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Wang Y, Zhang Y, Cui Q, Feng Y, Xuan J. Composition of Lignocellulose Hydrolysate in Different Biorefinery Strategies: Nutrients and Inhibitors. Molecules 2024; 29:2275. [PMID: 38792135 PMCID: PMC11123716 DOI: 10.3390/molecules29102275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
The hydrolysis and biotransformation of lignocellulose, i.e., biorefinery, can provide human beings with biofuels, bio-based chemicals, and materials, and is an important technology to solve the fossil energy crisis and promote global sustainable development. Biorefinery involves steps such as pretreatment, saccharification, and fermentation, and researchers have developed a variety of biorefinery strategies to optimize the process and reduce process costs in recent years. Lignocellulosic hydrolysates are platforms that connect the saccharification process and downstream fermentation. The hydrolysate composition is closely related to biomass raw materials, the pretreatment process, and the choice of biorefining strategies, and provides not only nutrients but also possible inhibitors for downstream fermentation. In this review, we summarized the effects of each stage of lignocellulosic biorefinery on nutrients and possible inhibitors, analyzed the huge differences in nutrient retention and inhibitor generation among various biorefinery strategies, and emphasized that all steps in lignocellulose biorefinery need to be considered comprehensively to achieve maximum nutrient retention and optimal control of inhibitors at low cost, to provide a reference for the development of biomass energy and chemicals.
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Affiliation(s)
- Yilan Wang
- Department of Bioscience and Bioengineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
| | - Yuedong Zhang
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinsong Xuan
- Department of Bioscience and Bioengineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China
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2
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Li J, Zhang H, Li D, Liu YJ, Bayer EA, Cui Q, Feng Y, Zhu P. Structure of the transcription open complex of distinct σ I factors. Nat Commun 2023; 14:6455. [PMID: 37833284 PMCID: PMC10575876 DOI: 10.1038/s41467-023-41796-4] [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: 03/22/2023] [Accepted: 09/15/2023] [Indexed: 10/15/2023] Open
Abstract
Bacterial σI factors of the σ70-family are widespread in Bacilli and Clostridia and are involved in the heat shock response, iron metabolism, virulence, and carbohydrate sensing. A multiplicity of σI paralogues in some cellulolytic bacteria have been shown to be responsible for the regulation of the cellulosome, a multienzyme complex that mediates efficient cellulose degradation. Here, we report two structures at 3.0 Å and 3.3 Å of two transcription open complexes formed by two σI factors, SigI1 and SigI6, respectively, from the thermophilic, cellulolytic bacterium, Clostridium thermocellum. These structures reveal a unique, hitherto-unknown recognition mode of bacterial transcriptional promoters, both with respect to domain organization and binding to promoter DNA. The key characteristics that determine the specificities of the σI paralogues were further revealed by comparison of the two structures. Consequently, the σI factors represent a distinct set of the σ70-family σ factors, thus highlighting the diversity of bacterial transcription.
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Affiliation(s)
- Jie Li
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Energy Institute, 266101, Qingdao, Shandong, China
- Qingdao New Energy Shandong Laboratory, 266101, Qingdao, Shandong, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Haonan Zhang
- University of Chinese Academy of Sciences, 100049, Beijing, China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Dongyu Li
- University of Chinese Academy of Sciences, 100049, Beijing, China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Energy Institute, 266101, Qingdao, Shandong, China
- Qingdao New Energy Shandong Laboratory, 266101, Qingdao, Shandong, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, 7610001, Rehovot, Israel
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, 8499000, Beer-Sheva, Israel
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China
- Shandong Energy Institute, 266101, Qingdao, Shandong, China
- Qingdao New Energy Shandong Laboratory, 266101, Qingdao, Shandong, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China.
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China.
- Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, Shandong, China.
- Shandong Energy Institute, 266101, Qingdao, Shandong, China.
- Qingdao New Energy Shandong Laboratory, 266101, Qingdao, Shandong, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Ping Zhu
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
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3
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Xiao Y, Dong S, Liu YJ, You C, Feng Y, Cui Q. Key roles of β-glucosidase BglA for the catabolism of both laminaribiose and cellobiose in the lignocellulolytic bacterium Clostridium thermocellum. Int J Biol Macromol 2023; 250:126226. [PMID: 37558019 DOI: 10.1016/j.ijbiomac.2023.126226] [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: 04/05/2023] [Revised: 07/31/2023] [Accepted: 08/06/2023] [Indexed: 08/11/2023]
Abstract
The thermophilic bacterium Clostridium thermocellum efficiently degrades polysaccharides into oligosaccharides. The metabolism of β-1,4-linked cello-oligosaccharides is initiated by three enzymes, i.e., the cellodextrin phosphorylase (Cdp), the cellobiose phosphorylase (Cbp), and the β-glucosidase A (BglA), in C. thermocellum. In comparison, how the oligosaccharides containing other kinds of linkage are utilized is rarely understood. In this study, we found that BglA could hydrolyze the β-1,3-disaccharide laminaribiose with much higher activity than that against the β-1,4-disaccharide cellobiose. The structural basis of the substrate specificity was analyzed by crystal structure determination and molecular docking. Genetic deletions of BglA and Cbp, respectively, and enzymatic analysis of cell extracts demonstrated that BglA is the key enzyme responsible for laminaribiose metabolism. Furthermore, the deletion of BglA can suppress the expression of Cbp and the deletion of Cbp can up-regulate the expression of BglA, indicating that BglA and Cbp have cross-regulation and BglA is also critical for cellobiose metabolism. These insights pave the way for both a fundamental understanding of metabolism and regulation in C. thermocellum and emphasize the importance of the degradation and utilization of polysaccharides containing β-1,3-linked glycosidic bonds in lignocellulose biorefinery.
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Affiliation(s)
- Yan Xiao
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Sheng Dong
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chun You
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China.
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China.
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4
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Chen C, Dong S, Yu Z, Qiao Y, Li J, Ding X, Li R, Lin J, Bayer EA, Liu YJ, Cui Q, Feng Y. Essential autoproteolysis of bacterial anti-σ factor RsgI for transmembrane signal transduction. SCIENCE ADVANCES 2023; 9:eadg4846. [PMID: 37418529 PMCID: PMC10328401 DOI: 10.1126/sciadv.adg4846] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 06/06/2023] [Indexed: 07/09/2023]
Abstract
Autoproteolysis has been discovered to play key roles in various biological processes, but functional autoproteolysis has been rarely reported for transmembrane signaling in prokaryotes. In this study, an autoproteolytic effect was discovered in the conserved periplasmic domain of anti-σ factor RsgIs from Clostridium thermocellum, which was found to transmit extracellular polysaccharide-sensing signals into cells for regulation of the cellulosome system, a polysaccharide-degrading multienzyme complex. Crystal and NMR structures of periplasmic domains from three RsgIs demonstrated that they are different from all known proteins that undergo autoproteolysis. The RsgI-based autocleavage site was located at a conserved Asn-Pro motif between the β1 and β2 strands in the periplasmic domain. This cleavage was demonstrated to be essential for subsequent regulated intramembrane proteolysis to activate the cognate SigI, in a manner similar to that of autoproteolysis-dependent activation of eukaryotic adhesion G protein-coupled receptors. These results indicate the presence of a unique prevalent type of autoproteolytic phenomenon in bacteria for signal transduction.
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Affiliation(s)
- Chao Chen
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sheng Dong
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaoli Yu
- State Key Laboratory of Genetic Engineering, Department of Biochemistry, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China
| | - Yichen Qiao
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Li
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoke Ding
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Renmin Li
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, Department of Biochemistry, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai 200438, China
| | - Edward A. Bayer
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8499000, Israel
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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5
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Liu YJ, Zhang Y, Chi F, Chen C, Wan W, Feng Y, Song X, Cui Q. Integrated lactic acid production from lignocellulosic agricultural wastes under thermal conditions. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118281. [PMID: 37290309 DOI: 10.1016/j.jenvman.2023.118281] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/10/2023]
Abstract
The production of lactic acid (LA) from agricultural wastes attracts great attention because of the sustainability and abundance of lignocellulosic feedstocks, as well as the increasing demand for biodegradable polylactic acid. In this study, we isolated a thermophilic strain Geobacillus stearothermophilus 2H-3 for use in robust production of L-(+)LA under the optimal conditions of 60 °C, pH 6.5, which were consistent with the whole-cell-based consolidated bio-saccharification (CBS) process. Sugar-rich CBS hydrolysates derived from various agricultural wastes, including corn stover, corncob residue, and wheat straw, were used as the carbon sources for 2H-3 fermentation by directly inoculating 2H-3 cells into the CBS system, without intermediate sterilization, nutrient supplementation, or adjustment of fermentation conditions. Thus, we successfully combined two whole-cell-based steps into a one-pot successive fermentation process to efficiently produce LA with high optical purity (99.5%), titer (51.36 g/L), and yield (0.74 g/gbiomass). This study provides a promising strategy for LA production from lignocellulose through CBS and 2H-3 fermentation integration.
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Affiliation(s)
- Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yuedong Zhang
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Fang Chi
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chaoyang Chen
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Weijian Wan
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xiaojin Song
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; Dalian National Laboratory for Clean Energy, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China.
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6
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Uke A, Sornyotha S, Baramee S, Tachaapaikoon C, Pason P, Waeonukul R, Ratanakhanokchai K, Kosugi A. Genomic analysis of Paenibacillus macerans strain I6, which can effectively saccharify oil palm empty fruit bunches under nutrient-free conditions. J Biosci Bioeng 2023:S1389-1723(23)00111-1. [PMID: 37095007 DOI: 10.1016/j.jbiosc.2023.03.016] [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: 12/21/2022] [Revised: 03/17/2023] [Accepted: 03/30/2023] [Indexed: 04/26/2023]
Abstract
The improper disposal of palm oil industrial waste has led to serious environmental pollution. In this study, we isolated Paenibacillus macerans strain I6, which can degrade oil palm empty fruit bunches generated by the palm oil industry in nutrient-free water, from bovine manure biocompost and sequenced its genome on PacBio RSII and Illumina NovaSeq 6000 platforms. We obtained 7.11 Mbp of genomic sequences with 52.9% GC content from strain I6. Strain I6 was phylogenetically closely related to P. macerans strains DSM24746 and DSM24 and was positioned close to the head of the branch containing strains I6, DSM24746, and DSM24 in the phylogenetic tree. We used the RAST (rapid annotation using subsystem technology) server to annotate the strain I6 genome and discovered genes related to biological saccharification; 496 genes were related to carbohydrate metabolism and 306 genes were related to amino acids and derivatives. Among them were carbohydrate-active enzymes (CAZymes), including 212 glycoside hydrolases. Up to 23.6% of the oil palm empty fruit bunches was degraded by strain I6 under anaerobic and nutrient-free conditions. Evaluation of the enzymatic activity of extracellular fractions of strain I6 showed that amylase and xylanase activity was highest when xylan was the carbon source. The high enzyme activity and the diversity in the associated genes may contribute to the efficient degradation of oil palm empty fruit bunches by strain I6. Our results indicate the potential utility of P. macerans strain I6 for lignocellulosic biomass degradation.
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Affiliation(s)
- Ayaka Uke
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan
| | - Somphit Sornyotha
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan; Department of Biology, School of Science, King Mongkut's Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520, Thailand
| | - Sirilak Baramee
- Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand
| | - Chakrit Tachaapaikoon
- Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand; School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand
| | - Patthra Pason
- Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand; School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand
| | - Rattiya Waeonukul
- Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand; School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand
| | - Khanok Ratanakhanokchai
- Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand; School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10150, Thailand
| | - Akihiko Kosugi
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan.
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7
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Liu GL, Bu XY, Chen C, Fu C, Chi Z, Kosugi A, Cui Q, Chi ZM, Liu YJ. Bioconversion of non-food corn biomass to polyol esters of fatty acid and single-cell oils. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:9. [PMID: 36650607 PMCID: PMC9844004 DOI: 10.1186/s13068-023-02260-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/05/2023] [Indexed: 01/18/2023]
Abstract
BACKGROUND Lignocellulose is a valuable carbon source for the production of biofuels and biochemicals, thus having the potential to substitute fossil resources. Consolidated bio-saccharification (CBS) is a whole-cell-based catalytic technology previously developed to produce fermentable sugars from lignocellulosic agricultural wastes. The deep-sea yeast strain Rhodotorula paludigena P4R5 can produce extracellular polyol esters of fatty acids (PEFA) and intracellular single-cell oils (SCO) simultaneously. Therefore, the integration of CBS and P4R5 fermentation processes would achieve high-value-added conversion of lignocellulosic biomass. RESULTS The strain P4R5 could co-utilize glucose and xylose, the main monosaccharides from lignocellulose, and also use fructose and arabinose for PEFA and SCO production at high levels. By regulating the sugar metabolism pathways for different monosaccharides, the strain could produce PEFA with a single type of polyol head. The potential use of PEFA as functional micelles was also determined. Most importantly, when sugar-rich CBS hydrolysates derived from corn stover or corncob residues were used to replace grain-derived pure sugars for P4R5 fermentation, similar PEFA and SCO productions were obtained, indicating the robust conversion of non-food corn plant wastes to high-value-added glycolipids and lipids. Since the produced PEFA could be easily collected from the culture via short-time standing, we further developed a semi-continuous process for PEFA production from corncob residue-derived CBS hydrolysate, and the PEFA titer and productivity were enhanced up to 41.1 g/L and 8.22 g/L/day, respectively. CONCLUSIONS Here, we integrated the CBS process and the P4R5 fermentation for the robust production of high-value-added PEFA and SCO from non-food corn plant wastes. Therefore, this study suggests a feasible way for lignocellulosic agro-waste utilization and the potential application of P4R5 in industrial PEFA production.
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Affiliation(s)
- Guang-Lei Liu
- grid.4422.00000 0001 2152 3263College of Marine Life Sciences, Ocean University of China, Qingdao, 266101 People’s Republic of China ,grid.484590.40000 0004 5998 3072Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266101 China
| | - Xian-Ying Bu
- grid.4422.00000 0001 2152 3263College of Marine Life Sciences, Ocean University of China, Qingdao, 266101 People’s Republic of China
| | - Chaoyang Chen
- grid.9227.e0000000119573309CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China ,Shandong Energy Institute, Qingdao, China ,Qingdao New Energy Shandong Laboratory, Qingdao, China ,grid.410752.5Dalian National Laboratory for Clean Energy, Qingdao, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Chunxiang Fu
- grid.9227.e0000000119573309CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China ,Shandong Energy Institute, Qingdao, China ,Qingdao New Energy Shandong Laboratory, Qingdao, China ,grid.410752.5Dalian National Laboratory for Clean Energy, Qingdao, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Zhe Chi
- grid.4422.00000 0001 2152 3263College of Marine Life Sciences, Ocean University of China, Qingdao, 266101 People’s Republic of China ,grid.484590.40000 0004 5998 3072Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266101 China
| | - Akihiko Kosugi
- grid.452611.50000 0001 2107 8171Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki Japan
| | - Qiu Cui
- grid.9227.e0000000119573309CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China ,Shandong Energy Institute, Qingdao, China ,Qingdao New Energy Shandong Laboratory, Qingdao, China ,grid.410752.5Dalian National Laboratory for Clean Energy, Qingdao, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Zhen-Ming Chi
- grid.4422.00000 0001 2152 3263College of Marine Life Sciences, Ocean University of China, Qingdao, 266101 People’s Republic of China ,grid.484590.40000 0004 5998 3072Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266101 China
| | - Ya-Jun Liu
- grid.9227.e0000000119573309CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China ,Shandong Energy Institute, Qingdao, China ,Qingdao New Energy Shandong Laboratory, Qingdao, China ,grid.410752.5Dalian National Laboratory for Clean Energy, Qingdao, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
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Tao S, Qingbin M, Zhiling L, Caiyu S, Lixin L, Lilai L. Comparative genomics reveals cellobiose hydrolysis mechanism of Ruminiclostridium thermocellum M3, a cellulosic saccharification bacterium. Front Microbiol 2023; 13:1079279. [PMID: 36687593 PMCID: PMC9852859 DOI: 10.3389/fmicb.2022.1079279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/07/2022] [Indexed: 01/08/2023] Open
Abstract
The cellulosome of Ruminiclostridium thermocellum was one of the most efficient cellulase systems in nature. However, the product of cellulose degradation by R. thermocellum is cellobiose, which leads to the feedback inhibition of cellulosome, and it limits the R. thermocellum application in the field of cellulosic biomass consolidated bioprocessing (CBP) industry. In a previous study, R. thermocellum M3, which can hydrolyze cellulosic feedstocks into monosaccharides, was isolated from horse manure. In this study, the complete genome of R. thermocellum M3 was sequenced and assembled. The genome of R. thermocellum M3 was compared with the other R. thermocellum to reveal the mechanism of cellulosic saccharification by R. thermocellum M3. In addition, we predicted the key genes for the elimination of feedback inhibition of cellobiose in R. thermocellum. The results indicated that the whole genome sequence of R. thermocellum M3 consisted of 3.6 Mb of chromosomes with a 38.9% of GC%. To be specific, eight gene islands and 271 carbohydrate-active enzyme-encoded proteins were detected. Moreover, the results of gene function annotation showed that 2,071, 2,120, and 1,246 genes were annotated into the Clusters of Orthologous Groups (COG), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively, and most of the genes were involved in carbohydrate metabolism and enzymatic catalysis. Different from other R. thermocellum, strain M3 has three proteins related to β-glucosidase, and the cellobiose hydrolysis was enhanced by the synergy of gene BglA and BglX. Meanwhile, the GH42 family, CBM36 family, and AA8 family might participate in cellobiose degradation.
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Affiliation(s)
- Sheng Tao
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China,*Correspondence: Sheng Tao,
| | - Meng Qingbin
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
| | - Li Zhiling
- State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China,Li Zhiling,
| | - Sun Caiyu
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
| | - Li Lixin
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
| | - Liu Lilai
- College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin, China
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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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Balagurunathan B, Ling H, Choi WJ, Chang MW. Potential use of microbial engineering in single-cell protein production. Curr Opin Biotechnol 2022; 76:102740. [PMID: 35660478 DOI: 10.1016/j.copbio.2022.102740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 04/08/2022] [Accepted: 04/28/2022] [Indexed: 12/16/2022]
Abstract
Single-cell proteins (SCPs) have been widely used in human food and animal feed applications, still, there are challenges in their production and commercialization. Recently, advances in microbial synthetic biology, genomic engineering, and biofoundry technologies have offered capabilities to effectively and rapidly engineer microorganisms for improving the productivity, nutritional, and functional quality of SCPs. In this review, we discuss various synthetic biology, genomic engineering, and biofoundry tools that can be harnessed for SCP production and genetic modification. We also describe the current and potential applications of genetic modification in producing intermediate feedstocks, as well as biomass-based and multifunctional SCPs. Finally, we discuss the technological and policy-control related challenges encountered when deploying genetic modification in SCP production for animal feed and human food applications.
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Affiliation(s)
- Balaji Balagurunathan
- Singapore Institute of Food and Biotechnology Innovation, Agency for Science, Technology and Research (A⁎STAR) 1, Pesek Road, Jurong Island, 627833, Singapore.
| | - Hua Ling
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; Wilmar-NUS Corporate Laboratory (WIL@NUS), National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore.
| | - Won Jae Choi
- Singapore Institute of Food and Biotechnology Innovation, Agency for Science, Technology and Research (A⁎STAR) 1, Pesek Road, Jurong Island, 627833, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research in Singapore (A⁎STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore; Singapore Institute of Technology, 10 Dover Dr, Singapore 138683, Singapore
| | - Matthew Wook Chang
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; Wilmar-NUS Corporate Laboratory (WIL@NUS), National University of Singapore, 14 Medical Drive, Singapore 117599, Singapore.
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Chen C, Qi K, Chi F, Song X, Feng Y, Cui Q, Liu YJ. Dissolved xylan inhibits cellulosome-based saccharification by binding to the key cellulosomal component of Clostridium thermocellum. Int J Biol Macromol 2022; 207:784-790. [PMID: 35351552 DOI: 10.1016/j.ijbiomac.2022.03.158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 03/01/2022] [Accepted: 03/24/2022] [Indexed: 12/16/2022]
Abstract
Polysaccharides derived from lignocellulose are promising sustainable carbon sources. Cellulosome is a supramolecular machine integrating multi-function enzymes for effective lignocellulose bio-saccharification. However, how various non-cellulose components of lignocellulose affect the cellulosomal saccharification is hitherto unclear. This study first investigated the stability and oxygen sensitivity of the cellulosome from Clostridium thermocellum during long-term saccharification process. Then, the differential inhibitory effects of non-cellulose components, including lignin, xylan, and arabinoxylan, on the cellulosome-based saccharification were determined. The results showed that lignin played inhibitory roles by non-productively adsorbing extracellular proteins of C. thermocellum. Differently, arabinoxylan preferred to bind with the cellulosomal components. Almost no adsorption of cellulosomal proteins on solid xylan was detected. Instead, xylan in water-dissolved form interacted with the cellulosomal proteins, especially the key exoglucanase Cel48S, leading to the xylan inhibitory effect. Compared to xylan, xylooligosaccharides influenced the cellulosome activity slightly. Hence, this work demonstrates that the timely hydrolysis or removal of dissolved xylan is important for cellulosome-based lignocellulose saccharification.
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Affiliation(s)
- Chao Chen
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Kuan Qi
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Fang Chi
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiaojin Song
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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12
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Synergy of Cellulase Systems between Acetivibrio thermocellus and Thermoclostridium stercorarium in Consolidated-Bioprocessing for Cellulosic Ethanol. Microorganisms 2022; 10:microorganisms10030502. [PMID: 35336078 PMCID: PMC8951355 DOI: 10.3390/microorganisms10030502] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 11/18/2022] Open
Abstract
Anaerobes harbor some of the most efficient biological machinery for cellulose degradation, especially thermophilic bacteria, such as Acetivibrio thermocellus and Thermoclostridium stercorarium, which play a fundamental role in transferring lignocellulose into ethanol through consolidated bioprocessing (CBP). In this study, we compared activities of two cellulase systems under varying kinds of hemicellulose and cellulose. A. thermocellus was identified to contribute specifically to cellulose hydrolysis, whereas T. stercorarium contributes to hemicellulose hydrolysis. The two systems were assayed in various combinations to assess their synergistic effects using cellulose and corn stover as the substrates. Their maximum synergy degrees on cellulose and corn stover were, respectively, 1.26 and 1.87 at the ratio of 3:2. Furthermore, co-culture of these anaerobes on the mixture of cellulose and xylan increased ethanol concentration from 21.0 to 40.4 mM with a high cellulose/xylan-to-ethanol conversion rate of up to 20.7%, while the conversion rates of T. stercorarium and A. thermocellus monocultures were 19.3% and 15.2%. The reason is that A. thermocellus had the ability to rapidly degrade cellulose while T. stercorarium co-utilized both pentose and hexose, the metabolites of cellulose degradation, to produce ethanol. The synergistic effect of cellulase systems and metabolic pathways in A. thermocellus and T. stercorarium provides a novel strategy for the design, selection, and optimization of ethanol production from cellulosic biomass through CBP.
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Nhim S, Waeonukul R, Uke A, Baramee S, Ratanakhanokchai K, Tachaapaikoon C, Pason P, Liu YJ, Kosugi A. Biological cellulose saccharification using a coculture of Clostridium thermocellum and Thermobrachium celere strain A9. Appl Microbiol Biotechnol 2022; 106:2133-2145. [PMID: 35157106 PMCID: PMC8930880 DOI: 10.1007/s00253-022-11818-0] [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] [Received: 10/13/2021] [Revised: 12/30/2021] [Accepted: 01/30/2022] [Indexed: 11/29/2022]
Abstract
Abstract An anaerobic thermophilic bacterial strain, A9 (NITE P-03545), that secretes β-glucosidase was newly isolated from wastewater sediments by screening using esculin. The 16S rRNA gene sequence of strain A9 had 100% identity with that of Thermobrachium celere type strain JW/YL-NZ35. The complete genome sequence of strain A9 showed 98.4% average nucleotide identity with strain JW/YL-NZ35. However, strain A9 had different physiological properties from strain JW/YL-NZ35, which cannot secrete β-glucosidases or grow on cellobiose as the sole carbon source. The key β-glucosidase gene (TcBG1) of strain A9, which belongs to glycoside hydrolase family 1, was characterized. Recombinant β-glucosidase (rTcBG1) hydrolyzed cellooligosaccharides to glucose effectively. Furthermore, rTcBG1 showed high thermostability (at 60°C for 2 days) and high glucose tolerance (IC50 = 0.75 M glucose), suggesting that rTcBG1 could be used for biological cellulose saccharification in cocultures with Clostridium thermocellum. High cellulose degradation was observed when strain A9 was cocultured with C. thermocellum in a medium containing 50 g/l crystalline cellulose, and glucose accumulation in the culture supernatant reached 35.2 g/l. In contrast, neither a monoculture of C. thermocellum nor coculture of C. thermocellum with strain JW/YL-NZ35 realized efficient cellulose degradation or high glucose accumulation. These results show that the β-glucosidase secreted by strain A9 degrades cellulose effectively in combination with C. thermocellum cellulosomes and has the potential to be used in a new biological cellulose saccharification process that does not require supplementation with β-glucosidases. Key points • Strain A9 can secrete a thermostable β-glucosidase that has high glucose tolerance • A coculture of strain A9 and C. thermocellum showed high cellulose degradation • Strain A9 achieves biological saccharification without addition of β-glucosidase Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-11818-0.
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Affiliation(s)
- Sreyneang Nhim
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), 10150, Bangkok, Thailand
| | - Rattiya Waeonukul
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), 10150, Bangkok, Thailand.,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10150, Thailand
| | - Ayaka Uke
- Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki, 305-8686, Japan
| | - Sirilak Baramee
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), 10150, Bangkok, Thailand.,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10150, Thailand
| | - Khanok Ratanakhanokchai
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), 10150, Bangkok, Thailand
| | - Chakrit Tachaapaikoon
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), 10150, Bangkok, Thailand.,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10150, Thailand
| | - Patthra Pason
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), 10150, Bangkok, Thailand.,Excellent Center of Enzyme Technology and Microbial Utilization, Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10150, Thailand
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, People's Republic of China.,Shandong Energy Institute, Qingdao, 266101, People's Republic of China.,Qingdao New Energy Shandong Laboratory, Qingdao, 266101, People's Republic of China
| | - Akihiko Kosugi
- Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki, 305-8686, Japan.
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Ichikawa S, Ito D, Asaoka S, Abe R, Katsuo N, Ito T, Ito D, Karita S. The expression of alternative sigma-I7 factor induces the transcription of cellulosomal genes in the cellulolytic bacterium Clostridium thermocellum. Enzyme Microb Technol 2022; 156:110002. [DOI: 10.1016/j.enzmictec.2022.110002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/12/2022] [Accepted: 01/31/2022] [Indexed: 01/07/2023]
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15
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An Q, Lin HN, Wang YT, Deng MC, Zhu MJ. Improved saccharification of pretreated lignocellulose by Clostridium thermocellum with the addition of surfactant, low loading of cellulose. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Handling Several Sugars at a Time: a Case Study of Xyloglucan Utilization by Ruminiclostridium cellulolyticum. mBio 2021; 12:e0220621. [PMID: 34749527 PMCID: PMC8576529 DOI: 10.1128/mbio.02206-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Xyloglucan utilization by Ruminiclostridium cellulolyticum was formerly shown to imply the uptake of large xylogluco-oligosaccharides, followed by cytosolic depolymerization into glucose, galactose, xylose, and cellobiose. This raises the question of how the anaerobic bacterium manages the simultaneous presence of multiple sugars. Using genetic and biochemical approaches targeting the corresponding metabolic pathways, we observed that, surprisingly, all sugars are catabolized, collectively, but glucose consumption is prioritized. Most selected enzymes display unusual features, especially the GTP-dependent hexokinase of glycolysis, which appeared reversible and crucial for xyloglucan utilization. In contrast, mutant strains lacking either galactokinase, cellobiose-phosphorylase, or xylulokinase still catabolize xyloglucan but display variably altered growth. Furthermore, the xylogluco-oligosaccharide depolymerization process appeared connected to the downstream pathways through an intricate network of competitive and noncompetitive inhibitions. Altogether, our data indicate that xyloglucan utilization by R. cellulolyticum relies on an energy-saving central carbon metabolism deviating from current bacterial models, which efficiently prevents carbon overflow. IMPORTANCE The study of the decomposition of recalcitrant plant biomass is of great interest as the limiting step of terrestrial carbon cycle and to produce plant-derived valuable chemicals and energy. While extracellular cellulose degradation and catabolism have been studied in detail, few publications describe the complete metabolism of hemicelluloses and, to date, the published models are limited to the extracellular degradation and sequential entry of simple sugars. Here, we describe how the model anaerobic bacterium Ruminiclostridium cellulolyticum deals with the synchronous intracellular release of glucose, galactose, xylose, and cellobiose upon cytosolic depolymerization of imported xyloglucan oligosaccharides. The described novel metabolic strategy involves the simultaneous activity of different metabolic pathways coupled to a network of inhibitions controlling the carbon flux and is distinct from the ubiquitously observed sequential uptake and metabolism of carbohydrates known as the diauxic shift. Our results highlight the diversity of cellular responses related to a complex environment.
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Gardner JG, Schreier HJ. Unifying themes and distinct features of carbon and nitrogen assimilation by polysaccharide-degrading bacteria: a summary of four model systems. Appl Microbiol Biotechnol 2021; 105:8109-8127. [PMID: 34611726 DOI: 10.1007/s00253-021-11614-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 11/24/2022]
Abstract
Our current understanding of enzymatic polysaccharide degradation has come from a huge number of in vitro studies with purified enzymes. While this vast body of work has been invaluable in identifying and characterizing novel mechanisms of action and engineering desirable traits into these enzymes, a comprehensive picture of how these enzymes work as part of a native in vivo system is less clear. Recently, several model bacteria have emerged with genetic systems that allow for a more nuanced study of carbohydrate active enzymes (CAZymes) and how their activity affects bacterial carbon metabolism. With these bacterial model systems, it is now possible to not only study a single nutrient system in isolation (i.e., carbohydrate degradation and carbon metabolism), but also how multiple systems are integrated. Given that most environmental polysaccharides are carbon rich but nitrogen poor (e.g., lignocellulose), the interplay between carbon and nitrogen metabolism in polysaccharide-degrading bacteria can now be studied in a physiologically relevant manner. Therefore, in this review, we have summarized what has been experimentally determined for CAZyme regulation, production, and export in relation to nitrogen metabolism for two Gram-positive (Caldicellulosiruptor bescii and Clostridium thermocellum) and two Gram-negative (Bacteroides thetaiotaomicron and Cellvibrio japonicus) polysaccharide-degrading bacteria. By comparing and contrasting these four bacteria, we have highlighted the shared and unique features of each, with a focus on in vivo studies, in regard to carbon and nitrogen assimilation. We conclude with what we believe are two important questions that can act as guideposts for future work to better understand the integration of carbon and nitrogen metabolism in polysaccharide-degrading bacteria. KEY POINTS: • Regardless of CAZyme deployment system, the generation of a local pool of oligosaccharides is a common strategy among Gram-negative and Gram-positive polysaccharide degraders as a means to maximally recoup the energy expenditure of CAZyme production and export. • Due to the nitrogen deficiency of insoluble polysaccharide-containing substrates, Gram-negative and Gram-positive polysaccharide degraders have a diverse set of strategies for supplementation and assimilation. • Future work needs to precisely characterize the energetic expenditures of CAZyme deployment and bolster our understanding of how carbon and nitrogen metabolism are integrated in both Gram-negative and Gram-positive polysaccharide-degrading bacteria, as both of these will significantly influence a given bacterium's suitability for biotechnology applications.
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Affiliation(s)
- Jeffrey G Gardner
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA.
| | - Harold J Schreier
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA.,Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland, Baltimore County, Baltimore, MD, USA
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18
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Qi K, Chen C, Yan F, Feng Y, Bayer EA, Kosugi A, Cui Q, Liu YJ. Coordinated β-glucosidase activity with the cellulosome is effective for enhanced lignocellulose saccharification. BIORESOURCE TECHNOLOGY 2021; 337:125441. [PMID: 34182347 DOI: 10.1016/j.biortech.2021.125441] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Consolidated bio-saccharification (CBS) technology employs cellulosome-producing bacterial cells, rather than fungal cellulases, as biocatalysts for cost-effective production of lignocellulosic sugars. Extracellular β-glucosidase (BGL) expression in the whole-cell arsenal is indispensable, due to severe cellobiose inhibition of the cellulosome. However, high-level BGL expression in Clostridium thermocellum is challenging, and the optimal BGL production level for efficient cellulose saccharification is currently unknown. Herein, we obtained new CBS biocatalysts by transforming BGL-expressing plasmids into C. thermocellum, which produced abundant BGL proteins and hydrolyzed cellulose effectively. The optimal ratio of extracellular BGL-to-cellulosome activity was determined to be in a range of 5.5 to 21.6. Despite the critical impact of BGL, both excessive BGL expression and its assembly on the cellulosome via type I cohesin-dockerin interaction led to reduced cellulosomal activity, which further confirmed the importance of coordinated BGL expression with the cellulosome. This study will further promote industrial CBS application in lignocellulose conversion.
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Affiliation(s)
- Kuan Qi
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chao Chen
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Fei Yan
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel; Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8499000, Israel
| | - Akihiko Kosugi
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), 1-1 Ohwashi, Tsukuba, Ibaraki 305-8686, Japan
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Engineering Laboratory for Single Cell Oil, Qingdao Engineering Laboratory for Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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19
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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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20
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Yan F, Wei R, Cui Q, Bornscheuer UT, Liu Y. Thermophilic whole-cell degradation of polyethylene terephthalate using engineered Clostridium thermocellum. Microb Biotechnol 2021; 14:374-385. [PMID: 32343496 PMCID: PMC7936307 DOI: 10.1111/1751-7915.13580] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/03/2022] Open
Abstract
Polyethylene terephthalate (PET) is a mass-produced synthetic polyester contributing remarkably to the accumulation of solid plastics waste and plastics pollution in the natural environments. Recently, bioremediation of plastics waste using engineered enzymes has emerged as an eco-friendly alternative approach for the future plastic circular economy. Here we genetically engineered a thermophilic anaerobic bacterium, Clostridium thermocellum, to enable the secretory expression of a thermophilic cutinase (LCC), which was originally isolated from a plant compost metagenome and can degrade PET at up to 70°C. This engineered whole-cell biocatalyst allowed a simultaneous high-level expression of LCC and conspicuous degradation of commercial PET films at 60°C. After 14 days incubation of a batch culture, more than 60% of the initial mass of a PET film (approximately 50 mg) was converted into soluble monomer feedstocks, indicating a markedly higher degradation performance than previously reported whole-cell-based PET biodegradation systems using mesophilic bacteria or microalgae. Our findings provide clear evidence that, compared to mesophilic species, thermophilic microbes are a more promising synthetic microbial chassis for developing future biodegradation processes of PET waste.
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Affiliation(s)
- Fei Yan
- CAS Key Laboratory of BiofuelsShandong Provincial Key Laboratory of Synthetic BiologyQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao266101China
- Dalian National Laboratory for Clean EnergyQingdao266101China
- University of Chinese Academy of SciencesChinese Academy of SciencesBeijing100049China
| | - Ren Wei
- Department of Biotechnology and Enzyme CatalysisInstitute of BiochemistryGreifswald UniversityFelix-Hausdorff-Str. 4D-17487GreifswaldGermany
| | - Qiu Cui
- CAS Key Laboratory of BiofuelsShandong Provincial Key Laboratory of Synthetic BiologyQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao266101China
- Dalian National Laboratory for Clean EnergyQingdao266101China
- University of Chinese Academy of SciencesChinese Academy of SciencesBeijing100049China
| | - Uwe T. Bornscheuer
- Department of Biotechnology and Enzyme CatalysisInstitute of BiochemistryGreifswald UniversityFelix-Hausdorff-Str. 4D-17487GreifswaldGermany
| | - Ya‐Jun Liu
- CAS Key Laboratory of BiofuelsShandong Provincial Key Laboratory of Synthetic BiologyQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao266101China
- Dalian National Laboratory for Clean EnergyQingdao266101China
- University of Chinese Academy of SciencesChinese Academy of SciencesBeijing100049China
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21
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Consolidated bio-saccharification: Leading lignocellulose bioconversion into the real world. Biotechnol Adv 2020; 40:107535. [DOI: 10.1016/j.biotechadv.2020.107535] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/03/2020] [Accepted: 02/12/2020] [Indexed: 11/22/2022]
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22
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Blumer-Schuette SE. Insights into Thermophilic Plant Biomass Hydrolysis from Caldicellulosiruptor Systems Biology. Microorganisms 2020; 8:E385. [PMID: 32164310 PMCID: PMC7142884 DOI: 10.3390/microorganisms8030385] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/06/2020] [Accepted: 03/07/2020] [Indexed: 11/16/2022] Open
Abstract
Plant polysaccharides continue to serve as a promising feedstock for bioproduct fermentation. However, the recalcitrant nature of plant biomass requires certain key enzymes, including cellobiohydrolases, for efficient solubilization of polysaccharides. Thermostable carbohydrate-active enzymes are sought for their stability and tolerance to other process parameters. Plant biomass degrading microbes found in biotopes like geothermally heated water sources, compost piles, and thermophilic digesters are a common source of thermostable enzymes. While traditional thermophilic enzyme discovery first focused on microbe isolation followed by functional characterization, metagenomic sequences are negating the initial need for species isolation. Here, we summarize the current state of knowledge about the extremely thermophilic genus Caldicellulosiruptor, including genomic and metagenomic analyses in addition to recent breakthroughs in enzymology and genetic manipulation of the genus. Ten years after completing the first Caldicellulosiruptor genome sequence, the tools required for systems biology of this non-model environmental microorganism are in place.
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23
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Yu G, Liu S, Feng X, Zhang Y, Liu C, Liu YJ, Li B, Cui Q, Peng H. Impact of ammonium sulfite-based sequential pretreatment combinations on two distinct saccharifications of wheat straw. RSC Adv 2020; 10:17129-17142. [PMID: 35521439 PMCID: PMC9053470 DOI: 10.1039/d0ra01759k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/22/2020] [Indexed: 01/27/2023] Open
Abstract
The properties of lignocellulosic substrates obtained from different pretreatments have a big impact on downstream saccharification based on both the fungal cellulase system and the cellulosome-based whole-cell biocatalysis system. However the corresponding effect of these two distinct saccharification strategies has not been comparatively analyzed. In this work, three ammonium sulfite (AS)-based pretreatment combinations (i.e., AS + hydrothermal (HT) pretreatment, AS + xylanase (X) pretreatment, and HT + AS pretreatment) were conducted to treat wheat straw. The obtained pretreated substrates with different properties were saccharified using fungal cellulase or an engineered Clostridium thermocellum strain as the whole-cell biocatalyst, and the ability to release sugar was comparatively evaluated. It was found that for the whole-cell saccharification, the total sugar digestibility of AS + HT/X pretreated wheat straw was 10% higher than that of HT + AS pretreated wheat straw. However, for fungal cellulase-based saccharification, the enzymatic hydrolysis efficiency was less susceptible to the sequence of pretreatment combinations. Hence, the whole-cell biocatalysis system was more sensitive to substrate accessibility compared to the free enzymes. In addition, the characterization and analyses showed that AS + HT/X pretreatment could remove more lignin, generating a more accessible surface with a larger external surface and lower surface lignin coverage, compared to the HT + AS pretreatment. Therefore, the AS + HT/X pretreatment was more compatible with the cellulosome-based whole-cell saccharification. The impact of substrate properties on wheat straw sugar release from fungal cellulase and whole cell-based CBS was comparatively investigated.![]()
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Affiliation(s)
- Guang Yu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Shiyue Liu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Xiaoyan Feng
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Yuedong Zhang
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Chao Liu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Bin Li
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Qiu Cui
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
| | - Hui Peng
- CAS Key Laboratory of Biofuels
- Shandong Provincial Key Laboratory of Synthetic Biology
- Shandong Engineering Laboratory of Single Cell Oil
- Qingdao Engineering Laboratory of Single Cell Oil
- Dalian National Laboratory for Clean Energy
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24
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Hirano K, Saito T, Shinoda S, Haruki M, Hirano N. In vitro assembly and cellulolytic activity of a β-glucosidase-integrated cellulosome complex. FEMS Microbiol Lett 2019; 366:5581498. [DOI: 10.1093/femsle/fnz209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 10/02/2019] [Indexed: 11/13/2022] Open
Abstract
ABSTRACTThe cellulosome is a supramolecular multi-enzyme complex formed by protein interactions between the cohesin modules of scaffoldin proteins and the dockerin module of various polysaccharide-degrading enzymes. In general, the cellulosome exhibits no detectable β-glucosidase activity to catalyze the conversion of cellobiose to glucose. Because β-glucosidase prevents product inhibition of cellobiohydrolase by cellobiose, addition of β-glucosidase to the cellulosome greatly enhances the saccharification of crystalline cellulose and plant biomass. Here, we report the in vitro assembly and cellulolytic activity of a β-glucosidase-coupled cellulosome complex comprising the three major cellulosomal cellulases and full-length scaffoldin protein of Clostridium (Ruminiclostridium) thermocellum, and Thermoanaerobacter brockii β-glucosidase fused to the type-I dockerin module of C. thermocellum. We show that the cellulosome complex composed of nearly equal numbers of cellulase and β-glucosidase molecules exhibits maximum activity toward crystalline cellulose, and saccharification activity decreases as the enzymatic ratio of β-glucosidase increases. Moreover, β-glucosidase-coupled and β-glucosidase-supplemented cellulosome complexes similarly exhibit maximum activity toward crystalline cellulose (i.e. 1.7-fold higher than that of the β-glucosidase-free cellulosome complex). These results suggest that the enzymatic ratio of cellulase and β-glucosidase in the assembled complex is crucial for the efficient saccharification of crystalline cellulose by the β-glucosidase-integrated cellulosome complex.
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Affiliation(s)
- Katsuaki Hirano
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
| | - Tsubasa Saito
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
| | - Suguru Shinoda
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
| | - Mitsuru Haruki
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
| | - Nobutaka Hirano
- Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama, Fukushima 963-8642, Japan
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25
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Glucose production from cellulose through biological simultaneous enzyme production and saccharification using recombinant bacteria expressing the β-glucosidase gene. J Biosci Bioeng 2019; 127:340-344. [DOI: 10.1016/j.jbiosc.2018.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/16/2018] [Accepted: 08/20/2018] [Indexed: 12/18/2022]
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26
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Liu S, Liu YJ, Feng Y, Li B, Cui Q. Construction of consolidated bio-saccharification biocatalyst and process optimization for highly efficient lignocellulose solubilization. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:35. [PMID: 30820245 PMCID: PMC6378752 DOI: 10.1186/s13068-019-1374-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND The industrial conversion of biomass to high-value biofuels and biochemical is mainly restricted by lignocellulose solubilization. Consolidated bio-saccharification (CBS) is considered a promising process for lignocellulose solubilization depending on whole-cell biocatalysts that simultaneously perform effective cellulase production and hydrolysis. However, it usually takes a long time to reach a high saccharification level using the current CBS biocatalyst and process. RESULTS To promote the saccharification efficiency and reduce the cost, a Clostridium thermocellum recombinant strain ∆pyrF::KBm was constructed as a new CBS biocatalyst in this study. The key CBS factors, including the medium, inoculum size and cultivation, and substrate load, were investigated and optimized. The saccharification process was also stimulated by adding free hemicellulases, suggesting the need to further enhance hemicellulase activity of the whole-cell catalyst. Under the optimal conditions, the CBS process was shortened by 50% with pretreated wheat straw as the substrate. The sugar yield reached 0.795 g/g and the saccharification level was 89.3%. CONCLUSIONS This work provided a new biocatalyst and an optimized process of CBS and confirmed that CBS is a feasible strategy for cost-efficient solubilization of lignocellulose, which will greatly promote the industrial utilization of lignocellulosic biomass.
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Affiliation(s)
- Shiyue Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
| | - Bin Li
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, China
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27
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Xin F, Dong W, Zhang W, Ma J, Jiang M. Biobutanol Production from Crystalline Cellulose through Consolidated Bioprocessing. Trends Biotechnol 2019; 37:167-180. [DOI: 10.1016/j.tibtech.2018.08.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 01/08/2023]
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28
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Liu YJ, Qi K, Zhang J, Chen C, Cui Q, Feng Y. Firmicutes-enriched IS 1447 represents a group of IS 3-family insertion sequences exhibiting unique + 1 transcriptional slippage. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:300. [PMID: 30410575 PMCID: PMC6211511 DOI: 10.1186/s13068-018-1304-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/27/2018] [Indexed: 05/12/2023]
Abstract
BACKGROUND Bacterial insertion sequences (ISs) are ubiquitous mobile genetic elements that play important roles in genome plasticity, cell adaptability, and function evolution. ISs of various families and subgroups contain significantly diverse molecular features and functional mechanisms that are not fully understood. RESULTS IS1447 is a member of the widespread IS3 family and was previously detected to have transposing activity in a typical thermophilic and cellulolytic microorganism Clostridium thermocellum. Phylogenetic analysis showed that IS1447-like elements are widely distributed in Firmicutes and possess unique features in the IS3 family. Therefore, IS1447 may represent a novel subgroup of the IS3 family. Unlike other well-known IS3 subgroups performing programmed - 1 translational frameshifting for the expression of the transposase, IS1447 exhibits transcriptional slippage in both the + 1 and - 1 directions, each with a frequency of ~ 16%, and only + 1 slippage results in full-length and functional transposase. The slippage-prone region of IS1447 contains a run of nine A nucleotides following a stem-loop structure in mRNA, but mutagenesis analysis indicated that seven of them are sufficient for the observed slippage. Western blot analysis indicated that IS1447 produces three types of transposases with alternative initiations. Furthermore, the IS1447-subgroup elements are abundant in the genomes of several cellulolytic bacteria. CONCLUSION Our result indicated that IS1447 represents a new Firmicutes-enriched subgroup of the IS3 family. The characterization of the novel IS3-family member will enrich our understanding of the transposition behavior of IS elements and may provide insight into developing IS-based mutagenesis tools for thermophiles.
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Affiliation(s)
- Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Dalian, China
| | - Kuan Qi
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Dalian, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Jie Zhang
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Dalian, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Present Address: Department of Biosystems Engineering, Auburn University, Auburn, AL 36849 USA
| | - Chao Chen
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Dalian, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Dalian, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- Dalian National Laboratory for Clean Energy, Dalian, China
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Li R, Feng Y, Liu S, Qi K, Cui Q, Liu YJ. Inducing effects of cellulosic hydrolysate components of lignocellulose on cellulosome synthesis in Clostridium thermocellum. Microb Biotechnol 2018; 11:905-916. [PMID: 29943510 PMCID: PMC6116742 DOI: 10.1111/1751-7915.13293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/25/2018] [Accepted: 06/04/2018] [Indexed: 02/06/2023] Open
Abstract
Cellulosome is a highly efficient supramolecular machine for lignocellulose degradation, and its substrate‐coupled regulation requires soluble transmembrane signals. However, the inducers for cellulosome synthesis and the inducing effect have not been clarified quantitatively. Values of cellulosome production capacity (CPC) and estimated specific activity (eSA) were calculated based on the primary scaffoldin ScaA to define the stimulating effects on the cellulosome synthesis in terms of quantity and quality respectively. The estimated cellulosome production of Clostridium thermocellum on glucose was at a low housekeeping level. Both Avicel and cellobiose increased CPCs of the cells instead of the eSAs of the cellulosome. The CPC of Avicel‐grown cells was over 20‐fold of that of glucose‐grown cells, while both Avicel‐ and glucose‐derived cellulosomes showed similar eSA. The CPC of cellobiose‐grown cells was also over three times higher than glucose‐grown cells, but the eSA of cellobiose‐derived cellulosome was 16% lower than that of the glucose‐derived cellulosome. Our results indicated that cello‐oligosaccharides played the key roles in inducing the synthesis of the cellulosome, but non‐cellulosic polysaccharides showed no inducing effects.
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Affiliation(s)
- Renmin Li
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yingang Feng
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Shiyue Liu
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Kuan Qi
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qiu Cui
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Ya-Jun Liu
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
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Li X, Xiao Y, Feng Y, Li B, Li W, Cui Q. The spatial proximity effect of beta-glucosidase and cellulosomes on cellulose degradation. Enzyme Microb Technol 2018; 115:52-61. [PMID: 29859603 DOI: 10.1016/j.enzmictec.2018.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/30/2018] [Accepted: 04/23/2018] [Indexed: 01/05/2023]
Abstract
Low-cost saccharification is one of the key bottlenecks hampering the further application of lignocellulosic biomass. Clostridium thermocellum is a naturally ideal cellulose degrading bacterium armed with cellulosomes, which are multienzyme complexes that are capable of efficiently degrading cellulose. However, under controlled condition, the inhibition effect of hydrolysate cellobiose severely restricts the hydrolytic ability of cellulosomes. Although the addition of beta-glucosidase (Bgl) could effectively relieve this inhibition, the spatial proximity effect of Bgl and cellulosomes on cellulose degradation is still unclear. To address this issue, free Bgl from Caldicellulosiruptor sp. F32 (CaBglA), carbohydrate-binding module (CBM) fused CaBglA (CaBglA-CBM) and cellulosomal type II cohesin module (CohII) fused to CaBglA (CaBglA-CohII) were successfully constructed, and their enzymatic activities, binding abilities and saccharification efficiencies were systematically investigated in vitro and in vivo. In vivo, with the adjacency of CaBglA to cellulosomes, the saccharification efficiency of microcrystalline cellulose increased from 40% to 50%. For the pretreated wheat straw, the degradation rate of the combination of cells and the CaBglA-CohII or the CaBglA-CBM was as efficient as that of the free CaBglA (approximately 60%). This study demonstrated that the proximity of CaBglA to cellulosomes had a positive effect on microcrystalline cellulose but not on pretreated wheat straw, which may result from the nonproductive adsorption of lignin and the decreased thermostability of CaBglA-CBM and CaBglA-CohII compared to that of CaBglA. The above results will contribute to the design of cost-effective Bgls for industrial cellulose degradation.
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Affiliation(s)
- Xiaoyi Li
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Yan Xiao
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Yingang Feng
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Bin Li
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Wenli Li
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China.
| | - Qiu Cui
- Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
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Wu B, Zheng S, Pedroso MM, Guddat LW, Chang S, He B, Schenk G. Processivity and enzymatic mechanism of a multifunctional family 5 endoglucanase from Bacillus subtilis BS-5 with potential applications in the saccharification of cellulosic substrates. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:20. [PMID: 29422948 PMCID: PMC5787917 DOI: 10.1186/s13068-018-1022-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 01/11/2018] [Indexed: 05/28/2023]
Abstract
BACKGROUND Presently, enzymes still constitute a major part of the cost of biofuel production from lignocellulosic biomass. Processive endoglucanases, which possess both endoglucanase and exoglucanase activity, have the potential to reduce the costs of biomass saccharification when used together with commercial cellulases. Therefore, the exploration of new processive endoglucanases has attracted much attention with a view to accelerating the industrialization of biofuels and biochemicals. RESULTS The endoglucanase EG5C and its truncated form EG5C-1 from Bacillus subtilis BS-5 were expressed and characterized. EG5C was a typical endoglucanase, comprised of a family 5 catalytic domain and family 3 carbohydrate-binding domain, and which had high activity toward soluble cellulosic substrates, but low activity toward insoluble cellulosic substrates. Importantly, the truncated form EG5C-1 was a processive endoglucanase that hydrolyzed not only carboxymethyl cellulose (CMC), but also insoluble cellulosic substrates. The hydrolytic activities of EG5C-1 towards CMC, phosphoric acid-swollen cellulose (PASC), p-nitrophenyl-β-d-cellobioside, filter paper and Avicel are 4170, 700, 2550, 405 and 320 U/μmol, respectively. These data demonstrated that EG5C-1 had higher activity ratio of exoglucanase to endoglucanase than other known processive endoglucanases. When PASC was degraded by EG5C-1, the ratio of soluble to insoluble reducing sugars was about 3.7 after 3 h of incubation with cellobiose and cellotriose as the main products. Importantly, EG5C-1 alone was able to hydrolyze filter paper and PASC. At 5% substrate concentration and 10 FPU/g PASC enzyme loading, the saccharification yield was 76.5% after 60 h of incubation. Replacement of a phenylalanine residue (F238) by an alanine at the entrance/exit of the substrate binding cleft significantly reduces the ability of EG5C-1 to degrade filter paper and Avicel, but this mutation has little impact on CMCase activity. The processivity of this mutant was also greatly reduced while its cellulose binding ability was markedly enhanced. CONCLUSIONS The processive endoglucanase EG5C-1 from B. subtilis BS-5 exhibits excellent properties that render it a suitable candidate for use in biofuel and biochemical production from lignocellulosic biomass. In addition, our studies also provide useful information for research on enzyme processivity at the molecular level.
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Affiliation(s)
- Bin Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhunan road, Nanjing, 211816 Jiangsu China
- China Jiangsu National Synergetic Innovation Center for Advanced Materials, 30 Puzhunan road, Nanjing, 211816 Jiangsu China
| | - Shan Zheng
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072 Australia
| | - Marcelo Monteiro Pedroso
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072 Australia
| | - Luke W. Guddat
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072 Australia
| | - Siyuan Chang
- School of Pharmaceutical Sciences, Nanjing Tech University, 30 Puzhunan road, Nanjing, 211816 Jiangsu China
| | - Bingfang He
- China Jiangsu National Synergetic Innovation Center for Advanced Materials, 30 Puzhunan road, Nanjing, 211816 Jiangsu China
- School of Pharmaceutical Sciences, Nanjing Tech University, 30 Puzhunan road, Nanjing, 211816 Jiangsu China
| | - Gerhard Schenk
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072 Australia
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Liu YJ, Liu S, Dong S, Li R, Feng Y, Cui Q. Determination of the native features of the exoglucanase Cel48S from Clostridium thermocellum. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:6. [PMID: 29344087 PMCID: PMC5766998 DOI: 10.1186/s13068-017-1009-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 12/29/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Clostridium thermocellum is considered one of the most efficient natural cellulose degraders because of its cellulosomal system. As the major exoglucanase of cellulosome in C. thermocellum, Cel48S plays key roles and influences the activity and features of cellulosome to a great extent. Thus, it is of great importance to reveal the enzymatic features of Cel48S. However, Cel48S has not been well performed due to difficulties in purifying either recombinant or native Cel48S proteins. RESULTS We observed that the soluble fraction of the catalytic domain of Cel48S (Cel48S_CD) obtained by heterologous expression in Escherichia coli and denaturation-refolding treatment contained a large portion of incorrectly folded proteins with low activity. Using a previously developed seamless genome-editing system for C. thermocellum, we achieved direct purification of Cel48S_CD from the culture supernatant of C. thermocellum DSM1313 by inserting a sequence encoding 12 successive histidine residues and a TAA stop codon immediately behind the GH domain of Cel48S. Based on the fully active protein, biochemical and structural analyses were performed to reveal its innate characteristics. The native Cel48S_CD showed high activity of 117.61 ± 2.98 U/mg and apparent substrate preference for crystalline cellulose under the assay conditions. The crystal structure of the native GH48 protein revealed substrate-coupled changes in the residue conformation, indicating induced-fit effects between Cel48S_CD and substrates. Mass spectrum and crystal structural analyses suggested no significant posttranslational modification in the native Cel48S_CD protein. CONCLUSION Our results confirmed that the high activity and substrate specificity of Cel48S_CD from C. thermocellum were consistent with its importance in the cellulosome. The structure of the native Cel48S_CD protein revealed evidence of conformational changes during substrate binding. In addition, our study provided a reliable method for in situ purification of cellulosomal and other secretive proteins from C. thermocellum.
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Affiliation(s)
- Ya-Jun Liu
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 People’s Republic of China
| | - Shiyue Liu
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 People’s Republic of China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Sheng Dong
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 People’s Republic of China
| | - Renmin Li
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 People’s Republic of China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Yingang Feng
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 People’s Republic of China
| | - Qiu Cui
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 People’s Republic of China
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