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Xu W, Ren Y, Xia Y, Liu L, Meng X, Chen G, Zhang W, Liu W. A novel transcriptional repressor specifically regulates xylanase gene 1 in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:161. [PMID: 37891680 PMCID: PMC10612264 DOI: 10.1186/s13068-023-02417-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023]
Abstract
BACKGROUND The well-known industrial fungus Trichoderma reesei has an excellent capability of secreting a large amount of cellulases and xylanases. The induced expression of cellulase and xylanase genes is tightly controlled at the transcriptional level. However, compared to the intensive studies on the intricate regulatory mechanism of cellulase genes, efforts to understand how xylanase genes are regulated are relatively limited, which impedes the further improvement of xylanase production by T. reesei via rational strain engineering. RESULTS To identify transcription factors involved in regulating xylanase gene expression in T. reesei, yeast one-hybrid screen was performed based on the promoters of two major extracellular xylanase genes xyn1 and xyn2. A putative transcription factor named XTR1 showing significant binding capability to the xyn1 promoter but not that of xyn2, was successfully isolated. Deletion of xtr1 significantly increased the transcriptional level of xyn1, but only exerted a minor promoting effect on that of xyn2. The xylanase activity was increased by ~ 50% with XTR1 elimination but the cellulase activity was hardly affected. Subcellular localization analysis of XTR1 fused to a green fluorescence protein demonstrated that XTR1 is a nuclear protein. Further analyses revealed the precise binding site of XTR1 and nucleotides critical for the binding within the xyn1 promoter. Moreover, competitive EMSAs indicated that XTR1 competes with the essential transactivator XYR1 for binding to the xyn1 promoter. CONCLUSIONS XTR1 represents a new transcriptional repressor specific for controlling xylanase gene expression. Isolation and functional characterization of this new factor not only contribute to further understanding the stringent regulatory network of xylanase genes, but also provide important clues for boosting xylanase biosynthesis in T. reesei.
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Affiliation(s)
- Wenqiang Xu
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
- Shandong Lishan Biotechnology Co., LTD, Jinan, China
| | - Yajing Ren
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Yuxiao Xia
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Lin Liu
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China.
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, No.72 Binhai Road, Qingdao, 266237, People's Republic of China
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Lv D, Zhang W, Meng X, Liu W. Single Mutation in Transcriptional Activator Xyr1 Enhances Cellulase and Xylanase Production in Trichoderma reesei on Glucose. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:11993-12003. [PMID: 37523749 DOI: 10.1021/acs.jafc.3c03466] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
To achieve cost-effective production of lignocellulolytic enzymes for biorefinery processes, engineering transcription factors represents a powerful strategy to boost cellulase and xylanase in Trichoderma reesei. In this study, a novel mutation (R434L) in xylanase regulator 1 (Xyr1) was identified based on the yeast one-hybrid screening system. The point mutation was located in the middle homology region of Xyr1 with unclear functions, indicating a significant role for this domain in tuning Xyr1 transactivation. When constitutively expressed in T. reesei Δxyr1 (OEXR434L), Xyr1R434L led to highly improved production of both cellulases and xylanases on glucose compared with a strain similarly expressing Xyr1 (OEX). The respective 0.8- and 0.7-fold increases in extracellular pNPCase and xylanolytic activity were further verified to result from the greatly elevated transcription of major cellulase and xylanase genes in OEXR434L. Moreover, the saccharification efficiency of corn stover with OEXR434L enzyme cocktails was enhanced by 21% compared with that of OEX.
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Affiliation(s)
- Dongmei Lv
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao 266237, P. R. China
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Yang J, Yue HR, Pan LY, Feng JX, Zhao S, Suwannarangsee S, Chempreda V, Liu CG, Zhao XQ. Fungal strain improvement for efficient cellulase production and lignocellulosic biorefinery: Current status and future prospects. BIORESOURCE TECHNOLOGY 2023:129449. [PMID: 37406833 DOI: 10.1016/j.biortech.2023.129449] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023]
Abstract
Lignocellulosic biomass (LCB) has been recognized as a valuable carbon source for the sustainable production of biofuels and value-added biochemicals. Crude enzymes produced by fungal cell factories benefit economic LCB degradation. However, high enzyme production cost remains a great challenge. Filamentous fungi have been widely used to produce cellulolytic enzymes. Metabolic engineering of fungi contributes to efficient cellulase production for LCB biorefinery. Here the latest progress in utilizing fungal cell factories for cellulase production was summarized, including developing genome engineering tools to improve the efficiency of fungal cell factories, manipulating promoters, and modulating transcription factors. Multi-omics analysis of fungi contributes to identifying novel genetic elements for enhancing cellulase production. Furthermore, the importance of translation regulation of cellulase production are emphasized. Efficient development of fungal cell factories based on integrative strain engineering would benefit the overall bioconversion efficacy of LCB for sustainable bioproduction.
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Affiliation(s)
- Jie Yang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hou-Ru Yue
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li-Ya Pan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Surisa Suwannarangsee
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathumthani 12120, Thailand
| | - Verawat Chempreda
- National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Khlong Luang, Pathumthani 12120, Thailand
| | - Chen-Guang Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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4
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Li N, Qiu Z, Cai W, Shen Y, Wei D, Chen Y, Wang W. The Ras small GTPase RSR1 regulates cellulase production in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:87. [PMID: 37218014 DOI: 10.1186/s13068-023-02341-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 05/13/2023] [Indexed: 05/24/2023]
Abstract
BACKGROUND Lignocellulose is the most abundant renewable resource in the world and has attracted widespread attention. It can be hydrolyzed into sugars with the help of cellulases and hemicellulases that are secreted by filamentous fungi. Several studies have revealed that the Ras small GTPase superfamily regulates important cellular physiological processes, including synthesis of metabolites, sporulation, and cell growth and differentiation. However, it remains unknown how and to what extent Ras small GTPases participate in cellulase production. RESULTS In this study, we found that the putative Ras small GTPase RSR1 negatively regulated the expression of cellulases and xylanases. Deletion of rsr1 (∆rsr1) significantly increased cellulase production and decreased the expression levels of ACY1-cAMP-protein kinase A (PKA) signaling pathway genes and the concentration of intracellular cyclic adenosine monophosphate (cAMP). Loss of acy1 based on ∆rsr1 (∆rsr1∆acy1) could further increase cellulase production and the expression levels of cellulase genes, while overexpression of acy1 based on ∆rsr1 (∆rsr1-OEacy1) significantly reduced cellulase production and transcriptional levels of cellulase genes. In addition, our results revealed that RSR1 negatively controlled cellulase production via the ACY1-cAMP-PKA pathway. Transcriptome analysis revealed significantly increased expression of three G-protein coupled receptors (GPCRs; tre62462, tre58767, and tre53238) and approximately two-fold higher expression of ACE3 and XYR1, which transcriptionally activated cellulases with the loss of rsr1. ∆rsr1∆ tre62462 exhibited a decrease in cellulase activity compared to ∆rsr1, while that of ∆rsr1∆tre58767 and ∆rsr1∆tre53238 showed a remarkable improvement compared to ∆rsr1. These findings revealed that GPCRs on the membrane may sense extracellular signals and transmit them to rsr1 and then to ACY1-cAMP-PKA, thereby negatively controlling the expression of the cellulase activators ACE3 and XYR1. These data indicate the crucial role of Ras small GTPases in regulating cellulase gene expression. CONCLUSIONS Here, we demonstrate that some GPCRs and Ras small GTPases play key roles in the regulation of cellulase genes in Trichoderma reesei. Understanding the roles of these components in the regulation of cellulase gene transcription and the signaling processes in T. reesei can lay the groundwork for understanding and transforming other filamentous fungi.
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Affiliation(s)
- Ni Li
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China
| | - Zhouyuan Qiu
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China
| | - Wanchuan Cai
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China
| | - Yaling Shen
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China
| | - Dongzhi Wei
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China
| | - Yumeng Chen
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China
| | - Wei Wang
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237, China.
- Jiangsu Yiming Biological Technology Co., Ltd., Suqian, 223699, Jiangsu, China.
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5
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Li N, Li J, Chen Y, Shen Y, Wei D, Wang W. Mechanism of Zn 2+ regulation of cellulase production in Trichoderma reesei Rut-C30. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:73. [PMID: 37118821 PMCID: PMC10148476 DOI: 10.1186/s13068-023-02323-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/18/2023] [Indexed: 04/30/2023]
Abstract
BACKGROUND Trichoderma reesei Rut-C30 is a hypercellulolytic mutant strain that degrades abundant sources of lignocellulosic plant biomass, yielding renewable biofuels. Although Zn2+ is an activator of enzymes in almost all organisms, its effects on cellulase activity in T. reesei have yet to be reported. RESULTS Although high concentrations of Zn2+ severely suppressed the extension of T. reesei mycelia, the application of 1-4 mM Zn2+ enhanced cellulase and xylanase production in the high-yielding cellulase-producing Rut-C30 strain of T. reesei. Expression of the major cellulase, xylanase, and two essential transcription activator genes (xyr1 and ace3) increased in response to Zn2+ stimulation. Transcriptome analysis revealed that the mRNA levels of plc-e encoding phospholipase C, which is involved in the calcium signaling pathway, were enhanced by Zn2+ application. The disruption of plc-e abolished the cellulase-positive influence of Zn2+ in the early phase of induction, indicating that plc-e is involved in Zn2+-induced cellulase production. Furthermore, treatment with LaCl3 (a plasma membrane Ca2+ channel blocker) and deletion of crz1 (calcineurin-responsive zinc finger transcription factor 1) indicated that calcium signaling is partially involved in this process. Moreover, we identified the zinc-responsive transcription factor zafA, the transcriptional levels of which declined in response to Zn2+ stress. Deletion of zafA indicates that this factor plays a prominent role in mediating the Zn2+-induced excessive production of cellulase. CONCLUSIONS For the first time, we have demonstrated that Zn2+ is toxic to T. reesei, although promotes a marked increase in cellulase production. This positive influence of Zn2+ is facilitated by the plc-e gene and zafA transcription factor. These findings provide insights into the role of Zn2+ in T. reesei and the mechanisms underlying signal transduction in cellulase synthesis.
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Affiliation(s)
- Ni Li
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Jing Li
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Yumeng Chen
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Yaling Shen
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Dongzhi Wei
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China
| | - Wei Wang
- The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 311, Shanghai, 200237, China.
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6
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Chen Y, Han A, Wang M, Wei D, Wang W. Metabolic Engineering of Trichoderma reesei for l-Malic Acid Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:4043-4050. [PMID: 36812909 DOI: 10.1021/acs.jafc.2c09078] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
l-Malic acid has various applications in the chemical and food industries. The filamentous fungus Trichoderma reesei is known to be an efficient enzyme producer. Here, through metabolic engineering, T. reesei was constructed for the first time as an excellent cell factory for l-malic acid production. The heterologous overexpression of genes encoding the C4-dicarboxylate transporter from Aspergillus oryzae and Schizosaccharomyces pombe initiated l-malic acid production. The overexpression of pyruvate carboxylase from A. oryzae in the reductive tricarboxylic acid pathway further increased both the titer and yield of l-malic acid, resulting in the highest titer reported in a shake-flask culture. Furthermore, the deletion of malate thiokinase blocked l-malic acid degradation. Finally, the engineered T. reesei strain produced 220.5 g/L of l-malic acid in a 5 L fed-batch culture (productivity of 1.15 g/L/h). A T. reesei cell factory was created for the efficient production of l-malic acid.
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Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Ao Han
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Meng Wang
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
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Chen Y, Wang M, Wang W, Zeng Y, Fan X, Tu M, Ma Y, Wei D. Metabolic Engineering for the Comprehensive Utilization of N, N-Dimethylformamide-Containing Wastewater. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:13574-13582. [PMID: 36223298 DOI: 10.1021/acs.jafc.2c05240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
N, N-dimethylformamide is frequently present in industrial wastewater and is environmentally detrimental. The current study aims to assess the utilization and biodegradation of N, N-dimethylformamide-containing wastewater to lessen the associated environmental load. Results show that addition of wastewater containing N, N-dimethylformamide to Trichoderma reesei fermentation media enhances cellulase production and facilitates cellulose hydrolysis. However, N, N-dimethylformamide is a cellulase enhancer that is not degraded during cellulase production in T. reesei fermentation and is retained in the N, N-dimethylformamide-enhanced cellulase solution. Indeed, the cellulosic sugar solution generated via lignocellulose hydrolysis with N, N-dimethylformamide-enhanced cellulase retains N, N-dimethylformamide. We further identified three core enzyme modules─N, N-dimethylformamidase, dimethylamine dehydrogenase, and methylamine dehydrogenase enzyme─which were inserted into Escherichia coli to develop metabolically engineered strains. These strains degraded N, N-dimethylformamide and produced succinate using N, N-dimethylformamide-enhanced cellulosic sugar as the substrate. The platform described here can be applied to effectively convert waste into valuable bioproducts.
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Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Meng Wang
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
- Jiangsu YIMING Biological Technology CO., LTD, 22 Wenzhou Road, Shuyang County, Suqian City, Jiangsu 223699, China
| | - Yi Zeng
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xingjia Fan
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Maobing Tu
- Department of Chemical and environmental Engineering, University of Cincinnati, 2901 Woodside Dr, Cincinnati, Ohio 45221, United States
| | - Yushu Ma
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
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Guo Y, Liu G, Ning Y, Li X, Hu S, Zhao J, Qu Y. Production of cellulosic ethanol and value-added products from corn fiber. BIORESOUR BIOPROCESS 2022; 9:81. [PMID: 38647596 PMCID: PMC10991675 DOI: 10.1186/s40643-022-00573-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 08/03/2022] [Indexed: 11/10/2022] Open
Abstract
Corn fiber, a by-product from the corn processing industry, mainly composed of residual starch, cellulose, and hemicelluloses, is a promising raw material for producing cellulosic ethanol and value-added products due to its abundant reserves and low costs of collection and transportation. Now, several technologies for the production of cellulosic ethanol from corn fiber have been reported, such as the D3MAX process, Cellerate™ process, etc., and part of the technologies have also been used in industrial production in the United States. The ethanol yields range from 64 to 91% of the theoretical maximum, depending on different production processes. Because of the multicomponent of corn fiber and the complex structures highly substituted by a variety of side chains in hemicelluloses of corn fiber, however, there are many challenges in cellulosic ethanol production from corn fiber, such as the low conversion of hemicelluloses to fermentable sugars in enzymatic hydrolysis, high production of inhibitors during pretreatment, etc. Some technologies, including an effective pretreatment process for minimizing inhibitors production and maximizing fermentable sugars recovery, production of enzyme preparations with suitable protein compositions, and the engineering of microorganisms capable of fermenting hexose and pentose in hydrolysates and inhibitors tolerance, etc., need to be further developed. The process integration of cellulosic ethanol and value-added products also needs to be developed to improve the economic benefits of the whole process. This review summarizes the status and progresses of cellulosic ethanol production and potential value-added products from corn fiber and presents some challenges in this field at present.
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Affiliation(s)
- Yingjie Guo
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao, 266237, Shandong, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao, 266237, Shandong, China
| | - Yanchun Ning
- Research Institute of Jilin Petrochemical Company, PetroChina, No. 27, Zunyidong Road, Jilin City, 132021, Jilin, China
| | - Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao, 266237, Shandong, China.
| | - Shiyang Hu
- Research Institute of Jilin Petrochemical Company, PetroChina, No. 27, Zunyidong Road, Jilin City, 132021, Jilin, China
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao, 266237, Shandong, China.
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, No. 72, Binhai Road, Qingdao, 266237, Shandong, China
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Mattam AJ, Chaudhari YB, Velankar HR. Factors regulating cellulolytic gene expression in filamentous fungi: an overview. Microb Cell Fact 2022; 21:44. [PMID: 35317826 PMCID: PMC8939176 DOI: 10.1186/s12934-022-01764-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/27/2022] [Indexed: 12/19/2022] Open
Abstract
The growing demand for biofuels such as bioethanol has led to the need for identifying alternative feedstock instead of conventional substrates like molasses, etc. Lignocellulosic biomass is a relatively inexpensive feedstock that is available in abundance, however, its conversion to bioethanol involves a multistep process with different unit operations such as size reduction, pretreatment, saccharification, fermentation, distillation, etc. The saccharification or enzymatic hydrolysis of cellulose to glucose involves a complex family of enzymes called cellulases that are usually fungal in origin. Cellulose hydrolysis requires the synergistic action of several classes of enzymes, and achieving the optimum secretion of these simultaneously remains a challenge. The expression of fungal cellulases is controlled by an intricate network of transcription factors and sugar transporters. Several genetic engineering efforts have been undertaken to modulate the expression of cellulolytic genes, as well as their regulators. This review, therefore, focuses on the molecular mechanism of action of these transcription factors and their effect on the expression of cellulases and hemicellulases.
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Affiliation(s)
- Anu Jose Mattam
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India
| | - Yogesh Babasaheb Chaudhari
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India
| | - Harshad Ravindra Velankar
- Hindustan Petroleum Green R and D Centre (HPGRDC), KIADB Industrial Area, Tarabanahalli, Devanagundi, Hoskote, Bangalore, 560067, India.
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