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Zhao S, Zhang T, Hasunuma T, Kondo A, Zhao XQ, Feng JX. Every road leads to Rome: diverse biosynthetic regulation of plant cell wall-degrading enzymes in filamentous fungi Penicillium oxalicum and Trichoderma reesei. Crit Rev Biotechnol 2024; 44:1241-1261. [PMID: 38035670 DOI: 10.1080/07388551.2023.2280810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/23/2023] [Accepted: 10/16/2023] [Indexed: 12/02/2023]
Abstract
Cellulases and xylanases are plant cell wall-degrading enzymes (CWDEs) that are critical to sustainable bioproduction based on renewable lignocellulosic biomass to reduce carbon dioxide emission. Currently, these enzymes are mainly produced from filamentous fungi, especially Trichoderma reesei and Penicillium oxalicum. However, an in-depth comparison of these two producers has not been performed. Although both P. oxalicum and T. reesei harbor CWDE systems, they exhibit distinct features regulating the production of these enzymes, mainly through different transcriptional regulatory networks. This review presents the strikingly different modes of genome-wide regulation of cellulase and xylanase biosynthesis in P. oxalicum and T. reesei, including sugar transporters, signal transduction cascades, transcription factors, chromatin remodeling, and three-dimensional organization of chromosomes. In addition, different molecular breeding approaches employed, based on the understanding of the regulatory networks, are summarized. This review highlights the existence of very different regulatory modes leading to the efficient regulation of CWDE production in filamentous fungi, akin to the adage that "every road leads to Rome." An understanding of this divergence may help further improvements in fungal enzyme production through the metabolic engineering and synthetic biology of certain fungal species.
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Affiliation(s)
- 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, China
| | - Ting Zhang
- 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, China
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 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, China
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Hu Z, Liu Q, Ouyang B, Wang G, Wei C, Zhao X. Recent advances in genetic engineering to enhance plant-polysaccharide-degrading enzyme expression in Penicillium oxalicum: A brief review. Int J Biol Macromol 2024; 278:134775. [PMID: 39153674 DOI: 10.1016/j.ijbiomac.2024.134775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 08/13/2024] [Accepted: 08/13/2024] [Indexed: 08/19/2024]
Abstract
With the depletion of non-renewable fossil fuels, there has been an increasing emphasis on renewable biomass. Penicillium oxalicum is notable for its exceptional capacity to secrete a diverse array of enzymes that degrade plant polysaccharides into monosaccharides. These valuable monosaccharides can be harnessed in the production of bioethanol and other sustainable forms of energy. By enhancing the production of plant-polysaccharide-degrading enzymes (PPDEs) in P. oxalicum, we can optimize the utilization of plant biomass. This paper presents recent advances in augmenting PPDE expression in P. oxalicum through genetic engineering strategies involving protoplast preparation, transformation, and factors influencing PPDE gene expression.
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Affiliation(s)
- Ziyan Hu
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Qiling Liu
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Bei Ouyang
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Guoping Wang
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Chenyang Wei
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Xihua Zhao
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China.
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Xu L, Li J, Gonzalez Ramos VM, Lyra C, Wiebenga A, Grigoriev IV, de Vries RP, Mäkelä MR, Peng M. Genome-wide prediction and transcriptome analysis of sugar transporters in four ascomycete fungi. BIORESOURCE TECHNOLOGY 2024; 391:130006. [PMID: 37952592 DOI: 10.1016/j.biortech.2023.130006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023]
Abstract
The import of plant-derived small sugars by sugar transporters (STs) has received increasing interest due to its important biological role and great industrial potential. STs are important targets of genetic engineering to improve fungal plant biomass conversion. Comparatively analysis of the genome-wide prevalence and transcriptomics of STs was performed in four filamentous fungi: Aspergillus niger, Aspergillus nidulans, Penicillium subrubescens and Trichoderma reesei. Using phylogenetic analysis and literature mining, their predicted STs were divided into ten subfamilies with putative sugar specificities assigned. In addition, transcriptome analysis revealed complex expression profiles among different STs subfamilies and fungal species, indicating a sophisticated transcriptome regulation and functional diversity of fungal STs. Several STs showed strong co-expression with other genes involved in sugar utilization, encoding CAZymes and sugar catabolic enzymes. This study provides new insights into the diversity of STs at the genomic/transcriptomic level, facilitating their biochemical characterization and metabolic engineering.
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Affiliation(s)
- Li Xu
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
| | - Jiajia Li
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
| | | | - Christina Lyra
- Department of Microbiology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland.
| | - Ad Wiebenga
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Igor V Grigoriev
- USA Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
| | - Miia R Mäkelä
- Department of Microbiology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland.
| | - Mao Peng
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
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Zhao S, Wang JX, Hou R, Ning YN, Chen ZX, Liu Q, Luo XM, Feng JX. Novel Transcription Factor CXRD Regulates Cellulase and Xylanase Biosynthesis in Penicillium oxalicum under Solid-State Fermentation. Appl Environ Microbiol 2023; 89:e0036023. [PMID: 37191516 PMCID: PMC10305053 DOI: 10.1128/aem.00360-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/24/2023] [Indexed: 05/17/2023] Open
Abstract
Penicillium oxalicum produces an integrated, extracellular cellulase and xylanase system, strictly regulated by several transcription factors. However, the understanding of the regulatory mechanism of cellulase and xylanase biosynthesis in P. oxalicum is limited, particularly under solid-state fermentation (SSF) conditions. In our study, deletion of a novel gene, cxrD (cellulolytic and xylanolytic regulator D), resulted in 49.3 to 2,230% enhanced production of cellulase and xylanase, except for 75.0% less xylanase at 2 days, compared with the P. oxalicum parental strain, when cultured on solid medium containing wheat bran plus rice straw for 2 to 4 days after transfer from glucose. In addition, the deletion of cxrD delayed conidiospore formation, leading to 45.1 to 81.8% reduced asexual spore production and altered mycelial accumulation to various extents. Comparative transcriptomics and real-time quantitative reverse transcription-PCR found that CXRD dynamically regulated the expression of major cellulase and xylanase genes and conidiation-regulatory gene brlA under SSF. In vitro electrophoretic mobility shift assays demonstrated that CXRD bound to the promoter regions of these genes. The core DNA sequence 5'-CYGTSW-3' was identified to be specifically bound by CXRD. These findings will contribute to understanding the molecular mechanism of negative regulation of fungal cellulase and xylanase biosynthesis under SSF. IMPORTANCE Application of plant cell wall-degrading enzymes (CWDEs) as catalysts in biorefining of lignocellulosic biomass into bioproducts and biofuels reduces both chemical waste production and carbon footprint. The filamentous fungus Penicillium oxalicum can secrete integrated CWDEs, with potential for industrial application. Solid-state fermentation (SSF), simulating the natural habitat of soil fungi, such as P. oxalicum, is used for CWDE production, but a limited understanding of CWDE biosynthesis hampers the improvement of CWDE yields through synthetic biology. Here, we identified a novel transcription factor CXRD, which negatively regulates the biosynthesis of cellulase and xylanase in P. oxalicum under SSF, providing a potential target for genetic engineering to improve CWDE production.
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Affiliation(s)
- 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, Guangxi, People’s Republic of China
| | - Jiu-Xiang Wang
- 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, Guangxi, People’s Republic of China
| | - Run Hou
- 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, Guangxi, People’s Republic of China
| | - Yuan-Ni Ning
- 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, Guangxi, People’s Republic of China
| | - Zhao-Xing Chen
- 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, Guangxi, People’s Republic of China
| | - Qi Liu
- 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, Guangxi, People’s Republic of China
| | - Xue-Mei Luo
- 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, Guangxi, People’s Republic of 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, Guangxi, People’s Republic of China
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Ma B, Luo XM, Zhao S, Feng JX. Protein Kinase PoxMKK1 Regulates Plant-Polysaccharide-Degrading Enzyme Biosynthesis, Mycelial Growth and Conidiation in Penicillium oxalicum. J Fungi (Basel) 2023; 9:jof9040397. [PMID: 37108852 PMCID: PMC10143691 DOI: 10.3390/jof9040397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
The ability to adapt to changing environmental conditions is crucial for living organisms, as it enables them to successfully compete in natural niches, a process which generally depends upon protein phosphorylation-mediated signaling transduction. In the present study, protein kinase PoxMKK1, an ortholog of mitogen-activated protein kinase kinase Ste7 in Saccharomyces cerevisiae, was identified and characterized in the filamentous fungus Penicillium oxalicum. Deletion of PoxMKK1 in P. oxalicum ΔPoxKu70 led the fungus to lose 64.4-88.6% and 38.0-86.1% of its plant-polysaccharide-degrading enzyme (PPDE) production on day 4 after a shift under submerged- and solid-state fermentation, respectively, compared with the control strain ΔPoxKu70. In addition, PoxMKK1 affected hypha growth and sporulation, though this was dependent on culture formats and carbon sources. Comparative transcriptomics and real-time quantitative reverse transcription PCR assay revealed that PoxMKK1 activated the expression of genes encoding major PPDEs, known regulatory genes (i.e., PoxClrB and PoxCxrB) and cellodextrin transporter genes (i.e., PoxCdtD and PoxCdtC), while it inhibited the essential conidiation-regulating genes, including PoxBrlA, PoxAbaA and PoxFlbD. Notably, regulons modulated by PoxMKK1 and its downstream mitogen-activated protein kinase PoxMK1 co-shared 611 differential expression genes, including 29 PPDE genes, 23 regulatory genes, and 16 sugar-transporter genes. Collectively, these data broaden our insights into the diverse functions of Ste7-like protein kinase, especially regulation of PPDE biosynthesis, in filamentous fungi.
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Affiliation(s)
- Bo Ma
- 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
| | - Xue-Mei Luo
- 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
| | - 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
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Wang H, Pang AP, Li B, Huo L, Wu FG, Lin F. Intracellular Sugar Transporters Facilitate Cellulase Synthesis in Trichoderma reesei Using Lactose. Biomolecules 2023; 13:biom13020295. [PMID: 36830663 PMCID: PMC9953249 DOI: 10.3390/biom13020295] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/28/2022] [Accepted: 01/31/2023] [Indexed: 02/09/2023] Open
Abstract
Sugar transporters play an important role in the cellulase production of lignocellulose-degrading fungi. Nevertheless, the role and function of these transporters are still unclear. Here we first report intracellular sugar transporters assisting cellulase production in Trichoderma reesei (T. reesei) using lactose. The mRNA levels of sugar transporter genes mfs, gst, and lac1 were substantially upregulated in T. reesei cultivated on lactose, with the most abundant mRNA levels at 24 h as compared to glucose. Moreover, the individual deletion of these sugar transporters significantly inhibited cellulase production, solid cell growth, and sporulation of T. reesei, suggesting they play a supporting role in cellulase production when grown in lactose. Surprisingly, MFS, GST, and LAC1 were mainly localized in the cytoplasm, with MFS and LAC1 in the endoplasmic reticulum (ER), representing the first discovery of intracellular sugar transporters involved in cellulase biosynthesis in lactose culture. The absence of the gene lac1 noticeably inhibited most of the crucial genes related to cellulase production, including cellulase-encoding genes, transcription factors, and sugar transporters, at 24 h, which was fully relieved at 48 h or 72 h, indicating that lac1 affects cellulase production more at the early step. This research advances the understanding of the function of intracellular sugar transporters in fungi, particularly for fungal cellulase production.
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Affiliation(s)
- Haiyan Wang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300453, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Liujie Huo
- Helmholtz International Laboratory, State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Fengming Lin
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300453, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
- Correspondence:
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Zhou T, Hu Y, Yan X, Cui J, Wang Y, Luo F, Yuan Y, Yu Z, Zhou Y. Molecular Cloning and Characterization of a Novel Exo-β-1,3-Galactanase from Penicillium oxalicum sp. 68. J Microbiol Biotechnol 2022; 32:1064-1071. [PMID: 35879293 PMCID: PMC9628948 DOI: 10.4014/jmb.2204.04012] [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: 04/08/2022] [Revised: 06/30/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Arabinogalactans have diverse biological properties and can be used as pharmaceutical agents. Most arabinogalactans are composed of β-(1→3)-galactan, so it is particularly important to identify β-1,3-galactanases that can selectively degrade them. In this study, a novel exo-β-1,3-galactanase, named PoGal3, was screened from Penicillium oxalicum sp. 68, and hetero-expressed in P. pastoris GS115 as a soluble protein. PoGal3 belongs to glycoside hydrolase family 43 (GH43) and has a 1,356-bp gene length that encodes 451 amino acids residues. To study the enzymatic properties and substrate selectivity of PoGal3, β-1,3-galactan (AG-P-I) from larch wood arabinogalactan (LWAG) was prepared and characterized by HPLC and NMR. Using AG-P-I as substrate, purified PoGal3 exhibited an optimal pH of 5.0 and temperature of 40°C. We also discovered that Zn2+ had the strongest promoting effect on enzyme activity, increasing it by 28.6%. Substrate specificity suggests that PoGal3 functions as an exo-β-1,3-galactanase, with its greatest catalytic activity observed on AG-P-I. Hydrolytic products of AG-P-I are mainly composed of galactose and β-1,6-galactobiose. In addition, PoGal3 can catalyze hydrolysis of LWAG to produce galacto-oligomers. PoGal3 is the first enzyme identified as an exo-β-1,3-galactanase that can be used in building glycan blocks of crucial glycoconjugates to assess their biological functions.
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Affiliation(s)
- Tong Zhou
- Department of Endocrinology and Metabolism, Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun 130021, P.R. China
| | - Yanbo Hu
- School of Food Sciences and Engineering, Chang Chun University, Changchun 130022, P.R. China
| | - Xuecui Yan
- Engineering Research Center of Glycoconjugates, Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, P.R. China
| | - Jing Cui
- Central Laboratory, Changchun Normal University, Changchun Jilin province, P.R. China
| | - Yibing Wang
- Engineering Research Center of Glycoconjugates, Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, P.R. China
| | - Feng Luo
- Engineering Research Center of Glycoconjugates, Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, P.R. China
| | - Ye Yuan
- Engineering Research Center of Glycoconjugates, Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, P.R. China
| | - Zhenxiang Yu
- Department of Endocrinology and Metabolism, Department of Respiratory Medicine, The First Hospital of Jilin University, Changchun 130021, P.R. China,Corresponding authors Y. Zhou Phone/Fax: +86-431-85098212 E-mail:
| | - Yifa Zhou
- Engineering Research Center of Glycoconjugates, Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, P.R. China,
Z. Yu Phone: +86-431-85098212 Fax: +86-431-85098212 E-mail:
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Analysis of carbohydrate-active enzymes and sugar transporters in Penicillium echinulatum: A genome-wide comparative study of the fungal lignocellulolytic system. Gene 2022; 822:146345. [PMID: 35189252 DOI: 10.1016/j.gene.2022.146345] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 02/09/2022] [Accepted: 02/15/2022] [Indexed: 02/06/2023]
Abstract
Penicillium echinulatum 2HH is an ascomycete well known for its production of cellulolytic enzymes. Understanding lignocellulolytic and sugar uptake systems is essential to obtain efficient fungi strains for the production of bioethanol. In this study we performed a genome-wide functional annotation of carbohydrate-active enzymes and sugar transporters involved in the lignocellulolytic system of P. echinulatum 2HH and S1M29 strains (wildtype and mutant, respectively) and eleven related fungi. Additionally, signal peptide and orthology prediction were carried out. We encountered a diverse assortment of cellulolytic enzymes in P. echinulatum, especially in terms of β-glucosidases and endoglucanases. Other enzymes required for the breakdown of cellulosic biomass were also found, including cellobiohydrolases, lytic cellulose monooxygenases and cellobiose dehydrogenases. The S1M29 mutant, which is known to produce an increased cellulase activity, and the 2HH wild type strain of P. echinulatum did not show significant differences between their enzymatic repertoire. Nevertheless, we unveiled an amino acid substitution for a predicted intracellular β-glucosidase of the mutant, which might contribute to hyperexpression of cellulases through a cellodextrin induction pathway. Most of the P. echinulatum enzymes presented orthologs in P. oxalicum 114-2, supporting the presence of highly similar cellulolytic mechanisms and a close phylogenetic relationship between these fungi. A phylogenetic analysis of intracellular β-glucosidases and sugar transporters allowed us to identify several proteins potentially involved in the accumulation of intracellular cellodextrins. These may prove valuable targets in the genetic engineering of P. echinulatum focused on industrial cellulases production. Our study marks an important step in characterizing and understanding the molecular mechanisms employed by P. echinulatum in the enzymatic hydrolysis of lignocellulosic biomass.
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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: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [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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10
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Zhang T, Mai RM, Fang QQ, Ou JF, Mo LX, Tian D, Li CX, Gu LS, Luo XM, Feng JX, Zhao S. Regulatory function of the novel transcription factor CxrC in Penicillium oxalicum. Mol Microbiol 2021; 116:1512-1532. [PMID: 34797006 DOI: 10.1111/mmi.14843] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 10/24/2021] [Accepted: 11/08/2021] [Indexed: 12/31/2022]
Abstract
Numerous transcription factors (TFs) in ascomycete fungi play crucial roles in cellular processes; however, how most of them function is poorly understood. Here, we identified and characterized a novel TF, CxrC (POX01387), acting downstream of the key TF CxrA, which is essential for plant-biomass-degrading-enzyme (PBDE) production in Penicillium oxalicum. Deletion of cxrC in P. oxalicum significantly affected the production of PBDEs, as well as mycelial growth and conidiospore production. CxrA directly repressed the expression of cxrC after about 12 hr following switch to Avicel culture. CxrC bound the promoters of major PBDE genes and genes involved in conidiospore development. CxrC was found to bind the TSSGTYR core sequence (S: C and G; Y: T and C; R: G and A) of the important cellulase genes cbh1 and eg1. Both N- and C-terminal peptides of CxrC and the CxrC phosphorylation were found to mediate its homodimerization. The conserved motif LPSVRSLLTP (65-74) in CxrC was found to be required for regulating cellulase production. This study reveals novel mechanisms of TF-mediated regulation of the expression of PBDE genes and genes involved in cellular processes in an ascomycete fungus.
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Affiliation(s)
- Ting Zhang
- 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, People's Republic of China
| | - Rong-Ming Mai
- 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, People's Republic of China
| | - Qi-Qi Fang
- 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, People's Republic of China
| | - Jian-Feng Ou
- 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, People's Republic of China
| | - Li-Xiang Mo
- 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, People's Republic of China
| | - Di Tian
- 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, People's Republic of China
| | - Cheng-Xi Li
- 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, People's Republic of China
| | - Li-Sha Gu
- 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, People's Republic of China
| | - Xue-Mei Luo
- 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, People's Republic of 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, People's Republic of 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, People's Republic of China
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11
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Pang XM, Tian D, Zhang T, Liao LS, Li CX, Luo XM, Feng JX, Zhao S. G protein γ subunit modulates expression of plant-biomass-degrading enzyme genes and mycelial-development-related genes in Penicillium oxalicum. Appl Microbiol Biotechnol 2021; 105:4675-4691. [PMID: 34076714 DOI: 10.1007/s00253-021-11370-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/05/2021] [Accepted: 05/26/2021] [Indexed: 01/24/2023]
Abstract
Heterotrimeric-G-protein-mediated signaling pathways modulate the expression of the essential genes in many fundamental cellular processes in fungi at the transcription level. However, these processes remain unclear in Penicillium oxalicum. In this study, we generated knockout and knockout-complemented strains of gng-1 (POX07071) encoding the Gγ protein and found that GNG-1 modulated the expression of genes encoding plant-biomass-degrading enzymes (PBDEs) and sporulation-related activators. Interestingly, GNG-1 affected expression of the cxrB that encodes a known transcription factor required for the expression of major cellulase and xylanase genes. Constitutive overexpression of cxrB in ∆gng-1 circumvented the dependence of PBDE production on GNG-1. Further evidence indicated that CxrB indirectly regulated the transcription levels of key amylase genes by controlling the expression of the regulatory gene amyR. These data extended the diversity of Gγ protein functions and provided new insight into the signal transduction and regulation of PBDE gene expression in filamentous fungi. KEY POINTS: • GNG-1 modulates the expression of PBDE genes and sporulation-related genes. • GNG-1 controls expression of the key regulatory gene cxrB. • Overexpression of cxrB circumvents dependence of PBDE production on GNG-1.
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Affiliation(s)
- Xiao-Ming Pang
- 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Di Tian
- 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Ting Zhang
- 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Lu-Sheng Liao
- 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Cheng-Xi Li
- 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Xue-Mei Luo
- 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of 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, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China.
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12
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A mitogen-activated protein kinase PoxMK1 mediates regulation of the production of plant-biomass-degrading enzymes, vegetative growth, and pigment biosynthesis in Penicillium oxalicum. Appl Microbiol Biotechnol 2021; 105:661-678. [PMID: 33409610 DOI: 10.1007/s00253-020-11020-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/20/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades are broadly conserved and play essential roles in multiple cellular processes, including fungal development, pathogenicity, and secondary metabolism. Their function, however, also exhibits species and strain specificity. Penicillium oxalicum secretes plant-biomass-degrading enzymes (PBDEs) that contribute to the carbon cycle in the natural environment and to utilization of lignocellulose in industrial processes. However, knowledge of the MAPK pathway in P. oxalicum has been relatively limited. In this study, comparative transcriptomic analysis of P. oxalicum, cultured on different carbon sources, found ten putative kinase genes with significantly modified transcriptional levels. Six of these putative kinase genes were knocked out in the parental strain ∆PoxKu70, and deletion of the gene, Fus3/Kss1-like PoxMK1 (POX00158), resulted in the largest reduction (91.1%) in filter paper cellulase production. Further tests revealed that the mutant ∆PoxMK1 lost 37.1 to 92.2% of PBDE production, under both submerged- and solid-state fermentation conditions, compared with ∆PoxKu70. In addition, the mutant ∆PoxMK1 had reduced vegetative growth and increased pigment biosynthesis. Comparative transcriptomic analysis showed that PoxMK1 deletion from P. oxalicum downregulated the expression of major PBDE genes and known regulatory genes such as PoxClrB and PoxCxrB, whereas the transcription of pigment biosynthesis-related genes was upregulated. Comparative phosphoproteomic analysis revealed that PoxMK1 deletion considerably modified phosphorylation of key transcription- and signal transduction-associated proteins, including transcription factors Mcm1 and Atf1, RNA polymerase II subunits Rpb1 and Rpb9, MAPK-associated Hog1 and Ste7, and cyclin-dependent kinase Kin28. These findings provide novel insights into understanding signal transduction and regulation of PBDE gene expression in fungi.Key points• PoxMK1 is involved in expression of PBDE- and pigment synthesis-related genes.• PoxMK1 is required for vegetative growth of P. oxalicum.• PoxMK1 is involved in phosphorylation of key TFs, kinases, and RNA polymerase II.
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13
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Li SH, Gu LS, Qu XY, Zhang T, Li CX, Mai RM, Liao LS, Zhang FF, Luo XM, Zhao S, Feng JX. Involvement of phospholipase PLA 2 in production of cellulase and xylanase by Penicillium oxalicum. Appl Microbiol Biotechnol 2021; 105:679-694. [PMID: 33394158 DOI: 10.1007/s00253-020-11065-1] [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: 07/03/2020] [Revised: 12/07/2020] [Accepted: 12/15/2020] [Indexed: 10/22/2022]
Abstract
Phospholipases play vital roles in immune and inflammatory responses in mammals and plants; however, knowledge of phospholipase functions in fungi is limited. In this study, we investigated the effects of deleting predicted phospholipase genes on cellulase and xylanase production, and morphological phenotype, in Penicillium oxalicum. Individual deletion of nine of the ten predicted phospholipase genes resulted in alteration of cellulase and xylanase production, and the morphological phenotypes, to various degrees. The mutant ∆POX07277 lost 22.5 to 82.8% of cellulase (i.e., filter paper cellulase, carboxymethylcellulase, and p-nitrophenyl-β-cellobiosidase) and xylanase production, whereas p-nitrophenyl-β-glucopyranosidase production increased by 5.8-127.8 fold. POX07277 (P. oxalicum gene No. 07277) was predicted to encode phospholipase A2 and was found to negatively affect the sporulation of P. oxalicum. Comparative transcriptomic and quantitative reverse transcription-PCR analysis indicated that POX07277 dynamically affected the expression of cellulase and xylanase genes and the regulatory genes for fungal sporulation, under micro-crystalline cellulose induction. POX07277 was required for the expression of the known regulatory gene PoxCxrB (cellulolytic and xylanolytic regulator B in P. oxalicum), which is involved in cellulase and xylanase gene expression in P. oxalicum. Conversely, POX07277 expression was regulated by PoxCxrB. These findings will aid the understanding of phospholipase functions and provide novel insights into the mechanism of fungal cellulase and xylanase gene expression. KEY POINTS : • The roles of phospholipases were investigated in Penicillium oxalicum. • POX07277 (PLA2) is required for the expression of cellulase and xylanase genes. • PoxCxrB dynamically regulated POX07277 expression.
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Affiliation(s)
- Shi-Huan Li
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Li-Sha Gu
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Xiao-Yi Qu
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Ting Zhang
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Cheng-Xi Li
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Rong-Ming Mai
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Lu-Sheng Liao
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Feng-Fei Zhang
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China
| | - Xue-Mei Luo
- 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of 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, 100 Daxue Road, Nanning, 530004, Guangxi, People's Republic of China.
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14
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Lenz AR, Galán-Vásquez E, Balbinot E, de Abreu FP, Souza de Oliveira N, da Rosa LO, de Avila e Silva S, Camassola M, Dillon AJP, Perez-Rueda E. Gene Regulatory Networks of Penicillium echinulatum 2HH and Penicillium oxalicum 114-2 Inferred by a Computational Biology Approach. Front Microbiol 2020; 11:588263. [PMID: 33193246 PMCID: PMC7652724 DOI: 10.3389/fmicb.2020.588263] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/23/2020] [Indexed: 11/29/2022] Open
Abstract
Penicillium echinulatum 2HH and Penicillium oxalicum 114-2 are well-known cellulase fungal producers. However, few studies addressing global mechanisms for gene regulation of these two important organisms are available so far. A recent finding that the 2HH wild-type is closely related to P. oxalicum leads to a combined study of these two species. Firstly, we provide a global gene regulatory network for P. echinulatum 2HH and P. oxalicum 114-2, based on TF-TG orthology relationships, considering three related species with well-known regulatory interactions combined with TFBSs prediction. The network was then analyzed in terms of topology, identifying TFs as hubs, and modules. Based on this approach, we explore numerous identified modules, such as the expression of cellulolytic and xylanolytic systems, where XlnR plays a key role in positive regulation of the xylanolytic system. It also regulates positively the cellulolytic system by acting indirectly through the cellodextrin induction system. This remarkable finding suggests that the XlnR-dependent cellulolytic and xylanolytic regulatory systems are probably conserved in both P. echinulatum and P. oxalicum. Finally, we explore the functional congruency on the genes clustered in terms of communities, where the genes related to cellular nitrogen, compound metabolic process and macromolecule metabolic process were the most abundant. Therefore, our approach allows us to confer a degree of accuracy regarding the existence of each inferred interaction.
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Affiliation(s)
- Alexandre Rafael Lenz
- Unidad Académica Yucatán, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de Mexico, Mérida, Mexico
- Laboratório de Bioinformática e Biologia Computacional, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
- Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Salvador, Brazil
| | - Edgardo Galán-Vásquez
- Departamento de Ingeniería de Sistemas Computacionales y Automatización, Instituto de Investigaciones en Matemàticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de Mexico, Ciudad Universitaria, Mexico
| | - Eduardo Balbinot
- Laboratório de Bioinformática e Biologia Computacional, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Fernanda Pessi de Abreu
- Laboratório de Bioinformática e Biologia Computacional, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Nikael Souza de Oliveira
- Laboratório de Bioinformática e Biologia Computacional, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
- Laboratório de Enzimas e Biomassas, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Letícia Osório da Rosa
- Laboratório de Enzimas e Biomassas, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Scheila de Avila e Silva
- Laboratório de Bioinformática e Biologia Computacional, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Marli Camassola
- Laboratório de Enzimas e Biomassas, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Aldo José Pinheiro Dillon
- Laboratório de Enzimas e Biomassas, Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, Brazil
| | - Ernesto Perez-Rueda
- Unidad Académica Yucatán, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de Mexico, Mérida, Mexico
- Facultad de Ciencias, Centro de Genómica y Bioinformática, Universidad Mayor, Santiago, Chile
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15
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Bermejo PM, Raghavendran V, Gombert AK. Neither 1G nor 2G fuel ethanol: setting the ground for a sugarcane-based biorefinery using an iSUCCELL yeast platform. FEMS Yeast Res 2020; 20:5836716. [PMID: 32401320 DOI: 10.1093/femsyr/foaa027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/11/2020] [Indexed: 11/12/2022] Open
Abstract
First-generation (1G) fuel ethanol production in sugarcane-based biorefineries is an established economic enterprise in Brazil. Second-generation (2G) fuel ethanol from lignocellulosic materials, though extensively investigated, is currently facing severe difficulties to become economically viable. Some of the challenges inherent to these processes could be resolved by efficiently separating and partially hydrolysing the cellulosic fraction of the lignocellulosic materials into the disaccharide cellobiose. Here, we propose an alternative biorefinery, where the sucrose-rich stream from the 1G process is mixed with a cellobiose-rich stream in the fermentation step. The advantages of mixing are 3-fold: (i) decreased concentrations of metabolic inhibitors that are typically produced during pretreatment and hydrolysis of lignocellulosic materials; (ii) decreased cooling times after enzymatic hydrolysis prior to fermentation; and (iii) decreased availability of free glucose for contaminating microorganisms and undesired glucose repression effects. The iSUCCELL platform will be built upon the robust Saccharomyces cerevisiae strains currently present in 1G biorefineries, which offer competitive advantage in non-aseptic environments, and into which intracellular hydrolyses of sucrose and cellobiose will be engineered. It is expected that high yields of ethanol can be achieved in a process with cell recycling, lower contamination levels and decreased antibiotic use, when compared to current 2G technologies.
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Affiliation(s)
| | - Vijayendran Raghavendran
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
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16
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de Ruijter JC, Igarashi K, Penttilä M. The Lipomyces starkeyi gene Ls120451 encodes a cellobiose transporter that enables cellobiose fermentation in Saccharomyces cerevisiae. FEMS Yeast Res 2020; 20:foaa019. [PMID: 32310262 PMCID: PMC7204792 DOI: 10.1093/femsyr/foaa019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 04/17/2020] [Indexed: 12/14/2022] Open
Abstract
Processed lignocellulosic biomass is a source of mixed sugars that can be used for microbial fermentation into fuels or higher value products, like chemicals. Previously, the yeast Saccharomyces cerevisiae was engineered to utilize its cellodextrins through the heterologous expression of sugar transporters together with an intracellular expressed β-glucosidase. In this study, we screened a selection of eight (putative) cellodextrin transporters from different yeast and fungal hosts in order to extend the catalogue of available cellobiose transporters for cellobiose fermentation in S. cerevisiae. We confirmed that several in silico predicted cellodextrin transporters from Aspergillus niger were capable of transporting cellobiose with low affinity. In addition, we found a novel cellobiose transporter from the yeast Lipomyces starkeyi, encoded by the gene Ls120451. This transporter allowed efficient growth on cellobiose, while it also grew on glucose and lactose, but not cellotriose nor cellotetraose. We characterized the transporter more in-depth together with the transporter CdtG from Penicillium oxalicum. CdtG showed to be slightly more efficient in cellobiose consumption than Ls120451 at concentrations below 1.0 g/L. Ls120451 was more efficient in cellobiose consumption at higher concentrations and strains expressing this transporter grew slightly slower, but produced up to 30% more ethanol than CdtG.
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Affiliation(s)
- Jorg C de Ruijter
- VTT Technical Research Centre of Finland, Tietotie 2, FI-02150 Espoo, Finland
| | - Kiyohiko Igarashi
- VTT Technical Research Centre of Finland, Tietotie 2, FI-02150 Espoo, Finland
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yajoi, Bunkyo, Tokyo 113–8657, Japan
| | - Merja Penttilä
- VTT Technical Research Centre of Finland, Tietotie 2, FI-02150 Espoo, Finland
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17
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Li CX, Zhao S, Luo XM, Feng JX. Weighted Gene Co-expression Network Analysis Identifies Critical Genes for the Production of Cellulase and Xylanase in Penicillium oxalicum. Front Microbiol 2020; 11:520. [PMID: 32292397 PMCID: PMC7118919 DOI: 10.3389/fmicb.2020.00520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/10/2020] [Indexed: 11/25/2022] Open
Abstract
Genes involved in cellular processes undergo environment-dependent co-regulation, but the co-expression patterns of fungal cellulase and xylanase-encoding genes remain unclear. Here, we identified two novel carbon sources, methylcellulose and 2-hydroxyethyl cellulose, which efficiently induced the secretion of cellulases and xylanases in Penicillium oxalicum. Comparative transcriptomic analyses identified carbon source-specific transcriptional patterns, mainly including major cellulase and xylanase-encoding genes, genes involved in glycolysis/gluconeogenesis and the tricarboxylic acid cycle, and genes encoding transcription factors, transporters and G protein-coupled receptors. Moreover, the weighted correlation network analysis of time-course transcriptomes, generated 17 highly connected modules. Module MEivory, comprising 120 members, included major cellulase and xylanase-encoding genes, genes encoding the key regulators PoxClrB and PoxXlnR, and a cellodextrin transporter POX06051/CdtC, which were tightly correlated with the filter-paper cellulase, carboxymethylcellulase and xylanase activities in P. oxalicum. An expression kinetic analysis indicated that members in MEivory were activated integrally by carbon sources, but their expressional levels were carbon source- and/or induction duration-dependent. Three uncharacterized regulatory genes in MEivory were identified, which regulate the production of cellulases and xylanases in P. oxalicum. These findings provide insights into the mechanisms associated with the synthesis and secretion of fungal cellulases and xylanases, and a guide for P. oxalicum application in biotechnology.
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Affiliation(s)
- Cheng-Xi Li
- 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, 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, China
| | - Xue-Mei Luo
- 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, 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, China
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18
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Lin H, Zhao J, Zhang Q, Cui S, Fan Z, Chen H, Tian C. Identification and Characterization of a Cellodextrin Transporter in Aspergillus niger. Front Microbiol 2020; 11:145. [PMID: 32117164 PMCID: PMC7020610 DOI: 10.3389/fmicb.2020.00145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 01/21/2020] [Indexed: 11/13/2022] Open
Abstract
Aspergillus niger produces a wide spectrum of extracellular polysaccharide hydrolases that hydrolyze cellulose into soluble glucose and cellodextrins. Transporters are essential for sugar uptake, yet it is not clear whether cellodextrin transporters exist in A. niger. Here, one cellulose inducible cellodextrin transporter CtA was identified in A. niger B2. It was found that CtA not only could transport cellobiose, but also cellotriose, cellotetraose, and cellopentaose. The yeast strain YPβG-CtA, expressing cellodextrin transporter CtA and an intracellular β-glucosidase, grew on cellobiose with the cell growth rate of 0.0830 ± 0.0113 h–1 under aerobic condition. Furthermore, the engineered yeast could produce 1.1 g/L ethanol anaerobically on cellobiose in 2 days. The identification of CtA provides evidence that the cellodextrin uptake is a complementary strategy of cellulose utilization in A. niger, and the CtA could be a strong transporter candidate for constructing engineered cellodextrin-utilizing microorganisms.
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Affiliation(s)
- Hui Lin
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Jun Zhao
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Qingqing Zhang
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Shixiu Cui
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Zhiliang Fan
- Department of Biological and Agricultural Engineering, University of California, Davis, Davis, CA, United States
| | - Hongge Chen
- College of Life Sciences, Henan Agricultural University, Zhengzhou, China
| | - Chaoguang Tian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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19
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Havukainen S, Valkonen M, Koivuranta K, Landowski CP. Studies on sugar transporter CRT1 reveal new characteristics that are critical for cellulase induction in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:158. [PMID: 32944074 PMCID: PMC7491124 DOI: 10.1186/s13068-020-01797-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/03/2020] [Indexed: 05/08/2023]
Abstract
BACKGROUND Trichoderma reesei is an ascomycete fungus that has a tremendous capability of secreting extracellular proteins, mostly lignocellulose-degrading enzymes. Although many aspects of the biology of this organism have been unfolded, the roles of the many sugar transporters coded in its genome are still a mystery with a few exceptions. One of the most interesting sugar transporters that has thus far been discovered is the cellulose response transporter 1 (CRT1), which has been suggested to be either a sugar transporter or a sensor due to its seemingly important role in cellulase induction. RESULTS Here we show that CRT1 is a high-affinity cellobiose transporter, whose function can be complemented by the expression of other known cellobiose transporters. Expression of two sequence variants of the crt1 gene in Saccharomyces cerevisiae revealed that only the variant listed in the RUT-C30 genome annotation has the capability to transport cellobiose and lactose. When expressed in the Δ crt1 strain, the variant listed in the QM6a genome annotation offers partial complementation of the cellulase induction, while the expression of the RUT-C30 variant or cellobiose transporters from two other fungal species fully restore the cellulase induction. CONCLUSIONS These results add to our knowledge about the fungal metabolism of cellulose-derived oligosaccharides, which have the capability of inducing the cellulase production in many species. They also help us to deepen our understanding of the T. reesei lactose metabolism, which can have important consequences as this sugar is used as the inducer of protein secretion in many industrial processes which employ this species.
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Affiliation(s)
- Sami Havukainen
- VTT Technical Research Center of Finland Ltd, Tietotie 2, 02150 Espoo, Finland
| | - Mari Valkonen
- VTT Technical Research Center of Finland Ltd, Tietotie 2, 02150 Espoo, Finland
| | - Kari Koivuranta
- VTT Technical Research Center of Finland Ltd, Tietotie 2, 02150 Espoo, Finland
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Liao LS, Li CX, Zhang FF, Yan YS, Luo XM, Zhao S, Feng JX. How an essential Zn2Cys6 transcription factor PoxCxrA regulates cellulase gene expression in ascomycete fungi? BIOTECHNOLOGY FOR BIOFUELS 2019; 12:105. [PMID: 31073329 PMCID: PMC6498484 DOI: 10.1186/s13068-019-1444-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 04/16/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Soil ascomycete fungi produce plant-biomass-degrading enzymes to facilitate nutrient and energy uptake in response to exogenous stress. This is controlled by a complex signal network, but the regulatory mechanisms are poorly understood. An essential Zn2Cys6 transcription factor (TF) PoxCxrA was identified to be required for cellulase and xylanase production in Penicillium oxalicum. The genome-wide regulon and DNA binding sequences of PoxCxrA were further identified through RNA-Sequencing, DNase I footprinting experiments and in vitro electrophoretic mobility shift assays. Moreover, a minimal DNA-binding domain in PoxCxrA was recognised. RESULTS A PoxCxrA regulon of 1970 members was identified in P. oxalicum, and it was displayed that PoxCxrA regulated the expression of genes encoding major plant cell wall-degrading enzymes, as well as important cellodextrin and/or glucose transporters. Interestingly, PoxCxrA positively regulated the expression of a known important TF PoxClrB. DNase I footprinting experiments and in vitro electrophoretic mobility shift assays further revealed that PoxCxrA directly bound the promoter regions of PoxClrB and a cellobiohydrolase gene cbh1 (POX05587/Cel7A-2) at different nucleic acid sequences. Remarkably, PoxCxrA autoregulated its own PoxCxrA gene expression. Additionally, a minimal 42-amino-acid PoxCxrA DNA-binding domain was identified. CONCLUSION PoxCxrA could directly regulate the expression of cellulase genes and the regulatory gene PoxClrB via binding their promoters at different nucleic acid sequences. This work expands the diversity of DNA-binding motifs known to be recognised by Zn2Cys6 TFs, and demonstrates novel regulatory mechanisms of fungal cellulase gene expression.
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Affiliation(s)
- Lu-Sheng Liao
- 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Cheng-Xi Li
- 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Feng-Fei Zhang
- 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Yu-Si Yan
- 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Xue-Mei Luo
- 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of 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, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
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21
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Cellobiose fermentation by Saccharomyces cerevisiae: Comparative analysis of intra versus extracellular sugar hydrolysis. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Wang Y, Ji H, Hu Y, Wang R, Rui J, Guo S. Different Selectivity in Fungal Communities Between Manure and Mineral Fertilizers: A Study in an Alkaline Soil After 30 Years Fertilization. Front Microbiol 2018; 9:2613. [PMID: 30429841 PMCID: PMC6220076 DOI: 10.3389/fmicb.2018.02613] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 10/12/2018] [Indexed: 11/24/2022] Open
Abstract
Fertilizer application has contributed substantially to increasing crop yield. Despite the important role of soil fungi in agricultural production, we still have limited understanding of the complex responses of fungal taxonomic and functional groups to organic and mineral fertilization in long term. Here we report the responses of the fungal communities in an alkaline soil to 30-year application of mineral fertilizer (NP), organic manure (M) and combined fertilizer (NPM) by the Illumina HiSeq sequencing and quantitative real-time PCR to target fungal internal transcribed spacer (ITS) genes. The results show: (1) compared to the unfertilized soil, fertilizer application increased fungal diversity and ITS gene copy numbers, and shifted fungal community structure. Such changes were more pronounced in the M and NPM soils than in the NP soil (except for fungal diversity), which can be largely attributed to the manure induced greater increases in soil total organic C, total N and available P. (2) Compared to the unfertilized soil, the NP and NPM soils reduced the proportion of saprotrophs by 40%, the predominant taxa of which may potentially affect cellulose decomposition. (3) Indicator species analysis suggested that the indicator operational taxonomic units (OTUs) in the M soil occupied 25.6% of its total community, but that only accounted for 0.9% in the NP soil. Our findings suggest that fertilization-induced changes of total fungal community were more responsive to organic manure than mineral fertilizer. The reduced proportion of cellulose decomposition-related saprotrophs in mineral fertilizer treatments may potentially contribute to increasing their soil C stocks.
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Affiliation(s)
- Ying Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
| | - Hongfei Ji
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
| | - Yaxian Hu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
| | - Rui Wang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
| | - Junpeng Rui
- Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Shengli Guo
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, China
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Hu Y, Yan X, Zhang H, Liu J, Luo F, Cui Y, Wang W, Zhou Y. Cloning and expression of a novel α-1,3-arabinofuranosidase from Penicillium oxalicum sp. 68. AMB Express 2018; 8:51. [PMID: 29611040 PMCID: PMC5880795 DOI: 10.1186/s13568-018-0577-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 03/24/2018] [Indexed: 01/11/2023] Open
Abstract
The discovery and creation of biocatalysts for plant biomass conversion are essential for industrial demand and scientific research of the plant cell wall. α-1,2 and α-1,3-L-arabinofuranosidases are debranching enzymes that catalyzing hydrolytic release of α-L-arabinofuranosyl residues in plant cell wall. Gene database analyses shows that GH62 family only contains specific α-L-arabinofuranosidases that play an important role in the degradation and structure of the plant cell wall. At present, there are only 22 enzymes in this group has been characterized. In this study, we cloned a novel α-1,3-arabinofuranosidase gene (poabf62a) belonging to glycoside hydrolase family 62 from Penicillium oxalicum sp. 68 and expressed it in Pichia pastoris. The molecular mass of recombinant PoAbf62A was estimated to be 32.9 kDa. Using p-nitrophenyl-α-l-arabinofuranoside (pNPαAbf) as substrate, purified PoAbf62A exhibited an optimal pH of 4.5 and temperature of 35 °C. Results of methylation and 13C NMR analyses showed that PoAbf62A was exclusively α-1,3-arabinofuranosidase, specific for cleavage of α-1,3-arabinofuranosyl residues, and with the absence of activity towards α-1,2-arabinofuranose and α-1,5-arabinofuranose. Therefore, PoAbf62A exhibits high activity on sugar beet arabinan and wheat arabinoxylan, because their branched side chain are decorated with α-1,3-arabinofuranose. On the other hand, there is a lack of activity with linear-α-L-1,5-arabinan and xylan that only contained α-L-1,5-arabinofuranose or β-1,4-xylose. The α-1,3-arabinofuranosidase activity identified here provides a new biocatalytic tool to degrade hemicellulose and analyze the structure of plant cell walls.
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Li Z, Liu G, Qu Y. Improvement of cellulolytic enzyme production and performance by rational designing expression regulatory network and enzyme system composition. BIORESOURCE TECHNOLOGY 2017; 245:1718-1726. [PMID: 28684177 DOI: 10.1016/j.biortech.2017.06.120] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Filamentous fungi are considered as the most efficient producers expressing lignocellulose-degrading enzymes. Penicillium oxalicum strains possess extraordinary fungal lignocellulolytic enzyme systems and can efficiently utilize plant biomass. In recent years, the regulatory aspects of production of hydrolytic enzymes by P. oxalicum have been well established. This review aims to discuss the recent developments for the production of lignocellulolytic enzymes by P. oxalicum. The main cellulolytic transcription factors mediating the complex transcriptional-regulatory network are highlighted. The genome-wide identification of cellulolytic transcription factors, the cascade regulation network for cellulolytic gene expression, and the synergistic and dose-controlled regulation by cellulolytic regulators are discussed. A cellulase regulatory network sensitive to inducers in intracellular environments, the cross-talk of regulation of lignocellulose-degrading enzyme and amylase, and accessory enzymes are also demonstrated. Finally, strategies for the metabolic engineering of P. oxalicum, which show promising applications in the enzymatic hydrolysis for biochemical production, are established.
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Affiliation(s)
- Zhonghai Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China; Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qi Lu University of Technology, Jinan 250353, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
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Parisutham V, Chandran SP, Mukhopadhyay A, Lee SK, Keasling JD. Intracellular cellobiose metabolism and its applications in lignocellulose-based biorefineries. BIORESOURCE TECHNOLOGY 2017; 239:496-506. [PMID: 28535986 DOI: 10.1016/j.biortech.2017.05.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/27/2017] [Accepted: 05/01/2017] [Indexed: 05/28/2023]
Abstract
Complete hydrolysis of cellulose has been a key characteristic of biomass technology because of the limitation of industrial production hosts to use cellodextrin, the partial hydrolysis product of cellulose. Cellobiose, a β-1,4-linked glucose dimer, is a major cellodextrin of the enzymatic hydrolysis (via endoglucanase and exoglucanase) of cellulose. Conversion of cellobiose to glucose is executed by β-glucosidase. The complete extracellular hydrolysis of celluloses has several critical barriers in biomass technology. An alternative bioengineering strategy to make the bioprocessing less challenging is to engineer microbes with the abilities to hydrolyze and assimilate the cellulosic-hydrolysate cellodextrin. Microorganisms engineered to metabolize cellobiose rather than the monomeric glucose can provide several advantages for lignocellulose-based biorefineries. This review describes the recent advances and challenges in engineering efficient intracellular cellobiose metabolism in industrial hosts. This review also describes the limitations of and future prospectives in engineering intracellular cellobiose metabolism.
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Affiliation(s)
- Vinuselvi Parisutham
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Sathesh-Prabu Chandran
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, Emeryville, CA 94608, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Sung Kuk Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea; School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| | - Jay D Keasling
- Joint BioEnergy Institute, Emeryville, CA 94608, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Chemical and Biomolecular Engineering & Department of Bioengineering, UC Berkeley, Berkeley, CA 94720, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, KogleAllé, DK2970 Hørsholm, Denmark; Synthetic Biology Engineering Research Center (Synberc), Berkeley, CA 94720, USA
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26
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Li CX, Zhao S, Zhang T, Xian L, Liao LS, Liu JL, Feng JX. Genome sequencing and analysis of Talaromyces pinophilus provide insights into biotechnological applications. Sci Rep 2017; 7:490. [PMID: 28352091 PMCID: PMC5428652 DOI: 10.1038/s41598-017-00567-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/03/2017] [Indexed: 11/09/2022] Open
Abstract
Species from the genus Talaromyces produce useful biomass-degrading enzymes and secondary metabolites. However, these enzymes and secondary metabolites are still poorly understood and have not been explored in depth because of a lack of comprehensive genetic information. Here, we report a 36.51-megabase genome assembly of Talaromyces pinophilus strain 1-95, with coverage of nine scaffolds of eight chromosomes with telomeric repeats at their ends and circular mitochondrial DNA. In total, 13,472 protein-coding genes were predicted. Of these, 803 were annotated to encode enzymes that act on carbohydrates, including 39 cellulose-degrading and 24 starch-degrading enzymes. In addition, 68 secondary metabolism gene clusters were identified, mainly including T1 polyketide synthase genes and nonribosomal peptide synthase genes. Comparative genomic analyses revealed that T. pinophilus 1-95 harbors more biomass-degrading enzymes and secondary metabolites than other related filamentous fungi. The prediction of the T. pinophilus 1-95 secretome indicated that approximately 50% of the biomass-degrading enzymes are secreted into the extracellular environment. These results expanded our genetic knowledge of the biomass-degrading enzyme system of T. pinophilus and its biosynthesis of secondary metabolites, facilitating the cultivation of T. pinophilus for high production of useful products.
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Affiliation(s)
- Cheng-Xi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Ting Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Liang Xian
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Lu-Sheng Liao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Jun-Liang Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi, 530004, People's Republic of China.
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Yan YS, Zhao S, Liao LS, He QP, Xiong YR, Wang L, Li CX, Feng JX. Transcriptomic profiling and genetic analyses reveal novel key regulators of cellulase and xylanase gene expression in Penicillium oxalicum. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:279. [PMID: 29201143 PMCID: PMC5700522 DOI: 10.1186/s13068-017-0966-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 11/10/2017] [Indexed: 05/07/2023]
Abstract
BACKGROUND The transition to a more environmentally friendly economy has prompted studies of modern biorefineries, including the utilization of low-value lignocellulose. The major challenge facing the widespread application of biorefineries is the high cost of enzymes that can efficiently hydrolyze recalcitrant cellulose to sugars. Penicillium oxalicum produces large amounts of plant-cell-wall-degrading enzymes, but their production is tightly controlled by complex regulatory networks, resulting in low yields of the native enzymes. Regulatory genes have been the targets of genetic engineering to improve enzyme production in microorganisms. In this study, we used transcriptomic profiling and genetic analyses to screen for and identify novel key regulators of cellulase and xylanase gene expression in P. oxalicum. RESULTS A comparative analysis of the transcriptomes of P. oxalicum HP7-1 on different carbon sources, including glucose, wheat bran, and wheat bran plus Avicel, identified 40 candidate genes regulating the expression of cellulolytic enzyme genes. Deletion mutants of 31 candidate genes were constructed in P. oxalicum ∆PoxKu70 and 11 resultant mutants showed significant changes in their filter-paper cellulase production compared with the parental strain ∆PoxKu70. Among these 11 mutants, ΔPoxCxrA, ΔPoxCxrB, and ΔPoxNsdD showed the most significant reduction in the enzyme production (96.8, 75.9, and 58.5%, respectively). Ten of these 11 genes are here reported to be involved in cellulase production for the first time. Further tests revealed that ΔPoxCxrA, ΔPoxCxrB, and ΔPoxNsdD displayed significantly reduced xylanase production, whereas ΔPoxCxrA produced negligible xylanase. Interestingly, ΔPoxCxrB and ΔPoxNsdD showed significantly increased β-glucosidase production. Real-time quantitative reverse transcription-PCR and an electrophoretic mobility shift assay (EMSA) showed that PoxCxrA, PoxCxrB, and PoxNsdD regulate the expression of one another, but the mode of regulation changes dynamically during the growth of fungal cells in the presence of cellulose. EMSA showed that PoxCxrA, PoxCxrB, and PoxNsdD directly bind the putative promoters of major cellulase and xylanase genes. CONCLUSIONS We have detected and identified three key new regulatory genes, PoxCxrA, PoxCxrB, and PoxNsdD, that directly and indirectly regulate the expression of cellulase and xylanase genes in P. oxalicum. This study provides novel insights into the regulatory mechanisms of fungal cellulase and xylanase gene expression.
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Affiliation(s)
- Yu-Si Yan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Lu-Sheng Liao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Qi-Peng He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Ya-Ru Xiong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Long Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Cheng-Xi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
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Antoniêto ACC, de Paula RG, Castro LDS, Silva-Rocha R, Persinoti GF, Silva RN. Trichoderma reesei CRE1-mediated Carbon Catabolite Repression in Re-sponse to Sophorose Through RNA Sequencing Analysis. Curr Genomics 2016; 17:119-31. [PMID: 27226768 PMCID: PMC4864841 DOI: 10.2174/1389202917666151116212901] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 01/10/2023] Open
Abstract
Carbon catabolite repression (CCR) mediated by CRE1 in Trichoderma reesei emerged as a mechanism by which the fungus could adapt to new environments. In the presence of readily available carbon sources such as glucose, the fungus activates this mechanism and inhibits the production of cellulolytic complex enzymes to avoid unnecessary energy expenditure. CCR has been well described for the growth of T. reesei in cellulose and glucose, however, little is known about this process when the carbon source is sophorose, one of the most potent inducers of cellulase production. Thus, we performed high-throughput RNA sequencing to better understand CCR during cellulase formation in the presence of sophorose, by comparing the mutant ∆cre1 with its parental strain, QM9414. Of the 9129 genes present in the genome of T. reesei, 184 were upregulated and 344 downregulated in the mutant strain ∆cre1 compared to QM9414. Genes belonging to the CAZy database, and those encoding transcription factors and transporters are among the gene classes that were repressed by CRE1 in the presence of sophorose; most were possible indirectly regulated by CRE1. We also observed that CRE1 activity is carbon-dependent. A recent study from our group showed that in cellulose, CRE1 repress different groups of genes when compared to sophorose. CCR differences between these carbon sources may be due to the release of cellodextrins in the cellulose polymer, resulting in different targets of CRE1 in both carbon sources. These results contribute to a better understanding of CRE1-mediated CCR in T. reesei when glucose comes from a potent inducer of cellulase production such as sophorose, which could prove useful in improving cellulase production by the biotechnology sector.
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Affiliation(s)
- Amanda Cristina Campos Antoniêto
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo 14049-900, Ribeirão Preto, SP, Brazil
| | - Renato Graciano de Paula
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo 14049-900, Ribeirão Preto, SP, Brazil
| | - Lílian Dos Santos Castro
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo 14049-900, Ribeirão Preto, SP, Brazil
| | - Rafael Silva-Rocha
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo 14049-900, Ribeirão Preto, SP, Brazil
| | - Gabriela Felix Persinoti
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional, de Pesquisa em Energia e Materiais (CNPEM), Campinas, São Paulo, Brazil
| | - Roberto Nascimento Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo 14049-900, Ribeirão Preto, SP, Brazil
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Yao G, Wu R, Kan Q, Gao L, Liu M, Yang P, Du J, Li Z, Qu Y. Production of a high-efficiency cellulase complex via β-glucosidase engineering in Penicillium oxalicum. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:78. [PMID: 27034716 PMCID: PMC4815182 DOI: 10.1186/s13068-016-0491-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/18/2016] [Indexed: 05/07/2023]
Abstract
BACKGROUND Trichoderma reesei is a widely used model cellulolytic fungus, supplying a highly effective cellulase production system. Recently, the biofuel industry discovered filamentous fungi from the Penicillium genus as a promising alternative to T. reesei. RESULTS In our study, we present a systematic over-expression analysis of nine β-glucosidase encoding genes in the wild-type strain 114-2 of Penicillium oxalicum. We found that the over-expression of BGL1, BGL4, or BGL5 significantly enhanced both β-glucosidase activity and hydrolysis efficiency of the enzyme system on filter paper. We utilised two strategies to over-express β-glucosidase in the strain RE-10 that-although over-producing cellulase, does so at the cost of the cellulase mixture deficiency. The constitutive promoter of gene pde_02864 encoding 40S ribosomal protein S8 was used to over-express three β-glucosidases: BGL1, BGL4, and BGL5. We found that all mutants show significantly enhanced levels of β-glucosidase at transcriptional, protein, and activity levels. Furthermore, the inducible promoter from bgl2 was used to conditionally over-express the β-glucosidases BGL1 and BGL4. Surprisingly, this induced expression strategy enables significantly improved expression efficiency. The BGL1 over-expressing mutant I1-13 particularly improved the β-glucosidase activity at a factor of 65-folds, resulting in levels of up to 150 U/ml. All our BGL over-expression mutants displayed significant enhancement of cellulolytic ability on both microcrystalline cellulose and filter paper. In addition, they substantially reduced the enzyme loads in the saccharification of a natural lignocellulose material delignified corncob residue (DCCR). The mutant I4-32 with over-expression of BGL4 achieved the highest glucose yield in the saccharification of DCCR at only 25 % enzyme load compared to the parental strain RE-10. CONCLUSIONS In summary, genetically engineering P. oxalicum to significantly improve β-glucosidase activity is a potent strategy to substantially boost the hydrolytic efficiency of the cellulase cocktail, which will ultimately lead to a considerable reduction of cost for biomass-based biofuel.
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Affiliation(s)
- Guangshan Yao
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Ruimei Wu
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Qinbiao Kan
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Liwei Gao
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Meng Liu
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Piao Yang
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Jian Du
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
| | - Zhonghai Li
- />Department of Bioengineering, Qilu University of Technology, Jinan City, 250353 Shandong Province China
| | - Yinbo Qu
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, 250100 Shandong Province China
- />National Glycoengineering Research Center, Shandong University, Jinan City, 250100 Shandong Province China
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Yao G, Li Z, Wu R, Qin Y, Liu G, Qu Y. Penicillium oxalicum PoFlbC regulates fungal asexual development and is important for cellulase gene expression. Fungal Genet Biol 2016; 86:91-102. [DOI: 10.1016/j.fgb.2015.12.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/25/2022]
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Zhao S, Yan YS, He QP, Yang L, Yin X, Li CX, Mao LC, Liao LS, Huang JQ, Xie SB, Nong QD, Zhang Z, Jing L, Xiong YR, Duan CJ, Liu JL, Feng JX. Comparative genomic, transcriptomic and secretomic profiling of Penicillium oxalicum HP7-1 and its cellulase and xylanase hyper-producing mutant EU2106, and identification of two novel regulatory genes of cellulase and xylanase gene expression. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:203. [PMID: 27688806 PMCID: PMC5035457 DOI: 10.1186/s13068-016-0616-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 09/14/2016] [Indexed: 05/07/2023]
Abstract
BACKGROUND The filamentous fungus Penicillium oxalicum is a potential alternative to Trichoderma reesei for industrial production of a complete cellulolytic enzyme system for a bio-refinery. Comparative omics approaches can support rational genetic engineering and/or breeding of filamentous fungi with improved cellulase production capacity. In this study, comparative genomic, transcriptomic and secretomic profiling of P. oxalicum HP7-1 and its cellulase and xylanase hyper-producing mutant EU2106 were employed to screen for novel regulators of cellulase and xylanase gene expression. RESULTS The 30.62 Mb P. oxalicum HP7-1 genome was sequenced, and 9834 protein-coding genes were annotated. Re-sequencing of the mutant EU2106 genome identified 274 single nucleotide variations and 12 insertion/deletions. Comparative genomic, transcriptomic and secretomic profiling of HP7-1 and EU2106 revealed four candidate regulators of cellulase and xylanase gene expression. Deletion of these candidate genes and measurement of the enzymatic activity of the resultant mutants confirmed the identity of three regulatory genes. POX02484 and POX08522, encoding a putative Zn(II)2Cys6 DNA-binding domain and forkhead protein, respectively, were found to be novel, while PoxClrB is an ortholog of ClrB, a key transcriptional regulator of cellulolytic enzyme gene expression in filamentous fungi. ΔPOX02484 and ΔPOX08522 mutants exhibited significantly reduced β-glucosidase activity, increased carboxymethylcellulose cellulase and xylanase activities, and altered transcription level of cellulase and xylanase genes compared with the parent strain ΔPoxKu70, with Avicel as the sole carbon source. CONCLUSIONS Two novel genes, POX02484 and POX08522, were found and characterized to regulate the expression of cellulase and xylanase genes in P. oxalicum. These findings are important for engineering filamentous fungi to improve cellulase and xylanase production.
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Affiliation(s)
- Shuai Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Yu-Si Yan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Qi-Peng He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Lin Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Xin Yin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Cheng-Xi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Li-Chun Mao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Lu-Sheng Liao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Jin-Qun Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Shang-Bo Xie
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Qing-Dong Nong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Zheng Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Lei Jing
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Ya-Ru Xiong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Cheng-Jie Duan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Jun-Liang Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
| | - Jia-Xun Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004 Guangxi People’s Republic of China
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Li Z, Yao G, Wu R, Gao L, Kan Q, Liu M, Yang P, Liu G, Qin Y, Song X, Zhong Y, Fang X, Qu Y. Synergistic and Dose-Controlled Regulation of Cellulase Gene Expression in Penicillium oxalicum. PLoS Genet 2015; 11:e1005509. [PMID: 26360497 PMCID: PMC4567317 DOI: 10.1371/journal.pgen.1005509] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 08/17/2015] [Indexed: 11/24/2022] Open
Abstract
Filamentous fungus Penicillium oxalicum produces diverse lignocellulolytic enzymes, which are regulated by the combinations of many transcription factors. Here, a single-gene disruptant library for 470 transcription factors was constructed and systematically screened for cellulase production. Twenty transcription factors (including ClrB, CreA, XlnR, Ace1, AmyR, and 15 unknown proteins) were identified to play putative roles in the activation or repression of cellulase synthesis. Most of these regulators have not been characterized in any fungi before. We identified the ClrB, CreA, XlnR, and AmyR transcription factors as critical dose-dependent regulators of cellulase expression, the core regulons of which were identified by analyzing several transcriptomes and/or secretomes. Synergistic and additive modes of combinatorial control of each cellulase gene by these regulatory factors were achieved, and cellulase expression was fine-tuned in a proper and controlled manner. With one of these targets, the expression of the major intracellular β-glucosidase Bgl2 was found to be dependent on ClrB. The Bgl2-deficient background resulted in a substantial gene activation by ClrB and proved to be closely correlated with the relief of repression mediated by CreA and AmyR during cellulase induction. Our results also signify that probing the synergistic and dose-controlled regulation mechanisms of cellulolytic regulators and using it for reconstruction of expression regulation network (RERN) may be a promising strategy for cellulolytic fungi to develop enzyme hyper-producers. Based on our data, ClrB was identified as focal point for the synergistic activation regulation of cellulase expression by integrating cellulolytic regulators and their target genes, which refined our understanding of transcriptional-regulatory network as a “seesaw model” in which the coordinated regulation of cellulolytic genes is established by counteracting activators and repressors. Cellulolytic fungi have evolved into sophisticated lignocellulolytic systems to adapt to their natural habitat. This trait is important for filamentous fungi, which are the main source of cellulases utilized to degrade lignocellulose to fermentable sugars. Penicillium oxalicum, which produces lignocellulolytic enzymes with more diverse components than Trichoderma reesei, has the capacity to secrete large amounts of cellulases. Meanwhile, cellulase expression is regulated by a complex network involved in many transcription factors in this organism. To better understand how cellulase genes are systematically regulated in P. oxalicum, we employed molecular genetics to uncover the cellulolytic transcription factors on a genome-wide scale. We discovered the synergistic and tunable regulation of cellulase expression by integrating cellulolytic regulators and their target genes, which refined our understanding of transcriptional-regulatory network as a “seesaw model” in which the coordinated regulation of cellulolytic genes is established by counteracting activators and repressors.
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Affiliation(s)
- Zhonghai Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Guangshan Yao
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Ruimei Wu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Liwei Gao
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Qinbiao Kan
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Meng Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Piao Yang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Yuqi Qin
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
- National Glycoengineering Research Center, Shandong University, Jinan, Shandong, China
| | - Xin Song
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Xu Fang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, Shandong, China
- National Glycoengineering Research Center, Shandong University, Jinan, Shandong, China
- * E-mail:
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Chen R. A paradigm shift in biomass technology from complete to partial cellulose hydrolysis: lessons learned from nature. Bioengineered 2015; 6:69-72. [PMID: 25587851 DOI: 10.1080/21655979.2014.1004019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A key characteristic of current biomass technology is the requirement for complete hydrolysis of cellulose and hemicellulose, which stems from the inability of microbial strains to use partially hydrolyzed cellulose, or cellodextrin. The complete hydrolysis paradigm has been practiced over the past 4 decades with major enzyme companies perfecting their cellulase mix for maximal yield of monosaccharides, with corresponding efforts in strain development focus almost solely on the conversion of monosaccharides, not cellodextrin, to products. While still in its nascent infancy, a new paradigm requiring only partial hydrolysis has begun to take hold, promising a shift in the biomass technology at its fundamental core. The new paradigm has the potential to reduce the requirement for cellulase enzymes in the hydrolysis step and provides new strategies for metabolic engineers, synthetic biologists and alike in engineering fermenting organisms. Several recent publications reveal that microorganisms engineered to metabolize cellodextrins, rather than monomer glucose, can reap significant energy gains in both uptake and subsequent phosphorylation. These energetic benefits can in turn be directed for enhanced robustness and increased productivity of a bioprocess. Furthermore, the new cellodextrin metabolism endows the biocatalyst the ability to evade catabolite repression, a cellular regulatory mechanism that is hampering rapid conversion of biomass sugars to products. Together, the new paradigm offers significant advantages over the old and promises to overcome several critical barriers in biomass technology. More research, however, is needed to realize these promises, especially in discovery and engineering of cellodextrin transporters, in developing a cost-effective method for cellodextrin generation, and in better integration of cellodextrin metabolism to endogenous glycolysis.
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Affiliation(s)
- Rachel Chen
- a School of Chemical and Biomolecular Engineering; Georgia Institute of Technology ; Atlanta , GA USA
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Yao G, Li Z, Gao L, Wu R, Kan Q, Liu G, Qu Y. Redesigning the regulatory pathway to enhance cellulase production in Penicillium oxalicum. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:71. [PMID: 25949521 PMCID: PMC4422585 DOI: 10.1186/s13068-015-0253-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 04/09/2015] [Indexed: 05/05/2023]
Abstract
BACKGROUND In cellulolytic fungi, induction and repression mechanisms synchronously regulate the synthesis of cellulolytic enzymes for accurate responses to carbon sources in the environment. Many proteins, particularly transcription regulatory factors involved in these processes, were identified and genetically engineered in Penicillium oxalicum and other cellulolytic fungi. Despite such great efforts, its effect of modifying a single target to improve the production of cellulase is highly limited. RESULTS In this study, we developed a systematic strategy for the genetic engineering of P. oxalicum to enhance cellulase yields, by enhancing induction (by blocking intracellular inducer hydrolysis and increasing the activator level) and relieving the repression. We obtained a trigenic recombinant strain named 'RE-10' by deleting bgl2 and creA, along with over-expressing the gene clrB. The cellulolytic ability of RE-10 was significantly improved; the filter paper activity and extracellular protein concentration increased by up to over 20- and 10-fold, respectively, higher than those of the wild-type (WT) strain 114-2 both on pure cellulose and complex wheat bran media. Most strikingly, the cellulolytic ability of RE-10 was comparable with that of the industrial P. oxalicum strain JU-A10-T obtained by random mutagenesis. Comparative proteomics analysis provided further insights into the differential secretomes between RE-10 and WT strains. In particular, the enzymes and accessory proteins involved in lignocellulose degradation were elevated specifically and dramatically in the recombinant, thereby confirming the importance of them in biomass deconstruction and implying a possible co-regulatory mechanism. CONCLUSIONS We established a novel route to substantially improve cellulolytic enzyme production up to the industrial level in P. oxalicum by combinational manipulation of three key genes to amplify the induction along with derepression, representing a milestone in strain engineering of filamentous fungi. Given the conservation in the mode of cellulose expression regulation among filamentous fungi, this strategy could be compatible with other cellulase-producing fungi.
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Affiliation(s)
- Guangshan Yao
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
| | - Zhonghai Li
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
- />Qingdao Vland Biotech Group Co. Ltd., Shandong Expressway Mansion, Miaoling Road, Qingdao, Shandong China
| | - Liwei Gao
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
| | - Ruimei Wu
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
| | - Qinbiao Kan
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
| | - Guodong Liu
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
| | - Yinbo Qu
- />State Key Laboratory of Microbial Technology, Shandong University, Jinan City, Shandong Province 250100 China
- />National Glycoengineering Research Center, Shandong University, Jinan City, Shandong Province 250100 China
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Cai P, Wang B, Ji J, Jiang Y, Wan L, Tian C, Ma Y. The putative cellodextrin transporter-like protein CLP1 is involved in cellulase induction in Neurospora crassa. J Biol Chem 2014; 290:788-96. [PMID: 25398875 DOI: 10.1074/jbc.m114.609875] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Neurospora crassa recently has become a novel system to investigate cellulase induction. Here, we discovered a novel membrane protein, cellodextrin transporter-like protein 1 (CLP1; NCU05853), a putative cellodextrin transporter-like protein that is a critical component of the cellulase induction pathway in N. crassa. Although CLP1 protein cannot transport cellodextrin, the suppression of cellulase induction by this protein was discovered on both cellobiose and Avicel. The co-disruption of the cellodextrin transporters cdt2 and clp1 in strain Δ3βG formed strain CPL7. With induction by cellobiose, cellulase production was enhanced 6.9-fold in CPL7 compared with Δ3βG. We also showed that the suppression of cellulase expression by CLP1 occurred by repressing the expression of cellodextrin transporters, particularly cdt1 expression. Transcriptome analysis of the hypercellulase-producing strain CPL7 showed that the cellulase expression machinery was dramatically stimulated, as were the cellulase enzyme genes including the inducer transporters and the major transcriptional regulators.
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Affiliation(s)
- Pengli Cai
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Bang Wang
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jingxiao Ji
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yongsheng Jiang
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Li Wan
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Chaoguang Tian
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yanhe Ma
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
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Cai P, Gu R, Wang B, Li J, Wan L, Tian C, Ma Y. Evidence of a critical role for cellodextrin transporte 2 (CDT-2) in both cellulose and hemicellulose degradation and utilization in Neurospora crassa. PLoS One 2014; 9:e89330. [PMID: 24586693 PMCID: PMC3930720 DOI: 10.1371/journal.pone.0089330] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 01/18/2014] [Indexed: 11/19/2022] Open
Abstract
CDT-1 and CDT-2 are two cellodextrin transporters discovered in the filamentous fungus Neurospora crassa. Previous studies focused on characterizing the role of these transporters in only a few conditions, including cellulose degradation, and the function of these two transporters is not yet completely understood. In this study, we show that deletion of cdt-2, but not cdt-1, results in growth defects not only on Avicel but also on xylan. cdt-2 can be highly induced by xylan, and this mutant has a xylodextrin consumption defect. Transcriptomic analysis of the cdt-2 deletion strain on Avicel and xylan showed that major cellulase and hemicellulase genes were significantly down-regulated in the cdt-2 deletion strain and artificial over expression of cdt-2 in N. crassa increased cellulase and hemicellulase production. Together, these data clearly show that CDT-2 plays a critical role in hemicellulose sensing and utilization. This is the first time a sugar transporter has been assigned a function in the hemicellulose degradation pathway. Furthermore, we found that the transcription factor XLR-1 is the major regulator of cdt-2, while cdt-1 is primarily regulated by CLR-1. These results deepen our understanding of the functions of both cellodextrin transporters, particularly for CDT-2. Our study also provides novel insight into the mechanisms for hemicellulose sensing and utilization in N. crassa, and may be applicable to other cellulolytic filamentous fungi.
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Affiliation(s)
- Pengli Cai
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Ruimeng Gu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Bang Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Li Wan
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yanhe Ma
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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