasmic reticulum (ER) retention signal for the accumulation of the produced GtCel12A in the ER. To achieve enhanced enzyme expression, we incorporated the M-domain of the human receptor-type tyrosine-protein phosphatase C into the construct. In addition, to enable the removal of N-terminal domains that are not necessary after protein expression, we further incorporated the cleavage site of Brachypodium distachyon small ubiquitin-like modifier. The GtCel12A-CBM3 fusion protein produced in the leaves of Nicotiana benthamiana exhibited not only high solubility but also efficient endoglucanase activity on the carboxymethyl cellulose substrate as determined by 3,5-dinitrosalicylic acid assay. The endoglucanase activity of GtCel12A-CBM3 was maintained even when immobilized on microcrystalline cellulose beads. Taken together, these results indicate that GtCel12A endoglucanase produced in plants might be used to provide monomeric sugars from lignocellulosic biomass for bioethanol production.
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Affiliation(s)
- Kyoung Rok Geem
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, South Korea
| | - Younho Song
- Bio-Energy Research Center, Chonnam National University, Gwangju, South Korea
| | - Inhwan Hwang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Hyeun-Jong Bae
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, South Korea
- Bio-Energy Research Center, Chonnam National University, Gwangju, South Korea
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Dong Wook Lee
- Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, South Korea
- Bio-Energy Research Center, Chonnam National University, Gwangju, South Korea
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
- *Correspondence: Dong Wook Lee
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Bioinformatics Applications in Fungal Siderophores: Omics Implications. Fungal Biol 2021. [DOI: 10.1007/978-3-030-53077-8_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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30
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All4894 encoding a novel fasciclin (FAS-1 domain) protein of Anabaena sp. PCC7120 revealed the presence of a thermostable β-glucosidase. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.102036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Recombinant chimeric enzymes for lignocellulosic biomass hydrolysis. Enzyme Microb Technol 2020; 140:109647. [DOI: 10.1016/j.enzmictec.2020.109647] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/19/2022]
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Dong C, Qiao J, Wang X, Sun W, Chen L, Li S, Wu K, Ma L, Liu Y. Engineering Pichia pastoris with surface-display minicellulosomes for carboxymethyl cellulose hydrolysis and ethanol production. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:108. [PMID: 32549912 PMCID: PMC7296672 DOI: 10.1186/s13068-020-01749-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUNDS Engineering yeast as a consolidated bioprocessing (CBP) microorganism by surface assembly of cellulosomes has been aggressively utilized for cellulosic ethanol production. However, most of the previous studies focused on Saccharomyces cerevisiae, achieving efficient conversion of phosphoric acid-swollen cellulose (PASC) or microcrystalline cellulose (Avicel) but not carboxymethyl cellulose (CMC) to ethanol, with an average titer below 2 g/L. RESULTS Harnessing an ultra-high-affinity IM7/CL7 protein pair, here we describe a method to engineer Pichia pastoris with minicellulosomes by in vitro assembly of three recombinant cellulases including an endoglucanase (EG), an exoglucanase (CBH) and a β-glucosidase (BGL), as well as a carbohydrate-binding module (CBM) on the cell surface. For the first time, the engineered yeasts enable efficient and direct conversion of CMC to bioethanol, observing an impressive ethanol titer of 5.1 g/L. CONCLUSIONS The research promotes the application of P. pastoris as a CBP cell factory in cellulosic ethanol production and provides a promising platform for screening the cellulases from different species to construct surface-assembly celluosome.
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Affiliation(s)
- Ce Dong
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Jie Qiao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Xinping Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Wenli Sun
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Lixia Chen
- Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Shuntang Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Ke Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
- BravoVax Co., Ltd., Wuhan, 430000 Hubei China
| | - Lixin Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
- Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
| | - Yi Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
- Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, 430062 Hubei China
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Exploiting strain diversity and rational engineering strategies to enhance recombinant cellulase secretion by Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2020; 104:5163-5184. [PMID: 32337628 DOI: 10.1007/s00253-020-10602-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022]
Abstract
Consolidated bioprocessing (CBP) of lignocellulosic material into bioethanol has progressed in the past decades; however, several challenges still exist which impede the industrial application of this technology. Identifying the challenges that exist in all unit operations is crucial and needs to be optimised, but only the barriers related to the secretion of recombinant cellulolytic enzymes in Saccharomyces cerevisiae will be addressed in this review. Fundamental principles surrounding CBP as a biomass conversion platform have been established through the successful expression of core cellulolytic enzymes, namely β-glucosidases, endoglucanases, and exoglucanases (cellobiohydrolases) in S. cerevisiae. This review will briefly address the challenges involved in the construction of an efficient cellulolytic yeast, with particular focus on the secretion efficiency of cellulases from this host. Additionally, strategies for studying enhanced cellulolytic enzyme secretion, which include both rational and reverse engineering approaches, will be discussed. One such technique includes bio-engineering within genetically diverse strains, combining the strengths of both natural strain diversity and rational strain development. Furthermore, with the advancement in next-generation sequencing, studies that utilise this method of exploiting intra-strain diversity for industrially relevant traits will be reviewed. Finally, future prospects are discussed for the creation of ideal CBP strains with high enzyme production levels.Key Points• Several challenges are involved in the construction of efficient cellulolytic yeast, in particular, the secretion efficiency of cellulases from the hosts.• Strategies for enhancing cellulolytic enzyme secretion, a core requirement for CBP host microorganism development, include both rational and reverse engineering approaches.• One such technique includes bio-engineering within genetically diverse strains, combining the strengths of both natural strain diversity and rational strain development.
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Shahab RL, Brethauer S, Luterbacher JS, Studer MH. Engineering of ecological niches to create stable artificial consortia for complex biotransformations. Curr Opin Biotechnol 2020; 62:129-136. [DOI: 10.1016/j.copbio.2019.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 12/13/2022]
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35
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van Eerde A, Várnai A, Jameson JK, Paruch L, Moen A, Anonsen JH, Chylenski P, Steen HS, Heldal I, Bock R, Eijsink VGH, Liu‐Clarke J. In-depth characterization of Trichoderma reesei cellobiohydrolase TrCel7A produced in Nicotiana benthamiana reveals limitations of cellulase production in plants by host-specific post-translational modifications. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:631-643. [PMID: 31373133 PMCID: PMC7004914 DOI: 10.1111/pbi.13227] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/01/2019] [Accepted: 07/26/2019] [Indexed: 05/17/2023]
Abstract
Sustainable production of biofuels from lignocellulose feedstocks depends on cheap enzymes for degradation of such biomass. Plants offer a safe and cost-effective production platform for biopharmaceuticals, vaccines and industrial enzymes boosting biomass conversion to biofuels. Production of intact and functional protein is a prerequisite for large-scale protein production, and extensive host-specific post-translational modifications (PTMs) often affect the catalytic properties and stability of recombinant enzymes. Here we investigated the impact of plant PTMs on enzyme performance and stability of the major cellobiohydrolase TrCel7A from Trichoderma reesei, an industrially relevant enzyme. TrCel7A was produced in Nicotiana benthamiana using a vacuum-based transient expression technology, and this recombinant enzyme (TrCel7Arec ) was compared with the native fungal enzyme (TrCel7Anat ) in terms of PTMs and catalytic activity on commercial and industrial substrates. We show that the N-terminal glutamate of TrCel7Arec was correctly processed by N. benthamiana to a pyroglutamate, critical for protein structure, while the linker region of TrCel7Arec was vulnerable to proteolytic digestion during protein production due to the absence of O-mannosylation in the plant host as compared with the native protein. In general, the purified full-length TrCel7Arec had 25% lower catalytic activity than TrCel7Anat and impaired substrate-binding properties, which can be attributed to larger N-glycans and lack of O-glycans in TrCel7Arec . All in all, our study reveals that the glycosylation machinery of N. benthamiana needs tailoring to optimize the production of efficient cellulases.
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Affiliation(s)
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - John Kristian Jameson
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Lisa Paruch
- NIBIONorwegian Institute of Bioeconomy ResearchÅsNorway
| | - Anders Moen
- Department of BiosciencesFaculty of Mathematics and Natural SciencesUniversity of Oslo (UiO)OsloNorway
| | - Jan Haug Anonsen
- Department of BiosciencesFaculty of Mathematics and Natural SciencesUniversity of Oslo (UiO)OsloNorway
| | - Piotr Chylenski
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | | | - Inger Heldal
- NIBIONorwegian Institute of Bioeconomy ResearchÅsNorway
| | - Ralph Bock
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | - Vincent G. H. Eijsink
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
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Anandharaj M, Lin YJ, Rani RP, Nadendla EK, Ho MC, Huang CC, Cheng JF, Chang JJ, Li WH. Constructing a yeast to express the largest cellulosome complex on the cell surface. Proc Natl Acad Sci U S A 2020; 117:2385-2394. [PMID: 31953261 PMCID: PMC7007581 DOI: 10.1073/pnas.1916529117] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cellulosomes, which are multienzyme complexes from anaerobic bacteria, are considered nature's finest cellulolytic machinery. Thus, constructing a cellulosome in an industrial yeast has long been a goal pursued by scientists. However, it remains highly challenging due to the size and complexity of cellulosomal genes. Here, we overcame the difficulties by synthesizing the Clostridium thermocellum scaffoldin gene (CipA) and the anchoring protein gene (OlpB) using advanced synthetic biology techniques. The engineered Kluyveromyces marxianus, a probiotic yeast, secreted a mixture of dockerin-fused fungal cellulases, including an endoglucanase (TrEgIII), exoglucanase (CBHII), β-glucosidase (NpaBGS), and cellulase boosters (TaLPMO and MtCDH). The confocal microscopy results confirmed the cell-surface display of OlpB-ScGPI and fluorescence-activated cell sorting analysis results revealed that almost 81% of yeast cells displayed OlpB-ScGPI. We have also demonstrated the cellulosome complex formation using purified and crude cellulosomal proteins. Native polyacrylamide gel electrophoresis and mass spectrometric analysis further confirmed the cellulosome complex formation. Our engineered cellulosome can accommodate up to 63 enzymes, whereas the largest engineered cellulosome reported thus far could accommodate only 12 enzymes and was expressed by a plasmid instead of chromosomal integration. Interestingly, CipA 2B9C (with two cellulose binding modules, CBM) released significantly higher quantities of reducing sugars compared with other CipA variants, thus confirming the importance of cohesin numbers and CBM domain on cellulosome complex. The engineered yeast host efficiently degraded cellulosic substrates and released 3.09 g/L and 8.61 g/L of ethanol from avicel and phosphoric acid-swollen cellulose, respectively, which is higher than any previously constructed yeast cellulosome.
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Affiliation(s)
- Marimuthu Anandharaj
- Biodiversity Research Center, Academia Sinica, 11529 Taipei, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, 11529 Taipei, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, 40227 Taichung, Taiwan
| | - Yu-Ju Lin
- Biodiversity Research Center, Academia Sinica, 11529 Taipei, Taiwan
| | | | | | - Meng-Chiao Ho
- Institute of Biological Chemistry, Academia Sinica, 11529 Taipei, Taiwan
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, 40227 Taichung, Taiwan
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, 40227 Taichung, Taiwan
| | - Jan-Fang Cheng
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Walnut Creek, CA 94598
| | - Jui-Jen Chang
- Department of Medical Research, China Medical University Hospital, China Medical University, 402 Taichung, Taiwan;
| | - Wen-Hsiung Li
- Biodiversity Research Center, Academia Sinica, 11529 Taipei, Taiwan;
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, 11529 Taipei, Taiwan
- Biotechnology Center, National Chung Hsing University, 40227 Taichung, Taiwan
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637
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37
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Nakamura Y, Hirose S, Taniguchi Y, Moriya Y, Yamada T. Targeted enzyme gene re-positioning: A computational approach for discovering alternative bacterial enzymes for the synthesis of plant-specific secondary metabolites. Metab Eng Commun 2019; 9:e00102. [PMID: 31720217 PMCID: PMC6838473 DOI: 10.1016/j.mec.2019.e00102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/19/2019] [Accepted: 09/08/2019] [Indexed: 12/27/2022] Open
Abstract
Plant-biosynthesised secondary metabolites are unique sources of pharmaceuticals, food additives, and flavourings, among other industrial uses. However, industrial production of these metabolites is difficult because of their structural complexity, dangerousness and unfriendliness to natural environment, so the development of new methods to synthesise them is required. In this study, we developed a novel approach to identifying alternative bacterial enzyme to produce plant-biosynthesised secondary metabolites. Based on the similarity of enzymatic reactions, we searched for candidate bacterial genes encoding enzymes that could potentially replace the enzymes in plant-specific secondary metabolism reactions that are contained in the KEGG database (enzyme re-positioning). As a result, we discovered candidate bacterial alternative enzyme genes for 447 plant-specific secondary metabolic reaction. To validate our approach, we focused on the ability of an enzyme from Streptomyces coelicolor strain A3(2) strain to convert valencene to the grapefruit metabolite nootkatone, and confirmed its enzymatic activity by gas chromatography-mass spectrometry. This enzyme re-positioning approach may offer an entirely new way of screening enzymes that cannot be achieved by most of other conventional methods, and it is applicable to various other metabolites and may enable microbial production of compounds that are currently difficult to produce industrially.
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Affiliation(s)
- Yuya Nakamura
- School of Life Science and Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8550, Japan
| | - Shuichi Hirose
- NAGASE R&D Center, Nagase & Co., Ltd, Kobe High Tech Park 2-2-3 Murotani, Nishi- ku, Kobe, Hyogo, 651-2241, Japan
| | - Yuko Taniguchi
- NAGASE R&D Center, Nagase & Co., Ltd, Kobe High Tech Park 2-2-3 Murotani, Nishi- ku, Kobe, Hyogo, 651-2241, Japan
| | - Yuki Moriya
- Database Center for Life Science, Joint Support-Center for Data Science Research, Research Organization of Information and Systems, Kashiwa, 277-0871, Japan
| | - Takuji Yamada
- School of Life Science and Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8550, Japan
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama, 332-0012, Japan
- Metabologenomics Inc, 246-2 Kakuganji, Tsuruoka, Yamagata, 997-0052, Japan
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38
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Bashir Z, Sheng L, Anil A, Lali A, Minton NP, Zhang Y. Engineering Geobacillus thermoglucosidasius for direct utilisation of holocellulose from wheat straw. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:199. [PMID: 31452680 PMCID: PMC6701081 DOI: 10.1186/s13068-019-1540-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 08/06/2019] [Indexed: 05/29/2023]
Abstract
BACKGROUND A consolidated bioprocessing (CBP), where lignocellulose is converted into the desired product(s) in a single fermentative step without the addition of expensive degradative enzymes, represents the ideal solution of renewable routes to chemicals and fuels. Members of the genus Geobacillus are able to grow at elevated temperatures and are able to utilise a wide range of oligosaccharides derived from lignocellulose. This makes them ideally suited to the development of CBP. RESULTS In this study, we engineered Geobacillus thermoglucosidasius NCIMB 11955 to utilise lignocellulosic biomass, in the form of nitric acid/ammonia treated wheat straw to which expensive hydrolytic enzymes had not been added. Two different strains, BZ9 and BZ10, were generated by integrating the cglT (β-1,4-glucosidase) gene from Thermoanaerobacter brockii into the genome, and localising genes encoding different cellulolytic enzymes on autonomous plasmids. The plasmid of strain BZ10 carried a synthetic cellulosomal operon comprising the celA (Endoglucanase A) gene from Clostridium thermocellum and cel6B (Exoglucanase) from Thermobifida fusca; whereas, strain BZ9 contained a plasmid encoding the celA (multidomain cellulase) gene from Caldicellulosiruptor bescii. All of the genes were successfully expressed, and their encoded products secreted in a functionally active form, as evidenced by their detection in culture supernatants by Western blotting and enzymatic assay. In the case of the C. bescii CelA enzyme, this is one of the first times that the heterologous production of this multi-functional enzyme has been achieved in a heterologous host. Both strains (BZ9 and BZ10) exhibited improved growth on pre-treated wheat straw, achieving a higher final OD600 and producing greater numbers of viable cells. To demonstrate that cellulosic ethanol can be produced directly from lignocellulosic biomass by a single organism, we established our consortium of hydrolytic enzymes in a previously engineered ethanologenic G. thermoglucosidasius strain, LS242. We observed approximately twofold and 1.6-fold increase in ethanol production in the recombinant G. thermoglucosidasius equivalent to BZ9 and BZ10, respectively, compared to G. thermoglucosidasius LS242 strain at 24 h of growth. CONCLUSION We engineered G. thermoglucosidasius to utilise a real-world lignocellulosic biomass substrate and demonstrated that cellulosic ethanol can be produced directly from lignocellulosic biomass in one step. Direct conversion of biomass into desired products represents a new paradigm for CBP, offering the potential for carbon neutral, cost-effective production of sustainable chemicals and fuels.
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Affiliation(s)
- Zeenat Bashir
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Lili Sheng
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Annamma Anil
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Nathalal Parikh Marg, Mumbai, 400019 India
| | - Arvind Lali
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Nathalal Parikh Marg, Mumbai, 400019 India
| | - Nigel P. Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Ying Zhang
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD UK
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Ribeiro LF, Amarelle V, Alves LDF, Viana de Siqueira GM, Lovate GL, Borelli TC, Guazzaroni ME. Genetically Engineered Proteins to Improve Biomass Conversion: New Advances and Challenges for Tailoring Biocatalysts. Molecules 2019; 24:molecules24162879. [PMID: 31398877 PMCID: PMC6719137 DOI: 10.3390/molecules24162879] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 07/30/2019] [Accepted: 08/06/2019] [Indexed: 01/02/2023] Open
Abstract
Protein engineering emerged as a powerful approach to generate more robust and efficient biocatalysts for bio-based economy applications, an alternative to ecologically toxic chemistries that rely on petroleum. On the quest for environmentally friendly technologies, sustainable and low-cost resources such as lignocellulosic plant-derived biomass are being used for the production of biofuels and fine chemicals. Since most of the enzymes used in the biorefinery industry act in suboptimal conditions, modification of their catalytic properties through protein rational design and in vitro evolution techniques allows the improvement of enzymatic parameters such as specificity, activity, efficiency, secretability, and stability, leading to better yields in the production lines. This review focuses on the current application of protein engineering techniques for improving the catalytic performance of enzymes used to break down lignocellulosic polymers. We discuss the use of both classical and modern methods reported in the literature in the last five years that allowed the boosting of biocatalysts for biomass degradation.
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Affiliation(s)
- Lucas Ferreira Ribeiro
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil.
| | - Vanesa Amarelle
- Department of Microbial Biochemistry and Genomics, Biological Research Institute Clemente Estable, Montevideo, PC 11600, Uruguay
| | - Luana de Fátima Alves
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | | | - Gabriel Lencioni Lovate
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Tiago Cabral Borelli
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
| | - María-Eugenia Guazzaroni
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil.
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40
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Wierzbicka-Woś A, Henneberger R, Batista-García RA, Martínez-Ávila L, Jackson SA, Kennedy J, Dobson ADW. Biochemical Characterization of a Novel Monospecific Endo-β-1,4-Glucanase Belonging to GH Family 5 From a Rhizosphere Metagenomic Library. Front Microbiol 2019; 10:1342. [PMID: 31258522 PMCID: PMC6587912 DOI: 10.3389/fmicb.2019.01342] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 05/29/2019] [Indexed: 11/16/2022] Open
Abstract
Cellulases have a broad range of different industrial applications, ranging from food and beverages to pulp and paper and the biofuels area. Here a metagenomics based strategy was used to identify the cellulolytic enzyme CelRH5 from the rhizosphere. CelRH5 is a novel monospecific endo-β-1,4-glucanase belonging to the glycosyl hydrolase family 5 (GH5). Structural based modeling analysis indicated that CelRH5 is related to endo-β-1,4-glucanases derived from thermophilic microorganisms such as Thermotoga maritima, Fervidobacterium nodosum, and Ruminiclostridium thermocellum sharing 30-40% amino acid sequence identity. The molecular weight of the enzyme was determined as 40.5 kDa. Biochemical analyses revealed that the enzyme displayed good activity with soluble forms of cellulose as a substrate such as ostazin brilliant red hydroxyethyl cellulose (OBR-HEC), carboxymethylcellulose (CMC), hydroxyethyl cellulose (HEC), and insoluble azurine cross-linked hydroxyethylcellulose (AZCL-HEC). The enzyme shows highest enzymatic activity at pH 6.5 with high pH tolerance, remaining stable in the pH range 4.5–8.5. Highest activity was observed at 40°C, but CelRH5 is psychrotolerant being active and stable at temperatures below 30°C. The presence of the final products of cellulose hydrolysis (glucose and cellobiose) or metal ions such as Na+, K+, Li+, and Mg2+, as well as ethylenediaminetetraacetic acid (EDTA), urea, dithiothreitol (DTT), dimethyl sulfoxide (DMSO), 2-mercaptoethanol (2-ME) or glycerol, did not have a marked effect on CelRH5 activity. However, the enzyme is quite sensitive to the presence of 10 mM ions Zn2+, Ni2+, Co2+, Fe3+ and reagents such as 1 M guanidine HCl, 0.1% sodium dodecyl sulfate (SDS) and 20% ethanol. Given that it is psychrotolerant and retains activity in the presence of final cellulose degradation products, metal ions and various reagents, which are common in many technological processes; CelRH5 may be potential suitability for a variety of different biotechnological applications.
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Affiliation(s)
- Anna Wierzbicka-Woś
- Environmental Research Institute, University College Cork, Cork, Ireland.,Department of Microbiology, Faculty of Biology, University of Szczecin, Szczecin, Poland
| | - Ruth Henneberger
- Environmental Research Institute, University College Cork, Cork, Ireland.,Institute for Molecular Health Sciences, ETH Zürich, Zurich, Switzerland
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Liliana Martínez-Ávila
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Stephen A Jackson
- Environmental Research Institute, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | | | - Alan D W Dobson
- Environmental Research Institute, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
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41
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Song X, Li Y, Wu Y, Cai M, Liu Q, Gao K, Zhang X, Bai Y, Xu H, Qiao M. Metabolic engineering strategies for improvement of ethanol production in cellulolytic Saccharomyces cerevisiae. FEMS Yeast Res 2019; 18:5071949. [PMID: 30107496 DOI: 10.1093/femsyr/foy090] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/09/2018] [Indexed: 01/31/2023] Open
Abstract
As a traditional ethanol-producing microorganism, Saccharomyces cerevisiae is an ideal host for consolidated bioprocessing. However, expression of heterologous cellulase increases the metabolic burden in yeast, which results in low cellulase activity and poor cellulose degradation efficiency. In this study, cellulase-expressing yeast strains that could efficiently degrade different cellulosic substrates were created by optimizing cellulase ratios through a POT1-mediated δ-integration strategy. Metabolic engineering strategies, including optimization of codon usage, promoter and signal peptide, were also included in this system. We also confirmed that heterologous cellulase expression in cellulosic yeast induced the unfolded protein response. To enhance protein folding capacity, the endoplasmic reticulum chaperone protein BiP and the disulfide isomerase Pdi1p were overexpressed, and the Golgi membrane protein Ca2+/Mn2+ ATPase Pmr1p was disrupted to decrease the glycosylation of cellulase. The resultant strain, SK18-3, could produce 5.4 g L-1 ethanol with carboxymethyl-cellulose. Strain SK12-50 achieved 4.7 g L-1 ethanol production with phosphoric acid swollen cellulose hydrolysis. When Avicel was used as the substrate, 3.8 g L-1 ethanol (75% of the theoretical maximum yield) was produced in SK13-34. This work will significantly increase our knowledge of how to engineer optimal yeast strains for biofuel production from cellulosic biomass.
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Affiliation(s)
- Xiaofei Song
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Yuanzi Li
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Yuzhen Wu
- Department of Microbiology, College of Life Sciences, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Miao Cai
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Quanli Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Kai Gao
- Tianjin Academy of Environmental Sciences, No. 17 Fukang Road, Nankai District, Tianjin 300071, China
| | - Xiuming Zhang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Yanling Bai
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Haijin Xu
- Department of Microbiology, College of Life Sciences, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
| | - Mingqiang Qiao
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China
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42
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Sahoo K, Sahoo RK, Gaur M, Subudhi E. Cellulolytic thermophilic microorganisms in white biotechnology: a review. Folia Microbiol (Praha) 2019; 65:25-43. [DOI: 10.1007/s12223-019-00710-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 04/15/2019] [Indexed: 10/26/2022]
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43
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Petrović DM, Bissaro B, Chylenski P, Skaugen M, Sørlie M, Jensen MS, Aachmann FL, Courtade G, Várnai A, Eijsink VGH. Methylation of the N-terminal histidine protects a lytic polysaccharide monooxygenase from auto-oxidative inactivation. Protein Sci 2019; 27:1636-1650. [PMID: 29971843 DOI: 10.1002/pro.3451] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 12/29/2022]
Abstract
The catalytically crucial N-terminal histidine (His1) of fungal lytic polysaccharide monooxygenases (LPMOs) is post-translationally modified to carry a methylation. The functional role of this methylation remains unknown. We have carried out an in-depth functional comparison of two variants of a family AA9 LPMO from Thermoascus aurantiacus (TaLPMO9A), one with, and one without the methylation on His1. Various activity assays showed that the two enzyme variants are identical in terms of substrate preferences, cleavage specificities and the ability to activate molecular oxygen. During the course of this work, new functional features of TaLPMO9A were discovered, in particular the ability to cleave xyloglucan, and these features were identical for both variants. Using a variety of techniques, we further found that methylation has minimal effects on the pKa of His1, the affinity for copper and the redox potential of bound copper. The two LPMOs did, however, show clear differences in their resistance against oxidative damage. Studies with added hydrogen peroxide confirmed recent claims that low concentrations of H2 O2 boost LPMO activity, whereas excess H2 O2 leads to LPMO inactivation. The methylated variant of TaLPMO9A, produced in Aspergillus oryzae, was more resistant to excess H2 O2 and showed better process performance when using conditions that promote generation of reactive-oxygen species. LPMOs need to protect themselves from reactive oxygen species generated in their active sites and this study shows that methylation of the fully conserved N-terminal histidine provides such protection.
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Affiliation(s)
- Dejan M Petrović
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Bastien Bissaro
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Piotr Chylenski
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Morten Skaugen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Marianne S Jensen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Finn L Aachmann
- Department of Biotechnology and Food Science, NOBIPOL, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Gaston Courtade
- Department of Biotechnology and Food Science, NOBIPOL, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
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Liu Q, Li J, Zhao J, Wu J, Shao T. Enhancement of lignocellulosic degradation in high-moisture alfalfa via anaerobic bioprocess of engineered Lactococcus lactis with the function of secreting cellulase. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:88. [PMID: 31015862 PMCID: PMC6469111 DOI: 10.1186/s13068-019-1429-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Butyric fermentation and a substantial loss of dry matter (DM) often occur in alfalfa silage during the rainy season, which is not conducive to subsequent biofuel production. Currently, there have been negative effects on the combination of cellulases and lactic acid bacteria (LAB) on processing high-moisture alfalfa silage; however, transgenically engineered LAB strains that secrete cellulase have been proposed as an alternative approach to avoid the above problem. The objective of the present study was to construct engineered Lactococcus lactis strains with high-efficiency secretory-expressing cellulase genes from Trichoderma reesei and to investigate the effects of the combination of transgenically engineered L. lactis strains HT1/pMG36e-usp45-bgl1, HT1/pMG36e-usp45-cbh2, and HT1/pMG36e-usp45-egl3 (HT2) on fermentation quality, structural carbohydrate degradability and nonstructural carbohydrate fermentation kinetics of high-moisture alfalfa silage treated without additive as a negative control (Control), or/and with cellulase (EN), wild-type L. lactis subsp. lactis MG1363 (HT1) and the combination of HT1 and EN (HT1 + EN) as positive additive controls. RESULTS Engineered L. lactis strains were successfully constructed and efficiently secreted endoglucanase (1118 mU/mL), cellobiohydrolase (222 mU/mL), and β-glucosidase (131 mU/mL) and had high filter paper activity (236 mU/mL). Ensiling experiments verified that HT2 obtained the highest fermentation quality score (83.6) and most efficiently processed high-moisture alfalfa silage, demonstrated by a low pH (4.49) and ammonia-N content (106 g/kg nitrogen) and a high lactic acid content (67.1 g/kg DM) and without butyric acid. Change curves of structural carbohydrates revealed that HT2 degraded more lignocelluloses, demonstrated by the lowest contents of neutral detergent fibre, acid detergent fibre, cellulose and hemicellulose after ensiling for 60 days. Kinetic analysis showed that the most residual water-soluble carbohydrates, glucose, fructose and xylose generated by lignocellulose degradation were produced by HT2, followed by HT1 + EN. The HT2-treated silages had the highest DM recovery, had the fewest Clostridia spores, emitted a fragrance and were not sticky. CONCLUSION HT2 improved the conversion of lignocellulose to sugars and processed high-moisture alfalfa silage efficiently. This is a novel strategy that can be used to enhance lignocellulosic degradation in high-moisture alfalfa via a bioprocess with transgenically engineered L. lactis strains, which could enhance the development of alfalfa as a biomass feedstock and promote second-generation biofuel development in the rainy season.
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Affiliation(s)
- Qinhua Liu
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Weigang 1, Nanjing, 210095 China
| | - Junfeng Li
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Weigang 1, Nanjing, 210095 China
| | - Jie Zhao
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Weigang 1, Nanjing, 210095 China
| | - Jingxing Wu
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Weigang 1, Nanjing, 210095 China
| | - Tao Shao
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Weigang 1, Nanjing, 210095 China
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Bashirova A, Pramanik S, Volkov P, Rozhkova A, Nemashkalov V, Zorov I, Gusakov A, Sinitsyn A, Schwaneberg U, Davari MD. Disulfide Bond Engineering of an Endoglucanase from Penicillium verruculosum to Improve Its Thermostability. Int J Mol Sci 2019; 20:E1602. [PMID: 30935060 PMCID: PMC6479618 DOI: 10.3390/ijms20071602] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 01/29/2023] Open
Abstract
Endoglucanases (EGLs) are important components of multienzyme cocktails used in the production of a wide variety of fine and bulk chemicals from lignocellulosic feedstocks. However, a low thermostability and the loss of catalytic performance of EGLs at industrially required temperatures limit their commercial applications. A structure-based disulfide bond (DSB) engineering was carried out in order to improve the thermostability of EGLII from Penicillium verruculosum. Based on in silico prediction, two improved enzyme variants, S127C-A165C (DSB2) and Y171C-L201C (DSB3), were obtained. Both engineered enzymes displayed a 15⁻21% increase in specific activity against carboxymethylcellulose and β-glucan compared to the wild-type EGLII (EGLII-wt). After incubation at 70 °C for 2 h, they retained 52⁻58% of their activity, while EGLII-wt retained only 38% of its activity. At 80 °C, the enzyme-engineered forms retained 15⁻22% of their activity after 2 h, whereas EGLII-wt was completely inactivated after the same incubation time. Molecular dynamics simulations revealed that the introduced DSB rigidified a global structure of DSB2 and DSB3 variants, thus enhancing their thermostability. In conclusion, this work provides an insight into DSB protein engineering as a potential rational design strategy that might be applicable for improving the stability of other enzymes for industrial applications.
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Affiliation(s)
- Anna Bashirova
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Subrata Pramanik
- Institute of Biotechnology, RWTH Aachen University, Aachen 52074, Worringerweg 3, Germany.
| | - Pavel Volkov
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Aleksandra Rozhkova
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, Moscow 119071, Russia.
| | - Vitaly Nemashkalov
- G.K.Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142292, Moscow region, Russia.
| | - Ivan Zorov
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, Moscow 119071, Russia.
- Department of Chemistry, M.V.Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Alexander Gusakov
- Department of Chemistry, M.V.Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Arkady Sinitsyn
- Federal Research Centre «Fundamentals of Biotechnology» of the Russian Academy of Sciences, Moscow 119071, Russia.
- Department of Chemistry, M.V.Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Aachen 52074, Worringerweg 3, Germany.
- DWI-Leibniz Institut für Interaktive Materialien, Forckenbeckstrasse 50, Aachen 52056, Germany.
| | - Mehdi D Davari
- Institute of Biotechnology, RWTH Aachen University, Aachen 52074, Worringerweg 3, Germany.
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46
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Gao M, Ploessl D, Shao Z. Enhancing the Co-utilization of Biomass-Derived Mixed Sugars by Yeasts. Front Microbiol 2019; 9:3264. [PMID: 30723464 PMCID: PMC6349770 DOI: 10.3389/fmicb.2018.03264] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/14/2018] [Indexed: 12/11/2022] Open
Abstract
Plant biomass is a promising carbon source for producing value-added chemicals, including transportation biofuels, polymer precursors, and various additives. Most engineered microbial hosts and a select group of wild-type species can metabolize mixed sugars including oligosaccharides, hexoses, and pentoses that are hydrolyzed from plant biomass. However, most of these microorganisms consume glucose preferentially to non-glucose sugars through mechanisms generally defined as carbon catabolite repression. The current lack of simultaneous mixed-sugar utilization limits achievable titers, yields, and productivities. Therefore, the development of microbial platforms capable of fermenting mixed sugars simultaneously from biomass hydrolysates is essential for economical industry-scale production, particularly for compounds with marginal profits. This review aims to summarize recent discoveries and breakthroughs in the engineering of yeast cell factories for improved mixed-sugar co-utilization based on various metabolic engineering approaches. Emphasis is placed on enhanced non-glucose utilization, discovery of novel sugar transporters free from glucose repression, native xylose-utilizing microbes, consolidated bioprocessing (CBP), improved cellulase secretion, and creation of microbial consortia for improving mixed-sugar utilization. Perspectives on the future development of biorenewables industry are provided in the end.
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Affiliation(s)
- Meirong Gao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States.,NSF Engineering Research Center for Biorenewable Chemicals (CBiRC), Iowa State University, Ames, IA, United States
| | - Deon Ploessl
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States.,NSF Engineering Research Center for Biorenewable Chemicals (CBiRC), Iowa State University, Ames, IA, United States
| | - Zengyi Shao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States.,NSF Engineering Research Center for Biorenewable Chemicals (CBiRC), Iowa State University, Ames, IA, United States.,The Ames Laboratory, Iowa State University, Ames, IA, United States.,The Interdisciplinary Microbiology Program, Biorenewables Research Laboratory, Iowa State University, Ames, IA, United States
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Buyel JF. Plant Molecular Farming - Integration and Exploitation of Side Streams to Achieve Sustainable Biomanufacturing. FRONTIERS IN PLANT SCIENCE 2019; 9:1893. [PMID: 30713542 PMCID: PMC6345721 DOI: 10.3389/fpls.2018.01893] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/06/2018] [Indexed: 05/22/2023]
Abstract
Plants have unique advantages over other systems such as mammalian cells for the production of valuable small molecules and proteins. The benefits cited most often include safety due to the absence of replicating human pathogens, simplicity because sterility is not required during production, scalability due to the potential for open-field cultivation with transgenic plants, and the speed of transient expression potentially providing gram quantities of product in less than 4 weeks. Initially there were also significant drawbacks, such as the need to clarify feed streams with a high particle burden and the large quantities of host cell proteins, but efficient clarification is now readily achieved. Several additional advantages have also emerged reflecting the fact that plants are essentially biodegradable, single-use bioreactors. This article will focus on the exploitation of this concept for the production of biopharmaceutical proteins, thus improving overall process economics. Specifically, we will discuss the single-use properties of plants, the sustainability of the production platform, and the commercial potential of different biomass side streams. We find that incorporating these side streams through rational process integration has the potential to more than double the revenue that can currently be achieved using plant-based production systems.
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Affiliation(s)
- Johannes F. Buyel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
- Institute for Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
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48
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Singh G, Patel AK, Gupta A, Gupta D, Mishra VK. Current Advancements in Recombinant Technology for Industrial Production of Cellulases: Part-II. Fungal Biol 2019. [DOI: 10.1007/978-3-030-14726-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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49
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Xu Q, Alahuhta M, Wei H, Knoshaug EP, Wang W, Baker JO, Vander Wall T, Himmel ME, Zhang M. Expression of an endoglucanase-cellobiohydrolase fusion protein in Saccharomyces cerevisiae, Yarrowia lipolytica, and Lipomyces starkeyi. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:322. [PMID: 30524504 PMCID: PMC6278004 DOI: 10.1186/s13068-018-1301-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/25/2018] [Indexed: 05/28/2023]
Abstract
The low secretion levels of cellobiohydrolase I (CBHI) in yeasts are one of the key barriers preventing yeast from directly degrading and utilizing lignocellulose. To overcome this obstacle, we have explored the approach of genetically linking an easily secreted protein to CBHI, with CBHI being the last to be folded. The Trichoderma reesei eg2 (TrEGII) gene was selected as the leading gene due to its previously demonstrated outstanding secretion in yeast. To comprehensively characterize the effects of this fusion protein, we tested this hypothesis in three industrially relevant yeasts: Saccharomyces cerevisiae, Yarrowia lipolytica, and Lipomyces starkeyi. Our initial assays with the L. starkeyi secretome expressing differing TrEGII domains fused to a chimeric Talaromyces emersonii-T. reesei CBHI (TeTrCBHI) showed that the complete TrEGII enzyme, including the glycoside hydrolase (GH) 5 domain is required for increased expression level of the fusion protein when linked to CBHI. We found that this new construct (TrEGII-TeTrCBHI, Fusion 3) had an increased secretion level of at least threefold in L. starkeyi compared to the expression level of the chimeric TeTrCBHI. However, the same improvements were not observed when Fusion 3 construct was expressed in S. cerevisiae and Y. lipolytica. Digestion of pretreated corn stover with the secretomes of Y. lipolytica and L. starkeyi showed that conversion was much better using Y. lipolytica secretomes (50% versus 29%, respectively). In Y. lipolytica, TeTrCBHI performed better than the fusion construct. Furthermore, S. cerevisiae expression of Fusion 3 construct was poor and only minimal activity was observed when acting on the substrate, pNP-cellobiose. No activity was observed for the pNP-lactose substrate. Clearly, this approach is not universally applicable to all yeasts, but works in specific cases. With purified protein and soluble substrates, the exoglucanase activity of the GH7 domain embedded in the Fusion 3 construct in L. starkeyi was significantly higher than that of the GH7 domain in TeTrCBHI expressed alone. It is probable that a higher fraction of fusion construct CBHI is in an active form in Fusion 3 compared to just TeTrCBHI. We conclude that the strategy of leading TeTrCBHI expression with a linked TrEGII module significantly improved the expression of active CBHI in L. starkeyi.
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Affiliation(s)
- Qi Xu
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Markus Alahuhta
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Eric P. Knoshaug
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Wei Wang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - John O. Baker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Todd Vander Wall
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Min Zhang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
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50
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Jain KK, Kumar S, Bhardwaj KN, Kuhad RC. Functional Expression of a Thermostable Endoglucanase from Thermoascus aurantiacus RCKK in Pichia pastoris X-33 and Its Characterization. Mol Biotechnol 2018; 60:736-748. [PMID: 30076532 DOI: 10.1007/s12033-018-0106-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Thermostable cellulases offer several advantages like higher rates of substrate hydrolysis, lowered risk of contamination, and increased flexibility with respect to process design. In the present study, a thermostable native endoglucanase nEG (EC 3.2.1.4) was purified and characterized from T. aurantiacus RCKK. Further, it was cloned in P. pastoris X-33 and processed for over expression. Expression of recombinant endoglucanase (rEG) of molecular size ~ 33 kDa was confirmed by SDS-PAGE and western blotting followed by in gel activity determination by zymogram analysis. Similar to nEG, the purified rEG was characterized to harbor high thermostability while retaining 50% of its initial activity even after 6- and 10-h incubation at 80 and 70 °C, respectively, and exhibited considerable stability in pH range 3.0-7.0. CD spectroscopy revealed more than 20% β-sheets in protein structure consistently when incubated upto 85 °C as a speculated reason for protein high thermostability. Interestingly, both nEG and rEG were found tolerant up to 10% of the presence of 1-ethyl-3-methylimidazolium acetate [C2mim][OAc]. Values of the catalytic constants Km and Vmax for rEG were recorded as 2.5 mg/ml and 303.4 µmol/mg/min, respectively. Thermostability, pH stability, and resistance to the presence of ionic liquid signify the potential applicability of present enzyme in cellulose hydrolysis and enzymatic deinking of recycled paper pulp.
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Affiliation(s)
- Kavish Kumar Jain
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.,Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Sandeep Kumar
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Kailash N Bhardwaj
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.,Uttarakhan State Council of Science and Technology [UCOST], Vigyan Dham, Post Office- Jhajra, Dehradun, Uttarakhand, 248007, India
| | - Ramesh Chander Kuhad
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. .,Central University of Haryana, Jant-Pali Village, Mahendergarh District, Haryana, 123029, India.
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