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Borin GP, Oliveira JVDC. Assessing the intracellular primary metabolic profile of Trichoderma reesei and Aspergillus niger grown on different carbon sources. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:998361. [PMID: 37746225 PMCID: PMC10512294 DOI: 10.3389/ffunb.2022.998361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/29/2022] [Indexed: 09/26/2023]
Abstract
Trichoderma reesei and Aspergillus niger are efficient biological platforms for the production of various industrial products, including cellulases and organic acids. Nevertheless, despite the extensive research on these fungi, integrated analyses of omics-driven approaches are still missing. In this study, the intracellular metabolic profile of T. reesei RUT-C30 and A. niger N402 strains grown on glucose, lactose, carboxymethylcellulose (CMC), and steam-exploded sugarcane bagasse (SEB) as carbon sources for 48 h was analysed by proton nuclear magnetic resonance. The aim was to verify the changes in the primary metabolism triggered by these substrates and use transcriptomics data from the literature to better understand the dynamics of the observed alterations. Glucose and CMC induced higher fungal growth whereas fungi grown on lactose showed the lowest dry weight. Metabolic profile analysis revealed that mannitol, trehalose, glutamate, glutamine, and alanine were the most abundant metabolites in both fungi regardless of the carbon source. These metabolites are of particular interest for the mobilization of carbon and nitrogen, and stress tolerance inside the cell. Their concomitant presence indicates conserved mechanisms adopted by both fungi to assimilate carbon sources of different levels of recalcitrance. Moreover, the higher levels of galactose intermediates in T. reesei suggest its better adaptation in lactose, whereas glycolate and malate in CMC might indicate activation of the glyoxylate shunt. Glycerol and 4-aminobutyrate accumulated in A. niger grown on CMC and lactose, suggesting their relevant role in these carbon sources. In SEB, a lower quantity and diversity of metabolites were identified compared to the other carbon sources, and the metabolic changes and higher xylanase and pNPGase activities indicated a better utilization of bagasse by A. niger. Transcriptomic analysis supported the observed metabolic changes and pathways identified in this work. Taken together, we have advanced the knowledge about how fungal primary metabolism is affected by different carbon sources, and have drawn attention to metabolites still unexplored. These findings might ultimately be considered for developing more robust and efficient microbial factories.
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Affiliation(s)
- Gustavo Pagotto Borin
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), São Paulo, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo, Brazil
| | - Juliana Velasco de Castro Oliveira
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), São Paulo, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas (UNICAMP), São Paulo, Brazil
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Fodor A, Gualtieri M, Zeller M, Tarasco E, Klein MG, Fodor AM, Haynes L, Lengyel K, Forst SA, Furgani GM, Karaffa L, Vellai T. Type Strains of Entomopathogenic Nematode-Symbiotic Bacterium Species, Xenorhabdus szentirmaii (EMC) and X. budapestensis (EMA), Are Exceptional Sources of Non-Ribosomal Templated, Large-Target-Spectral, Thermotolerant-Antimicrobial Peptides (by Both), and Iodinin (by EMC). Pathogens 2022; 11:pathogens11030342. [PMID: 35335666 PMCID: PMC8950435 DOI: 10.3390/pathogens11030342] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 01/26/2023] Open
Abstract
Antimicrobial multidrug resistance (MDR) is a global challenge, not only for public health, but also for sustainable agriculture. Antibiotics used in humans should be ruled out for use in veterinary or agricultural settings. Applying antimicrobial peptide (AMP) molecules, produced by soil-born organisms for protecting (soil-born) plants, seems a preferable alternative. The natural role of peptide-antimicrobials, produced by the prokaryotic partner of entomopathogenic-nematode/bacterium (EPN/EPB) symbiotic associations, is to sustain monoxenic conditions for the EPB in the gut of the semi-anabiotic infective dauer juvenile (IJ) EPN. They keep pathobiome conditions balanced for the EPN/EPB complex in polyxenic (soil, vanquished insect cadaver) niches. Xenorhabdus szentirmaii DSM16338(T) (EMC), and X. budapestensis DSM16342(T) (EMA), are the respective natural symbionts of EPN species Steinernema rarum and S. bicornutum. We identified and characterized both of these 15 years ago. The functional annotation of the draft genome of EMC revealed 71 genes encoding non-ribosomal peptide synthases, and polyketide synthases. The large spatial Xenorhabdus AMP (fabclavine), was discovered in EMA, and its biosynthetic pathway in EMC. The AMPs produced by EMA and EMC are promising candidates for controlling MDR prokaryotic and eukaryotic pathogens (bacteria, oomycetes, fungi, protozoa). EMC releases large quantity of iodinin (1,6-dihydroxyphenazine 5,10-dioxide) in a water-soluble form into the media, where it condenses to form spectacular water-insoluble, macroscopic crystals. This review evaluates the scientific impact of international research on EMA and EMC.
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Affiliation(s)
- András Fodor
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- Department of Genetics, University of Szeged, Középfasor 52, H-6726 Szeged, Hungary
- Correspondence: ; Tel.: +36-(30)-490-9294
| | - Maxime Gualtieri
- Nosopharm, 110 Allée Charles Babbage, Espace Innovation 2, 30000 Nîmes, France;
| | - Matthias Zeller
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47906, USA;
| | - Eustachio Tarasco
- Department of Soil, Plant and Food Sciences, University of Bari “Aldo Moro”, Via Amendola 165/A, 70126 Bari, Italy;
- Institute for Sustainable Plant Protection of CNR, Via Amendola 122/D, 70126 Bari, Italy
| | - Michael G. Klein
- USDA-ARS & Department of Entomology, The Ohio State University, 13416 Claremont Ave, Cleveland, OH 44130, USA;
| | - Andrea M. Fodor
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
| | - Leroy Haynes
- Department of Chemistry, The College of Wooster, Wooster, OH 44691, USA;
| | - Katalin Lengyel
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- National Institute of Pharmacy and Nutrition (NIPN), Zrinyi utca 3, H-1051 Budapest, Hungary
| | - Steven A. Forst
- Department of Biological Sciences, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA;
| | - Ghazala M. Furgani
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- Department of Plant Protection, Faculty of Agriculture, University of Tripoli, Tripoli P.O. Box 13793, Libya
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem Tér 1, H-4032 Debrecen, Hungary;
- Institute of Metagenomics, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Tibor Vellai
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- MTA-ELTE Genetics Research Group, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary
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3
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Promoter regulation and genetic engineering strategies for enhanced cellulase expression in Trichoderma reesei. Microbiol Res 2022; 259:127011. [DOI: 10.1016/j.micres.2022.127011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 01/18/2023]
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Laothanachareon T, Bunterngsook B, Champreda V. Profiling multi-enzyme activities of Aspergillus niger strains growing on various agro-industrial residues. 3 Biotech 2022; 12:17. [PMID: 34926121 PMCID: PMC8671598 DOI: 10.1007/s13205-021-03086-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/03/2021] [Indexed: 01/03/2023] Open
Abstract
Agro-industrial wastes provide potential sources of carbon for production of fungal enzymes applied for various biotechnological applications. In this study, 23 strains of Aspergillus niger were systematically investigated for their capability on production of carbohydrate-processing enzymes used in industries. The strains were grown on glucose or selected agricultural wastes comprising varied chemical compositions as the sole carbon source. As a control, glucose induced basal activities of amylase, pectinase, and xylanase in only a few strains, while the CMCase, β-glucanase, and invertase activities were detected only when the carbon source was switched to the agro-industrial biomass. According to one-way ANOVA analysis, banana peels containing lignocellulosic components with high pectin and starch contents with its easily digestible nature, were found to be the best carbon source for inducing production of most target enzymes, while the cellulose-rich sugarcane bagasse efficiently promoted maximal levels of β-glucanase and xylanase activities. The starch fiber-rich cassava pulp also effectively supported the activities of amylase and most other enzymes, but at relatively lower levels compared to those obtained with banana peel. The A. niger TL11 strain was considered the most potent strain for production of all target enzymes with the CMCase, xylanase, pectinase, β-glucanase, amylase, and invertase activities of 76.15, 601.59, 160.89, 409.20, 426.73, and 1186.94 U/mL, respectively. The results provide insights into the efficiency of various carbon sources with different chemical compositions on inducing the target enzymes as well as the dissimilarity of A. niger strains on the production of different carbohydrate-processing enzymes. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-03086-y.
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Affiliation(s)
- Thanaporn Laothanachareon
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Khlong Luang, 12120 Pathumthani Thailand
| | - Benjarat Bunterngsook
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Khlong Luang, 12120 Pathumthani Thailand
| | - Verawat Champreda
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Khlong Luang, 12120 Pathumthani Thailand
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Yan S, Xu Y, Yu XW. From induction to secretion: a complicated route for cellulase production in Trichoderma reesei. BIORESOUR BIOPROCESS 2021; 8:107. [PMID: 38650205 PMCID: PMC10991602 DOI: 10.1186/s40643-021-00461-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/16/2021] [Indexed: 11/10/2022] Open
Abstract
The filamentous fungus Trichoderma reesei has been widely used for cellulase production that has extensive applications in green and sustainable development. Increasing costs and depletion of fossil fuels provoke the demand for hyper-cellulase production in this cellulolytic fungus. To better manipulate T. reesei for enhanced cellulase production and to lower the cost for large-scale fermentation, it is wise to have a comprehensive understanding of the crucial factors and complicated biological network of cellulase production that could provide new perspectives for further exploration and modification. In this review, we summarize recent progress and give an overview of the cellular process of cellulase production in T. reesei, including the carbon source-dependent cellulase induction, complicated transcriptional regulation network, and efficient protein assembly and trafficking. Among that, the key factors involved in cellulase production were emphasized, shedding light on potential perspectives for further engineering.
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Affiliation(s)
- Su Yan
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China
| | - Xiao-Wei Yu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, People's Republic of China.
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Daranagama ND, Shioya K, Yuki M, Sato H, Ohtaki Y, Suzuki Y, Shida Y, Ogasawara W. Proteolytic analysis of Trichoderma reesei in celluase-inducing condition reveals a role for trichodermapepsin (TrAsP) in cellulase production. ACTA ACUST UNITED AC 2019; 46:831-842. [DOI: 10.1007/s10295-019-02155-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/12/2019] [Indexed: 12/22/2022]
Abstract
Abstract
Filamentous fungi produce a variety of proteases with significant biotechnological potential and show diverse substrate specificities. Proteolytic analysis of the industrial enzyme producer Trichoderma reesei has been sparse. Therefore, we determined the substrate specificity of T. reesei secretome and its main protease Trichodermapepsin (TrAsP) up to P1 position using FRETS-25Xaa-libraries. The role of TrAsP was analyzed using T. reesei QM9414 and the deletant QM∆trasp in Avicel. We observed higher activities of CMCase, Avicelase, and Xylanase in QM∆t rasp compared to that of QM9414. Saccharification rate of cellulosic biomass also increased when using secretome of QM∆trasp but the effect was not significant due to the absence of difference in BGL activity compared to QM9414. Higher TrAsP was produced when monosaccharides were used as a carbon source compared to cellulase inducers such as Avicel and α-sophorose. These results elucidate the relationship between TrAsP and cellulase production in T. reesei and suggest a physiological role for TrAsP.
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Affiliation(s)
- Nayani Dhanushka Daranagama
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Koki Shioya
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Masahiro Yuki
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Haruna Sato
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Yuki Ohtaki
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Yoshiyuki Suzuki
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Yosuke Shida
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Wataru Ogasawara
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
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Zou G, Jiang Y, Liu R, Zhu Z, Zhou Z. The putative β-glucosidase BGL3I regulates cellulase induction in Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:314. [PMID: 30473732 PMCID: PMC6240962 DOI: 10.1186/s13068-018-1314-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina) displays increased cellulase expression while growing on inducers such as lactose or cellulose. However, the mechanism of cellulase induction in T. reesei is not yet completely characterized. Here, a protein annotated as β-glucosidase (BGL3I) was found to be involved in cellulase induction in T. reesei. The effects of BGL3I on cellulase production have not yet been fully understood. RESULTS Deletion of the bgl3i gene had no influence on the growth of T. reesei, but significantly increased its cellulase activities. Deletion of bgl3i also resulted in decreased extracellular galactosidase activity, but significantly increased transcription of lactose permeases, which might be involved in lactose transport. Furthermore, deletion of bgl3i enhanced the transcription levels of intracellular β-glucosidases cel1a, cel1b and the regulator xyr1, which are all essential for lactose induction in T. reesei. BGL3I was found to have a relatively high ability to hydrolyze sophorose, which is proposed to be the strongest natural inducer of cellulase synthesis in T. reesei. CONCLUSIONS BGL3I may take part in the complex regulating system of cellulase induction. The deletion of bgl3i offers a new strategy to improve T. reesei strain performance.
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Affiliation(s)
- Gen Zou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
- Shanghai Key Laboratory of Agricultural Genetics and Breeding; Institute of Edible Fungi, Shanghai Academy of Agriculture Science, 1000 Jinqi Rd, Fengxian, 201403 Shanghai China
| | - Yanping Jiang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
- Southwest Jiaotong University, Chengdu, 611756 Sichuan China
| | - Rui Liu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
| | - Zhihua Zhu
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai, 200032 China
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Benocci T, Aguilar-Pontes MV, Kun RS, Seiboth B, de Vries RP, Daly P. ARA1 regulates not only l-arabinose but also d-galactose catabolism in Trichoderma reesei. FEBS Lett 2017; 592:60-70. [PMID: 29215697 DOI: 10.1002/1873-3468.12932] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/18/2017] [Accepted: 11/29/2017] [Indexed: 11/11/2022]
Abstract
Trichoderma reesei is used to produce saccharifying enzyme cocktails for biofuels. There is limited understanding of the transcription factors (TFs) that regulate genes involved in release and catabolism of l-arabinose and d-galactose, as the main TF XYR1 is only partially involved. Here, the T. reesei ortholog of ARA1 from Pyricularia oryzae that regulates l-arabinose releasing and catabolic genes was deleted and characterized by growth profiling and transcriptomics along with a xyr1 mutant and xyr1/ara1 double mutant. Our results show that in addition to the l-arabinose-related role, T. reesei ARA1 is essential for expression of d-galactose releasing and catabolic genes, while XYR1 is not involved in this process.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Roland Sándor Kun
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Bernhard Seiboth
- Research Area Biochemical Technology, Institute of Chemical, Environmental and Biological Engineering, TU Wien, Vienna, Austria
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Paul Daly
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
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Jiang F, Ma L, Cai R, Ma Q, Guo G, Du L, Xiao D. Efficient crude multi-enzyme produced by Trichoderma reesei using corncob for hydrolysis of lignocellulose. 3 Biotech 2017; 7:339. [PMID: 28955636 DOI: 10.1007/s13205-017-0982-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/15/2017] [Indexed: 01/02/2023] Open
Abstract
To improve the efficiency of enzymatic saccharification for lignocellulose, an efficient crude multi-enzyme was produced by Trichoderma reesei using corncob, a low cost inducer. Expression of cbh1, bgl1, egl1, xyn1 and positive regulator xyr1 induced by corncob increased significantly compared to that by cellulose. After 120 h induction by corncob, enzymatic activities on filter, CMC, β-glucose and xylan increased 86.5, 46.9, 120.9 and 291.2% compared to those induced by cellulose, and the concentration of secreted protein increased by 120.8%. FPase:β-glucosidase and FPase:xylanase values in crude multi-enzyme I (ECI, induced by corncob) were higher than that in crude multi-enzyme II (ECII, induced by cellulose). Under the same hydrolysis conditions, the volume dosage of ECI was only half of ECII, but ECI still showed a maximum of 12.5 and 33.4% higher than ECII in the total reducing sugar and glucose yield in lignocellulose hydrolysis. Corncob could be a candidate for low cost production of multi-enzyme for efficient lignocellulose degradation, and this work could guide the genetic modification of T. reesei to obtain efficient multi-enzyme for lignocellulose hydrolysis.
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Affiliation(s)
- Fengchao Jiang
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
| | - Lijuan Ma
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
| | - Rui Cai
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
| | - Qing Ma
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
| | - Gaojie Guo
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
| | - Liping Du
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
| | - Dongguang Xiao
- Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 People's Republic of China
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Benocci T, Aguilar-Pontes MV, Zhou M, Seiboth B, de Vries RP. Regulators of plant biomass degradation in ascomycetous fungi. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:152. [PMID: 28616076 PMCID: PMC5468973 DOI: 10.1186/s13068-017-0841-x] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/06/2017] [Indexed: 05/05/2023]
Abstract
Fungi play a major role in the global carbon cycle because of their ability to utilize plant biomass (polysaccharides, proteins, and lignin) as carbon source. Due to the complexity and heterogenic composition of plant biomass, fungi need to produce a broad range of degrading enzymes, matching the composition of (part of) the prevalent substrate. This process is dependent on a network of regulators that not only control the extracellular enzymes that degrade the biomass, but also the metabolic pathways needed to metabolize the resulting monomers. This review will summarize the current knowledge on regulation of plant biomass utilization in fungi and compare the differences between fungal species, focusing in particular on the presence or absence of the regulators involved in this process.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Bernhard Seiboth
- Research Area Biochemical Technology, Institute of Chemical and Biological Engineering, TU Wien, 1060 Vienna, Austria
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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Kameshwar AKS, Qin W. Metadata Analysis of Phanerochaete chrysosporium Gene Expression Data Identified Common CAZymes Encoding Gene Expression Profiles Involved in Cellulose and Hemicellulose Degradation. Int J Biol Sci 2017; 13:85-99. [PMID: 28123349 PMCID: PMC5264264 DOI: 10.7150/ijbs.17390] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/10/2016] [Indexed: 01/04/2023] Open
Abstract
In literature, extensive studies have been conducted on popular wood degrading white rot fungus, Phanerochaete chrysosporium about its lignin degrading mechanisms compared to the cellulose and hemicellulose degrading abilities. This study delineates cellulose and hemicellulose degrading mechanisms through large scale metadata analysis of P. chrysosporium gene expression data (retrieved from NCBI GEO) to understand the common expression patterns of differentially expressed genes when cultured on different growth substrates. Genes encoding glycoside hydrolase classes commonly expressed during breakdown of cellulose such as GH-5,6,7,9,44,45,48 and hemicellulose are GH-2,8,10,11,26,30,43,47 were found to be highly expressed among varied growth conditions including simple customized and complex natural plant biomass growth mediums. Genes encoding carbohydrate esterase class enzymes CE (1,4,8,9,15,16) polysaccharide lyase class enzymes PL-8 and PL-14, and glycosyl transferases classes GT (1,2,4,8,15,20,35,39,48) were differentially expressed in natural plant biomass growth mediums. Based on these results, P. chrysosporium, on natural plant biomass substrates was found to express lignin and hemicellulose degrading enzymes more than cellulolytic enzymes except GH-61 (LPMO) class enzymes, in early stages. It was observed that the fate of P. chrysosporium transcriptome is significantly affected by the wood substrate provided. We believe, the gene expression findings in this study plays crucial role in developing genetically efficient microbe with effective cellulose and hemicellulose degradation abilities.
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Affiliation(s)
| | - Wensheng Qin
- Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1, Canada
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Németh Z, Molnár ÁP, Fejes B, Novák L, Karaffa L, Keller NP, Fekete E. Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans. Toxins (Basel) 2016; 8:E354. [PMID: 27916804 PMCID: PMC5198170 DOI: 10.3390/toxins8120354] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/20/2016] [Accepted: 11/23/2016] [Indexed: 11/24/2022] Open
Abstract
Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST) produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L-1 ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.
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Affiliation(s)
- Zoltán Németh
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Ákos P Molnár
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Balázs Fejes
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Levente Novák
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA.
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA.
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen H-4032, Hungary.
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Manfredi AP, Pisa JH, Valdeón DH, Perotti NI, Martínez MA. Synergistic Effect of Simple Sugars and Carboxymethyl Cellulose on the Production of a Cellulolytic Cocktail from Bacillus sp. AR03 and Enzyme Activity Characterization. Appl Biochem Biotechnol 2016; 179:16-32. [DOI: 10.1007/s12010-015-1976-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/29/2015] [Indexed: 11/27/2022]
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Druzhinina IS, Kubicek CP. Familiar Stranger: Ecological Genomics of the Model Saprotroph and Industrial Enzyme Producer Trichoderma reesei Breaks the Stereotypes. ADVANCES IN APPLIED MICROBIOLOGY 2016; 95:69-147. [PMID: 27261782 DOI: 10.1016/bs.aambs.2016.02.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The filamentous fungus Trichoderma reesei (Hypocreales, Ascomycota) has properties of an efficient cell factory for protein production that is exploited by the enzyme industry, particularly with respect to cellulase and hemicellulase formation. Under conditions of industrial fermentations it yields more than 100g secreted protein L(-1). Consequently, T. reesei has been intensively studied in the 20th century. Most of these investigations focused on the biochemical characteristics of its cellulases and hemicellulases, on the improvement of their properties by protein engineering, and on enhanced enzyme production by recombinant strategies. However, as the fungus is rare in nature, its ecology remained unknown. The breakthrough in the understanding of the fundamental biology of T. reesei only happened during 2000s-2010s. In this review, we compile the current knowledge on T. reesei ecology, physiology, and genomics to present a holistic view on the natural behavior of the organism. This is not only critical for science-driven further improvement of the biotechnological applications of this fungus, but also renders T. reesei as an attractive model of filamentous fungi with superior saprotrophic abilities.
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Affiliation(s)
- I S Druzhinina
- Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - C P Kubicek
- Institute of Chemical Engineering, TU Wien, Vienna, Austria
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Paudel YP, Qin W. Characterization of Novel Cellulase-producing Bacteria Isolated From Rotting Wood Samples. Appl Biochem Biotechnol 2015; 177:1186-98. [DOI: 10.1007/s12010-015-1806-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/10/2015] [Indexed: 11/30/2022]
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Fekete E, Karaffa L, Karimi Aghcheh R, Németh Z, Fekete E, Orosz A, Paholcsek M, Stágel A, Kubicek CP. The transcriptome of lae1 mutants of Trichoderma reesei cultivated at constant growth rates reveals new targets of LAE1 function. BMC Genomics 2014; 15:447. [PMID: 24909838 PMCID: PMC4061448 DOI: 10.1186/1471-2164-15-447] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 06/04/2014] [Indexed: 01/02/2023] Open
Abstract
Background The putative methyltransferase LaeA is a global regulator that affects the expression of multiple secondary metabolite gene clusters in several fungi. In Trichoderma reesei, its ortholog LAE1 appears to predominantly regulate genes involved in increasing competitive fitness in its environment, including expression of cellulases and polysaccharide hydrolases. A drawback in all studies related to LaeA/LAE1 function so far, however, is that the respective loss-of-function and overexpressing mutants display different growth rates. Thus some of the properties attributed to LaeA/LAE1 could be simply due to changes of the growth rate. Results We cultivated T. reesei, a Δlae1 mutant and a lae1-overexpressing strain in chemostats on glucose at two different growth rates (0.075 and 0.020 h-1) which resemble growth rates at repressing and derepressing conditions, respectively. Under these conditions, the effect of modulating LAE1 expression was mainly visible in the Δlae1 mutant, whereas the overexpressing strain showed little differences to the parent strain. The effect on the expression of some gene categories identified earlier (polyketide synthases, heterokaryon incompatibility proteins, PTH11-receptors) was confirmed, but in addition GCN5-N-acetyltransferases, amino acid permeases and flavin monooxygenases were identified as so far unknown major targets of LAE1 action. LAE1 was also shown to interfere with the regulation of expression of several genes by the growth rate. About a tenth of the genes differentially expressed in the Δlae1 mutant under either growth condition were found to be clustered in the genome, but no specific gene group was associated with this phenomenon. Conclusions Our data show that – using T. reesei LAE1 as a model - the investigation of transcriptome in regulatory mutants at constant growth rates leads to new insights into the physiological roles of the respective regulator. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-447) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary.
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Huang Y, Jin Y, Shen W, Fang Y, Zhang G, Zhao H. The use of plant cell wall-degrading enzymes from newly isolatedPenicillium ochrochloronBiourge for viscosity reduction in ethanol production with fresh sweet potato tubers as feedstock. Biotechnol Appl Biochem 2014; 61:480-91. [DOI: 10.1002/bab.1190] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 12/03/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Yuhong Huang
- Environmental Microbiology Key Laboratory of Sichuan Province; Chengdu Institute of Biology; Chinese Academy of Sciences; Chengdu Sichuan People's Republic of China
- Graduate University of the Chinese Academy of Sciences; Beijing People's Republic of China
- Key Laboratory of Environmental and Applied Microbiology; Chinese Academy of Sciences; Chengdu People's Republic of China
| | - Yanling Jin
- Environmental Microbiology Key Laboratory of Sichuan Province; Chengdu Institute of Biology; Chinese Academy of Sciences; Chengdu Sichuan People's Republic of China
- Key Laboratory of Environmental and Applied Microbiology; Chinese Academy of Sciences; Chengdu People's Republic of China
| | - Weiliang Shen
- Environmental Microbiology Key Laboratory of Sichuan Province; Chengdu Institute of Biology; Chinese Academy of Sciences; Chengdu Sichuan People's Republic of China
- Key Laboratory of Environmental and Applied Microbiology; Chinese Academy of Sciences; Chengdu People's Republic of China
| | - Yang Fang
- Environmental Microbiology Key Laboratory of Sichuan Province; Chengdu Institute of Biology; Chinese Academy of Sciences; Chengdu Sichuan People's Republic of China
- Key Laboratory of Environmental and Applied Microbiology; Chinese Academy of Sciences; Chengdu People's Republic of China
| | - Guohua Zhang
- Environmental Microbiology Key Laboratory of Sichuan Province; Chengdu Institute of Biology; Chinese Academy of Sciences; Chengdu Sichuan People's Republic of China
- Key Laboratory of Environmental and Applied Microbiology; Chinese Academy of Sciences; Chengdu People's Republic of China
| | - Hai Zhao
- Environmental Microbiology Key Laboratory of Sichuan Province; Chengdu Institute of Biology; Chinese Academy of Sciences; Chengdu Sichuan People's Republic of China
- Key Laboratory of Environmental and Applied Microbiology; Chinese Academy of Sciences; Chengdu People's Republic of China
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Intracellular β-glucosidases CEL1a and CEL1b are essential for cellulase induction on lactose in Trichoderma reesei. EUKARYOTIC CELL 2014; 13:1001-13. [PMID: 24879125 DOI: 10.1128/ec.00100-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Lactose (1,4-O-β-d-galacto-pyranosyl-d-glucose) induces cellulolytic enzymes in Trichoderma reesei and is in fact one of the most important soluble carbon sources used to produce cellulases on an industrial level. The mechanism underlying the induction is, however, not fully understood. In this study, we investigated the cellular functions of the intracellular β-glucosidases CEL1a and CEL1b in the induction of cellulase genes by lactose in T. reesei. We demonstrated that while CEL1a and CEL1b were functionally equivalent in mediating the induction, the simultaneous absence of these intracellular β-glucosidases abolished cbh1 gene expression on lactose. d-Galactose restored the efficient cellulase gene induction in the Δcel1a strain independently of its reductive metabolism, but not in the Δcel1a Δcel1b strain. A further comparison of the transcriptional responses of the Δcel1a Δcel1b strain complemented with wild-type CEL1a or a catalytically inactive CEL1a version and the Δcel1a strain constitutively expressing CEL1a or the Kluyveromyces lactis β-galactosidase LAC4 showed that both the CEL1a protein and its glycoside hydrolytic activity were indispensable for cellulase induction by lactose. We also present evidence that intracellular β-glucosidase-mediated lactose induction is further conveyed to XYR1 to ensure the efficiently induced expression of cellulase genes.
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Complex regulation of hydrolytic enzyme genes for cellulosic biomass degradation in filamentous fungi. Appl Microbiol Biotechnol 2014; 98:4829-37. [DOI: 10.1007/s00253-014-5707-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 03/17/2014] [Accepted: 03/17/2014] [Indexed: 12/17/2022]
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20
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Horta MAC, Vicentini R, Delabona PDS, Laborda P, Crucello A, Freitas S, Kuroshu RM, Polikarpov I, Pradella JGDC, Souza AP. Transcriptome profile of Trichoderma harzianum IOC-3844 induced by sugarcane bagasse. PLoS One 2014; 9:e88689. [PMID: 24558413 PMCID: PMC3928278 DOI: 10.1371/journal.pone.0088689] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 01/09/2014] [Indexed: 12/03/2022] Open
Abstract
Profiling the transcriptome that underlies biomass degradation by the fungus Trichoderma harzianum allows the identification of gene sequences with potential application in enzymatic hydrolysis processing. In the present study, the transcriptome of T. harzianum IOC-3844 was analyzed using RNA-seq technology. The sequencing generated 14.7 Gbp for downstream analyses. De novo assembly resulted in 32,396 contigs, which were submitted for identification and classified according to their identities. This analysis allowed us to define a principal set of T. harzianum genes that are involved in the degradation of cellulose and hemicellulose and the accessory genes that are involved in the depolymerization of biomass. An additional analysis of expression levels identified a set of carbohydrate-active enzymes that are upregulated under different conditions. The present study provides valuable information for future studies on biomass degradation and contributes to a better understanding of the role of the genes that are involved in this process.
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Affiliation(s)
| | - Renato Vicentini
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Priscila da Silva Delabona
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Prianda Laborda
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Aline Crucello
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Sindélia Freitas
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Reginaldo Massanobu Kuroshu
- Physics Institute of São Carlos, University of São Paulo (USP), São Carlos, SP, Brazil
- Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Igor Polikarpov
- Physics Institute of São Carlos, University of São Paulo (USP), São Carlos, SP, Brazil
| | - José Geraldo da Cruz Pradella
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Anete Pereira Souza
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
- Department of Plant Biology, Biology Institute, University of Campinas (UNICAMP), Campinas, SP, Brazil
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Liao H, Li S, Wei Z, Shen Q, Xu Y. Insights into high-efficiency lignocellulolytic enzyme production by Penicillium oxalicum GZ-2 induced by a complex substrate. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:162. [PMID: 25419234 PMCID: PMC4239378 DOI: 10.1186/s13068-014-0162-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 10/21/2014] [Indexed: 05/15/2023]
Abstract
BACKGROUND Agricultural residue is more efficient than purified cellulose at inducing lignocellulolytic enzyme production in Penicillium oxalicum GZ-2, but in Trichoderma reesei RUT-C30, cellulose induces a more efficient response. To understand the reasons, we designed an artificially simulated plant biomass (cellulose plus xylan) to study the roles and relationships of each component in the production of lignocellulolytic enzymes by P. oxalicum GZ-2. RESULTS The changes in lignocellulolytic enzyme activity, gene expression involving (hemi)cellulolytic enzymes, and the secretome of cultures grown on Avicel (A), xylan (X), or a mixture of both (AX) were studied. The addition of xylan to the cellulose culture did not affect fungal growth but significantly increased the activity of cellulase and hemicellulase. In the AX treatment, the transcripts of cellulase genes (egl1, egl2, egl3, sow, and cbh2) and hemicellulase genes (xyl3 and xyl4) were significantly upregulated (P <0.05). The proportion of biomass-degrading proteins in the secretome was altered; in particular, the percentage of cellulases and hemicellulases was increased. The percentage of cellulases and hemicellulases in the AX secretome increased from 4.5% and 7.6% to 10.3% and 21.8%, respectively, compared to the secretome of the A treatment. Cellobiohydrolase II (encoded by cbh2) and xylanase II (encoded by xyl2) were the main proteins in the secretome, and their corresponding genes (cbh2 and xyl2) were transcripted at the highest levels among the cellulolytic and xylanolytic genes. Several important proteins such as swollenin, cellobiohydrolase, and endo-beta-1,4-xylanase were only induced by AX. Bray-Curtis similarity indices, a dendrogram analysis, and a diversity index all demonstrated that the secretome produced by P. oxalicum GZ-2 depended on the substrate and that strain GZ-2 directionally adjusted the compositions of lignocellulolytic enzymes in its secretome to preferably degrade a complex substrate. CONCLUSION The addition of xylan to the cellulose medium not only induces more hemicellulases but also strongly activates cellulase production. The proportion of the biomass-degrading proteins in the secretome was altered significantly, with the proportion of cellulases and hemicellulases especially increased. Xylan and cellulose have positively synergistic effects, and they play a key role in the induction of highly efficient lignocellulolytic enzymes.
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Affiliation(s)
- Hanpeng Liao
- National Enginnering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, 210095 China
| | - Shuixian Li
- National Enginnering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, 210095 China
| | - Zhong Wei
- National Enginnering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, 210095 China
| | - Qirong Shen
- National Enginnering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, 210095 China
| | - Yangchun Xu
- National Enginnering Research Center for Organic-based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Utilization, College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing, 210095 China
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Insights into enzyme secretion by filamentous fungi: comparative proteome analysis of Trichoderma reesei grown on different carbon sources. J Proteomics 2013; 89:191-201. [PMID: 23796490 DOI: 10.1016/j.jprot.2013.06.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/20/2013] [Accepted: 06/13/2013] [Indexed: 11/21/2022]
Abstract
UNLABELLED Trichoderma reesei is the main industrial producer of lignocellulolytic enzymes, and the secretory behavior of this fungus strongly depends on the carbon sources. To gain insights into how the T. reesei adapts to various carbons and regulates enzyme production, the extra- and intracellular proteomes of T. reesei grown in defined medium with lactose or xylose as the carbon source were investigated. Results indicated that the composition of extracellular proteome differed considerably depending on the carbons. The main cellobiohydrolases, i.e. Cel7a/Cel6 were the most abundant cellulolytic enzymes identified in both media, and found to be more abundant in lactose-grown culture. As compared to lactose, xylose can serve as a potent inducer of xylanolytic enzymes. Interestingly, most identified intracellular proteins are involved in carbon metabolism. Enzymes involved in utilization of xylose, such as d-xylose reductase (Xyl1p) and d-xylose dehydrogenase (Xyl2p), were present at elevated levels in the culture growing on xylose but only in minor amounts in the lactose culture. However, lactose induction significantly activated the expression of key enzymes involved in glycolysis pathway and citrate cycle. Importantly, the protein Xyl1p which participates both in the lactose and the xylose catabolism was verified as a potential regulator for cellulase formation in T. reesei. BIOLOGICAL SIGNIFICANCE This study not only gives an overview of the ubiquitous cellular changes induced by the two conventional carbon substrates, but offers the framework for understanding the mechanisms behind the carbon-dependent induction of extracellular enzymes in T. reesei. Moreover, this study provides a potential target (Xyl1p) that could be tentatively used for metabolic engineering of T. reesei for cost-effective cellulase production.
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Amore A, Giacobbe S, Faraco V. Regulation of cellulase and hemicellulase gene expression in fungi. Curr Genomics 2013; 14:230-49. [PMID: 24294104 PMCID: PMC3731814 DOI: 10.2174/1389202911314040002] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 04/22/2013] [Accepted: 04/23/2013] [Indexed: 11/22/2022] Open
Abstract
Research on regulation of cellulases and hemicellulases gene expression may be very useful for increasing the production of these enzymes in their native producers. Mechanisms of gene regulation of cellulase and hemicellulase expression in filamentous fungi have been studied, mainly in Aspergillus and Trichoderma. The production of these extracellular enzymes is an energy-consuming process, so the enzymes are produced only under conditions in which the fungus needs to use plant polymers as an energy and carbon source. Moreover, production of many of these enzymes is coordinately regulated, and induced in the presence of the substrate polymers. In addition to induction by mono- and oligo-saccharides, genes encoding hydrolytic enzymes involved in plant cell wall deconstruction in filamentous fungi can be repressed during growth in the presence of easily metabolizable carbon sources, such as glucose. Carbon catabolite repression is an important mechanism to repress the production of plant cell wall degrading enzymes during growth on preferred carbon sources. This manuscript reviews the recent advancements in elucidation of molecular mechanisms responsible for regulation of expression of cellulase and hemicellulase genes in fungi.
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Affiliation(s)
- Antonella Amore
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
| | - Simona Giacobbe
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
| | - Vincenza Faraco
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
- School of Biotechnological Sciences, University of Naples “Federico II” Italy
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The intracellular galactoglycome in Trichoderma reesei during growth on lactose. Appl Microbiol Biotechnol 2013; 97:5447-56. [PMID: 23299458 DOI: 10.1007/s00253-012-4667-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 12/15/2012] [Accepted: 12/17/2012] [Indexed: 10/27/2022]
Abstract
Lactose (1,4-0-β-D-galactopyranosyl-D-glucose) is used as a soluble carbon source for the production of cellulases and hemicellulases for-among other purposes-use in biofuel and biorefinery industries. The mechanism how lactose induces cellulase formation in T. reesei is enigmatic, however. Previous results from our laboratory raised the hypothesis that intermediates from the two galactose catabolic pathway may give rise to the accumulation of intracellular oligogalactosides that could act as inducer. Here we have therefore used high-performance anion-exchange chromatography-mass spectrometry to study the intracellular galactoglycome of T. reesei during growth on lactose, in T. reesei mutants impaired in galactose catabolism, and in strains with different cellulase productivities. Lactose, allo-lactose, and lactulose were detected in the highest amounts in all strains, and two trisaccharides (Gal-β-1,6-Gal-β-1,4-Glc/Fru and Gal-β-1,4-Gal-β-1,4-Glc/Fru) also accumulated to significant levels. Glucose and galactose, as well as four further oligosaccharides (Gal-β-1,3/1,4/1,6-Gal; Gal-β-1,2-Glc) were only detected in minor amounts. In addition, one unknown disaccharide (Hex-β-1,1-Hex) and four trisaccharides were also detected. The accumulation of the unknown hexose disaccharide was shown to correlate with cellulase formation in the improved mutant strains as well as the galactose pathway mutants, and Gal-β-1,4-Gal-β-1,4-Glc/Fru and two other unknown hexose trisaccharides correlated with cellulase production only in the pathway mutants, suggesting that these compounds could be involved in cellulase induction by lactose. The nature of these oligosaccharides, however, suggests their formation by transglycosylation rather than by glycosyltransferases. Based on our results, the obligate nature of both galactose catabolic pathways for this induction must have another biochemical basis than providing substrates for inducer formation.
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Sadhu S, Ghosh PK, De TK, Maiti TK. Optimization of Cultural Condition and Synergistic Effect of Lactose with Carboxymethyl Cellulose on Cellulase Production by <i>Bacillus</i> sp. Isolated from Fecal Matter of Elephant (<i>Elephas maximus</i>). ACTA ACUST UNITED AC 2013. [DOI: 10.4236/aim.2013.33040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kunitake E, Tani S, Sumitani JI, Kawaguchi T. A novel transcriptional regulator, ClbR, controls the cellobiose- and cellulose-responsive induction of cellulase and xylanase genes regulated by two distinct signaling pathways in Aspergillus aculeatus. Appl Microbiol Biotechnol 2012; 97:2017-28. [DOI: 10.1007/s00253-012-4305-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/13/2012] [Accepted: 07/13/2012] [Indexed: 10/28/2022]
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Fekete E, de Vries RP, Seiboth B, vanKuyk PA, Sándor E, Fekete E, Metz B, Kubicek CP, Karaffa L. D-Galactose uptake is nonfunctional in the conidiospores of Aspergillus niger. FEMS Microbiol Lett 2012; 329:198-203. [PMID: 22324294 DOI: 10.1111/j.1574-6968.2012.02524.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 02/02/2012] [Accepted: 02/03/2012] [Indexed: 11/28/2022] Open
Abstract
The majority of black Aspergilli (Aspergillus section Nigri), including Aspergillus niger, as well as many other Ascomycetes fail to germinate on d-galactose as a sole carbon source. Here, we provide evidence that the ability of A. niger to transport D-galactose is growth stage dependent, being absent in the conidiospores but present in the mycelia. Despite earlier claims, we could identify galactokinase activity in growing cells and all genes of the Leloir pathway (responsible for channelling D-galactose into the EMP pathway) are well induced on D-galactose (and also on lactose, D-xylose and L-arabinose) in the mycelial stage. Expression of all Leloir pathway genes was also detectable in conidiospores, although galE (encoding a galactokinase) and galD (encoding a galactose-1-phosphate uridylyl transferase) were expressed poorly. These results suggest that the D-galactose-negative phenotype of A. niger conidiospores may be due to the lack of inducer uptake.
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Affiliation(s)
- Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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Tani S, Kanamasa S, Sumitani JI, Arai M, Kawaguchi T. XlnR-independent signaling pathway regulates both cellulase and xylanase genes in response to cellobiose in Aspergillus aculeatus. Curr Genet 2012; 58:93-104. [PMID: 22371227 DOI: 10.1007/s00294-012-0367-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 01/23/2012] [Accepted: 02/04/2012] [Indexed: 10/28/2022]
Abstract
The expression levels of the cellulase and xylanase genes between the host strain and an xlnR disruptant were compared by quantitative RT-PCR (qPCR) to identify the genes controlled by XlnR-independent signaling pathway. The cellulose induction of the FI-carboxymethyl cellulase (cmc1) and FIb-xylanase (xynIb) genes was controlled by XlnR; in contrast, the cellulose induction of the FIII-avicelase (cbhI), FII-carboxymethyl cellulase (cmc2), and FIa-xylanase (xynIa) genes was controlled by an XlnR-independent signaling pathway. To gain deeper insight into the XlnR-independent signaling pathway, the expression profile of cbhI was analyzed as a representative target gene. Cellobiose together with 1-deoxynojirimycin (DNJ), a glucosidase inhibitor, induced cbhI the most efficiently among disaccharides composed of β-glucosidic bonds. Furthermore, cellobiose with DNJ induced the transcription of cmc2 and xynIa, whereas cmc1 and xynIb were not induced. GUS reporter fusion analyses of truncated and mutated cbhI promoters revealed that three regions were necessary for effective cellulose-induced transcription, all of which contained the conserved sequence 5'-CCGN(2)CCN(7)G(C/A)-3' within the CeRE, which has been identified as the upstream activating element essential for expression of eglA in A. nidulans (Endo et al. 2008). The data therefore delineate a pathway in which A. aculeatus perceives the presence of cellobiose, thereby activating a signaling pathway that drives cellulase and hemicellulase gene expression under the control of the XlnR-independent regulation through CeRE.
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Affiliation(s)
- Shuji Tani
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Seiboth B, Herold S, Kubicek CP. Metabolic engineering of inducer formation for cellulase and hemicellulase gene expression in Trichoderma reesei. Subcell Biochem 2012; 64:367-90. [PMID: 23080260 DOI: 10.1007/978-94-007-5055-5_18] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The filamentous fungus T. reeseiis today a paradigm for the commercial scale production of different plant cell wall degrading enzymes mainly cellulases and hemicellulases. Its enzymes have a long history of safe use in industry and well established applications are found within the pulp, paper, food, feed or textile processing industries. However, when these enzymes are to be used for the saccharification of cellulosic plant biomass to simple sugars which can be further converted to biofuels or other biorefinery products, and thus compete with chemicals produced from fossil sources, additional efforts are needed to reduce costs and maximize yield and efficiency of the produced enzyme mixtures. One approach to this end is the use of genetic engineering to manipulate the biochemical and regulatory pathways that operate during enzyme production and control enzyme yield. This review aims at a description of the state of art in this area.
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Affiliation(s)
- Bernhard Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorferstraße 1a, 166-5, A-1060, Vienna, Austria
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Wei X, Zheng K, Chen M, Liu G, Li J, Lei Y, Qin Y, Qu Y. Transcription analysis of lignocellulolytic enzymes of Penicillium decumbens 114-2 and its catabolite-repression-resistant mutant. C R Biol 2011; 334:806-11. [PMID: 22078737 DOI: 10.1016/j.crvi.2011.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Penicillium decumbens 114-2 is a fast-growing filamentous fungus which secretes a variety of lignocellulolytic enzymes. Its catabolite-repression-resistant mutant JU-A10 with high secretion capacity of cellulolytic enzymes has been used industrially for biomass hydrolysis. Transcription levels of 6 important lignocellulolytic enzymes genes (cel5A, cel6A, cel7A, cel7B, xyn10A, and xyn11A) from both strains were determined on different carbon sources (glucose, sorbose, lactose, cellobiose, cellulose, and cellulose-wheat bran), by means of a real-time quantitative polymerase chain reaction. For both strains, the 6 genes are coordinately regulated at transcriptional level. Glucose and cellobiose repressed whereas cellulose and cellulose-wheat bran induced expression of 6 genes in both strains. Expression levels of all genes tested in the mutant strain JU-A10 were substantially higher than those in wild-type strain 114-2 on all carbon sources. On glucose repression condition, the mutant JU-A10 appeared obviously derepressed. Lactose was first proved to have an inductive effect on lignocellulolytic enzyme genes expression at lower concentration in Penicillium spp.
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Affiliation(s)
- Xiaomin Wei
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, PR China
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Jun H, Kieselbach T, Jönsson LJ. Enzyme production by filamentous fungi: analysis of the secretome of Trichoderma reesei grown on unconventional carbon source. Microb Cell Fact 2011; 10:68. [PMID: 21861877 PMCID: PMC3179704 DOI: 10.1186/1475-2859-10-68] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 08/23/2011] [Indexed: 12/17/2022] Open
Abstract
Background Spent hydrolysates from bioethanolic fermentation processes based on agricultural residues have potential as an abundant and inexpensive source of pentose sugars and acids that could serve as nutrients for industrial enzyme-producing microorganisms, especially filamentous fungi. However, the enzyme mixtures produced in such media are poorly defined. In this study, the secretome of Trichoderma reesei Rut C-30 grown either on a spent hydrolysate model medium (SHMM) or on a lactose-based standard medium (LBSM) was explored using proteomics. Results Our results show that both the SHMM and LBSM serve as excellent growth media for T. reesei Rut C-30. In total, 52 protein spots on 2-D gels were identified by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and electrospray ionization liquid chromatography tandem mass spectrometry (ESI-LC MS/MS). As expected, a considerable number of the identified proteins were related to the degradation of lignocellulosic biomass. The enzyme production profiles in the two media were similar, but β-glucosidase and β-galactosidase were only produced in LBSM. The main cellobiohydrolases (Cel7A/Cel6A) and endoglucanases (Cel7B/Cel5A) were identified in both media and the cellobiohydrolases, i.e. Cel7A and Cel6A, were the most abundant cellulolytic enzymes. Moreover, both media can also serve as a potent inducer of xylanolytic enzymes. Several key enzymes involved in sugar assimilation and regulation of cellulase formation were identified, and were found to be differentially expressed in the two growth media. Conclusions This study not only provides a catalogue of the prevalent proteins secreted by T. reesei in the two media, but the results also suggest that production of hydrolytic enzymes using unconventional carbon sources, such as components in spent hydrolysates, deserves further attention in the future.
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Affiliation(s)
- He Jun
- Department of Chemistry, Umeå University, Umeå, Sweden.
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Unique regulatory mechanism for D-galactose utilization in Aspergillus nidulans. Appl Environ Microbiol 2011; 77:7084-7. [PMID: 21821745 DOI: 10.1128/aem.05290-11] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study describes two novel regulators, GalX and GalR, that control d-galactose utilization in Aspergillus nidulans. This system is unique for A. nidulans since no GalR homologs were found in other ascomycetes. GalR shares significant sequence identity with the arabinanolytic and xylanolytic regulators AraR and XlnR, but GalX is more distantly related.
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Portnoy T, Margeot A, Linke R, Atanasova L, Fekete E, Sándor E, Hartl L, Karaffa L, Druzhinina IS, Seiboth B, Le Crom S, Kubicek CP. The CRE1 carbon catabolite repressor of the fungus Trichoderma reesei: a master regulator of carbon assimilation. BMC Genomics 2011; 12:269. [PMID: 21619626 PMCID: PMC3124439 DOI: 10.1186/1471-2164-12-269] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 05/27/2011] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The identification and characterization of the transcriptional regulatory networks governing the physiology and adaptation of microbial cells is a key step in understanding their behaviour. One such wide-domain regulatory circuit, essential to all cells, is carbon catabolite repression (CCR): it allows the cell to prefer some carbon sources, whose assimilation is of high nutritional value, over less profitable ones. In lower multicellular fungi, the C2H2 zinc finger CreA/CRE1 protein has been shown to act as the transcriptional repressor in this process. However, the complete list of its gene targets is not known. RESULTS Here, we deciphered the CRE1 regulatory range in the model cellulose and hemicellulose-degrading fungus Trichoderma reesei (anamorph of Hypocrea jecorina) by profiling transcription in a wild-type and a delta-cre1 mutant strain on glucose at constant growth rates known to repress and de-repress CCR-affected genes. Analysis of genome-wide microarrays reveals 2.8% of transcripts whose expression was regulated in at least one of the four experimental conditions: 47.3% of which were repressed by CRE1, whereas 29.0% were actually induced by CRE1, and 17.2% only affected by the growth rate but CRE1 independent. Among CRE1 repressed transcripts, genes encoding unknown proteins and transport proteins were overrepresented. In addition, we found CRE1-repression of nitrogenous substances uptake, components of chromatin remodeling and the transcriptional mediator complex, as well as developmental processes. CONCLUSIONS Our study provides the first global insight into the molecular physiological response of a multicellular fungus to carbon catabolite regulation and identifies several not yet known targets in a growth-controlled environment.
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Affiliation(s)
- Thomas Portnoy
- IFP Energies nouvelles, Département Biotechnologie, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison Cedex, France
- École normale supérieure, Institut de Biologie de l'ENS, IBENS, Paris, F-75005 France. Inserm, U1024, Paris, F-75005 France. CNRS, UMR 8197, Paris, F-75005 France
| | - Antoine Margeot
- IFP Energies nouvelles, Département Biotechnologie, 1-4 Avenue de Bois-Préau, 92852 Rueil-Malmaison Cedex, France
| | - Rita Linke
- Austrian Center of Industrial Biotechnology, c/o Institute of Chemical Engineering, Technische Universität Wien, Getreidemarkt 9/166, A-1060 Vienna, Austria
| | - Lea Atanasova
- Research Area Gene Technology and Applied Biochemistry, Institute of ChemicalEngineering, Technische Universität Wien, Getreidemarkt 9/166, A-1060 Vienna, Austria
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4010, P.O.Box 56, Debrecen, Hungary
| | - Erzsébet Sándor
- Department of Plant Protection, Faculty of Agriculture and Food Sciences and Environmental Management, University of Debrecen, H-4032 Böszörményi út 138., Debrecen, Hungary
| | - Lukas Hartl
- Research Area Gene Technology and Applied Biochemistry, Institute of ChemicalEngineering, Technische Universität Wien, Getreidemarkt 9/166, A-1060 Vienna, Austria
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, H-4010, P.O.Box 56, Debrecen, Hungary
| | - Irina S Druzhinina
- Research Area Gene Technology and Applied Biochemistry, Institute of ChemicalEngineering, Technische Universität Wien, Getreidemarkt 9/166, A-1060 Vienna, Austria
| | - Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of ChemicalEngineering, Technische Universität Wien, Getreidemarkt 9/166, A-1060 Vienna, Austria
| | - Stéphane Le Crom
- École normale supérieure, Institut de Biologie de l'ENS, IBENS, Paris, F-75005 France. Inserm, U1024, Paris, F-75005 France. CNRS, UMR 8197, Paris, F-75005 France
| | - Christian P Kubicek
- Research Area Gene Technology and Applied Biochemistry, Institute of ChemicalEngineering, Technische Universität Wien, Getreidemarkt 9/166, A-1060 Vienna, Austria
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Rosso LC, Finetti-Sialer MM, Hirsch PR, Ciancio A, Kerry BR, Clark IM. Transcriptome analysis shows differential gene expression in the saprotrophic to parasitic transition of Pochonia chlamydosporia. Appl Microbiol Biotechnol 2011; 90:1981-94. [PMID: 21541788 DOI: 10.1007/s00253-011-3282-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 03/25/2011] [Accepted: 03/26/2011] [Indexed: 11/26/2022]
Abstract
Expression profiles were identified in the fungus Pochonia chlamydosporia, a biological control agent of plant parasitic nematodes, through a cDNA-amplified fragment length polymorphism approach. Two isolates with different host ranges, IMI 380407 and IMI 331547, were assayed in conditions of saprotrophic-to-parasitic transition, through in vitro assays. Gene expression profiles from three different nutritional conditions and four sampling times were generated, with eggs of host nematodes Globodera pallida and Meloidogyne incognita. Expression of transcripts changed in RNA fingerprints obtained under different nutritional stresses (starvation in presence/absence of eggs, or rich growth media). Transcript derived fragments (TDFs) obtained from the expression profiles corresponded to 6,800 products. A subset was sequenced and their expression profile confirmed through RT PCR. A total of 57 TDFs were selected for further analysis, based on similarities to translated or annotated sequences. Genes expressed during egg parasitism for both IMI 380407 and IMI 331547 were involved in metabolic functions, cellular signal regulation, cellular transport, regulation of gene expression, DNA repair, and other unknown functions. Multivariate analysis of TDF expression showed three groups for IMI 380407 and one for IMI 331547, each characterized by expression of genes related to eggs parasitism. Common amplification profiles among TDF clusters from both isolates also reflected a pool of constitutive genes, not affected by the nutritional conditions and nematode associations, related to general metabolic functions. The differential expression of parasitism related genes suggest a network of induced/repressed products, playing a role in fungal signaling and infection, with partial overlaps in host infection and parasitism traits.
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Affiliation(s)
- Laura C Rosso
- Istituto per la Protezione delle Piante, Consiglio Nazionale delle Ricerche, Via G. Amendola 165/A, Bari, Italy
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Differential regulation of the cellulase transcription factors XYR1, ACE2, and ACE1 in Trichoderma reesei strains producing high and low levels of cellulase. EUKARYOTIC CELL 2010; 10:262-71. [PMID: 21169417 DOI: 10.1128/ec.00208-10] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Due to its capacity to produce large amounts of cellulases, Trichoderma reesei is increasingly being investigated for second-generation biofuel production from lignocellulosic biomass. The induction mechanisms of T. reesei cellulases have been described recently, but the regulation of the genes involved in their transcription has not been studied thoroughly. Here we report the regulation of expression of the two activator genes xyr1 and ace2, and the corepressor gene ace1, during the induction of cellulase biosynthesis by the inducer lactose in T. reesei QM 9414, a strain producing low levels of cellulase (low producer). We show that all three genes are induced by lactose. xyr1 was also induced by d-galactose, but this induction was independent of d-galactose metabolism. Moreover, ace1 was carbon catabolite repressed, whereas full induction of xyr1 and ace2 in fact required CRE1. Significant differences in these regulatory patterns were observed in the high-producer strain RUT C30 and the hyperproducer strain T. reesei CL847. These observations suggest that a strongly elevated basal transcription level of xyr1 and reduced upregulation of ace1 by lactose may have been important for generating the hyperproducer strain and that thus, these genes are major control elements of cellulase production.
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Lactose-Enhanced Cellulase Production by Microbacterium sp. Isolated from Fecal Matter of Zebra (Equus zebra). Curr Microbiol 2010; 62:1050-5. [DOI: 10.1007/s00284-010-9816-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 11/03/2010] [Indexed: 11/25/2022]
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Comparison of endoglucanase-1 (EG1) induction in the edible straw mushroom Volvariella volvacea by lactose and/or cellobiose with or without added sorbose. Appl Microbiol Biotechnol 2010; 89:1939-46. [DOI: 10.1007/s00253-010-2995-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 10/25/2010] [Accepted: 10/28/2010] [Indexed: 11/30/2022]
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Roles of extracellular lactose hydrolysis in cellulase production by Trichoderma reesei Rut C30 using lactose as inducing substrate. Process Biochem 2010. [DOI: 10.1016/j.procbio.2010.05.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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39
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Characterisation of specific activities and hydrolytic properties of cell-wall-degrading enzymes produced by Trichoderma reesei Rut C30 on different carbon sources. Appl Biochem Biotechnol 2009; 161:347-64. [PMID: 19898963 DOI: 10.1007/s12010-009-8824-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 10/13/2009] [Indexed: 10/20/2022]
Abstract
Conversion of lignocellulosic substrates is limited by several factors, in terms of both the enzymes and the substrates. Better understanding of the hydrolysis mechanisms and the factors determining their performance is crucial for commercial lignocelluloses-based processes. Enzymes produced on various carbon sources (Solka Floc 200, lactose and steam-pre-treated corn stover) by Trichoderma reesei Rut C30 were characterised by their enzyme profile and hydrolytic performance. The results showed that there was a clear correlation between the secreted amount of xylanase and mannanase enzymes and that their production was induced by the presence of xylan in the carbon source. Co-secretion of alpha-arabinosidase and alpha-galactosidase was also observed. Secretion of beta-glucosidase was found to be clearly dependent on the composition of the carbon source, and in the case of lactose, 2-fold higher specific activity was observed compared to Solka Floc and steam-pre-treated corn stover. Hydrolysis experiments showed a clear connection between glucan and xylan conversion and highlighted the importance of beta-glucosidase and xylanase activities. When hydrolysis was performed using additional purified beta-glucosidase and xylanase, the addition of beta-glucosidase was found to significantly improve both the xylan and glucan conversion.
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Kubicek CP, Mikus M, Schuster A, Schmoll M, Seiboth B. Metabolic engineering strategies for the improvement of cellulase production by Hypocrea jecorina. BIOTECHNOLOGY FOR BIOFUELS 2009; 2:19. [PMID: 19723296 PMCID: PMC2749017 DOI: 10.1186/1754-6834-2-19] [Citation(s) in RCA: 244] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2009] [Accepted: 09/01/2009] [Indexed: 05/05/2023]
Abstract
Hypocrea jecorina (= Trichoderma reesei) is the main industrial source of cellulases and hemicellulases used to depolymerise plant biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. Cellulases are formed adaptively, and several positive (XYR1, ACE2, HAP2/3/5) and negative (ACE1, CRE1) components involved in this regulation are now known. In addition, its complete genome sequence has been recently published, thus making the organism susceptible to targeted improvement by metabolic engineering. In this review, we summarise current knowledge about how cellulase biosynthesis is regulated, and outline recent approaches and suitable strategies for facilitating the targeted improvement of cellulase production by genetic engineering.
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Affiliation(s)
- Christian P Kubicek
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt, A-1060 Vienna, Austria
| | - Marianna Mikus
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt, A-1060 Vienna, Austria
| | - André Schuster
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt, A-1060 Vienna, Austria
| | - Monika Schmoll
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt, A-1060 Vienna, Austria
| | - Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt, A-1060 Vienna, Austria
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Sophorolipids-induced cellulase production in cocultures of Hypocrea jecorina Rut C30 and Candida bombicola. Enzyme Microb Technol 2009. [DOI: 10.1016/j.enzmictec.2008.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Induction of the galactose enzymes in Escherichia coli is independent of the C-1-hydroxyl optical configuration of the inducer D-galactose. J Bacteriol 2008; 190:7932-8. [PMID: 18931131 DOI: 10.1128/jb.01008-08] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The two optical forms of aldohexose galactose differing at the C-1 position, alpha-D-galactose and beta-D-galactose, are widespread in nature. The two anomers also occur in di- and polysaccharides, as well as in glycoconjugates. The anomeric form of D-galactose, when present in complex carbohydrates, e.g., cell wall, glycoproteins, and glycolipids, is specific. Their interconversion occurs as monomers and is effected by the enzyme mutarotase (aldose-1-epimerase). Mutarotase and other D-galactose-metabolizing enzymes are coded by genes that constitute an operon in Escherichia coli. The operon is repressed by the repressor GalR and induced by D-galactose. Since, depending on the carbon source during growth, the cell can make only one of the two anomers of D-galactose, the cell must also convert one anomer to the other for use in specific biosynthetic pathways. Thus, it is imperative that induction of the gal operon, specifically the mutarotase, be achievable by either anomer of D-galactose. Here we report in vivo and in vitro experiments showing that both alpha-D-galactose and beta-D-galactose are capable of inducing transcription of the gal operon with equal efficiency and kinetics. Whereas all substitutions at the C-1 position in the alpha configuration inactivate the induction capacity of the sugar, the effect of substitutions in the beta configuration varies depending upon the nature of the substitution; methyl and phenyl derivatives induce weakly, but the glucosyl derivative does not.
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Fang X, Yano S, Inoue H, Sawayama S. Lactose enhances cellulase production by the filamentous fungus Acremonium cellulolyticus. J Biosci Bioeng 2008; 106:115-20. [DOI: 10.1263/jbb.106.115] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 04/27/2008] [Indexed: 11/17/2022]
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Fekete E, Seiboth B, Kubicek CP, Szentirmai A, Karaffa L. Lack of aldose 1-epimerase in Hypocrea jecorina (anamorph Trichoderma reesei): a key to cellulase gene expression on lactose. Proc Natl Acad Sci U S A 2008; 105:7141-6. [PMID: 18480250 PMCID: PMC2438218 DOI: 10.1073/pnas.0802789105] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Indexed: 11/18/2022] Open
Abstract
The heterodisaccharide lactose (1,4-O-beta-D-galactopyranosyl-D-glucose) induces cellulase formation in the ascomycete Hypocrea jecorina (= Trichoderma reesei). Lactose assimilation is slow, and the assimilation of its beta-D-galactose moiety depends mainly on the operation of a recently described reductive pathway and depends less on the Leloir pathway, which accepts only alpha-D-galactose. We therefore reasoned whether galactomutarotase [aldose 1-epimerase (AEP)] activity might limit lactose assimilation and thus influence cellulase formation. We identified three putative AEP-encoding genes (aep1, aep2, aep3) in H. jecorina, of which two encoded intracellular protein (AEP1 and AEP2) and one encoded an extracellular protein (AEP3). Although all three were transcribed, only the aep3 transcript was detected on lactose. However, no mutarotase activity was detected in the mycelia, their cell walls, or the extracellular medium during growth on lactose. Therefore, the effect of galactomutarotase activity on lactose assimilation was studied with H. jecorina strains expressing the C-terminal galactose mutarotase part of the Saccharomyces cerevisiae Gal10. These strains showed increased growth on lactose in a gene copy number-dependent manner, although their formation of extracellular beta-galactosidase activity and transcription of the genes encoding the first steps in the Leloir and the reductive pathway was similar to the parental strain QM9414. Cellulase gene transcription on lactose dramatically decreased in these strains, but remained unaffected during growth on cellulose. Our data show that cellulase induction in H. jecorina by lactose requires the beta-anomer of D-galactose and reveal the lack of mutarotase activity during growth on lactose as an important key for cellulase formation on this sugar.
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Affiliation(s)
- Erzsébet Fekete
- *Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 56, H-4010, Debrecen, Hungary; and
| | - Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/1665, A-1060 Vienna, Austria
| | - Christian P. Kubicek
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/1665, A-1060 Vienna, Austria
| | - Attila Szentirmai
- *Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 56, H-4010, Debrecen, Hungary; and
| | - Levente Karaffa
- *Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 56, H-4010, Debrecen, Hungary; and
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Seiboth B, Gamauf C, Pail M, Hartl L, Kubicek CP. The d-xylose reductase of Hypocrea jecorina is the major aldose reductase in pentose and d-galactose catabolism and necessary for β-galactosidase and cellulase induction by lactose. Mol Microbiol 2007; 66:890-900. [DOI: 10.1111/j.1365-2958.2007.05953.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Stricker AR, Steiger MG, Mach RL. Xyr1 receives the lactose induction signal and regulates lactose metabolism in Hypocrea jecorina. FEBS Lett 2007; 581:3915-20. [PMID: 17662982 DOI: 10.1016/j.febslet.2007.07.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 07/01/2007] [Accepted: 07/08/2007] [Indexed: 11/29/2022]
Abstract
This study reports the vital regulatory influence of Xyr1 (xylanase regulator 1) on the transcription of hydrolytic enzyme-encoding genes and hydrolase formation on lactose in Hypocrea jecorina. While the transcription of the xyr1 gene itself is achieved by release of carbon catabolite repression, the transcript formation of xyn1 (xylanase 1) is regulated by an additional induction mechanism mediated by lactose. Xyr1 has an important impact on lactose metabolism by directly activating xyl1 (xylose reductase 1) transcription and indirectly influencing transcription of bga1 (beta-galactosidase 1). The latter is achieved by regulating the conversion of D-galactose to the inducing carbon source galactitol.
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Affiliation(s)
- Astrid R Stricker
- Gene Technology, Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166/5/2, A-1060 Wien, Austria
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Hartl L, Kubicek CP, Seiboth B. Induction of the gal pathway and cellulase genes involves no transcriptional inducer function of the galactokinase in Hypocrea jecorina. J Biol Chem 2007; 282:18654-18659. [PMID: 17452322 DOI: 10.1074/jbc.m700955200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Saccharomyces cerevisiae galactokinase ScGal1, a key enzyme for D-galactose metabolism, catalyzes the conversion of D-galactose to D-galactose 1-phosphate, whereas its catalytically inactive paralogue, ScGal3, activates the transcription of the GAL pathway genes. In Kluyveromyces lactis the transcriptional inducer function and the galactokinase activity are encoded by a single bifunctional KlGal1. Here, we investigated the cellular function of the single galactokinase GAL1 in the multicellular ascomycete Hypocrea jecorina (=Trichoderma reesei) in the induction of the gal genes and of the galactokinase-dependent induction of the cellulase genes by lactose (1,4-O-beta-D-galactopyranosyl-D-glucose). A comparison of the transcriptional response of a strain deleted in the gal1 gene (no putative transcriptional inducer and no galactokinase activity), a strain expressing a catalytically inactive GAL1 version (no galactokinase activity but a putative inducer function), and a strain expressing the Escherichia coli galK (no putative transcriptional inducer but galactokinase activity) showed that, in contrast to the two yeasts, both the GAL1 protein and the galactokinase activity are fully dispensable for induction of the Leloir pathway gene gal7 by D-galactose and that only the galactokinase activity is required for cellulase induction by lactose. The data document a fundamental difference in the mechanisms by which yeasts and multicellular fungi respond to the presence of D-galactose, showing that the Gal1/Gal3-Gal4-Gal80-dependent regulatory circuit does not operate in multicellular fungi.
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Affiliation(s)
- Lukas Hartl
- Molecular Biotechnology Group, Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Technische Universität Wien, Getreidemarkt 9-166.5, A-1060 Vienna, Austria.
| | - Christian P Kubicek
- Molecular Biotechnology Group, Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Technische Universität Wien, Getreidemarkt 9-166.5, A-1060 Vienna, Austria
| | - Bernhard Seiboth
- Molecular Biotechnology Group, Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Technische Universität Wien, Getreidemarkt 9-166.5, A-1060 Vienna, Austria
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Seiboth B, Pakdaman BS, Hartl L, Kubicek CP. Lactose metabolism in filamentous fungi: how to deal with an unknown substrate. FUNGAL BIOL REV 2007. [DOI: 10.1016/j.fbr.2007.02.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fekete E, Karaffa L, Kubicek CP, Szentirmai A, Seiboth B. Induction of extracellular β-galactosidase (Bga1) formation by d-galactose in Hypocrea jecorina is mediated by galactitol. Microbiology (Reading) 2007; 153:507-512. [PMID: 17259622 DOI: 10.1099/mic.0.2006/001602-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ability of Hypocrea jecorina (Trichoderma reesei) to grow on lactose strongly depends on the formation of an extracellular glycoside hydrolase (GH) family 35 beta-galactosidase, encoded by the bga1 gene. Previous studies, using batch or transfer cultures of pregrown cells, had shown that bga1 is induced by lactose and d-galactose, but to a lesser extent by galactitol. To test whether the induction level is influenced by the different growth rates attainable on these carbon sources, bga1 expression was compared in carbon-limited chemostat cultivations at defined dilution (=specific growth) rates. The data showed that bga1 expression by lactose, d-galactose and galactitol positively correlated with the dilution rate, and that galactitol and d-galactose induced the highest activities of beta-galactosidase at comparable growth rates. To know more about the actual inducer for beta-galactosidase formation, its expression in H. jecorina strains impaired in the first steps of the two d-galactose-degrading pathways was compared. Induction by d-galactose and galactitol was still found in strains deleted in the galactokinase-encoding gene gal1, which is responsible for the first step of the Leloir pathway of d-galactose catabolism. However, in a strain deleted in the aldose/d-xylose reductase gene xyl1, which performs the reduction of d-galactose to galactitol in a recently identified second pathway, induction by d-galactose, but not by galactitol, was impaired. On the other hand, induction by d-galactose and galactitol was not affected in an l-arabinitol 4-dehydrogenase (lad1)-deleted strain which is impaired in the subsequent step of galactitol degradation. These results indicate that galactitol is the actual inducer of Bga1 formation during growth on d-galactose in H. jecorina.
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Affiliation(s)
- Erzsébet Fekete
- Department of Genetics and Applied Microbiology, Faculty of Science, University of Debrecen, H-4010, PO Box 56, Debrecen, Hungary
| | - Levente Karaffa
- Department of Genetics and Applied Microbiology, Faculty of Science, University of Debrecen, H-4010, PO Box 56, Debrecen, Hungary
| | - Christian P Kubicek
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166-5, A-1060 Wien, Austria
| | - Attila Szentirmai
- Department of Genetics and Applied Microbiology, Faculty of Science, University of Debrecen, H-4010, PO Box 56, Debrecen, Hungary
| | - Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166-5, A-1060 Wien, Austria
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