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Carbonaro M, Aulitto M, Mazurkewich S, Fraia AD, Contursi P, Limauro D, Larsbrink J, Fiorentino G. Genomic mining of Geobacillus stearothermophilus GF16 for xylose production from hemicellulose-rich biomasses using secreted enzymes. N Biotechnol 2024; 82:14-24. [PMID: 38688408 DOI: 10.1016/j.nbt.2024.04.002] [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: 03/15/2024] [Revised: 04/11/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
The valorization of lignocellulosic biomass, derived from various bio-waste materials, has received considerable attention as a sustainable approach to improve production chains while reducing environmental impact. Microbial enzymes have emerged as key players in the degradation of polysaccharides, offering versatile applications in biotechnology and industry. Among these enzymes, glycoside hydrolases (GHs) play a central role. Xylanases, in particular, are used in a wide range of applications and are essential for the production of xylose, which can be fermented into bioethanol or find use in many other industries. Currently, fungal secretomes dominate as the main reservoir of lignocellulolytic enzymes, but thermophilic microorganisms offer notable advantages in terms of enzyme stability and production efficiency. Here we present the genomic characterization of Geobacillus stearothermophilus GF16 to identify genes encoding putative enzymes involved in lignocellulose degradation. Thermostable GHs secreted by G. stearothermophilus GF16 were investigated and found to be active on different natural polysaccharides and synthetic substrates, revealing an array of inducible GH activities. In particular, the concentrated secretome possesses significant thermostable xylanase and β-xylosidase activities (5 ×103 U/L and 1.7 ×105 U/L, respectively), highlighting its potential for application in biomass valorization. We assessed the hemicellulose hydrolysis capabilities of various agri-food wastes using the concentrated secretome of the strain cultivated on xylan. An impressive 300-fold increase in xylose release compared to a commercially available cocktail was obtained with the secretome, underscoring the remarkable efficacy of this approach.
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Affiliation(s)
- Miriam Carbonaro
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Martina Aulitto
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Scott Mazurkewich
- Wallenberg Wood Science Center, Division of Industrial Biotechnology, Department of Life Sciences, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Alessia Di Fraia
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Patrizia Contursi
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Danila Limauro
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Johan Larsbrink
- Wallenberg Wood Science Center, Division of Industrial Biotechnology, Department of Life Sciences, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
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2
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Ogugua PC, Su H, Wang E. Synergistic blending of biomass, sewage sludge, and coal for enhanced bioenergy production: Exploring residue combinations and optimizing thermal conversion parameters. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 352:120035. [PMID: 38244407 DOI: 10.1016/j.jenvman.2024.120035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/10/2023] [Accepted: 01/02/2024] [Indexed: 01/22/2024]
Abstract
Creating renewable energy from lignocellulosic biomass is essential for a sustainable future. Due to their abundance and the possibility of producing cheap and clean energy, non-lignocellulosic wastes like sewage sludge from industrial and municipal wastes have drawn attention as a feasible alternative to fossil fuels. These abundant, cost-effective resources may help minimize the effects of climate change since they produce less pollution. Several drawbacks are associated with using sewage sludge in thermal conversion procedures. These issues encompass suboptimal energy yield, elevated ash levels in the final product, and subpar biomass quality. Using these scraps in conjunction with coal might enhance energy conversion processes. This study has revealed the necessity for further investigation into how various combinations of residues interact with each other, influencing synergistic effects and degradation processes. The study's underlying objective was to provide a centralized database on the synergistic effects of mixing biomass and sewage sludge for bioenergy production, coal and biomass, and coal and sewage sludge through thermochemical processes like combustion, pyrolysis, gasification, and hydrolysis with Aspen Plus. This study will assist in enhancing biofuels' output from sewage sludge, coal, and coal/biomass blends in thermal conversion by defining the operating parameters (temperature, heat, and residence duration) of pyrolysis and combustion, features, and chemical properties that may influence these processes.
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Affiliation(s)
- Paul Chinonso Ogugua
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Huihui Su
- School of China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Enlu Wang
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
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3
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Zulfiqar M, Singh V, Steinbeck C, Sorokina M. Review on computer-assisted biosynthetic capacities elucidation to assess metabolic interactions and communication within microbial communities. Crit Rev Microbiol 2024:1-40. [PMID: 38270170 DOI: 10.1080/1040841x.2024.2306465] [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: 03/13/2023] [Accepted: 01/12/2024] [Indexed: 01/26/2024]
Abstract
Microbial communities thrive through interactions and communication, which are challenging to study as most microorganisms are not cultivable. To address this challenge, researchers focus on the extracellular space where communication events occur. Exometabolomics and interactome analysis provide insights into the molecules involved in communication and the dynamics of their interactions. Advances in sequencing technologies and computational methods enable the reconstruction of taxonomic and functional profiles of microbial communities using high-throughput multi-omics data. Network-based approaches, including community flux balance analysis, aim to model molecular interactions within and between communities. Despite these advances, challenges remain in computer-assisted biosynthetic capacities elucidation, requiring continued innovation and collaboration among diverse scientists. This review provides insights into the current state and future directions of computer-assisted biosynthetic capacities elucidation in studying microbial communities.
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Affiliation(s)
- Mahnoor Zulfiqar
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena, Germany
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
| | - Vinay Singh
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena, Germany
| | - Christoph Steinbeck
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena, Germany
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
| | - Maria Sorokina
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, Jena, Germany
- Data Science and Artificial Intelligence, Research and Development, Pharmaceuticals, Bayer, Berlin, Germany
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4
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Díaz-García L, Chuvochina M, Feuerriegel G, Bunk B, Spröer C, Streit WR, Rodriguez-R LM, Overmann J, Jiménez DJ. Andean soil-derived lignocellulolytic bacterial consortium as a source of novel taxa and putative plastic-active enzymes. Syst Appl Microbiol 2024; 47:126485. [PMID: 38211536 DOI: 10.1016/j.syapm.2023.126485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/19/2023] [Accepted: 12/01/2023] [Indexed: 01/13/2024]
Abstract
An easy and straightforward way to engineer microbial environmental communities is by setting up liquid enrichment cultures containing a specific substrate as the sole source of carbon. Here, we analyzed twenty single-contig high-quality metagenome-assembled genomes (MAGs) retrieved from a microbial consortium (T6) that was selected by the dilution-to-stimulation approach using Andean soil as inoculum and lignocellulose as a selection pressure. Based on genomic metrics (e.g., average nucleotide and amino acid identities) and phylogenomic analyses, 15 out of 20 MAGs were found to represent novel bacterial species, with one of those (MAG_26) belonging to a novel genus closely related to Caenibius spp. (Sphingomonadaceae). Following the rules and requirements of the SeqCode, we propose the name Andeanibacterium colombiense gen. nov., sp. nov. for this taxon. A subsequent functional annotation of all MAGs revealed that MAG_7 (Pseudobacter hemicellulosilyticus sp. nov.) contains 20, 19 and 16 predicted genes from carbohydrate-active enzymes families GH43, GH2 and GH92, respectively. Its lignocellulolytic gene profile resembles that of MAG_2 (the most abundant member) and MAG_3858, both of which belong to the Sphingobacteriaceae family. Using a database that contains experimentally verified plastic-active enzymes (PAZymes), twenty-seven putative bacterial polyethylene terephthalate (PET)-active enzymes (i.e., alpha/beta-fold hydrolases) were detected in all MAGs. A maximum of five putative PETases were found in MAG_3858, and two PETases were found to be encoded by A. colombiense. In conclusion, we demonstrate that lignocellulose-enriched liquid cultures coupled with genome-resolved metagenomics are suitable approaches to unveil the hidden bacterial diversity and its polymer-degrading potential in Andean soil ecosystems.
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Affiliation(s)
- Laura Díaz-García
- Department of Chemical and Biological Engineering, Advanced Biomanufacturing Centre, University of Sheffield, UK
| | - Maria Chuvochina
- The University of Queensland, School of Chemistry and Molecular Biosciences, Australian Centre for Ecogenomics, Brisbane, Queensland, Australia
| | - Golo Feuerriegel
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Luis M Rodriguez-R
- Department of Microbiology and Digital Science Center (DiSC), University of Innsbruck, Innsbruck, Austria
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany; Braunschweig University of Technology, Braunschweig, Germany
| | - Diego Javier Jiménez
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia; Microbiomes and Bioenergy Research Group, Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia.
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Sethupathy S, Xie R, Liang N, Shafreen RMB, Ali MY, Zhuang Z, Zhe L, Zahoor, Yong YC, Zhu D. Evaluation of a dye-decolorizing peroxidase from Comamonas serinivorans for lignin valorization potentials. Int J Biol Macromol 2023; 253:127117. [PMID: 37774822 DOI: 10.1016/j.ijbiomac.2023.127117] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/17/2023] [Accepted: 09/26/2023] [Indexed: 10/01/2023]
Abstract
Although dye-decolourising peroxidases (DyPs) are well-known for lignin degradation, a comprehensive understanding of their mechanism remains unclear. Therefore, studying the mechanism of lignin degradation by DyPs is necessary for industrial applications and enzyme engineering. In this study, a dye-decolourising peroxidase (CsDyP) gene from C. serinivorans was heterologously expressed and studied for its lignin degradation potential. Molecular docking analysis predicted the binding of 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), veratryl alcohol (VA), 2, 6-dimethylphenol (2, 6- DMP), guaiacol (GUA), and lignin to the substrate-binding pocket of CsDyP. Evaluation of the enzymatic properties showed that CsDyP requires pH 4.0 and 30 °C for optimal activity and has a high affinity for ABTS. In addition, CsDyP is stable over a wide range of temperatures and pH and can tolerate 5.0 mM organic solvents. Low NaCl concentrations promoted CsDyP activity. Further, CsDyP significantly reduced the chemical oxygen demand decolourised alkali lignin (AL) and milled wood lignin (MWL). CsDyP targets the β-O-4, CO, and CC bonds linking lignin's G, S, and H units to depolymerize and produce aromatic compounds. Overall, this study delivers valuable insights into the lignin degradation mechanism of CsDyP, which can benefit its industrial applications and lignin valorization.
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Affiliation(s)
- Sivasamy Sethupathy
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Rongrong Xie
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Nian Liang
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Raja Mohamed Beema Shafreen
- Department of Biotechnology, Dr. Umayal Ramanathan College for Women, Algappapuram, Karaikudi 630003, Tamil Nadu, India
| | - Mohamed Yassin Ali
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China; Biochemistry Department, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt
| | - Zhipeng Zhuang
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Liang Zhe
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Zahoor
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yang-Chun Yong
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Daochen Zhu
- Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
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Yang J, Yue HR, Pan LY, Feng JX, Zhao S, Suwannarangsee S, Chempreda V, Liu CG, Zhao XQ. Fungal strain improvement for efficient cellulase production and lignocellulosic biorefinery: Current status and future prospects. BIORESOURCE TECHNOLOGY 2023:129449. [PMID: 37406833 DOI: 10.1016/j.biortech.2023.129449] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023]
Abstract
Lignocellulosic biomass (LCB) has been recognized as a valuable carbon source for the sustainable production of biofuels and value-added biochemicals. Crude enzymes produced by fungal cell factories benefit economic LCB degradation. However, high enzyme production cost remains a great challenge. Filamentous fungi have been widely used to produce cellulolytic enzymes. Metabolic engineering of fungi contributes to efficient cellulase production for LCB biorefinery. Here the latest progress in utilizing fungal cell factories for cellulase production was summarized, including developing genome engineering tools to improve the efficiency of fungal cell factories, manipulating promoters, and modulating transcription factors. Multi-omics analysis of fungi contributes to identifying novel genetic elements for enhancing cellulase production. Furthermore, the importance of translation regulation of cellulase production are emphasized. Efficient development of fungal cell factories based on integrative strain engineering would benefit the overall bioconversion efficacy of LCB for sustainable bioproduction.
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Affiliation(s)
- Jie Yang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hou-Ru Yue
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li-Ya Pan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Surisa Suwannarangsee
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathumthani 12120, Thailand
| | - Verawat Chempreda
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathumthani 12120, Thailand
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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Wang L, Xie Y, Chang J, Wang J, Liu H, Shi M, Zhong Y. A novel sucrose-inducible expression system and its application for production of biomass-degrading enzymes in Aspergillus niger. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:23. [PMID: 36782304 PMCID: PMC9926565 DOI: 10.1186/s13068-023-02274-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
BACKGROUND Filamentous fungi are extensively exploited as important enzyme producers due to the superior secretory capability. However, the complexity of their secretomes greatly impairs the titer and purity of heterologous enzymes. Meanwhile, high-efficient evaluation and production of bulk enzymes, such as biomass-degrading enzymes, necessitate constructing powerful expression systems for bio-refinery applications. RESULTS A novel sucrose-inducible expression system based on the host strain Aspergillus niger ATCC 20611 and the β-fructofuranosidase promoter (PfopA) was constructed. A. niger ATCC 20611 preferentially utilized sucrose for rapid growth and β-fructofuranosidase production. Its secretory background was relatively clean because β-fructofuranosidase, the key enzyme responsible for sucrose utilization, was essentially not secreted into the medium and the extracellular protease activity was low. Furthermore, the PfopA promoter showed a sucrose concentration-dependent induction pattern and was not subject to glucose repression. Moreover, the strength of PfopA was 7.68-fold higher than that of the commonly used glyceraldehyde-3-phosphate dehydrogenase promoter (PgpdA) with enhanced green fluorescence protein (EGFP) as a reporter. Thus, A. niger ATCC 20611 coupled with the PfopA promoter was used as an expression system to express a β-glucosidase gene (bgla) from A. niger C112, allowing the production of β-glucosidase at a titer of 17.84 U/mL. The crude β-glucosidase preparation could remarkably improve glucose yield in the saccharification of pretreated corncob residues when added to the cellulase mixture of Trichoderma reesei QM9414. The efficacy of this expression system was further demonstrated by co-expressing the T. reesei-derived chitinase Chi46 and β-N-acetylglucosaminidase Nag1 to obtain an efficient chitin-degrading enzyme cocktail, which could achieve the production of N-acetyl-D-glucosamine from colloidal chitin with a conversion ratio of 91.83%. Besides, the purity of the above-secreted biomass-degrading enzymes in the crude culture supernatant was over 86%. CONCLUSIONS This PfopA-driven expression system expands the genetic toolbox of A. niger and broadens the application field of the traditional fructo-oligosaccharides-producing strain A. niger ATCC 20611, advancing it to become a high-performing enzyme-producing cell factory. In particular, the sucrose-inducible expression system possessed the capacity to produce biomass-degrading enzymes at a high level and evade endogenous protein interference, providing a potential purification-free enzyme production platform for bio-refinery applications.
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Affiliation(s)
- Lu Wang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Yijia Xie
- Qingdao Academy, Qingdao, 266111 People’s Republic of China
| | - Jingjing Chang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Juan Wang
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Hong Liu
- grid.27255.370000 0004 1761 1174State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237 People’s Republic of China
| | - Mei Shi
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
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Liew KJ, Zakaria MR, Hong CWL, Tan MCY, Chong CS. Draft genome sequence of Joostella atrarenae M1-2 T with cellulolytic and hemicellulolytic ability. 3 Biotech 2023; 13:50. [PMID: 36685320 PMCID: PMC9845502 DOI: 10.1007/s13205-023-03472-8] [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: 07/12/2022] [Accepted: 01/06/2023] [Indexed: 01/19/2023] Open
Abstract
The halophilic genus Joostella is one of the least-studied genera in the family of Flavobacteriaceae. So far, only two species were taxonomically identified with limited genomic analysis in the aspect of application has been reported. Joostella atrarenae M1-2T was previously isolated from a seashore sample and it is the second discovered species of the genus Joostella. In this project, the genome of J. atrarenae M1-2T was sequenced using NovaSeq 6000. The final assembled genome is comprised of 71 contigs, a total of 3,983,942 bp, a GC ratio of 33.2%, and encoded for 3,416 genes. The 16S rRNA gene sequence of J. atrarenae M1-2T shows 97.3% similarity against J. marina DSM 19592T. Genome-genome comparison between the two strains by ANI, dDDH, AAI, and POCP shows values of 80.8%, 23.3%, 83.4%, and 74.1% respectively. Pan-genome analysis shows that strain M1-2T and J. marina DSM 19592T shared a total of 248 core genes. Taken together, strain M-2T and J. marina DSM 19592T belong to the same genus but are two different species. CAZymes analysis revealed that strain M1-2T harbors 109 GHs, 40 GTs, 5 PLs, 9 CEs, and 6 AAs. Among these CAZymes, while 5 genes are related to cellulose degradation, 12 and 24 genes are found to encode for xylanolytic enzymes and other hemicellulases that involve majorly in the side chain removal of the lignocellulose structure, respectively. Furthermore, both the intracellular and extracellular crude extracts of strain M1-2T exhibited enzymatic activities against CMC, xylan, pNPG, and pNPX substrates, which corresponding to endoglucanase, xylanase, β-glucosidase, and β-xylosidase, respectively. Collectively, description of genome coupled with the enzyme assay results demonstrated that J. atrarenae M1-2T has a role in lignocellulosic biomass degradation, and the strain could be useful for lignocellulosic biorefining.
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Affiliation(s)
- Kok Jun Liew
- Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor Malaysia
| | | | - Clarine Wan Ling Hong
- Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor Malaysia
| | - Melvin Chun Yun Tan
- Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor Malaysia
| | - Chun Shiong Chong
- Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor Malaysia
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9
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Metasecretome and biochemical analysis of consortium PM-06 during the degradation of nixtamalized maize pericarp. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2023. [DOI: 10.1016/j.bcab.2023.102634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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10
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Zerva A, Siaperas R, Taxeidis G, Kyriakidi M, Vouyiouka S, Zervakis GI, Topakas E. Investigation of Abortiporus biennis lignocellulolytic toolbox, and the role of laccases in polystyrene degradation. CHEMOSPHERE 2023; 312:137338. [PMID: 36423718 DOI: 10.1016/j.chemosphere.2022.137338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 06/16/2023]
Abstract
White-rot basidiomycetes are the only microorganisms able to produce both hydrolytic (cellulases and hemicellulases) and oxidative (ligninolytic) enzymes for degrading all lignocellulose constituents. Their enzymatic machinery makes them ideal for the discovery of novel enzymes with desirable properties. In the present work, Abortiporus biennis, a white-rot fungus, was studied in regard to its lignocellulolytic potential. Secretomics and biochemical analyses were employed to study the strain's enzymatic arsenal, after growth in corn stover cultures and xylose-based defined media. The results revealed the presence of all the necessary enzymatic activities for complete breakdown of biomass, while the prominent role of oxidative enzymes in the lignocellulolytic strategy of the strain became evident. Two novel laccases, AbiLac1 and AbiLac2, were isolated from the culture supernatant with ion-exchange chromatography. Characterization of purified laccases revealed their ability to oxidize a wide variety of phenolic and non-phenolic substrates. AbiLac1 was found to oxidize polystyrene powder, showing high depolymerization potential, based on radical chain scission mechanism as evidenced by molecular weight decrease. The results of the present study demonstrate the biotechnological potential of the unexplored enzymatic machinery of white-rot basidiomycetes, including the design of improved lignocellulolytic cocktails, as well as the degradation and/or valorization of plastic waste materials.
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Affiliation(s)
- Anastasia Zerva
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, Athens, 15772, Greece
| | - Romanos Siaperas
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, Athens, 15772, Greece
| | - George Taxeidis
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, Athens, 15772, Greece
| | - Maria Kyriakidi
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, Athens, 15772, Greece
| | - Stamatina Vouyiouka
- Laboratory of Polymer Technology, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, Athens, 15772, Greece
| | - Georgios I Zervakis
- Agricultural University of Athens, Laboratory of General and Agricultural Microbiology, Iera Odos 75, 11855, Athens, Greece
| | - Evangelos Topakas
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, Athens, 15772, Greece.
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Barber-Zucker S, Mateljak I, Goldsmith M, Kupervaser M, Alcalde M, Fleishman SJ. Designed High-Redox Potential Laccases Exhibit High Functional Diversity. ACS Catal 2022; 12:13164-13173. [PMID: 36366766 PMCID: PMC9638991 DOI: 10.1021/acscatal.2c03006] [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: 06/22/2022] [Revised: 09/29/2022] [Indexed: 11/29/2022]
Abstract
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White-rot fungi secrete an impressive repertoire of high-redox
potential laccases (HRPLs) and peroxidases for efficient oxidation
and utilization of lignin. Laccases are attractive enzymes for the
chemical industry due to their broad substrate range and low environmental
impact. Since expression of functional recombinant HRPLs is challenging,
however, iterative-directed evolution protocols have been applied
to improve their expression, activity, and stability. We implement
a rational, stabilize-and-diversify strategy to two HRPLs that we
could not functionally express. First, we use the PROSS stability-design
algorithm to allow functional expression in yeast. Second, we use
the stabilized enzymes as starting points for FuncLib active-site
design to improve their activity and substrate diversity. Four of
the FuncLib-designed HRPLs and their PROSS progenitor exhibit substantial
diversity in reactivity profiles against high-redox potential substrates,
including lignin monomers. Combinations of 3–4 subtle mutations
that change the polarity, solvation, and sterics of the substrate-oxidation
site result in orders of magnitude changes in reactivity profiles.
These stable and versatile HRPLs are a step toward generating an effective
lignin-degrading consortium of enzymes that can be secreted from yeast.
The stabilize-and-diversify strategy can be applied to other challenging
enzyme families to study and expand the utility of natural enzymes.
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Affiliation(s)
- Shiran Barber-Zucker
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Ivan Mateljak
- Department of Biocatalysis, Institute of Catalysis, CSIC, Cantoblanco, Madrid 28049, Spain
- EvoEnzyme S.L., Parque Científico de Madrid, C/Faraday, 7, Campus de Cantoblanco, Madrid 28049, Spain
| | - Moshe Goldsmith
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Meital Kupervaser
- Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Miguel Alcalde
- Department of Biocatalysis, Institute of Catalysis, CSIC, Cantoblanco, Madrid 28049, Spain
| | - Sarel J. Fleishman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
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12
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Numerical investigation of bio-inspired mixing enhancement for enzymatic hydrolysis. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.117950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Zhang Y, Jiang Z, Li Y, Feng Z, Zhang X, Zhou R, Liu C, Yang L. The Combined Cultivation of Feruloyl Esterase-Producing Strains with CMCase and Xylanase-Producing Strains Increases the Release of Ferulic Acid. Microorganisms 2022; 10:1889. [PMID: 36296166 PMCID: PMC9610611 DOI: 10.3390/microorganisms10101889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/16/2022] [Accepted: 09/19/2022] [Indexed: 09/10/2023] Open
Abstract
Feruloyl esterase (FAE)-producing micro-organisms to obtain ferulic acid (FA) from natural substrates have good industrial prospects, and the synergistic effect of multiple bacteria can better improve the yield of FA. In this study, on the premise of the synergistic effect of FAE, hemicellulose, and cellulase, the key strain Klebsiella oxytoca Z28 with FAE was combined with CMCase and Xylanase-producing strains to produce FA. The combination of strains with higher FA production are Klebsiella oxytoca Z28, Klebsiella pneumoniae JZE, Bacillus velezensis G1, and their FA production can reach 109.67 μg/g, which is 15% higher than that of single bacteria. To explore the effects of temperature, Ph, inoculum amount, distillers grains concentration and fermentation time on the FAE activity of the combination of strains in the fermentation process, and determined that temperature, Ph, and fermentation time were the main influencing factors and optimized through orthogonal design. The optimized fermentation conditions are 34 °C, Ph 8.0, and fermentation days for 6 days, the FAE activity can reach 270.78 U/L, and the FA yield of the combined strain is 324.50 μg/g, which is 200% higher than that of single-strain fermentation.
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Affiliation(s)
- Yao Zhang
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Zhilin Jiang
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Yunran Li
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Zhiping Feng
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin 644000, China
- Liquor Making Bio-Technology & Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, China
| | - Xian Zhang
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin 644000, China
| | | | - Chao Liu
- Xufu Distillery Co., Ltd., Yibin 644000, China
| | - Lijuan Yang
- College of Bioengineering, Sichuan University of Science & Engineering, Yibin 644000, China
- Liquor Making Bio-Technology & Application of Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644000, China
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14
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Deciphering Cellodextrin and Glucose Uptake in Clostridium thermocellum. mBio 2022; 13:e0147622. [PMID: 36069444 PMCID: PMC9601137 DOI: 10.1128/mbio.01476-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Sugar uptake is of great significance in industrially relevant microorganisms. Clostridium thermocellum has extensive potential in lignocellulose biorefineries as an environmentally prominent, thermophilic, cellulolytic bacterium. The bacterium employs five putative ATP-binding cassette transporters which purportedly take up cellulose hydrolysates. Here, we first applied combined genetic manipulations and biophysical titration experiments to decipher the key glucose and cellodextrin transporters. In vivo gene inactivation of each transporter and in vitro calorimetric and nuclear magnetic resonance (NMR) titration of each putative sugar-binding protein with various saccharides supported the conclusion that only transporters A and B play the roles of glucose and cellodextrin transport, respectively. To gain insight into the structural mechanism of the transporter specificities, 11 crystal structures, both alone and in complex with appropriate saccharides, were solved for all 5 putative sugar-binding proteins, thus providing detailed specific interactions between the proteins and the corresponding saccharides. Considering the importance of transporter B as the major cellodextrin transporter, we further identified its cryptic, hitherto unknown ATPase-encoding gene as clo1313_2554, which is located outside the transporter B gene cluster. The crystal structure of the ATPase was solved, showing that it represents a typical nucleotide-binding domain of the ATP-binding cassette (ABC) transporter. Moreover, we determined that the inducing effect of cellobiose (G2) and cellulose on cellulosome production could be eliminated by deletion of transporter B genes, suggesting the coupling of sugar transport and regulation of cellulosome components. This study provides key basic information on the sugar uptake mechanism of C. thermocellum and will promote rational engineering of the bacterium for industrial application.
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15
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Wang H, Qi X, Gao S, Zhang Y, An Y. Biochemical characterization of an engineered bifunctional xylanase/feruloyl esterase and its synergistic effects with cellulase on lignocellulose hydrolysis. BIORESOURCE TECHNOLOGY 2022; 355:127244. [PMID: 35489578 DOI: 10.1016/j.biortech.2022.127244] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Herein, the xylanase and feruloyl esterase domains of the xylanase/feruloyl esterase bifunctional enzyme (Xyn-Fae) from Prevotella ruminicola 23 were identified using N- and C-terminal truncation mutagenesis. In addition, a novel and more efficient xylanase/feruloyl esterase bifunctional enzyme XynII-Fae was constructed, and its synergistic action with a commercial cellulase for lignocellulose hydrolysis was studied. When 40% cellulase was replaced by XynII-Fae, the production of reducing sugars increased by 65% than that with the cellulase alone, and the conversions of xylan and glucan were increased by 125.1% and 54.3%, respectively. When 80% cellulase was substituted by XynII-Fae, up to 43.5 μg/mL ferulic acid and 418.7 μg/mL acetic acid were obtained. The XynII-Fae could also accelerate the hydrolysis of wheat straw and sugarcane bagasse with commercial cellulase. These results indicated that the synergistic action of XynII-Fae with cellulase could dramatically improve the hydrolysis efficiency of lignocellulose, showing the great potential for industrial applications.
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Affiliation(s)
- Hongling Wang
- College of Food Science, Shenyang Agricultural University, Shenyang, China; College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Xianghui Qi
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China
| | - Song Gao
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Yifeng Zhang
- College of Food Science, Shenyang Agricultural University, Shenyang, China; College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Yingfeng An
- College of Food Science, Shenyang Agricultural University, Shenyang, China; College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, China.
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16
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Bhalla A, Arce J, Ubanwa B, Singh G, Sani RK, Balan V. Thermophilic Geobacillus WSUCF1 Secretome for Saccharification of Ammonia Fiber Expansion and Extractive Ammonia Pretreated Corn Stover. Front Microbiol 2022; 13:844287. [PMID: 35694290 PMCID: PMC9176393 DOI: 10.3389/fmicb.2022.844287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/18/2022] [Indexed: 11/13/2022] Open
Abstract
A thermophilic Geobacillus bacterial strain, WSUCF1 contains different carbohydrate-active enzymes (CAZymes) capable of hydrolyzing hemicellulose in lignocellulosic biomass. We used proteomic, genomic, and bioinformatic tools, and genomic data to analyze the relative abundance of cellulolytic, hemicellulolytic, and lignin modifying enzymes present in the secretomes. Results showed that CAZyme profiles of secretomes varied based on the substrate type and complexity, composition, and pretreatment conditions. The enzyme activity of secretomes also changed depending on the substrate used. The secretomes were used in combination with commercial and purified enzymes to carry out saccharification of ammonia fiber expansion (AFEX)-pretreated corn stover and extractive ammonia (EA)-pretreated corn stover. When WSUCF1 bacterial secretome produced at different conditions was combined with a small percentage of commercial enzymes, we observed efficient saccharification of EA-CS, and the results were comparable to using a commercial enzyme cocktail (87% glucan and 70% xylan conversion). It also opens the possibility of producing CAZymes in a biorefinery using inexpensive substrates, such as AFEX-pretreated corn stover and Avicel, and eliminates expensive enzyme processing steps that are used in enzyme manufacturing. Implementing in-house enzyme production is expected to significantly reduce the cost of enzymes and biofuel processing cost.
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Affiliation(s)
- Aditya Bhalla
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, United States
- Department of Chemistry, Biology and Health Science, South Dakota School of Mines and Technology, Rapid City, SD, United States
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, MI, United States
| | - Jessie Arce
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX, United States
| | - Bryan Ubanwa
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX, United States
| | - Gursharan Singh
- Department of Medical Laboratory Sciences, Lovely Professional University, Phagwara, India
| | - Rajesh K. Sani
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD, United States
- Department of Chemistry, Biology and Health Science, South Dakota School of Mines and Technology, Rapid City, SD, United States
| | - Venkatesh Balan
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, MI, United States
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX, United States
- *Correspondence: Venkatesh Balan,
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17
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Li J, Wang S, Zhao J, Dong Z, Shao T. Gut Microbiota of Ostrinia nubilalis Larvae Degrade Maize Cellulose. Front Microbiol 2022; 13:816954. [PMID: 35495661 PMCID: PMC9039043 DOI: 10.3389/fmicb.2022.816954] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/25/2022] [Indexed: 12/04/2022] Open
Abstract
Most arthropod guts harbor diverse microbiota for symbiotic digestion. The European corn borer (ECB), Ostrinia nubilalis (Hübner), is a devastating pest that feeds the lignocellulose-rich tissues of maize plants. However, the potential role of ECB gut microbes in degrading maize cellulose remains largely unexplored. Here, we investigated the gut microbiota of ECB fed with different diets and their potential function in maize lignocellulose degradation. The diversity and composition of gut bacterial communities varied dramatically between the ECB larva fed with artificial diets (ECB-D) and maize plants (ECB-M). Draft genomes of the microbial consortia from ECB-D and ECB-M showed that the principal degraders of cellulose mainly belonged to Firmicutes or Proteobacteria and they were primarily found in the midgut. The cellulolytic microbial consortia contained genes encoding various carbohydrate-active enzymes (CAZyme). Furthermore, scanning electron microscopy revealed significant breakdown of lignocellulose in maize treated by the two microbial consortia for 9 days in vitro. Metabolomic analyses show that maize particles treated by two microbial consortia generate distinctive metabolomic profiles, with enrichment for different monosaccharides (i.e., Glucose, Rhamnofuranose, Isomaltose, and Cellobiose) and amino acids (i.e., Threonine, Histidine, and Lysine). The results indicated that the diet of the host impacted the composition and function of its gut microbiota and ECB exploited specific gut microbes to digest maize lignocellulose with distinctive products. Our study provides valuable microbiota resources for lignocellulose bioconversion.
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Affiliation(s)
| | | | | | | | - Tao Shao
- Institute of Ensiling and Processing of Grass, College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, China
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18
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Barber-Zucker S, Mindel V, Garcia-Ruiz E, Weinstein JJ, Alcalde M, Fleishman SJ. Stable and Functionally Diverse Versatile Peroxidases Designed Directly from Sequences. J Am Chem Soc 2022; 144:3564-3571. [PMID: 35179866 PMCID: PMC8895400 DOI: 10.1021/jacs.1c12433] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
White-rot fungi secrete a repertoire
of high-redox potential oxidoreductases
to efficiently decompose lignin. Of these enzymes, versatile peroxidases
(VPs) are the most promiscuous biocatalysts. VPs are attractive enzymes
for research and industrial use but their recombinant production is
extremely challenging. To date, only a single VP has been structurally
characterized and optimized for recombinant functional expression,
stability, and activity. Computational enzyme optimization methods
can be applied to many enzymes in parallel but they require accurate
structures. Here, we demonstrate that model structures computed by
deep-learning-based ab initio structure prediction
methods are reliable starting points for one-shot PROSS stability-design
calculations. Four designed VPs encoding as many as 43 mutations relative
to the wildtype enzymes are functionally expressed in yeast, whereas
their wildtype parents are not. Three of these designs exhibit substantial
and useful diversity in their reactivity profiles and tolerance to
environmental conditions. The reliability of the new generation of
structure predictors and design methods increases the scale and scope
of computational enzyme optimization, enabling efficient discovery
and exploitation of the functional diversity in natural enzyme families
directly from genomic databases.
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Affiliation(s)
- Shiran Barber-Zucker
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Vladimir Mindel
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Eva Garcia-Ruiz
- Department of Biocatalysis, Institute of Catalysis, CSIC, Cantoblanco, Madrid 28094, Spain
| | - Jonathan J Weinstein
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
| | - Miguel Alcalde
- Department of Biocatalysis, Institute of Catalysis, CSIC, Cantoblanco, Madrid 28094, Spain
| | - Sarel J Fleishman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600001, Israel
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19
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Guo H, He T, Lee DJ. Contemporary proteomic research on lignocellulosic enzymes and enzymolysis: A review. BIORESOURCE TECHNOLOGY 2022; 344:126263. [PMID: 34728359 DOI: 10.1016/j.biortech.2021.126263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
This review overviewed the current researches on the isolation of novel strains, the development of novel identification protocols, the key enzymes and their synergistic interactions with other functional enzyme systems, and the strategies for enhancing enzymolysis efficiencies. The main obstacle for realizing biorefinery of lignocellulosic biomass to biofuels or biochemicals is the high cost of enzymolysis stage. Therefore, research prospects to reduce the costs for lignocellulose hydrolysis were outlined.
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Affiliation(s)
- Hongliang Guo
- College of Forestry, Northeast Forestry University, Harbin 150040, China; College of Food Engineering, Harbin University of Commerce, Harbin 150076, China
| | - Tongyuan He
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan; Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tang, Hong Kong.
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20
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Li J, Wang S, Zhao J, Dong Z, Liu Q, Dong D, Shao T. Two novel screened microbial consortia and their application in combination with Lactobacillus plantarum for improving fermentation quality of high-moisture alfalfa. J Appl Microbiol 2021; 132:2572-2582. [PMID: 34839576 DOI: 10.1111/jam.15388] [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: 09/19/2021] [Revised: 11/02/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022]
Abstract
AIMS To enrich lignocellulolytic microbial consortia and evaluate whether a combination of these consortia and Lactobacillus plantarum can facilitate degradation of structural carbohydrates and improve fermentation quality of high-moisture alfalfa silage. METHODS AND RESULTS Two novel microbial consortia (CL and YL) with high lignocellulolytic potential were enriched, and had higher enzyme activities at slightly acidic conditions (pH 3.5-6.5). Two consortia were inoculated with and without combined L. plantarum (LP) to alfalfa for up to 120 days of ensiling. The two consortia alone or combined with LP significantly (p < 0.05) increased lactic-to-acetic acid ratios and decreased contents of volatile organic acids and NH3 -N as compared to the control. Treatments that combining microbial consortia and LP further resulted in the higher contents of lactic acid (LA), water soluble carbohydrates (WSC) and crude protein, dry matter (DM) recovery, and lower neutral detergent fibre, acid detergent lignin and cellulose contents, with YLP silage showing the lowest pH (4.41) and highest LA content (76.72 g kg-1 DM) and the conversion of WSC into LA (184.03%). CONCLUSIONS The addition of lignocellulolytic microbial consortia (CL or YL) to alfalfa silages as attractive silage inoculants could improve fermentation quality, and that their combination with L. plantarum appeared more effective on the degradation of structural carbohydrates and conversion of soluble carbohydrates into LA. SIGNIFICANCE AND IMPACT OF THE STUDY High-moisture alfalfa is difficult to ensile due to its high buffering capacity and low readily fermentable carbohydrate contents. Microbial consortia (CL and YL) can encode a broad selection of multi-functional CAZymes, and their combination with LP could be promising for the degradation of structural carbohydrates simultaneously with improvement fermentation quality, with high performance in LA production.
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Affiliation(s)
- Junfeng Li
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Siran Wang
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Jie Zhao
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Zhihao Dong
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Qinhua Liu
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Dong Dong
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Tao Shao
- Institute of Ensiling and Processing of Grass, College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
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21
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Lan Q, Duan Y, Wu P, Li X, Yu Y, Shi B, Zhou J, Lu H. Coordinately express hemicellulolytic enzymes in Kluyveromyces marxianus to improve the saccharification and ethanol production from corncobs. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:220. [PMID: 34809677 PMCID: PMC8607645 DOI: 10.1186/s13068-021-02070-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Hemicellulose acts as one factor contributing to the recalcitrance of lignocellulose that prevents cellulases to degrade the cellulose efficiently even in low quantities. Supplement of hemicellulases can enhance the performance of commercial cellulases in the enzymatic hydrolyses of lignocellulose. Kluyveromyce marxianus is an attractive yeast for cellulosic ethanol fermentation, as well as a promising host for heterologous protein production, since it has remarkable thermotolerance, high growth rate, and broad substrate spectrum etc. In this study, we attempted to coordinately express multiple hemicellulases in K. marxianus through a 2A-mediated ribosome skipping to self-cleave polyproteins, and investigated their capabilities for saccharification and ethanol production from corncobs. RESULTS Two polycistronic genes IMPX and IMPαX were constructed to test the self-cleavage of P2A sequence from the Foot-and-Mouth Disease virus (FMDV) in K. marxianus. The IMPX gene consisted of a β-mannanase gene M330 (without the stop codon), a P2A sequence and a β-xylanase gene Xyn-CDBFV in turn. In the IMPαX gene, there was an additional α-factor signal sequence in frame with the N-terminus of Xyn-CDBFV. The extracellular β-mannanase activities of the IMPX and IMPαX strains were 21.34 and 15.50 U/mL, respectively, but the extracellular β-xylanase activity of IMPαX strain was much higher than that of the IMPX strain, which was 136.17 and 42.07 U/mL, respectively. Subsequently, two recombinant strains, the IXPαR and IMPαXPαR, were constructed to coordinately and secretorily express two xylantic enzymes, Xyn-CDBFV and β-D-xylosidase RuXyn1, or three hemicellulolytic enzymes including M330, Xyn-CDBFV and RuXyn1. In fed-batch fermentation, extracellular activities of β-xylanase and β-xylosidase in the IXPαR strain were 1664.2 and 0.90 U/mL. Similarly, the IMPαXPαR strain secreted the three enzymes, β-mannanase, β-xylanase, and β-xylosidase, with the activities of 159.8, 2210.5, and 1.25 U/mL, respectively. Hemicellulolases of both strains enhanced the yields of glucose and xylose from diluted acid pretreated (DAP) corncobs when acted synergistically with commercial cellulases. In hybrid saccharification and fermentation (HSF) of DAP corncobs, hemicellulases of the IMPαXPαR strain increased the ethanol yield by 8.7% at 144 h compared with the control. However, both ethanol and xylose yields were increased by 12.7 and 18.2%, respectively, at 120 h in HSF of aqueous ammonia pretreated (AAP) corncobs with this strain. Our results indicated that coordinate expression of hemicellulolytic enzymes in K. marxianus promoted the saccharification and ethanol production from corncobs. CONCLUSIONS The FMDV P2A sequence showed high efficiency in self-cleavage of polyproteins in K. marxianus and could be used for secretory expression of multiple enzymes in the presence of their signal sequences. The IMPαXPαR strain coexpressed three hemicellulolytic enzymes improved the saccharification and ethanol production from corncobs, and could be used as a promising strain for ethanol production from lignocelluloses.
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Affiliation(s)
- Qing Lan
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
| | - Yitong Duan
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
| | - Pingping Wu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
| | - Xueyin Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
| | - Yao Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China
| | - Bo Shi
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing, 100081, People's Republic of China
| | - Jungang Zhou
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China.
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China.
| | - Hong Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China.
- Shanghai Engineering Research Center of Industrial Microorganisms, Fudan University, 2005 Songhu Road, Shanghai, 200438, People's Republic of China.
- Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
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