1
|
Schalamun M, Molin EM, Schmoll M. RGS4 impacts carbohydrate and siderophore metabolism in Trichoderma reesei. BMC Genomics 2023; 24:372. [PMID: 37400774 PMCID: PMC10316542 DOI: 10.1186/s12864-023-09467-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/20/2023] [Indexed: 07/05/2023] Open
Abstract
BACKGROUND Adaptation to complex, rapidly changing environments is crucial for evolutionary success of fungi. The heterotrimeric G-protein pathway belongs to the most important signaling cascades applied for this task. In Trichoderma reesei, enzyme production, growth and secondary metabolism are among the physiological traits influenced by the G-protein pathway in a light dependent manner. RESULTS Here, we investigated the function of the SNX/H-type regulator of G-protein signaling (RGS) protein RGS4 of T. reesei. We show that RGS4 is involved in regulation of cellulase production, growth, asexual development and oxidative stress response in darkness as well as in osmotic stress response in the presence of sodium chloride, particularly in light. Transcriptome analysis revealed regulation of several ribosomal genes, six genes mutated in RutC30 as well as several genes encoding transcription factors and transporters. Importantly, RGS4 positively regulates the siderophore cluster responsible for fusarinine C biosynthesis in light. The respective deletion mutant shows altered growth on nutrient sources related to siderophore production such as ornithine or proline in a BIOLOG phenotype microarray assay. Additionally, growth on storage carbohydrates as well as several intermediates of the D-galactose and D-arabinose catabolic pathway is decreased, predominantly in light. CONCLUSIONS We conclude that RGS4 mainly operates in light and targets plant cell wall degradation, siderophore production and storage compound metabolism in T. reesei.
Collapse
Affiliation(s)
- Miriam Schalamun
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
| | - Eva Maria Molin
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Center for Health & Bioresources, Konrad Lorenz Strasse 24, Tulln, 3430 Austria
- Division of Terrestrial Ecosystem Research, Centre of Microbiology and Ecosystem Science, University of Vienna, Djerassiplatz 1, Vienna, 1030 Austria
| |
Collapse
|
2
|
Affiliation(s)
- Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria; Department of Microbiology and Ecosystem Science, Division of Terrestrial Ecosystem Research, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria.
| |
Collapse
|
3
|
Martzy R, Mello-de-Sousa TM, Mach RL, Yaver D, Mach-Aigner AR. The phenomenon of degeneration of industrial Trichoderma reesei strains. Biotechnol Biofuels 2021; 14:193. [PMID: 34598727 PMCID: PMC8487154 DOI: 10.1186/s13068-021-02043-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Even if the loss of production capacity of a microorganism is said to be a serious problem in various biotechnology industries, reports in literature are rather rare. Strains of the genera Trichoderma reesei are used for large-scale production of cellulases, which are needed in food and feed, textile, paper industries and biofuel production. RESULTS Here, we describe the phenomenon of spontaneous degeneration of T. reesei strains during large-scale cultivation. The phenotype of the degenerated population is characterized most importantly by a loss of any cellulase formation. Interestingly, promoter regions of relevant genes had a more compact chromatin in the (cel -) strains compared to productive strains. For a systematic investigation of the phenomenon a protocol for artificially induced and lab-scaled strain degeneration was developed. This workflow allows to determine the degeneration rate and thus, to compare the occurrence of a degenerated population in differently productive strains on the one hand, and to monitor the success of any strategies to prevent or decrease the degeneration on the other hand. While highly productive strains have higher degeneration rates compared to moderate producers, the degeneration can hardly be triggered in moderate producers. The observed (cel -) phenotype is not caused by a mutation in the gene encoding the essential transactivator Xyr1. The development of a non-producing population is also not triggered by any compounds released by either producing or non-producing cells. CONCLUSIONS The extent of the occurrence of a degenerated strain population relates to the production capacity of the strain and goes along with chromatin condensation in relevant promoter regions.
Collapse
Affiliation(s)
- R Martzy
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-Active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060, Vienna, Austria
| | - T M Mello-de-Sousa
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-Active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060, Vienna, Austria
| | - R L Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060, Vienna, Austria
| | - D Yaver
- Production Strain Technology, Novozymes Inc., Davis, CA, USA
| | - A R Mach-Aigner
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-Active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060, Vienna, Austria.
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060, Vienna, Austria.
| |
Collapse
|
4
|
Chen X, Song B, Liu M, Qin L, Dong Z. Understanding the Role of Trichoderma reesei Vib1 in Gene Expression during Cellulose Degradation. J Fungi (Basel) 2021; 7:jof7080613. [PMID: 34436152 PMCID: PMC8397228 DOI: 10.3390/jof7080613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
Vib1, a member of the Ndt80/PhoG-like transcription factor family, has been shown to be essential for cellulase production of Trichoderma reesei. Here, we combined transcriptomic and genetic analyses to gain mechanistic insights into the roles of Vib1 during cellulose degradation. Our transcriptome analysis showed that the vib1 deletion caused 586 genes with decreased expression and 431 genes with increased expression on cellulose. The downregulated genes were enriched for Gene Ontology terms associated with carbohydrate metabolism, transmembrane transport, oxidoreductase activity, and transcription factor activity. Of the 258 genes induced by cellulose, 229 showed no or decreased expression in Δvib1 on cellulose, including almost all (hemi)cellulase genes, crucial sugar transporter genes (IDs:69957, 3405), and the genes encoding main transcriptional activators Xyr1 and Ace3. Additionally, Vib1 also regulated the expression of genes involved in secondary metabolism. Further comparison of the transcriptomes of Δvib1 and Δxyr1 in cellulose revealed that the genes regulated by Vib1 had much overlap with Xyr1 targets especially for the gene set induced by cellulose, presumably whose expression requires the cooperativity between Vib1 and Xyr1. Genetic evidence indicated that Vib1 regulates cellulase gene expression partially via Xyr1. Our results will provide new clues for strain improvement.
Collapse
Affiliation(s)
- Xiuzhen Chen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Bingran Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Minglu Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
| | - Lina Qin
- National and Local Joint Engineering Research Center of Industrial Microbiology and Fermentation Technology, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China;
| | - Zhiyang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; (X.C.); (B.S.); (M.L.)
- Correspondence:
| |
Collapse
|
5
|
Hinterdobler W, Li G, Spiegel K, Basyouni-Khamis S, Gorfer M, Schmoll M. Trichoderma reesei Isolated From Austrian Soil With High Potential for Biotechnological Application. Front Microbiol 2021; 12:552301. [PMID: 33584603 PMCID: PMC7876326 DOI: 10.3389/fmicb.2021.552301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 01/12/2021] [Indexed: 11/24/2022] Open
Abstract
Fungi of the genus Trichoderma are of high importance for biotechnological applications, in biocontrol and for production of homologous and heterologous proteins. However, sexual crossing under laboratory conditions has so far only been achieved with the species Trichoderma reesei, which was so far only isolated from tropical regions. Our isolation efforts aimed at the collection of Trichoderma strains from Austrian soils surprisingly also yielded 12 strains of the species T. reesei, which was previously not known to occur in Europe. Their identity was confirmed with tef1- and rpb2-sequencing and phylogenetic analysis. They could clearly be distinguished from tropical strains including the common laboratory wildtypes by UP-PCR and genetic variations adjacent to the mating type locus. The strains readily mated with reference strains derived from CBS999.97. Secreted cellulase and xylanase levels of these isolates were up to six-fold higher than those of QM6a indicating a high potential for strain improvement. The strains showed different responses to injury in terms of induction of sporulation, but a correlation to alterations in the nox1-gene sequence was not detected. Several synonymous SNPs were found in the sequence of the regulator gene noxR of the soil isolates compared to QM6a. Only in one strain, non-synonymous SNPs were found which impact a PEST sequence of NoxR, suggesting altered protein stability. The availability of sexually fertile strains from middle Europe naturally producing decent amounts of plant cell wall degrading enzymes opens up novel perspectives for non-GMO strain improvement and biological pretreatment of plant biomass for bioethanol production. Moreover, the varied response of these strains to injury in terms of sporulation, which is independent of Nox1 and NoxR suggests that additional regulators impact this phenomenon in T. reesei.
Collapse
Affiliation(s)
- Wolfgang Hinterdobler
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Guofen Li
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Katharina Spiegel
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Samira Basyouni-Khamis
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria.,Department of Sustainable Agricultural Systems, Institute of Agricultural Engineering, University of Natural Resources and Life Sciences Vienna, Tulln, Austria
| | - Markus Gorfer
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Monika Schmoll
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| |
Collapse
|
6
|
Beier S, Hinterdobler W, Monroy AA, Bazafkan H, Schmoll M. The Kinase USK1 Regulates Cellulase Gene Expression and Secondary Metabolite Biosynthesis in Trichoderma reesei. Front Microbiol 2020; 11:974. [PMID: 32508786 PMCID: PMC7251307 DOI: 10.3389/fmicb.2020.00974] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/22/2020] [Indexed: 01/04/2023] Open
Abstract
The complex environment of fungi requires a delicate balance between the efforts to acquire nutrition, to reproduce, and to fend off competitors. In Trichoderma reesei, an interrelationship between regulation of enzyme gene expression and secondary metabolism was shown. In this study, we investigated the physiological relevance of the unique YPK1-type kinase USK1 of T. reesei. Usk1 is located in the vicinity of the SOR cluster and is involved in regulation of several genes from this secondary metabolite cluster as well as dihydrotrichotetronine and other secondary metabolites. Moreover, USK1 is required for biosynthesis of normal levels of secondary metabolites in liquid culture. USK1 positively influences cellulase gene regulation, secreted cellulase activity, and biomass formation upon growth in constant darkness on cellulose. Positive effects of USK1 on transcript abundance of the regulator of secondary metabolism, vel1, and the carbon catabolite repressor gene cre1 are in agreement with these functions. In summary, we found that with USK1, T. reesei comprises a unique kinase that adds an additional layer of regulation to the connection of secondary metabolism and enzyme production in fungi.
Collapse
Affiliation(s)
- Sabrina Beier
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Wolfgang Hinterdobler
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Alberto Alonso Monroy
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Hoda Bazafkan
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Monika Schmoll
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| |
Collapse
|
7
|
Mota EA, Felestrino ÉB, Leão VA, Guerra-Sá R. Manganese (II) removal from aqueous solutions by Cladosporium halotolerans and Hypocrea jecorina. Biotechnol Rep (Amst) 2020; 25:e00431. [PMID: 32071895 PMCID: PMC7013165 DOI: 10.1016/j.btre.2020.e00431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 01/20/2020] [Accepted: 02/03/2020] [Indexed: 11/26/2022]
Abstract
Manganese (Mn) is toxic at higher concentrations requiring its removal before returning the wastewater to the environment. This article reported the Mn removal of two fungi strains isolated from mine wastewater. ITS rRNA region sequencing identified the fungi strains as Cladosporium halotolerans and Hypocrea jecorina. Mn2+ removal assays were performed in Sabouraud broth with 50 mg L-1 Mn2+ supplemented and bioleaching assays using MnO2 instead of MnSO4 at the same conditions. C. halotolerans removed 96 % of 50 mg L-1 Mn2+ at two weeks without MnO2 bioleaching with 649.9 mg of biomass and H. jecorina removed about 50 % of Mn2+ in 21 days from initial 50 mg of Mn2+ L-1 with 316.8 mg of biomass. Extracellular laccases were present in C. halotolerans agar regardless of the Mn addition. Mn adsorbed was detected on C. halotolerans hyphae. Mn oxidation was positive to H. jecorina by reaction of its medium with Leucoberbelin blue.
Collapse
Key Words
- ABTS, 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)
- CTAB, Hexadecyltrimethylammonium bromide
- Chelating
- Cladosporium halotolerans
- EDX, Energy-dispersive spectroscopy
- Hypocrea jecorina
- ITS, Intergenic Spacer
- LAC1/2, Laccase genes 1/2
- LBB, Leucoberbelin blue or N.N'-Dimethylamino-β, β'-triphenylmethane-o-sulphonic acid
- Manganese
- Mcos, Multicopper oxidases
- Mn oxidation
- PCR, Polymerase Chain Reaction
- SEM, Scanning electronic microscopy
- nBLAST, nucleotide Basic Local Alignment Search Tool
- rRNA, ribosomal Ribonucleic Acid
Collapse
Affiliation(s)
- Ester Alves Mota
- Biochemistry and Molecular Biology Laboratory, Department of Biological Sciences, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG, Brazil
| | - Érica Barbosa Felestrino
- Biochemistry and Molecular Biology Laboratory, Department of Biological Sciences, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG, Brazil
| | - Versiane Albis Leão
- Bio & Hydrometallurgy Laboratory, Department of Metallurgical and Materials Engineering, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, MG, Ouro Preto, Brazil
| | - Renata Guerra-Sá
- Biochemistry and Molecular Biology Laboratory, Department of Biological Sciences, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG, Brazil,Corresponding author. Present address: Universidade Federal de Ouro Preto, Departamento de Ciências Biológicas/ Núcleo de Pesquisas em Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, ICEB 2, Sala 045 Campus Morro do Cruzeiro, 35400-000, Ouro Preto, MG, Brazil.
| |
Collapse
|
8
|
Beier S, Hinterdobler W, Bazafkan H, Schillinger L, Schmoll M. CLR1 and CLR2 are light dependent regulators of xylanase and pectinase genes in Trichoderma reesei. Fungal Genet Biol 2019; 136:103315. [PMID: 31816399 DOI: 10.1016/j.fgb.2019.103315] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/22/2019] [Accepted: 12/01/2019] [Indexed: 11/28/2022]
Abstract
Regulation of plant cell wall degradation is of utmost importance for understanding the carbon cycle in nature, but also to improve industrial processes aimed at enzyme production for next generation biofuels. Thereby, the transcription factor networks in different fungi show conservation as well as striking differences, particularly between Trichoderma reesei and Neurospora crassa. Here, we aimed to gain insight into the function of the transcription factors CLR1 and CLR2 in T. reesei, which are crucial for cellulase gene expression in N. crassa. We studied impacts on gene regulation with cellulose, xylan, pectin and chitin, growth on 95 different carbon sources as well as an involvement in regulation of secondary metabolism or development. We found that CLR1 is present in the genome of T. reesei and other Trichoderma spp., albeit with considerably lower homology compared to other ascomycetes. CLR1 and CLR2 regulate pectinase transcript levels upon growth on pectin, no major function was detected on chitin. CLR1 and CLR2 form a positive feedback cycle on xylan and were found to be responsible for balancing co-regulation of xylanase genes in light and darkness with distinct and in part opposite regulatory effects of up to 8fold difference. Our data suggest that CLR1 and CLR2 have evolved differently in T. reesei compared to other fungi. We propose a model in which their main function is in adjustment of regulation of xylanase gene expression to different light conditions and to balance transcript levels of genes involved in plant cell wall degradation according to their individual relevance for this process.
Collapse
Affiliation(s)
- Sabrina Beier
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Wolfgang Hinterdobler
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Hoda Bazafkan
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Lukas Schillinger
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Monika Schmoll
- AIT Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.
| |
Collapse
|
9
|
Zhang J, Chen Y, Wu C, Liu P, Wang W, Wei D. The transcription factor ACE3 controls cellulase activities and lactose metabolism via two additional regulators in the fungus Trichoderma reesei. J Biol Chem 2019; 294:18435-18450. [PMID: 31501242 PMCID: PMC6885621 DOI: 10.1074/jbc.ra119.008497] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 08/23/2019] [Indexed: 12/15/2022] Open
Abstract
Fungi of the genus Trichoderma are a rich source of enzymes, such as cellulases and hemicellulases, that can degrade lignocellulosic biomass and are therefore of interest for biotechnological approaches seeking to optimize biofuel production. The essential transcription factor ACE3 is involved in cellulase production in Trichoderma reesei; however, the mechanism by which ACE3 regulates cellulase activities is unknown. Here, we discovered that the nominal ace3 sequence in the T. reesei genome available through the Joint Genome Institute is erroneously annotated. Moreover, we identified the complete ace3 sequence, the ACE3 Zn(II)2Cys6 domain, and the ACE3 DNA-binding sites containing a 5'-CGGAN(T/A)3-3' consensus. We found that in addition to its essential role in cellulase production, ace3 is required for lactose assimilation and metabolism in T. reesei Transcriptional profiling with RNA-Seq revealed that ace3 deletion down-regulates not only the bulk of the major cellulase, hemicellulase, and related transcription factor genes, but also reduces the expression of lactose metabolism-related genes. Additionally, we demonstrate that ACE3 binds the promoters of many cellulase genes, the cellulose response transporter gene crt1, and transcription factor-encoding genes, including xyr1 We also observed that XYR1 dimerizes to facilitate cellulase production and that ACE3 interacts with XYR1. Together, these findings uncover how two essential transcriptional activators mediate cellulase gene expression in T. reesei On the basis of these observations, we propose a model of how the interactions between ACE3, Crt1, and XYR1 control cellulase expression and lactose metabolism in T. reesei.
Collapse
Affiliation(s)
- Jiajia Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Yumeng Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Chuan Wu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Pei Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Dongzhi Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| |
Collapse
|
10
|
Hinterdobler W, Schuster A, Tisch D, Özkan E, Bazafkan H, Schinnerl J, Brecker L, Böhmdorfer S, Schmoll M. The role of PKAc1 in gene regulation and trichodimerol production in Trichoderma reesei. Fungal Biol Biotechnol 2019; 6:12. [PMID: 31528353 PMCID: PMC6734591 DOI: 10.1186/s40694-019-0075-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
Background Trichoderma reesei represents a model system for investigation of plant cell wall degradation and its connection to light response. The cyclic adenosine monophosphate pathway (cAMP pathway) plays an important role in both physiological outputs, being crucial for regulation of photoreceptor function as well as for cellulase regulation on different carbon sources. Phosphorylation of photoreceptors and of the carbon catabolite repressor CRE1 was shown in ascomycetes, indicating a relevance of protein kinase A in regulation of the target genes of these transcription factors as well as an impact on regulation of induction specific genes. Moreover, the cAMP pathway impacts growth and development. Results Here, we investigated gene regulation by the catalytic subunit of protein kinase A (PKAc1) upon growth on cellulose. We found distinct gene sets for regulation upon growth in light and darkness with an overlap of only 13 genes. PKAc1 regulates metabolic genes as well as transport and defense functions. The overlap of gene regulation by PKAc1 with the genes representing the cAMP dependent regulatory output of the photoreceptor ENV1 indicates an involvement of PKA in this pathway, which counteracts its effects by contrasting regulation. Moreover, we found considerable overlap with the gene sets regulated under cellulase inducing conditions and by the carbon catabolite repressor CRE1. Our analysis also showed that PKAc1 regulates the genes of the SOR cluster associated with the biosynthesis of sorbicillinoids. The homologue of gin4, encoding a CAMK type kinase, which is regulated by PKAc1, CRE1 and YPR2 showed a moderate impact on trichodimerol production. We isolated trichodimerol as representative sorbicillin compound and established a method for its quantification in large sample sets using high performance thin layer chromatography (HPTLC), which can be broadly applied for secondary metabolite screening of mutants or different growth conditions. Due to the high expression levels of the SOR cluster under conditions of sexual development we crosschecked the relevance of PKAc1 under these conditions. We could show that PKAc1 impacts biosynthesis of trichodimerol in axenic growth and upon mating. Conclusions We conclude that PKAc1 is involved in light dependent regulation of plant cell wall degradation, including carbon catabolite repression as well as secondary metabolism and development in T. reesei.
Collapse
Affiliation(s)
- Wolfgang Hinterdobler
- 1Center for Health and Bioresources, AIT Austrian Institute of Technology, Konrad Lorenz Strasse 24, 3430 Tulln, Austria
| | - André Schuster
- 2Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Doris Tisch
- 2Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Ezgi Özkan
- 1Center for Health and Bioresources, AIT Austrian Institute of Technology, Konrad Lorenz Strasse 24, 3430 Tulln, Austria.,3Department of Chemistry, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Hoda Bazafkan
- 1Center for Health and Bioresources, AIT Austrian Institute of Technology, Konrad Lorenz Strasse 24, 3430 Tulln, Austria
| | - Johann Schinnerl
- 4Chemodiversity Research Group, Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Lothar Brecker
- 5Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, 1090 Vienna, Austria
| | - Stefan Böhmdorfer
- 3Department of Chemistry, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Monika Schmoll
- 1Center for Health and Bioresources, AIT Austrian Institute of Technology, Konrad Lorenz Strasse 24, 3430 Tulln, Austria
| |
Collapse
|
11
|
Hitzenhammer E, Büschl C, Sulyok M, Schuhmacher R, Kluger B, Wischnitzki E, Schmoll M. YPR2 is a regulator of light modulated carbon and secondary metabolism in Trichoderma reesei. BMC Genomics 2019; 20:211. [PMID: 30866811 PMCID: PMC6417087 DOI: 10.1186/s12864-019-5574-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/28/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Filamentous fungi have evolved to succeed in nature by efficient growth and degradation of substrates, but also due to the production of secondary metabolites including mycotoxins. For Trichoderma reesei, as a biotechnological workhorse for homologous and heterologous protein production, secondary metabolite secretion is of particular importance for industrial application. Recent studies revealed an interconnected regulation of enzyme gene expression and carbon metabolism with secondary metabolism. RESULTS Here, we investigated gene regulation by YPR2, one out of two transcription factors located within the SOR cluster of T. reesei, which is involved in biosynthesis of sorbicillinoids. Transcriptome analysis showed that YPR2 exerts its major function in constant darkness upon growth on cellulose. Targets (direct and indirect) of YPR2 overlap with induction specific genes as well as with targets of the carbon catabolite repressor CRE1 and a considerable proportion is regulated by photoreceptors as well. Functional category analysis revealed both effects on carbon metabolism and secondary metabolism. Further, we found indications for an involvement of YPR2 in regulation of siderophores. In agreement with transcriptome data, mass spectrometric analyses revealed a broad alteration in metabolite patterns in ∆ypr2. Additionally, YPR2 positively influenced alamethicin levels along with transcript levels of the alamethicin synthase tex1 and is essential for production of orsellinic acid in darkness. CONCLUSIONS YPR2 is an important regulator balancing secondary metabolism with carbon metabolism in darkness and depending on the carbon source. The function of YPR2 reaches beyond the SOR cluster in which ypr2 is located and happens downstream of carbon catabolite repression mediated by CRE1.
Collapse
Affiliation(s)
- Eva Hitzenhammer
- AIT - Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Christoph Büschl
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Michael Sulyok
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Rainer Schuhmacher
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Bernhard Kluger
- Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences Vienna, (BOKU), Konrad-Lorenz-Straße 20, 3430 Tulln, Austria
| | - Elisabeth Wischnitzki
- AIT - Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Monika Schmoll
- AIT - Austrian Institute of Technology GmbH, Center for Health and Bioresources, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| |
Collapse
|
12
|
Dattenböck C, Tisch D, Schuster A, Monroy AA, Hinterdobler W, Schmoll M. Gene regulation associated with sexual development and female fertility in different isolates of Trichoderma reesei. Fungal Biol Biotechnol 2018; 5:9. [PMID: 29785273 PMCID: PMC5952832 DOI: 10.1186/s40694-018-0055-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/12/2018] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Trichoderma reesei is one of the most frequently used filamentous fungi in industry for production of homologous and heterologous proteins. The ability to use sexual crossing in this fungus was discovered several years ago and opens up new perspectives for industrial strain improvement and investigation of gene regulation. RESULTS Here we investigated the female sterile strain QM6a in comparison to the fertile isolate CBS999.97 and backcrossed derivatives of QM6a, which have regained fertility (FF1 and FF2 strains) in both mating types under conditions of sexual development. We found considerable differences in gene regulation between strains with the CBS999.97 genetic background and the QM6a background. Regulation patterns of QM6a largely clustered with the backcrossed FF1 and FF2 strains. Differential regulation between QM6a and FF1/FF2 as well as clustering of QM6a patterns with those of CBS999.97 strains was also observed. Consistent mating type dependent regulation was limited to mating type genes and those involved in pheromone response, but included also nta1 encoding a putative N-terminal amidase previously not associated with development. Comparison of female sterile QM6a with female fertile strains showed differential expression in genes encoding several transcription factors, metabolic genes and genes involved in secondary metabolism. CONCLUSIONS Evaluation of the functions of genes specifically regulated under conditions of sexual development and of genes with highest levels of transcripts under these conditions indicated a relevance of secondary metabolism for sexual development in T. reesei. Among others, the biosynthetic genes of the recently characterized SOR cluster are in this gene group. However, these genes are not essential for sexual development, but rather have a function in protection and defence against competitors during reproduction.
Collapse
Affiliation(s)
- Christoph Dattenböck
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Straße 24, 3430 Tulln, Austria
| | - Doris Tisch
- Institute of Chemical Engineering, Research Area Molecular Biotechnology, TU Wien, 1060 Vienna, Austria
| | - Andre Schuster
- Institute of Chemical Engineering, Research Area Molecular Biotechnology, TU Wien, 1060 Vienna, Austria
| | - Alberto Alonso Monroy
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Straße 24, 3430 Tulln, Austria
| | - Wolfgang Hinterdobler
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Straße 24, 3430 Tulln, Austria
| | - Monika Schmoll
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Straße 24, 3430 Tulln, Austria
| |
Collapse
|
13
|
Abstract
Trichoderma reesei (syn. Hypocrea jecorina) is the model organism for industrial production of plant cell wall degradating enzymes. The integration of light and nutrient signals for adaptation of enzyme production in T. reesei emerged as an important regulatory mechanism to be tackled for strain improvement. Gene regulation specific for cellulase inducing conditions is different in light and darkness with substantial regulation by photoreceptors. Genes regulated by light are clustered in the genome, with several of the clusters overlapping with CAZyme clusters. Major cellulase transcription factor genes and at least 75% of glycoside hydrolase encoding genes show the potential of light dependent regulation. Accordingly, light dependent protein complex formation occurs within the promoters of cellulases and their regulators. Additionally growth on diverse carbon sources is different between light and darkness and dependent on the presence of photoreceptors in several cases. Thereby, also light intensity plays a regulatory role, with cellulase levels dropping at higher light intensities dependent in the strain background. The heterotrimeric G-protein pathway is the most important nutrient signaling pathway in the connection with light response and triggers posttranscriptional regulation of cellulase expression. All G-protein alpha subunits impact cellulase regulation in a light dependent manner. The downstream cAMP pathway is involved in light dependent regulation as well. Connections between the regulatory pathways are mainly established via the photoreceptor ENV1. The effect of photoreceptors on plant cell wall degradation also occurs in the model filamentous fungus Neurospora crassa. In the currently proposed model, T. reesei senses the presence of plant biomass in its environment by detection of building blocks of cellulose and hemicellulose. Interpretation of the respective signals is subsequently adjusted to the requirements in light and darkness (or on the surface versus within the substrate) by an interconnection of nutrient signaling with light response. This review provides an overview on the importance of light, photoreceptors and related signaling pathways for formation of plant cell wall degrading enzymes in T. reesei. Additionally, the relevance of light dependent gene regulation for industrial fermentations with Trichoderma as well as strategies for exploitation of the observed effects are discussed.
Collapse
Affiliation(s)
- Monika Schmoll
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Konrad Lorenz Straße 24, 3430 Tulln, Austria
| |
Collapse
|
14
|
Till P, Pucher ME, Mach RL, Mach-Aigner AR. A long noncoding RNA promotes cellulase expression in Trichoderma reesei. Biotechnol Biofuels 2018; 11:78. [PMID: 29588663 PMCID: PMC5865335 DOI: 10.1186/s13068-018-1081-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/14/2018] [Indexed: 05/31/2023]
Abstract
BACKGROUND Due to its capability to secrete large quantities of plant biomass degrading enzymes (PBDE), Trichoderma reesei is widely applied for industrial purposes. In nature, expression of PBDE is efficiently regulated in this fungus. Several factors involved in this regulatory network have been identified. However, most of them are transcription factors. Long noncoding RNAs (lncRNAs) emerged as common players acting on epigenetic or transcriptional regulation in several eukaryotic organisms. To date, no lncRNA has been described in filamentous fungi. RESULTS A lncRNA termed HAX1 was identified in T. reesei QM9414. In this study, it was characterized and evidence for its regulatory impact on cellulase expression was provided. Interestingly, different versions of HAX1 were identified in different strains (namely, QM6a, QM9414, and Rut-C30), varying in terms of RNA length. Remarkably, considerable longer variants of this lncRNA are present in hypercellulolytic strains compared to the wild-type strain QM6a. Based on these results, a correlation between RNA length and the functional impact of HAX1 on PBDE expression was supposed. This assumption was verified by overexpressing the most abundant HAX1 versions identified in QM6a, QM9414, and Rut-C30. Such HAX1 overexpression on the one hand was suitable for regaining the function in hax1 disruption strains, and on the other hand resulted in notably higher cellulase activities in QM6a, especially by the expression of longer HAX1 versions. CONCLUSION With HAX1, for the first time the regulatory role of a lncRNA in filamentous fungi was uncovered. Besides this, a new player involved in the complex regulation of PBDE expression in T. reesei was identified. Due to its enhancing effect on cellulase activity, HAX1 was shown to be not only interesting for basic research, but also a promising candidate for expanding the set of biotechnological tools for industrial application of T. reesei.
Collapse
Affiliation(s)
- Petra Till
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Marion E. Pucher
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Robert L. Mach
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| | - Astrid R. Mach-Aigner
- Christian Doppler Laboratory for Optimized Expression of Carbohydrate-active Enzymes, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorfer Str. 1a, 1060 Vienna, Austria
| |
Collapse
|
15
|
Stappler E, Walton JD, Beier S, Schmoll M. Abundance of Secreted Proteins of Trichoderma reesei Is Regulated by Light of Different Intensities. Front Microbiol 2017; 8:2586. [PMID: 29375497 PMCID: PMC5770571 DOI: 10.3389/fmicb.2017.02586] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 12/12/2017] [Indexed: 11/22/2022] Open
Abstract
In Trichoderma reesei light is an important factor in the regulation of glycoside hydrolase gene expression. We therefore investigated the influence of different light intensities on cellulase activity and protein secretion. Differentially secreted proteins in light and darkness as identified by mass spectrometry included members of different glycoside hydrolase families, such as CBH1, Cel3A, Cel61B, XYN2, and XYN4. Several of the associated genes showed light-dependent regulation on the transcript level. Deletion of the photoreceptor genes blr1 and blr2 resulted in a diminished difference of protein abundance between light and darkness. The amount of secreted proteins including that of the major exo-acting beta-1,4-glucanases CBH1 and CBH2 was generally lower in light-grown cultures than in darkness. In contrast, cbh1 transcript levels increased with increasing light intensity from 700 to 2,000 lux but dopped at high light intensity (5,000 lux). In the photoreceptor mutants Δblr1 and Δblr2 cellulase activity in light was reduced compared to activity in darkness, showing a discrepancy between transcript levels and secreted cellulase activity. Furthermore, evaluation of different light sensitivities revealed an increased light tolerance with respect to cellulase expression of QM9414 compared to its parental strain QM6a. Investigation of one of the differentially expressed proteins between light and darkness, CLF1, revealed its function as a factor involved in regulation of secreted protease activity. T. reesei secretes a different set of proteins in light compared to darkness, this difference being mainly due to the function of the major known photoreceptors. Moreover, cellulase regulation is adjusted to light intensity and improved light tolerance was correlated with increased cellulase production. Our findings further support the hypothesis of a light intensity dependent post-transcriptional regulation of cellulase gene expression in T. reesei.
Collapse
Affiliation(s)
- Eva Stappler
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Jonathan D. Walton
- MSU-DOE Plant Research Laboratory, Department of Plant Biology, Michigan State University, East Lansing, MI, United States
| | - Sabrina Beier
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| | - Monika Schmoll
- Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Tulln, Austria
| |
Collapse
|
16
|
Tisch D, Pomraning KR, Collett JR, Freitag M, Baker SE, Chen CL, Hsu PW, Chuang YC, Schuster A, Dattenböck C, Stappler E, Sulyok M, Böhmdorfer S, Oberlerchner J, Wang TF, Schmoll M. Omics Analyses of Trichoderma reesei CBS999.97 and QM6a Indicate the Relevance of Female Fertility to Carbohydrate-Active Enzyme and Transporter Levels. Appl Environ Microbiol 2017; 83. [PMID: 28916559 DOI: 10.1128/AEM.01578-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 08/31/2017] [Indexed: 01/07/2023] Open
Abstract
The filamentous fungus Trichoderma reesei is found predominantly in the tropics but also in more temperate regions, such as Europe, and is widely known as a producer of large amounts of plant cell wall-degrading enzymes. We sequenced the genome of the sexually competent isolate CBS999.97, which is phenotypically different from the female sterile strain QM6a but can cross sexually with QM6a. Transcriptome data for growth on cellulose showed that entire carbohydrate-active enzyme (CAZyme) families are consistently differentially regulated between these strains. We evaluated backcrossed strains of both mating types, which acquired female fertility from CBS999.97 but maintained a mostly QM6a genetic background, and we could thereby distinguish between the effects of strain background and female fertility or mating type. We found clear regulatory differences associated with female fertility and female sterility, including regulation of CAZyme and transporter genes. Analysis of carbon source utilization, transcriptomes, and secondary metabolites in these strains revealed that only a few changes in gene regulation are consistently correlated with different mating types. Different strain backgrounds (QM6a versus CBS999.97) resulted in the most significant alterations in the transcriptomes and in carbon source utilization, with decreased growth of CBS999.97 on several amino acids (for example proline or alanine), which further correlated with the downregulation of genes involved in the respective pathways. In combination, our findings support a role of fertility-associated processes in physiology and gene regulation and are of high relevance for the use of sexual crossing in combining the characteristics of two compatible strains or quantitative trait locus (QTL) analysis.IMPORTANCETrichoderma reesei is a filamentous fungus with a high potential for secretion of plant cell wall-degrading enzymes. We sequenced the genome of the fully fertile field isolate CBS999.97 and analyzed its gene regulation characteristics in comparison with the commonly used laboratory wild-type strain QM6a, which is not female fertile. Additionally, we also evaluated fully fertile strains with genotypes very close to that of QM6a in order to distinguish between strain-specific and fertility-specific characteristics. We found that QM6a and CBS999.97 clearly differ in their growth patterns on different carbon sources, CAZyme gene regulation, and secondary metabolism. Importantly, we found altered regulation of 90 genes associated with female fertility, including CAZyme genes and transporter genes, but only minor mating type-dependent differences. Hence, when using sexual crossing in research and for strain improvement, it is important to consider female fertile and female sterile strains for comparison with QM6a and to achieve optimal performance.
Collapse
|
17
|
Schmoll M. Light, stress, sex and carbon - The photoreceptor ENVOY as a central checkpoint in the physiology of Trichoderma reesei. Fungal Biol 2018; 122:479-86. [PMID: 29801792 DOI: 10.1016/j.funbio.2017.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/11/2017] [Accepted: 10/18/2017] [Indexed: 12/20/2022]
Abstract
Trichoderma reesei represents one of the most prolific producers of homologous and heterologous proteins. Discovery of the photoreceptor ENV1 as a regulator of cellulase gene expression initiated analysis of light response pathways and their physiological relevance for T. reesei. The function of ENV1 in regulation of plant cell wall degrading enzymes is conserved in Neurospora crassa. ENV1 emerged as a central checkpoint for integration of nutrient sensing, light response and development. This photoreceptor exerts its function by influencing transcript abundance and feedback cycles of the alpha subunits of the heterotrimeric G-protein pathway and impacts regulation of the beta and gamma subunits via mutual regulation with the phosducin PhLP1. The output of regulation by ENV1 is in part mediated by the cAMP pathway and likely aimed at cellulose recognition. Lack of ENV1 causes deregulation of the pheromone system and female sterility in light. A regulatory interconnection with VEL1 and influence on other regulators of secondary metabolism like YPR2 as well as polyketide synthase encoding genes indicates a function in secondary metabolism. The function of ENV1 in integrating light response with signaling of osmotic and oxidative stress is evolutionary conserved in Hypocreales and distinct from other sordariomycetes including N. crassa.
Collapse
|
18
|
Hansson H, Karkehabadi S, Mikkelsen N, Douglas NR, Kim S, Lam A, Kaper T, Kelemen B, Meier KK, Jones SM, Solomon EI, Sandgren M. High-resolution structure of a lytic polysaccharide monooxygenase from Hypocrea jecorina reveals a predicted linker as an integral part of the catalytic domain. J Biol Chem 2017; 292:19099-19109. [PMID: 28900033 DOI: 10.1074/jbc.m117.799767] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/29/2017] [Indexed: 12/17/2022] Open
Abstract
For decades, the enzymes of the fungus Hypocrea jecorina have served as a model system for the breakdown of cellulose. Three-dimensional structures for almost all H. jecorina cellulose-degrading enzymes are available, except for HjLPMO9A, belonging to the AA9 family of lytic polysaccharide monooxygenases (LPMOs). These enzymes enhance the hydrolytic activity of cellulases and are essential for cost-efficient conversion of lignocellulosic biomass. Here, using structural and spectroscopic analyses, we found that native HjLPMO9A contains a catalytic domain and a family-1 carbohydrate-binding module (CBM1) connected via a linker sequence. A C terminally truncated variant of HjLPMO9A containing 21 residues of the predicted linker was expressed at levels sufficient for analysis. Here, using structural, spectroscopic, and biochemical analyses, we found that this truncated variant exhibited reduced binding to and activity on cellulose compared with the full-length enzyme. Importantly, a 0.95-Å resolution X-ray structure of truncated HjLPMO9A revealed that the linker forms an integral part of the catalytic domain structure, covering a hydrophobic patch on the catalytic AA9 module. We noted that the oxidized catalytic center contains a Cu(II) coordinated by two His ligands, one of which has a His-brace in which the His-1 terminal amine group also coordinates to a copper. The final equatorial position of the Cu(II) is occupied by a water-derived ligand. The spectroscopic characteristics of the truncated variant were not measurably different from those of full-length HjLPMO9A, indicating that the presence of the CBM1 module increases the affinity of HjLPMO9A for cellulose binding, but does not affect the active site.
Collapse
Affiliation(s)
- Henrik Hansson
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Saeid Karkehabadi
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Nils Mikkelsen
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | | | - Steve Kim
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Anna Lam
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Thijs Kaper
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Brad Kelemen
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Katlyn K Meier
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Stephen M Jones
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Edward I Solomon
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Mats Sandgren
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden,
| |
Collapse
|
19
|
Stappler E, Dattenböck C, Tisch D, Schmoll M. Analysis of Light- and Carbon-Specific Transcriptomes Implicates a Class of G-Protein-Coupled Receptors in Cellulose Sensing. mSphere 2017; 2:e00089-17. [PMID: 28497120 DOI: 10.1128/mSphere.00089-17] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/14/2017] [Indexed: 01/16/2023] Open
Abstract
In fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific regulation to dark-specific regulation and to rule out effects specific for a single carbon source. We found close connections with respect to gene regulation as well as significant differences in dealing with carbon in the environment in light and darkness. Moreover, our analyses showed an intricate regulation mechanism for substrate degradation potentially involving surface sensing and provide a basis for knowledge-based screening for strain improvement. In fungi, most metabolic processes are subject to regulation by light. Trichoderma reesei is adapted to degradation of plant cell walls and regulates production of the required enzymes in a manner dependent on the nutrient source and the light status. Here we investigated the interrelated relevance of two regulation levels of the transcriptome of T. reesei: light regulation and carbon source-dependent control. We show that the carbon source (cellulose, lactose, sophorose, glucose, or glycerol) is the major source of variation, with light having a modulating effect on transcript regulation. A total of 907 genes were regulated under cellulase-inducing conditions in light, and 947 genes were regulated in darkness, with 530 genes overlapping (1,324 in total). Only 218 of the 1,324 induction-specific genes were independent of light and not regulated by the BLR1, BLR2, and ENV1 photoreceptors. Analysis of the genomic distribution of genes regulated by light upon growth on cellulose revealed considerable overlap of light-regulated clusters with induction-specific clusters and carbohydrate-active enzyme (CAZyme) clusters. Further, we found evidence for the operation of a sensing mechanism for solid cellulosic substrates, with regulation of genes such as swo1, cip1, and cip2 or of genes encoding hydrophobins which is related to the cyclic AMP (cAMP)-dependent regulatory output of ENV1. We identified class XIII G-protein-coupled receptors (GPCRs) CSG1 and CSG2 in T. reesei as putative cellulose/glucose-sensing GPCRs. Our data indicate that the cellulase regulation pathway is bipartite, comprising a section corresponding to transcriptional regulation and one corresponding to posttranscriptional regulation, with the two connected by the function of CSG1. IMPORTANCE In fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific regulation to dark-specific regulation and to rule out effects specific for a single carbon source. We found close connections with respect to gene regulation as well as significant differences in dealing with carbon in the environment in light and darkness. Moreover, our analyses showed an intricate regulation mechanism for substrate degradation potentially involving surface sensing and provide a basis for knowledge-based screening for strain improvement.
Collapse
|
20
|
Pakula TM, Nygren H, Barth D, Heinonen M, Castillo S, Penttilä M, Arvas M. Genome wide analysis of protein production load in Trichoderma reesei. Biotechnol Biofuels 2016; 9:132. [PMID: 27354857 PMCID: PMC4924338 DOI: 10.1186/s13068-016-0547-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/07/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina) is a widely used industrial host organism for protein production. In industrial cultivations, it can produce over 100 g/l of extracellular protein, mostly constituting of cellulases and hemicellulases. In order to improve protein production of T. reesei the transcriptional regulation of cellulases and secretory pathway factors have been extensively studied. However, the metabolism of T. reesei under protein production conditions has not received much attention. RESULTS To understand the physiology and metabolism of T. reesei under protein production conditions we carried out a well-controlled bioreactor experiment with extensive analysis. We used minimal media to make the data amenable for modelling and three strain pairs to cover different protein production levels. With RNA-sequencing transcriptomics we detected the concentration of the carbon source as the most important determinant of the transcriptome. As the major transcriptional response concomitant to protein production we detected the induction of selected genes that were putatively regulated by xyr1 and were related to protein transport, amino acid metabolism and transcriptional regulation. We found novel metabolic responses such as production of glycerol and a cellotriose-like compound. We then used this cultivation data for flux balance analysis of T. reesei metabolism and demonstrate for the first time the use of genome wide stoichiometric metabolic modelling for T. reesei. We show that our model can predict protein production rate and provides novel insight into the metabolism of protein production. We also provide this unprecedented cultivation and transcriptomics data set for future modelling efforts. CONCLUSIONS The use of stoichiometric modelling can open a novel path for the improvement of protein production in T. reesei. Based on this we propose sulphur assimilation as a major limiting factor of protein production. As an organism with exceptional protein production capabilities modelling of T. reesei can provide novel insight also to other less productive organisms.
Collapse
Affiliation(s)
- Tiina M. Pakula
- />VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 Espoo, Finland
| | - Heli Nygren
- />VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 Espoo, Finland
| | - Dorothee Barth
- />VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 Espoo, Finland
| | - Markus Heinonen
- />Department of Information and Computer Science, Aalto University, PO Box 15400, 00076 Espoo, Finland
- />Helsinki Institute for Information Technology HIIT, Espoo, Finland
| | - Sandra Castillo
- />VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 Espoo, Finland
| | - Merja Penttilä
- />VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 Espoo, Finland
| | - Mikko Arvas
- />VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box FI-1000, 02044 Espoo, Finland
| |
Collapse
|
21
|
Shida Y, Yamaguchi K, Nitta M, Nakamura A, Takahashi M, Kidokoro SI, Mori K, Tashiro K, Kuhara S, Matsuzawa T, Yaoi K, Sakamoto Y, Tanaka N, Morikawa Y, Ogasawara W. The impact of a single-nucleotide mutation of bgl2 on cellulase induction in a Trichoderma reesei mutant. Biotechnol Biofuels 2015; 8:230. [PMID: 26719764 PMCID: PMC4696228 DOI: 10.1186/s13068-015-0420-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/15/2015] [Indexed: 05/10/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina) produces increased cellulase expression when grown on cellulose or its derivatives as a sole carbon source. It has been believed that β-glucosidases of T. reesei not only metabolize cellobiose but also contribute in the production of inducers of cellulase gene expression by their transglycosylation activity. The cellulase hyper-producing mutant PC-3-7 developed in Japan has enhanced cellulase production ability when cellobiose is used as the inducer. The comparative genomics analysis of PC-3-7 and its parent revealed a single-nucleotide mutation within the bgl2 gene encoding intracellular β-glucosidase II (BGLII/Cel1a), giving rise to an amino acid substitution in PC-3-7, which could potentially account for the enhanced cellulase expression when these strains are cultivated on cellulose and cellobiose. RESULTS To analyze the effects of the BGLII mutation in cellulase induction, we constructed both a bgl2 revertant and a disruptant. Enzymatic analysis of the transformant lysates showed that the strain expressing mutant BGLII exhibited weakened cellobiose hydrolytic activity, but produced some transglycosylation products, suggesting that the SNP in bgl2 strongly diminished cellobiase activity, but did not result in complete loss of function of BGLII. The analysis of the recombinant BGLII revealed that transglycosylation products might be oligosaccharides, composed probably of glucose linked β-1,4, β-1,3, or a mixture of both. PC-3-7 revertants of bgl2 exhibited reduced expression and inducibility of cellulase during growth on cellulose and cellobiose substrates. Furthermore, the effect of this bgl2 mutation was reproduced in the common strain QM9414 in which the transformants showed cellulase production comparable to that of PC-3-7. CONCLUSION We conclude that BGLII plays an important role in cellulase induction in T. reesei and that the bgl2 mutation in PC-3-7 brought about enhanced cellulase expression on cellobiose. The results of the investigation using PC-3-7 suggested that other mutation(s) in PC-3-7 could also contribute to cellulase induction. Further investigation is essential to unravel the mechanism responsible for cellulase induction in T. reesei.
Collapse
Affiliation(s)
- Yosuke Shida
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Kaori Yamaguchi
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Mikiko Nitta
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
- />Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 Japan
| | - Ayana Nakamura
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Machiko Takahashi
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Shun-ichi Kidokoro
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Kazuki Mori
- />Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan
| | - Kosuke Tashiro
- />Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan
| | - Satoru Kuhara
- />Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan
| | - Tomohiko Matsuzawa
- />Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 Japan
| | - Katsuro Yaoi
- />Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 Japan
| | - Yasumitsu Sakamoto
- />School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694 Japan
| | - Nobutada Tanaka
- />School of Pharmacy, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555 Japan
| | - Yasushi Morikawa
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| | - Wataru Ogasawara
- />Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 Japan
| |
Collapse
|
22
|
Ouedraogo JP, Arentshorst M, Nikolaev I, Barends S, Ram AFJ. I-SceI-mediated double-strand DNA breaks stimulate efficient gene targeting in the industrial fungus Trichoderma reesei. Appl Microbiol Biotechnol 2015; 99:10083-95. [PMID: 26272087 PMCID: PMC4643118 DOI: 10.1007/s00253-015-6829-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 07/03/2015] [Accepted: 07/07/2015] [Indexed: 01/24/2023]
Abstract
Targeted integration of expression cassettes for enzyme production in industrial microorganisms is desirable especially when enzyme variants are screened for improved enzymatic properties. However, currently used methods for targeted integration are inefficient and result in low transformation frequencies. In this study, we expressed the Saccharomyces cerevisiae I-SceI meganuclease to generate double-strand breaks at a defined locus in the Trichoderma reesei genome. We showed that the double-strand DNA breaks mediated by I-SceI can be efficiently repaired when an exogenous DNA cassette flanked by regions homologous to the I-SceI landing locus was added during transformation. Transformation efficiencies increased approximately sixfold compared to control transformation. Analysis of the transformants obtained via I-SceI-mediated gene targeting showed that about two thirds of the transformants resulted from a homologous recombination event at the predetermined locus. Counter selection of the transformants for the loss of the pyrG marker upon integration of the DNA cassette showed that almost all of the clones contained the cassette at the predetermined locus. Analysis of independently obtained transformants using targeted integration of a glucoamylase expression cassette demonstrated that glucoamylase production among the transformants was high and showing limited variation. In conclusion, the gene targeting system developed in this study significantly increases transformation efficiency as well as homologous recombination efficiency and omits the use of Δku70 strains. It is also suitable for high-throughput screening of enzyme variants or gene libraries in T. reesei.
Collapse
Affiliation(s)
- Jean Paul Ouedraogo
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Kluyver Centre for Genomics of Industrial Fermentation, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Mark Arentshorst
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Kluyver Centre for Genomics of Industrial Fermentation, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Igor Nikolaev
- Dupont Industrial Biosciences, Archimedesweg 30, 2333 CN, Leiden, The Netherlands
| | - Sharief Barends
- Dupont Industrial Biosciences, Archimedesweg 30, 2333 CN, Leiden, The Netherlands
| | - Arthur F J Ram
- Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Kluyver Centre for Genomics of Industrial Fermentation, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| |
Collapse
|
23
|
Sørensen TH, Cruys-Bagger N, Windahl MS, Badino SF, Borch K, Westh P. Temperature Effects on Kinetic Parameters and Substrate Affinity of Cel7A Cellobiohydrolases. J Biol Chem 2015; 290:22193-202. [PMID: 26183777 DOI: 10.1074/jbc.m115.658930] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Indexed: 11/06/2022] Open
Abstract
We measured hydrolytic rates of four purified cellulases in small increments of temperature (10-50 °C) and substrate loads (0-100 g/liter) and analyzed the data by a steady state kinetic model that accounts for the processive mechanism. We used wild type cellobiohydrolases (Cel7A) from mesophilic Hypocrea jecorina and thermophilic Rasamsonia emersonii and two variants of these enzymes designed to elucidate the role of the carbohydrate binding module (CBM). We consistently found that the maximal rate increased strongly with temperature, whereas the affinity for the insoluble substrate decreased, and as a result, the effect of temperature depended strongly on the substrate load. Thus, temperature had little or no effect on the hydrolytic rate in dilute substrate suspensions, whereas strong temperature activation (Q10 values up to 2.6) was observed at saturating substrate loads. The CBM had a dual effect on the activity. On one hand, it diminished the tendency of heat-induced desorption, but on the other hand, it had a pronounced negative effect on the maximal rate, which was 2-fold larger in variants without CBM throughout the investigated temperature range. We conclude that although the CBM is beneficial for affinity it slows down the catalytic process. Cel7A from the thermophilic organism was moderately more activated by temperature than the mesophilic analog. This is in accord with general theories on enzyme temperature adaptation and possibly relevant information for the selection of technical cellulases.
Collapse
Affiliation(s)
- Trine Holst Sørensen
- From Roskilde University, Nature, Systems, and Models, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and
| | - Nicolaj Cruys-Bagger
- From Roskilde University, Nature, Systems, and Models, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and
| | - Michael Skovbo Windahl
- From Roskilde University, Nature, Systems, and Models, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and Novozymes A/S, Krogshøjvej 36, DK-2880 Bagsværd, Denmark
| | - Silke Flindt Badino
- From Roskilde University, Nature, Systems, and Models, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and Novozymes A/S, Krogshøjvej 36, DK-2880 Bagsværd, Denmark
| | - Kim Borch
- Novozymes A/S, Krogshøjvej 36, DK-2880 Bagsværd, Denmark
| | - Peter Westh
- From Roskilde University, Nature, Systems, and Models, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and
| |
Collapse
|
24
|
Sørensen TH, Cruys-Bagger N, Borch K, Westh P. Free Energy Diagram for the Heterogeneous Enzymatic Hydrolysis of Glycosidic Bonds in Cellulose. J Biol Chem 2015; 290:22203-11. [PMID: 26183776 DOI: 10.1074/jbc.m115.659656] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Indexed: 01/25/2023] Open
Abstract
Kinetic and thermodynamic data have been analyzed according to transition state theory and a simplified reaction scheme for the enzymatic hydrolysis of insoluble cellulose. For the cellobiohydrolase Cel7A from Hypocrea jecorina (Trichoderma reesei), we were able to measure or collect relevant values for all stable and activated complexes defined by the reaction scheme and hence propose a free energy diagram for the full heterogeneous process. For other Cel7A enzymes, including variants with and without carbohydrate binding module (CBM), we obtained activation parameters for the association and dissociation of the enzyme-substrate complex. The results showed that the kinetics of enzyme-substrate association (i.e. formation of the Michaelis complex) was almost entirely entropy-controlled and that the activation entropy corresponded approximately to the loss of translational and rotational degrees of freedom of the dissolved enzyme. This implied that the transition state occurred early in the path where the enzyme has lost these degrees of freedom but not yet established extensive contact interactions in the binding tunnel. For dissociation, a similar analysis suggested that the transition state was late in the path where most enzyme-substrate contacts were broken. Activation enthalpies revealed that the rate of dissociation was far more temperature-sensitive than the rates of both association and the inner catalytic cycle. Comparisons of one- and two-domain variants showed that the CBM had no influence on the transition state for association but increased the free energy barrier for dissociation. Hence, the CBM appeared to promote the stability of the complex by delaying dissociation rather than accelerating association.
Collapse
Affiliation(s)
- Trine Holst Sørensen
- From Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and
| | - Nicolaj Cruys-Bagger
- From Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and
| | - Kim Borch
- Novozymes A/S, Krogshøjvej 36, DK-2880 Bagsværd, Denmark
| | - Peter Westh
- From Roskilde University, NSM, Research Unit for Functional Biomaterials, 1 Universitetsvej, Building 28, DK-4000 Roskilde, Denmark and
| |
Collapse
|
25
|
Linger JG, Taylor LE, Baker JO, Vander Wall T, Hobdey SE, Podkaminer K, Himmel ME, Decker SR. A constitutive expression system for glycosyl hydrolase family 7 cellobiohydrolases in Hypocrea jecorina. Biotechnol Biofuels 2015; 8:45. [PMID: 25904982 PMCID: PMC4405872 DOI: 10.1186/s13068-015-0230-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 02/23/2015] [Indexed: 05/23/2023]
Abstract
BACKGROUND One of the primary industrial-scale cellulase producers is the ascomycete fungus, Hypocrea jecorina, which produces and secretes large quantities of diverse cellulolytic enzymes. Perhaps the single most important biomass degrading enzyme is cellobiohydrolase I (cbh1or Cel7A) due to its enzymatic proficiency in cellulose depolymerization. However, production of Cel7A with native-like properties from heterologous expression systems has proven difficult. In this study, we develop a protein expression system in H. jecorina (Trichoderma reesei) useful for production and secretion of heterologous cellobiohydrolases from glycosyl hydrolase family 7. Building upon previous work in heterologous protein expression in filamentous fungi, we have integrated a native constitutive enolase promoter with the native cbh1 signal sequence. RESULTS The constitutive eno promoter driving the expression of Cel7A allows growth on glucose and results in repression of the native cellulase system, severely reducing background endo- and other cellulase activity and greatly simplifying purification of the recombinant protein. Coupling this system to a Δcbh1 strain of H. jecorina ensures that only the recombinant Cel7A protein is produced. Two distinct transformant colony morphologies were observed and correlated with high and null protein production. Production levels in 'fast' transformants are roughly equivalent to those in the native QM6a strain of H. jecorina, typically in the range of 10 to 30 mg/L when grown in continuous stirred-tank fermenters. 'Slow' transformants showed no evidence of Cel7A production. Specific activity of the purified recombinant Cel7A protein is equivalent to that of native protein when assayed on pretreated corn stover, as is the thermal stability and glycosylation level. Purified Cel7A produced from growth on glucose demonstrated remarkably consistent specific activity. Purified Cel7A from the same strain grown on lactose demonstrated significantly higher variability in activity. CONCLUSIONS The elimination of background cellulase induction provides much more consistent measured specific activity compared to a traditional cbh1 promoter system induced with lactose. This expression system provides a powerful tool for the expression and comparison of mutant and/or phylogenetically diverse cellobiohydrolases in the industrially relevant cellulase production host H. jecorina.
Collapse
Affiliation(s)
- Jeffrey G Linger
- />National Bioenergy Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - Larry E Taylor
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - John O Baker
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - Todd Vander Wall
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - Sarah E Hobdey
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - Kara Podkaminer
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - Michael E Himmel
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| | - Stephen R Decker
- />Biosciences Center, National Renewable Energy Laboratory, 16253 Denver West Parkway, Golden, CO 80401 USA
| |
Collapse
|
26
|
Chuang YC, Li WC, Chen CL, Hsu PWC, Tung SY, Kuo HC, Schmoll M, Wang TF. Trichoderma reesei meiosis generates segmentally aneuploid progeny with higher xylanase-producing capability. Biotechnol Biofuels 2015; 8:30. [PMID: 25729429 PMCID: PMC4344761 DOI: 10.1186/s13068-015-0202-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 01/09/2015] [Indexed: 05/15/2023]
Abstract
BACKGROUND Hypocrea jecorina is the sexual form of the industrial workhorse fungus Trichoderma reesei that secretes cellulases and hemicellulases to degrade lignocellulosic biomass into simple sugars, such as glucose and xylose. H. jecorina CBS999.97 is the only T. reesei wild isolate strain that is sexually competent in laboratory conditions. It undergoes a heterothallic reproductive cycle and generates CBS999.97(1-1) and CBS999.97(1-2) haploids with MAT1-1 and MAT1-2 mating-type loci, respectively. T. reesei QM6a and its derivatives (RUT-C30 and QM9414) all have a MAT1-2 mating type locus, but they are female sterile. Sexual crossing of CBS999.97(1-1) with either CBS999.97(1-2) or QM6a produces fruiting bodies containing asci with 16 linearly arranged ascospores (the sexual spores specific to ascomycetes). This sexual crossing approach has created new opportunities for these biotechnologically important fungi. RESULTS Through genetic and genomic analyses, we show that the 16 ascospores are generated via meiosis followed by two rounds of postmeiotic mitosis. We also found that the haploid genomes of CBS999.97(1-2) and QM6a are similar to that of the ancestral T. reesei strain, whereas the CBS999.97(1-1) haploid genome contains a reciprocal arrangement between two scaffolds of the CBS999.97(1-2) genome. Due to sequence heterozygosity, most 16-spore asci (>90%) contain four or eight inviable ascospores and an equal number of segmentally aneuploid (SAN) ascospores. The viable SAN progeny produced higher levels of xylanases and white conidia due to segmental duplication and deletion, respectively. Moreover, they readily lost the duplicated segment approximately two weeks after germination. With better lignocellulosic biomass degradation capability, these SAN progeny gain adaptive advantages to the natural environment, especially in the early phase of colonization. CONCLUSIONS Our results have not only further elucidated T. reesei evolution and sexual development, but also provided new perspectives for improving T. reesei industrial strains.
Collapse
Affiliation(s)
- Yu-Chien Chuang
- />Taiwan International Graduate Program in Molecular and Cellular Biology, Academia Sinica, Taipei, 115 Taiwan
- />Institute of Life Sciences, National Defense Medical Center, Taipei, 115 Taiwan
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Wan-Chen Li
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- />Institute of Genome Sciences, National Yang-Ming University, Taipei, 112 Taiwan
| | - Chia-Ling Chen
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Paul Wei-Che Hsu
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Shu-Yun Tung
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Hsiao-Che Kuo
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- />Present address: Department of Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Monika Schmoll
- />Austrian Institute of Technology, Health and Environment Department, Bioresources, University and Research Center, UFT Campus Tulln, Tulln/Donau, 3430 Austria
| | - Ting-Fang Wang
- />Taiwan International Graduate Program in Molecular and Cellular Biology, Academia Sinica, Taipei, 115 Taiwan
- />Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| |
Collapse
|
27
|
Singh A, Taylor LE 2nd, Vander Wall TA, Linger J, Himmel ME, Podkaminer K, Adney WS, Decker SR. Heterologous protein expression in Hypocrea jecorina: a historical perspective and new developments. Biotechnol Adv 2015; 33:142-54. [PMID: 25479282 DOI: 10.1016/j.biotechadv.2014.11.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/18/2014] [Accepted: 11/23/2014] [Indexed: 10/24/2022]
Abstract
Hypocrea jecorina, the sexual teleomorph of Trichoderma reesei, has long been favored as an industrial cellulase producer, first utilizing its native cellulase system and later augmented by the introduction of heterologous enzymatic activities or improved variants of native enzymes. Expression of heterologous proteins in H. jecorina was once considered difficult when the target was an improved variant of a native cellulase. Developments over the past nearly 30 years have produced strains, vectors, and selection mechanisms that have continued to simplify and streamline heterologous protein expression in this fungus. More recent developments in fungal molecular biology have pointed the way toward a fundamental transformation in the ease and efficiency of heterologous protein expression in this important industrial host. Here, 1) we provide a historical perspective on advances in H. jecorina molecular biology, 2) outline host strain engineering, transformation, selection, and expression strategies, 3) detail potential pitfalls when working with this organism, and 4) provide consolidated examples of successful cellulase expression outcomes from our laboratory.
Collapse
|
28
|
Karkehabadi S, Helmich KE, Kaper T, Hansson H, Mikkelsen NE, Gudmundsson M, Piens K, Fujdala M, Banerjee G, Scott-Craig JS, Walton JD, Phillips GN, Sandgren M. Biochemical characterization and crystal structures of a fungal family 3 β-glucosidase, Cel3A from Hypocrea jecorina. J Biol Chem 2014; 289:31624-37. [PMID: 25164811 DOI: 10.1074/jbc.m114.587766] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cellulase mixtures from Hypocrea jecorina are commonly used for the saccharification of cellulose in biotechnical applications. The most abundant β-glucosidase in the mesophilic fungus Hypocrea jecorina is HjCel3A, which hydrolyzes the β-linkage between two adjacent molecules in dimers and short oligomers of glucose. It has been shown that enhanced levels of HjCel3A in H. jecorina cellulase mixtures benefit the conversion of cellulose to glucose. Biochemical characterization of HjCel3A shows that the enzyme efficiently hydrolyzes (1,4)- as well as (1,2)-, (1,3)-, and (1,6)-β-D-linked disaccharides. For crystallization studies, HjCel3A was produced in both H. jecorina (HjCel3A) and Pichia pastoris (Pp-HjCel3A). Whereas the thermostabilities of HjCel3A and Pp-HjCel3A are the same, Pp-HjCel3A has a higher degree of N-linked glycosylation. Here, we present x-ray structures of HjCel3A with and without glucose bound in the active site. The structures have a three-domain architecture as observed previously for other glycoside hydrolase family 3 β-glucosidases. Both production hosts resulted in HjCel3A structures that have N-linked glycosylations at Asn(208) and Asn(310). In H. jecorina-produced HjCel3A, a single N-acetylglucosamine is present at both sites, whereas in Pp-HjCel3A, the P. pastoris-produced HjCel3A enzyme, the glycan chains consist of 8 or 4 saccharides. The glycosylations are involved in intermolecular contacts in the structures derived from either host. Due to the different sizes of the glycosylations, the interactions result in different crystal forms for the two protein forms.
Collapse
Affiliation(s)
- Saeid Karkehabadi
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Kate E Helmich
- the Department of Energy Great Lakes Bioenergy Research Center and Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Thijs Kaper
- DuPont Industrial Biosciences, Palo Alto, California 94304
| | - Henrik Hansson
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Nils-Egil Mikkelsen
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Mikael Gudmundsson
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Kathleen Piens
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | | | - Goutami Banerjee
- the Department of Energy Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, and
| | - John S Scott-Craig
- the Department of Energy Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, and
| | - Jonathan D Walton
- the Department of Energy Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, and
| | - George N Phillips
- the Department of Energy Great Lakes Bioenergy Research Center and Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, the Department of Biochemistry and Cell Biology and Department of Chemistry, Rice University, Houston, Texas 77251
| | - Mats Sandgren
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden,
| |
Collapse
|
29
|
Bodenheimer AM, Cuneo MJ, Swartz PD, He J, O’Neill HM, Myles DAA, Evans BR, Meilleur F. Crystallization and preliminary X-ray diffraction analysis of Hypocrea jecorina Cel7A in two new crystal forms. Acta Crystallogr F Struct Biol Commun 2014; 70:773-6. [PMID: 24915091 PMCID: PMC4051535 DOI: 10.1107/s2053230x14008851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 04/17/2014] [Indexed: 11/10/2022] Open
Abstract
Cel7A (previously known as cellobiohydrolase I) from Hypocrea jecorina was crystallized in two crystalline forms, neither of which have been previously reported. Both forms co-crystallize under the same crystallization conditions. The first crystal form belonged to space group C2, with unit-cell parameters a=152.5, b=44.9, c=57.6 Å, β=101.2°, and diffracted X-rays to 1.5 Å resolution. The second crystal form belonged to space group P6₃22, with unit-cell parameters a=b≃155, c≃138 Å, and diffracted X-rays to 2.5 Å resolution. The crystals were obtained using full-length Cel7A, which consists of a large 434-residue N-terminal catalytic domain capable of cleaving cellulose, a 27-residue flexible linker and a small 36-residue C-terminal carbohydrate-binding module (CBM). However, a preliminary analysis of the electron-density maps suggests that the linker and CBM are disordered in both crystal forms. Complete refinement and structure analysis are currently in progress.
Collapse
Affiliation(s)
- Annette M. Bodenheimer
- Molecular and Structural Biochemistry Department, North Carolina State University, Raleigh, North Carolina, USA
| | - Matthew J. Cuneo
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Paul D. Swartz
- Molecular and Structural Biochemistry Department, North Carolina State University, Raleigh, North Carolina, USA
| | - Junhong He
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Hugh M. O’Neill
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Dean A. A. Myles
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Barbara R. Evans
- Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Flora Meilleur
- Molecular and Structural Biochemistry Department, North Carolina State University, Raleigh, North Carolina, USA
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| |
Collapse
|
30
|
Mello-de-Sousa TM, Gorsche R, Rassinger A, Poças-Fonseca MJ, Mach RL, Mach-Aigner AR. A truncated form of the Carbon catabolite repressor 1 increases cellulase production in Trichoderma reesei. Biotechnol Biofuels 2014; 7:129. [PMID: 25342970 PMCID: PMC4173072 DOI: 10.1186/s13068-014-0129-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/22/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND Rut-C30 is a cellulase-hyperproducing Trichoderma reesei strain and, consequently, became the ancestor of most industry strains used in the production of plant cell wall-degrading enzymes, in particular cellulases. Due to three rounds of undirected mutagenesis its genetic background differs from the wild-type QM6a in many ways, of which two are the lack of a 83 kb large sequence in scaffold 15 and the partial lack of the gene encoding the Carbon catabolite repressor 1 (CREI). However, it is still unclear, what exactly enhances cellulase production in Rut-C30. RESULTS The investigation of the expression of two genes encoding cellulases (cbh1 and cbh2) and the gene encoding their main transactivator (xyr1) revealed that the presence of the truncated form of CREI (CREI-96) contributes more to the Rut-C30 phenotype than a general loss of CREI-mediated carbon catabolite repression (cre1 deletion strain) or the deletion of 29 genes encoded in the scaffold 15 (83 kb deletion strain). We found that the remaining cre1 in Rut-C30 (cre1-96) is transcribed into mRNA, that its putative gene product (Cre1-96) is still able to bind DNA, and that the CREI-binding sites in the upstream regulatory regions of the chosen CREI-target genes are still protected in Rut-C30. As it was previously reported that CREI acts on the nucleosome positioning, we also analyzed chromatin accessibility of the core promoters of CREI-target genes and found them open even on D-glucose in the presence of CREI-96. CONCLUSIONS The lack of the full version of CREI in Rut-C30 corresponds with a partial release from carbon catabolite repression but is not completely explained by the lack of CREI. In contrast, the truncated CREI-96 of Rut-C30 exerts a positive regulatory influence on the expression of target genes. Mechanistically this might be explained at least partially by a CREI-96-mediated opening of chromatin.
Collapse
Affiliation(s)
- Thiago M Mello-de-Sousa
- />Department for Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Str. 1a, A-1060 Wien, Austria
| | - Rita Gorsche
- />Department for Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Str. 1a, A-1060 Wien, Austria
| | - Alice Rassinger
- />Department for Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Str. 1a, A-1060 Wien, Austria
| | - Marcio J Poças-Fonseca
- />Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasília, Campus Universitário Darcy Ribeiro, 70910-900 Brasília, DF Brazil
| | - Robert L Mach
- />Department for Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Str. 1a, A-1060 Wien, Austria
| | - Astrid R Mach-Aigner
- />Department for Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Str. 1a, A-1060 Wien, Austria
| |
Collapse
|
31
|
Schuster A, Schmoll M. Heterotrimeric G-protein signaling and light response: Two signaling pathways coordinated for optimal adjustment to nature. Commun Integr Biol 2013; 2:308-10. [PMID: 19721873 DOI: 10.4161/cib.2.4.8223] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 02/18/2009] [Indexed: 01/24/2023] Open
Abstract
Almost all creatures have invented sophisticated mechanisms to adjust their developmental and metabolic processes to the changing light intensities in day and night. Recent findings suggest that one such mechanism is signaling via heterotrimeric G-proteins.1 The Trichoderma reesei (anamorph of Hypocrea jecorina) G-alpha subunit gene gna3 was found to be responsive to light and influenced by the light regulatory protein ENVOY.2 GNA3 significantly impacts regulation of cellulase gene expression only in light.1 While the exact mechanism of this regulation remains to be determined, first hints point to a regulation at the transcriptional level, since we observed light induced complex formation within the gna3 promotor. At least some of the components of this putatively regulatory protein complex also bind to the env1-promotor. These data indicate that the signal related by GNA3 is of light-dependent significance for H. jecorina and that the pathway of heterotrimeric G-protein signaling may be a target of the light perception machinery in fungi.
Collapse
Affiliation(s)
- André Schuster
- Research Area Gene Technology and Applied Biochemistry; Institute of Chemical Engineering; Vienna University of Technology; Vienna, Austria
| | | |
Collapse
|
32
|
Pucher ME, Steiger MG, Mach RL, Mach-Aigner AR. A modified expression of the major hydrolase activator in Hypocrea jecorina ( Trichoderma reesei) changes enzymatic catalysis of biopolymer degradation. Catal Today 2011; 167:122-128. [PMID: 27667900 PMCID: PMC4461149 DOI: 10.1016/j.cattod.2010.12.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hypocrea jecorina (anamorph Trichoderma reesei) is a saprophytic fungus that produces hydrolases, which are applied in different types of industries and used for the production of biofuel. A recombinant Hypocrea strain, which constantly expresses the main transcription activator of hydrolases (Xylanase regulator 1), was found to grow faster on xylan and its monomeric backbone molecule d-xylose. This strain also showed improved ability of clearing xylan medium on plates. Furthermore, this strain has a changed transcription profile concerning genes encoding for hydrolases and enzymes associated with degradation of (hemi)celluloses. We demonstrated that enzymes of this strain from a xylan cultivation favoured break down of hemicelluloses to the monomer d-xylose compared to the parental strain, while the enzymes of the latter one formed more xylobiose. Applying supernatants from cultivation on carboxymethylcellulose in enzymatic conversion of hemicelluloses, the enzymes of the recombinant strain were clearly producing more of both, d-xylose and xylobiose, compared to the parental strain. Altogether, these results point to a changed hydrolase expression profile, an enhanced capability to form the xylan-monomer d-xylose and the assumption that there is a disordered induction pattern if the Xylanase regulator 1 is de-regulated in Hypocrea.
Collapse
Affiliation(s)
- Marion E Pucher
- Gene Technology, Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166/5/2, A-1060 Wien, Austria
| | - Matthias G Steiger
- Gene Technology, Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166/5/2, A-1060 Wien, Austria
| | - Robert L Mach
- Gene Technology, Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166/5/2, A-1060 Wien, Austria
| | - Astrid R Mach-Aigner
- Gene Technology, Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Wien, Getreidemarkt 9/166/5/2, A-1060 Wien, Austria
| |
Collapse
|