scholarly journals Regulation of transcription of cellulases- and hemicellulases-encoding genes in Aspergillus niger and Hypocrea jecorina (Trichoderma reesei)

2008 ◽  
Vol 78 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Astrid R. Stricker ◽  
Robert L. Mach ◽  
Leo H. de Graaff
Keyword(s):  
Aspergillus Niger ◽  
Trichoderma Reesei ◽  
Regulation Of Transcription ◽  
Hypocrea Jecorina ◽  
Encoding Genes

scholarly journals d-Xylose as a Repressor or Inducer of Xylanase Expression in Hypocrea jecorina (Trichoderma reesei)

2010 ◽  
Vol 76 (6) ◽  
pp. 1770-1776 ◽  
Author(s):  
Astrid R. Mach-Aigner ◽  
Marion E. Pucher ◽  
Robert L. Mach
Keyword(s):  
Trichoderma Reesei ◽  
Xylose Reductase ◽  
Negative Influence ◽  
Hypocrea Jecorina ◽  
Xylanase Gene ◽  
Catabolite Repressor ◽  
Encoding Gene ◽  
Encoding Genes ◽  
Xylose Concentration

ABSTRACT For Hypocrea jecorina (anamorph Trichoderma reesei), a filamentous fungus used for hydrolase production in different industries, it has been a long-term practice to use d-xylose as an inducing substance. We demonstrate in this study that the degree of xylanase-encoding gene induction strictly depends on the concentration of d-xylose, which was found to be optimal from 0.5 to 1 mM for 3 h of cultivation. At higher concentrations of d-xylose, a reduced level of xylanase gene expression was observed. In the present study, we also provide evidence that the d-xylose concentration-dependent induction is antagonized by carbon catabolite repressor 1. This repressor mediates its influence on d-xylose indirectly, by reducing the expression of xylanase regulator 1, the main activator of most hydrolase-encoding genes. Additionally, a direct influence of the repressor on xylanase 1 expression in the presence of d-xylose was found. Furthermore, we show that d-xylose reductase 1 is needed to metabolize d-xylose to achieve full induction of xylanase expression. Finally, a strain which expresses xylanase regulator 1 at a constant level was used to partially overcome the negative influence exerted by carbon catabolite repressor 1 on d-xylose.

scholarly journals Molecular Regulation of Arabinan and l-Arabinose Metabolism in Hypocrea jecorina (Trichoderma reesei)

2009 ◽  
Vol 8 (12) ◽  
pp. 1837-1844 ◽  
Author(s):  
Eda Akel ◽  
Benjamin Metz ◽  
Bernhard Seiboth ◽  
Christian P. Kubicek
Keyword(s):  
Trichoderma Reesei ◽  
Aldose Reductase ◽  
Parent Strain ◽  
Constitutive Expression ◽  
Molecular Regulation ◽  
Transcriptional Analysis ◽  
Loss Of Function ◽  
Hypocrea Jecorina ◽  
Slight Effect ◽  
Encoding Genes

ABSTRACT Hypocrea jecorina (anamorph: Trichoderma reesei) can grow on plant arabinans by the aid of secreted arabinan-degrading enzymes. This growth on arabinan and its degradation product l-arabinose requires the operation of the aldose reductase XYL1 and the l-arabinitol dehydrogenase LAD1. Growth on arabinan and l-arabinose is also severely affected in a strain deficient in the general cellulase and hemicellulase regulator XYR1, but this impairment can be overcome by constitutive expression of the xyl1 encoding the aldose reductase. An inspection of the genome of H. jecorina reveals four genes capable of degrading arabinan, i.e., the α-l-arabinofuranosidase encoding genes abf1, abf2, and abf3 and also bxl1, which encodes a β-xylosidase with a separate α-l-arabinofuranosidase domain and activity but no endo-arabinanase. Transcriptional analysis reveals that in the parent strain QM9414 the expression of all of these genes is induced by l-arabinose and to a lesser extent by l-arabinitol and absent on d-glucose. Induction by l-arabinitol, however, is strongly enhanced in a Δlad1 strain lacking l-arabinitol dehydrogenase activity and severely impaired in an aldose reductase (Δxyl1) strain, suggesting a cross talk between l-arabinitol and the aldose reductase XYL1 in an α-l-arabinofuranosidase gene expression. Strains bearing a knockout in the cellulase regulator xyr1 do not show any induction of abf2 and bxl1, and this phenotype cannot be reverted by constitutive expression of xyl1. The loss of function of xyr1 has also a slight effect on the expression of abf1 and abf3. We conclude that the expression of the four α-l-arabinofuranosidases of H. jecorina for growth on arabinan requires an early pathway intermediate (l-arabinitol or l-arabinose), the first enzyme of the pathway XYL1, and in the case of abf2 and bxl1 also the function of the cellulase regulator XYR1.

scholarly journals L-Arabitol Is the Actual Inducer of Xylanase Expression in Hypocrea jecorina (Trichoderma reesei)

2011 ◽  
Vol 77 (17) ◽  
pp. 5988-5994 ◽  
Author(s):  
Astrid R. Mach-Aigner ◽  
Loreta Gudynaite-Savitch ◽  
Robert L. Mach
Keyword(s):  
Trichoderma Reesei ◽  
Raw Materials ◽  
Hydrolytic Enzymes ◽  
Constitutive Expression ◽  
Deletion Strain ◽  
Hypocrea Jecorina ◽  
Content Type ◽  
Double Deletion ◽  
Encoding Genes ◽  
Pentose Pathway

ABSTRACTThe saprophytic fungusHypocrea jecorina(anamorph,Trichoderma reesei) is an important native producer of hydrolytic enzymes, including xylanases. Regarding principles of sustainability, cheap and renewable raw materials, such asd-xylose (the backbone monomer of xylan), have been receiving increasing attention from industries. Recently, it was demonstrated that small (0.5 to 1 mM) amounts ofd-xylose induce the highest expression of xylanase inH. jecorina. However, it was also reported that active metabolism ofd-xylose is necessary for induction. In this report, we demonstrate that xylitol, the next intermediate in the pentose pathway afterd-xylose, does not trigger transcription of xylanase-encoding genes inH. jecorinaQM9414. The highest level of transcription of xylanolytic enzyme-encoding genes occurred in anxdh1(encoding a xylitol dehydrogenase) deletion strain cultured in the presence of 0.5 mMd-xylose, suggesting that a metabolite upstream of xylitol is the inducer. The expression levels of xylanases in anxdh1-lad1double-deletion strain were lower than that of anxdh1deletion strain. This observation suggested thatl-xylulose is not an inducer and led to the hypothesis thatl-arabitol is the actual inducer of xylanase expression. A direct comparison of transcript levels following the incubation of theH. jecorinaparental strain with various metabolites of the pentose pathway confirmed this hypothesis. In addition, we demonstrate thatxyr1, the activator gene, is not induced in the presence of pentose sugars and polyols, regardless of the concentration used; instead, we observed low constitutive expression ofxyr1.

scholarly journals Spatial and Developmental Differentiation of Mannitol Dehydrogenase and Mannitol-1-Phosphate Dehydrogenase in Aspergillus niger

2010 ◽  
Vol 9 (9) ◽  
pp. 1398-1402 ◽  
Author(s):  
Guillermo Aguilar-Osorio ◽  
Patricia A. vanKuyk ◽  
Bernhard Seiboth ◽  
Dirk Blom ◽  
Peter S. Solomon ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Fluorescent Protein ◽  
Northern Analysis ◽  
Expression Data ◽  
Mannitol Dehydrogenase ◽  
Content Type ◽  
Green Fluorescent ◽  
Developmental Differentiation ◽  
Encoding Genes ◽  
Mannitol Cycle

ABSTRACT The presence of a mannitol cycle in fungi has been subject to discussion for many years. Recent studies have found no evidence for the presence of this cycle and its putative role in regenerating NADPH. However, all enzymes of the cycle could be measured in cultures of Aspergillus niger. In this study we have analyzed the localization of two enzymes from the pathway, mannitol dehydrogenase and mannitol-1-phosphate dehydrogenase, and the expression of their encoding genes in nonsporulating and sporulating cultures of A. niger. Northern analysis demonstrated that mpdA was expressed in both sporulating and nonsporulating mycelia, while expression of mtdA was expressed only in sporulating mycelium. More detailed studies using green fluorescent protein and dTomato fused to the promoters of mtdA and mpdA, respectively, demonstrated that expression of mpdA occurs in vegetative hyphae while mtdA expression occurs in conidiospores. Activity assays for MtdA and MpdA confirmed the expression data, indicating that streaming of these proteins is not likely to occur. These results confirm the absence of the putative mannitol cycle in A. niger as two of the enzymes of the cycle are not present in the same part of A. niger colonies. The results also demonstrate the existence of spore-specific genes and enzymes in A. niger.

scholarly journals Metabolic Engineering of Fungal Strains for Conversion of d-Galacturonate to meso-Galactarate

2009 ◽  
Vol 76 (1) ◽  
pp. 169-175 ◽  
Author(s):  
Dominik Mojzita ◽  
Marilyn Wiebe ◽  
Satu Hilditch ◽  
Harry Boer ◽  
Merja Penttilä ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Aspergillus Niger ◽  
Galacturonic Acid ◽  
Raw Material ◽  
High Yield ◽  
Hypocrea Jecorina ◽  
Bacterial Gene ◽  
Fungal Strains ◽  
Gene Coding ◽  
Reductive Pathway

ABSTRACT d-Galacturonic acid can be obtained by hydrolyzing pectin, which is an abundant and low value raw material. By means of metabolic engineering, we constructed fungal strains for the conversion of d-galacturonate to meso-galactarate (mucate). Galactarate has applications in food, cosmetics, and pharmaceuticals and as a platform chemical. In fungi d-galacturonate is catabolized through a reductive pathway with a d-galacturonate reductase as the first enzyme. Deleting the corresponding gene in the fungi Hypocrea jecorina and Aspergillus niger resulted in strains unable to grow on d-galacturonate. The genes of the pathway for d-galacturonate catabolism were upregulated in the presence of d-galacturonate in A. niger, even when the gene for d-galacturonate reductase was deleted, indicating that d-galacturonate itself is an inducer for the pathway. A bacterial gene coding for a d-galacturonate dehydrogenase catalyzing the NAD-dependent oxidation of d-galacturonate to galactarate was introduced to both strains with disrupted d-galacturonate catabolism. Both strains converted d-galacturonate to galactarate. The resulting H. jecorina strain produced galactarate at high yield. The A. niger strain regained the ability to grow on d-galacturonate when the d-galacturonate dehydrogenase was introduced, suggesting that it has a pathway for galactarate catabolism.

An accurate normalization strategy for RT-qPCR in Hypocrea jecorina (Trichoderma reesei)

2010 ◽  
Vol 145 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Matthias G. Steiger ◽  
Robert L. Mach ◽  
Astrid R. Mach-Aigner
Keyword(s):  
Trichoderma Reesei ◽  
Hypocrea Jecorina ◽  
Normalization Strategy ◽  
Accurate Normalization

scholarly journals A Novel Cys2His2 Zinc Finger Homolog of AZF1 Modulates Holocellulase Expression in Trichoderma reesei

mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Amanda Cristina Campos Antonieto ◽  
Karoline Maria Vieira Nogueira ◽  
Renato Graciano de Paula ◽  
Luísa Czamanski Nora ◽  
Murilo Henrique Anzolini Cassiano ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Filamentous Fungi ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Regulatory Elements ◽  
Biomass Degradation ◽  
Control Of Gene Expression ◽  
Content Type ◽  
Encoding Genes

ABSTRACT Filamentous fungi are remarkable producers of enzymes dedicated to the degradation of sugar polymers found in the plant cell wall. Here, we integrated transcriptomic data to identify novel transcription factors (TFs) related to the control of gene expression of lignocellulosic hydrolases in Trichoderma reesei and Aspergillus nidulans. Using various sets of differentially expressed genes, we identified some putative cis-regulatory elements that were related to known binding sites for Saccharomyces cerevisiae TFs. Comparative genomics allowed the identification of six transcriptional factors in filamentous fungi that have corresponding S. cerevisiae homologs. Additionally, a knockout strain of T. reesei lacking one of these TFs (S. cerevisiae AZF1 homolog) displayed strong reductions in the levels of expression of several cellulase-encoding genes in response to both Avicel and sugarcane bagasse, revealing a new player in the complex regulatory network operating in filamentous fungi during plant biomass degradation. Finally, RNA sequencing (RNA-seq) analysis showed the scope of the AZF1 homologue in regulating a number of processes in T. reesei, and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) provided evidence for the direct interaction of this TF in the promoter regions of cel7a, cel45a, and swo. Therefore, we identified here a novel TF which plays a positive effect in the expression of cellulase-encoding genes in T. reesei. IMPORTANCE In this work, we used a systems biology approach to map new regulatory interactions in Trichoderma reesei controlling the expression of genes encoding cellulase and hemicellulase. By integrating transcriptomics related to complex biomass degradation, we were able to identify a novel transcriptional regulator which is able to activate the expression of these genes in response to two different cellulose sources. In vivo experimental validation confirmed the role of this new regulator in several other processes related to carbon source utilization and nutrient transport. Therefore, this work revealed novel forms of regulatory interaction in this model system for plant biomass deconstruction and also represented a new approach that could be easy applied to other organisms.

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