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Coconi Linares N, Li X, Dilokpimol A, de Vries RP. Comparative characterization of nine novel GH51, GH54 and GH62 α-l-arabinofuranosidases from Penicillium subrubescens. FEBS Lett 2022; 596:360-368. [PMID: 35014696 DOI: 10.1002/1873-3468.14278] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 11/07/2022]
Abstract
α-l-Arabinofuranosidases (ABFs) are important enzymes in plant biomass degradation with a wide range of applications. The ascomycete fungus Penicillium subrubescens has more α-l-arabinofuranosidase-encoding genes in its genome compared to other Penicillia. We characterized nine ABFs from glycoside hydrolase (GH) families GH51, GH54 and GH62 from this fungus and demonstrated that they have highly diverse specificity and activity levels, indicating that the expansion was accompanied by diversification of the enzymes. Comparison of the substrate preference of the enzymes to the expression of the corresponding genes when the fungus was grown on either of two plant biomass substrates did not show a clear correlation, suggesting a more complex regulatory system governing l-arabinose release from plant biomass by P. subrubescens.
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Affiliation(s)
- Nancy Coconi Linares
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Xinxin Li
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Adiphol Dilokpimol
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, The Netherlands
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Li X, Dilokpimol A, Kabel MA, de Vries RP. Fungal xylanolytic enzymes: Diversity and applications. BIORESOURCE TECHNOLOGY 2022; 344:126290. [PMID: 34748977 DOI: 10.1016/j.biortech.2021.126290] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 05/26/2023]
Abstract
As important polysaccharide degraders in nature, fungi can diversify their extensive set of carbohydrate-active enzymes to survive in ecological habitats of various composition. Among these enzymes, xylanolytic ones can efficiently and sustainably degrade xylans into (fermentable) monosaccharides to produce valuable chemicals or fuels from, for example relevant for upgrading agro-food industrial side streams. Moreover, xylanolytic enzymes are being used in various industrial applications beyond biomass saccharification, e.g. food, animal feed, biofuel, pulp and paper. As a reference for researchers working in related areas, this review summarized the current knowledge on substrate specificity of xylanolytic enzymes from different families of the Carbohydrate-Active enZyme database. Additionally, the diversity of enzyme sets in fungi were discussed by comparing the number of genes encoding xylanolytic enzymes in selected fungal genomes. Finally, to support bio-economy, the current applications of fungal xylanolytic enzymes in industry were reviewed.
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Affiliation(s)
- Xinxin Li
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Adiphol Dilokpimol
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
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Effect of Oligosaccharide Degree of Polymerization on the Induction of Xylan-Degrading Enzymes by Fusarium oxysporum f. sp. Lycopersici. Molecules 2020; 25:molecules25245849. [PMID: 33322262 PMCID: PMC7764074 DOI: 10.3390/molecules25245849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 01/15/2023] Open
Abstract
Xylan is one of the most abundant carbohydrates on Earth. Complete degradation of xylan is achieved by the collaborative action of endo-β-1,4-xylanases and β-d-xylosidases and a number of accessories enzymes. In filamentous fungi, the xylanolytic system is controlled through induction and repression. However, the exact mechanism remains unclear. Substrates containing xylan promote the induction of xylanases, which release xylooligosaccharides. These, in turn, induce expression of xylanase-encoding genes. Here, we aimed to determine which xylan degradation products acted as inducers, and whether the size of the released oligomer correlated with its induction strength. To this end, we compared xylanase production by different inducers, such as sophorose, lactose, cellooligosaccharides, and xylooligosaccharides in Fusarium oxysporum f. sp. lycopersici. Results indicate that xylooligosaccharides are more effective than other substrates at inducing endoxylanase and β-xylosidases. Moreover, we report a correlation between the degree of xylooligosaccharide polymerization and induction efficiency of each enzyme. Specifically, xylotetraose is the best inducer of endoxylanase, xylohexaose of extracellular β-xylosidase, and xylobiose of cell-bound β-xylosidase.
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Poria V, Saini JK, Singh S, Nain L, Kuhad RC. Arabinofuranosidases: Characteristics, microbial production, and potential in waste valorization and industrial applications. BIORESOURCE TECHNOLOGY 2020; 304:123019. [PMID: 32089440 DOI: 10.1016/j.biortech.2020.123019] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/09/2020] [Accepted: 02/11/2020] [Indexed: 05/15/2023]
Abstract
Alpha-L-arabinofuranoside arabinofuranohydrolase (ARA), more commonly known as alpha-L-arabinofuranosidase (E.C. number 3.2.1.55), is a hydrolytic enzyme, catalyzing the cleavage of alpha-L-arabinose by acting on the non-reducing ends of alpha-L-arabinofuranosides, alpha-L-arabinans containing (1,3)- and/or (1,5)-linked arabinoxylans and arabinogalactans. ARA functions as debranching enzyme removing arabinose substituents from arabinoxylan and arabinoxylooligomers, thereby, boosting the hydrolysis of arabinoxylan fraction of hemicellulose and improving bioconversion of lignocellulosic biomass. Previously, comprehensive information on this enzyme has not been reviewed thoroughly. Therefore, the main aim of this review is to highlight the important properties of this interesting enzyme, microorganisms used for its production, and enhanced production using genetic engineering approach. An account on synergism with other biomass hydrolyzing enzymes and various industrial applications of this enzyme has also been provided along with an outlook on further research and development.
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Affiliation(s)
- Vikram Poria
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
| | - Jitendra Kumar Saini
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
| | - Surender Singh
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India; Division of Microbiology, Indian Agricultural Research Institute, New Delhi PIN-110012, India.
| | - Lata Nain
- Division of Microbiology, Indian Agricultural Research Institute, New Delhi PIN-110012, India
| | - Ramesh Chander Kuhad
- Central University of Haryana, Mahendergarh, Haryana PIN-123031, India; Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, New Delhi PIN-110021, India
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de Vries RP, Mäkelä MR. Genomic and Postgenomic Diversity of Fungal Plant Biomass Degradation Approaches. Trends Microbiol 2020; 28:487-499. [PMID: 32396827 DOI: 10.1016/j.tim.2020.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/15/2019] [Accepted: 01/16/2020] [Indexed: 10/25/2022]
Abstract
Plant biomass degradation by fungi is a widely studied and applied field of science, due to its relevance for the global carbon cycle and many biotechnological applications. Before the genome era, many of the in-depth studies focused on a relatively small number of species, whereas now, many species can be addressed in detail, revealing the large variety in the approach used by fungi to degrade plant biomass. This variation is found at many levels and includes genomic adaptation to the preferred biomass component, but also different approaches to degrade this component by diverse sets of activities encoded in the genome. Even larger differences have been observed using transcriptome and proteome studies, even between closely related species, suggesting a high level of adaptation in individual species. A better understanding of the drivers of this diversity could be highly valuable in developing more efficient biotechnology approaches for the enzymatic conversion of plant biomass.
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Affiliation(s)
- Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands.
| | - Miia R Mäkelä
- Department of Microbiology, University of Helsinki, Helsinki, Finland
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Gruben BS, Mäkelä MR, Kowalczyk JE, Zhou M, Benoit-Gelber I, De Vries RP. Expression-based clustering of CAZyme-encoding genes of Aspergillus niger. BMC Genomics 2017; 18:900. [PMID: 29169319 PMCID: PMC5701360 DOI: 10.1186/s12864-017-4164-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 10/05/2017] [Indexed: 11/29/2022] Open
Abstract
Background The Aspergillus niger genome contains a large repertoire of genes encoding carbohydrate active enzymes (CAZymes) that are targeted to plant polysaccharide degradation enabling A. niger to grow on a wide range of plant biomass substrates. Which genes need to be activated in certain environmental conditions depends on the composition of the available substrate. Previous studies have demonstrated the involvement of a number of transcriptional regulators in plant biomass degradation and have identified sets of target genes for each regulator. In this study, a broad transcriptional analysis was performed of the A. niger genes encoding (putative) plant polysaccharide degrading enzymes. Microarray data focusing on the initial response of A. niger to the presence of plant biomass related carbon sources were analyzed of a wild-type strain N402 that was grown on a large range of carbon sources and of the regulatory mutant strains ΔxlnR, ΔaraR, ΔamyR, ΔrhaR and ΔgalX that were grown on their specific inducing compounds. Results The cluster analysis of the expression data revealed several groups of co-regulated genes, which goes beyond the traditionally described co-regulated gene sets. Additional putative target genes of the selected regulators were identified, based on their expression profile. Notably, in several cases the expression profile puts questions on the function assignment of uncharacterized genes that was based on homology searches, highlighting the need for more extensive biochemical studies into the substrate specificity of enzymes encoded by these non-characterized genes. The data also revealed sets of genes that were upregulated in the regulatory mutants, suggesting interaction between the regulatory systems and a therefore even more complex overall regulatory network than has been reported so far. Conclusions Expression profiling on a large number of substrates provides better insight in the complex regulatory systems that drive the conversion of plant biomass by fungi. In addition, the data provides additional evidence in favor of and against the similarity-based functions assigned to uncharacterized genes. Electronic supplementary material The online version of this article (10.1186/s12864-017-4164-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Birgit S Gruben
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Miia R Mäkelä
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, Viikki Biocenter 1, University of Helsinki, Helsinki, Finland
| | - Joanna E Kowalczyk
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Current affiliation: ATGM, Avans University of Applied Sciences, Lovensdijkstraat 61-63, 4818, AJ, Breda, The Netherlands
| | - Isabelle Benoit-Gelber
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.,Current affiliation: Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke St. W, Montreal, QC, Canada
| | - Ronald P De Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands. .,Microbiology, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands. .,Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584, CT, Utrecht, The Netherlands.
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Park HS, Jun SC, Han KH, Hong SB, Yu JH. Diversity, Application, and Synthetic Biology of Industrially Important Aspergillus Fungi. ADVANCES IN APPLIED MICROBIOLOGY 2017; 100:161-202. [PMID: 28732553 DOI: 10.1016/bs.aambs.2017.03.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The filamentous fungal genus Aspergillus consists of over 340 officially recognized species. A handful of these Aspergillus fungi are predominantly used for food fermentation and large-scale production of enzymes, organic acids, and bioactive compounds. These industrially important Aspergilli primarily belong to the two major Aspergillus sections, Nigri and Flavi. Aspergillus oryzae (section Flavi) is the most commonly used mold for the fermentation of soybeans, rice, grains, and potatoes. Aspergillus niger (section Nigri) is used in the industrial production of various enzymes and organic acids, including 99% (1.4 million tons per year) of citric acid produced worldwide. Better understanding of the genomes and the signaling mechanisms of key Aspergillus species can help identify novel approaches to enhance these commercially significant strains. This review summarizes the diversity, current applications, key products, and synthetic biology of Aspergillus fungi commonly used in industry.
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Affiliation(s)
- Hee-Soo Park
- Kyungpook National University, Daegu, Republic of Korea
| | | | | | | | - Jae-Hyuk Yu
- University of Wisconsin, Madison, WI, United States
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Kiesenhofer D, Mach-Aigner AR, Mach RL. Understanding the Mechanism of Carbon Catabolite Repression to Increase Protein Production in Filamentous Fungi. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Liaud N, Giniés C, Navarro D, Fabre N, Crapart S, Gimbert IH, Levasseur A, Raouche S, Sigoillot JC. RNA-sequencing reveals the complexities of the transcriptional response to lignocellulosic biofuel substrates in Aspergillus niger. Fungal Biol Biotechnol 2014; 1:1-14. [PMID: 26457194 PMCID: PMC4599204 DOI: 10.1186/s40694-014-0003-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/23/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Saprobic fungi are the predominant industrial sources of Carbohydrate Active enZymes (CAZymes) used for the saccharification of lignocellulose during the production of second generation biofuels. The production of more effective enzyme cocktails is a key objective for efficient biofuel production. To achieve this objective, it is crucial to understand the response of fungi to lignocellulose substrates. Our previous study used RNA-seq to identify the genes induced in Aspergillus niger in response to wheat straw, a biofuel feedstock, and showed that the range of genes induced was greater than previously seen with simple inducers. RESULTS In this work we used RNA-seq to identify the genes induced in A. niger in response to short rotation coppice willow and compared this with the response to wheat straw from our previous study, at the same time-point. The response to willow showed a large increase in expression of genes encoding CAZymes. Genes encoding the major activities required to saccharify lignocellulose were induced on willow such as endoglucanases, cellobiohydrolases and xylanases. The transcriptome response to willow had many similarities with the response to straw with some significant differences in the expression levels of individual genes which are discussed in relation to differences in substrate composition or other factors. Differences in transcript levels include higher levels on wheat straw from genes encoding enzymes classified as members of GH62 (an arabinofuranosidase) and CE1 (a feruloyl esterase) CAZy families whereas two genes encoding endoglucanases classified as members of the GH5 family had higher transcript levels when exposed to willow. There were changes in the cocktail of enzymes secreted by A. niger when cultured with willow or straw. Assays for particular enzymes as well as saccharification assays were used to compare the enzyme activities of the cocktails. Wheat straw induced an enzyme cocktail that saccharified wheat straw to a greater extent than willow. Genes not encoding CAZymes were also induced on willow such as hydrophobins as well as genes of unknown function. Several genes were identified as promising targets for future study. CONCLUSIONS By comparing this first study of the global transcriptional response of a fungus to willow with the response to straw, we have shown that the inducing lignocellulosic substrate has a marked effect upon the range of transcripts and enzymes expressed by A. niger. The use by industry of complex substrates such as wheat straw or willow could benefit efficient biofuel production.
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Affiliation(s)
- Nadège Liaud
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- ARD, Agro-Industry Research and Development, Pômacle, F-51100 France
| | - Christian Giniés
- INRA, UMR 1260, « Nutrition, Obésité et Risque Thrombotique », Marseille, F-13385 France
- INSERM, UMR 1062, « Nutrition, Obésité et Risque Thrombotique », Marseille, F-13385 France
- Université d’Aix-Marseille, UMR 1260, « Nutrition, Obésité et Risque Thrombotique », Faculté de Médecine, Marseille, F-13385 France
| | - David Navarro
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- INRA, International Center for Microbial Resources collection-Filamentous fungi CIRM-CF, Marseille, F-13288 France
| | - Nicolas Fabre
- ARD, Agro-Industry Research and Development, Pômacle, F-51100 France
| | - Sylvaine Crapart
- ARD, Agro-Industry Research and Development, Pômacle, F-51100 France
| | - Isabelle Herpoël- Gimbert
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
| | - Anthony Levasseur
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
| | - Sana Raouche
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Polytech’ Marseille (ex ESIL), UMR 1163 BCF - INRA / AMU, 163 Avenue de Luminy CP 925, Marseille, F-13288 France
| | - Jean-Claude Sigoillot
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
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Kaur AP, Nocek BP, Xu X, Lowden MJ, Leyva JF, Stogios PJ, Cui H, Di Leo R, Powlowski J, Tsang A, Savchenko A. Functional and structural diversity in GH62 α-L-arabinofuranosidases from the thermophilic fungus Scytalidium thermophilum. Microb Biotechnol 2014; 8:419-33. [PMID: 25267315 PMCID: PMC4408175 DOI: 10.1111/1751-7915.12168] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 08/16/2014] [Indexed: 01/22/2023] Open
Abstract
The genome of the thermophilic fungus Scytalidium thermophilum (strain CBS 625.91) harbours a wide range of genes involved in carbohydrate degradation, including three genes, abf62A, abf62B and abf62C, predicted to encode glycoside hydrolase family 62 (GH62) enzymes. Transcriptome analysis showed that only abf62A and abf62C are actively expressed during growth on diverse substrates including straws from barley, alfalfa, triticale and canola. The abf62A and abf62C genes were expressed in Escherichia coli and the resulting recombinant proteins were characterized. Calcium-free crystal structures of Abf62C in apo and xylotriose bound forms were determined to 1.23 and 1.48 Å resolution respectively. Site-directed mutagenesis confirmed Asp55, Asp171 and Glu230 as catalytic triad residues, and revealed the critical role of non-catalytic residues Asp194, Trp229 and Tyr338 in positioning the scissile α-L-arabinofuranoside bond at the catalytic site. Further, the +2R substrate-binding site residues Tyr168 and Asn339, as well as the +2NR residue Tyr226, are involved in accommodating long-chain xylan polymers. Overall, our structural and functional analysis highlights characteristic differences between Abf62A and Abf62C, which represent divergent subgroups in the GH62 family.
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Affiliation(s)
- Amrit Pal Kaur
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, ON, M5S 3E5, Canada
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De La Mare M, Guais O, Bonnin E, Weber J, Francois JM. Molecular and biochemical characterization of three GH62 α-l-arabinofuranosidases from the soil deuteromycete Penicillium funiculosum. Enzyme Microb Technol 2013; 53:351-8. [DOI: 10.1016/j.enzmictec.2013.07.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/29/2013] [Accepted: 07/31/2013] [Indexed: 01/17/2023]
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Jovanović B, Mach RL, Mach-Aigner AR. Characterization of erythrose reductases from filamentous fungi. AMB Express 2013; 3:43. [PMID: 23924507 PMCID: PMC3751045 DOI: 10.1186/2191-0855-3-43] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/03/2013] [Indexed: 11/11/2022] Open
Abstract
Proteins with putative erythrose reductase activity have been identified in the filamentous fungi Trichoderma reesei, Aspergillus niger, and Fusarium graminearum by in silico analysis. The proteins found in T. reesei and A. niger had earlier been characterized as glycerol dehydrogenase and aldehyde reductase, respectively. Corresponding genes from all three fungi were cloned, heterologously expressed in Escherichia coli, and purified. Subsequently, they were used to establish optimal enzyme assay conditions. All three enzymes strictly require NADPH as cofactor, whereas with NADH no activity could be observed. The enzymatic characterization of the three enzymes using ten substrates revealed high substrate specificity and activity with D-erythrose and D-threose. The enzymes from T. reesei and A. niger herein showed comparable activities, whereas the one from F. graminearum reached only about a tenth of it for all tested substrates. In order to proof in vivo the proposed enzyme function, we overexpressed the erythrose reductase-encoding gene in T. reesei. An increased production of erythritol by the recombinant strain compared to the parental strain could be detected.
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Andersen MR, Giese M, de Vries RP, Nielsen J. Mapping the polysaccharide degradation potential of Aspergillus niger. BMC Genomics 2012; 13:313. [PMID: 22799883 PMCID: PMC3542576 DOI: 10.1186/1471-2164-13-313] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 06/08/2012] [Indexed: 11/10/2022] Open
Abstract
Background The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation. Results Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan. Conclusions The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger.
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Affiliation(s)
- Mikael R Andersen
- Department of Systems Biology, Technical University of Denmark, Kgs. Lyngby, Denmark
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Chlubnova I, Legentil L, Dureau R, Pennec A, Almendros M, Daniellou R, Nugier-Chauvin C, Ferrières V. Specific and non-specific enzymes for furanosyl-containing conjugates: biosynthesis, metabolism, and chemo-enzymatic synthesis. Carbohydr Res 2012; 356:44-61. [PMID: 22554502 DOI: 10.1016/j.carres.2012.04.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 04/02/2012] [Accepted: 04/03/2012] [Indexed: 11/27/2022]
Abstract
There is no doubt now that the synthesis of compounds of varying complexity such as saccharides and derivatives thereof continuously grows with enzymatic methods. This review focuses on recent basic knowledge on enzymes specifically involved in the biosynthesis and degradation of furanosyl-containing polysaccharides and conjugates. Moreover, and when possible, biocatalyzed approaches, alternative to standard synthesis, will be detailed in order to strengthen the high potential of these biocatalysts to go further with the preparation of rare furanosides. Interesting results will be also proposed with chemo-enzymatic processes based on nonfuranosyl-specific enzymes.
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Affiliation(s)
- Ilona Chlubnova
- Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708 Rennes Cedex 7, France
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16
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Krijgsheld P, Altelaar AFM, Post H, Ringrose JH, Müller WH, Heck AJR, Wösten HAB. Spatially resolving the secretome within the mycelium of the cell factory Aspergillus niger. J Proteome Res 2012; 11:2807-18. [PMID: 22443316 DOI: 10.1021/pr201157b] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aspergillus niger is an important cell factory for the industrial production of enzymes. These enzymes are released into the culture medium, from which they can be easily isolated. Here, we determined with stable isotope dimethyl labeling the secretome of five concentric zones of 7-day-old xylose-grown colonies of A. niger that had either or not been treated with cycloheximide. As expected, cycloheximide blocked secretion of proteins at the periphery of the colony. Unexpectedly, protein release was increased by cycloheximide in the intermediate and central zones of the mycelium when compared to nontreated colonies. Electron microscopy indicated that this is due to partial degradation of the cell wall. In total, 124 proteins were identified in cycloheximide-treated colonies, of which 19 secreted proteins had not been identified before. Within the pool of 124 proteins, 53 secreted proteins were absent in nontreated colonies, and additionally, 35 proteins were released ≥4-fold in the central and subperipheral zones of cycloheximide-treated colonies when compared to nontreated colonies. The composition of the secretome in each of the five concentric zones differed. This study thus describes spatial release of proteins in A. niger, which is instrumental in understanding how fungi degrade complex substrates in nature.
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Affiliation(s)
- Pauline Krijgsheld
- Microbiology and Kluyver Centre for Genomics of Industrial Fermentation, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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d-Xylose concentration-dependent hydrolase expression profiles and the function of CreA and XlnR in Aspergillus niger. Appl Environ Microbiol 2012; 78:3145-55. [PMID: 22344641 DOI: 10.1128/aem.07772-11] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aspergillus niger is an important organism for the production of industrial enzymes such as hemicellulases and pectinases. The xylan-backbone monomer, d-xylose, is an inducing substance for the coordinate expression of a large number of polysaccharide-degrading enzymes. In this study, the responses of 22 genes to low (1 mM) and high (50 mM) d-xylose concentrations were investigated. These 22 genes encode enzymes that function as xylan backbone-degrading enzymes, accessory enzymes, cellulose-degrading enzymes, or enzymes involved in the pentose catabolic pathway in A. niger. Notably, genes encoding enzymes that have a similar function (e.g., xylan backbone degradation) respond in a similar manner to different concentrations of d-xylose. Although low d-xylose concentrations provoke the greatest change in transcript levels, in particular, for hemicellulase-encoding genes, transcript formation in the presence of high concentrations of d-xylose was also observed. Interestingly, a high d-xylose concentration is favorable for certain groups of genes. Furthermore, the repressing influence of CreA on the transcription and transcript levels of a subset of these genes was observed regardless of whether a low or high concentration of d-xylose was used. Interestingly, the decrease in transcript levels of certain genes on high d-xylose concentrations is not reflected by the transcript level of their activator, XlnR. Regardless of the d-xylose concentration applied and whether CreA was functional, xlnR was constitutively expressed at a low level.
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Battaglia E, Visser L, Nijssen A, van Veluw G, Wösten H, de Vries R. Analysis of regulation of pentose utilisation in Aspergillus niger reveals evolutionary adaptations in Eurotiales. Stud Mycol 2011; 69:31-8. [PMID: 21892241 PMCID: PMC3161754 DOI: 10.3114/sim.2011.69.03] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aspergilli are commonly found in soil and on decaying plant material. D-xylose and L-arabinose are highly abundant components of plant biomass. They are released from polysaccharides by fungi using a set of extracellular enzymes and subsequently converted intracellularly through the pentose catabolic pathway (PCP). In this study, the L-arabinose responsive transcriptional activator (AraR) is identified in Aspergillus niger and was shown to control the L-arabinose catabolic pathway as well as expression of genes encoding extracellular L-arabinose releasing enzymes. AraR interacts with the D-xylose-responsive transcriptional activator XlnR in the regulation of the pentose catabolic pathway, but not with respect to release of L-arabinose and D-xylose. AraR was only identified in the Eurotiales, more specifically in the family Trichocomaceae and appears to have originated from a gene duplication event (from XlnR) after this order or family split from the other filamentous ascomycetes. XlnR is present in all filamentous ascomycetes with the exception of members of the Onygenales. Since the Onygenales and Eurotiales are both part of the subclass Eurotiomycetidae, this indicates that strong adaptation of the regulation of pentose utilisation has occurred at this evolutionary node. In Eurotiales a unique two-component regulatory system for pentose release and metabolism has evolved, while the regulatory system was lost in the Onygenales. The observed evolutionary changes (in Eurotiomycetidae) mainly affect the regulatory system as in contrast, homologues for most genes of the L-arabinose/D-xylose catabolic pathway are present in all the filamentous fungi, irrespective of the presence of XlnR and/or AraR.
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Affiliation(s)
- E. Battaglia
- Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - L. Visser
- Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - A. Nijssen
- Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - G.J. van Veluw
- Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - H.A.B. Wösten
- Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - R.P. de Vries
- Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- CBS-KNAW, Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Correspondence: Ronald P. de Vries,
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Fungal enzyme sets for plant polysaccharide degradation. Appl Microbiol Biotechnol 2011; 91:1477-92. [PMID: 21785931 PMCID: PMC3160556 DOI: 10.1007/s00253-011-3473-2] [Citation(s) in RCA: 347] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/27/2011] [Accepted: 07/10/2011] [Indexed: 02/01/2023]
Abstract
Enzymatic degradation of plant polysaccharides has many industrial applications, such as within the paper, food, and feed industry and for sustainable production of fuels and chemicals. Cellulose, hemicelluloses, and pectins are the main components of plant cell wall polysaccharides. These polysaccharides are often tightly packed, contain many different sugar residues, and are branched with a diversity of structures. To enable efficient degradation of these polysaccharides, fungi produce an extensive set of carbohydrate-active enzymes. The variety of the enzyme set differs between fungi and often corresponds to the requirements of its habitat. Carbohydrate-active enzymes can be organized in different families based on the amino acid sequence of the structurally related catalytic modules. Fungal enzymes involved in plant polysaccharide degradation are assigned to at least 35 glycoside hydrolase families, three carbohydrate esterase families and six polysaccharide lyase families. This mini-review will discuss the enzymes needed for complete degradation of plant polysaccharides and will give an overview of the latest developments concerning fungal carbohydrate-active enzymes and their corresponding families.
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20
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Samson RA, Noonim P, Meijer M, Houbraken J, Frisvad JC, Varga J. Diagnostic tools to identify black aspergilli. Stud Mycol 2011; 59:129-45. [PMID: 18490945 PMCID: PMC2275192 DOI: 10.3114/sim.2007.59.13] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The present taxonomy of the black aspergilli reveals that there are 19
accepted taxa. However the identification of species of Aspergillus
section Nigri is often problematic in spite of the existence of
numerous methods proposed. An overview is provided of phenotypic and molecular
methods to identify the accepted species of the black aspergilli. Colony
morphology, conidial size and ornamentation of the ex type cultures is
presented in a pictorial overview. The temperature range of all species is
given and their growth characteristics on creatine agar and boscalid agar, a
medium which was developed as a selective medium for the isolation of A.
carbonarius are also shown. The extrolites produced by each species are
listed while the response of the Ehrlich reaction is described. The literature
on the various molecular methods to be used for species identification is
reviewed and a critical evaluation of the usefulness of various techniques and
genomic loci for species identification of black aspergilli is presented.
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Affiliation(s)
- R A Samson
- CBS Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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21
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Seiboth B, Metz B. Fungal arabinan and L-arabinose metabolism. Appl Microbiol Biotechnol 2011; 89:1665-73. [PMID: 21212945 PMCID: PMC3044236 DOI: 10.1007/s00253-010-3071-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 12/08/2010] [Accepted: 12/08/2010] [Indexed: 12/04/2022]
Abstract
l-Arabinose is the second most abundant pentose beside d-xylose and is found in the plant polysaccharides, hemicellulose and pectin. The need to find renewable carbon and energy sources has accelerated research to investigate the potential of l-arabinose for the development and production of biofuels and other bioproducts. Fungi produce a number of extracellular arabinanases, including α-l-arabinofuranosidases and endo-arabinanases, to specifically release l-arabinose from the plant polymers. Following uptake of l-arabinose, its intracellular catabolism follows a four-step alternating reduction and oxidation path, which is concluded by a phosphorylation, resulting in d-xylulose 5-phosphate, an intermediate of the pentose phosphate pathway. The genes and encoding enzymes l-arabinose reductase, l-arabinitol dehydrogenase, l-xylulose reductase, xylitol dehydrogenase, and xylulokinase of this pathway were mainly characterized in the two biotechnological important fungi Aspergillus niger and Trichoderma reesei. Analysis of the components of the l-arabinose pathway revealed a number of specific adaptations in the enzymatic and regulatory machinery towards the utilization of l-arabinose. Further genetic and biochemical analysis provided evidence that l-arabinose and the interconnected d-xylose pathway are also involved in the oxidoreductive degradation of the hexose d-galactose.
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Affiliation(s)
- Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Wien, Austria.
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22
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Identification of a GH62 α-l-arabinofuranosidase specific for arabinoxylan produced by Penicillium chrysogenum. Appl Microbiol Biotechnol 2010; 90:137-46. [DOI: 10.1007/s00253-010-2988-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/25/2010] [Accepted: 10/25/2010] [Indexed: 01/13/2023]
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Ravanal MC, Callegari E, Eyzaguirre J. Novel bifunctional alpha-L-arabinofuranosidase/xylobiohydrolase (ABF3) from Penicillium purpurogenum. Appl Environ Microbiol 2010; 76:5247-53. [PMID: 20562284 PMCID: PMC2916492 DOI: 10.1128/aem.00214-10] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 06/09/2010] [Indexed: 11/20/2022] Open
Abstract
The soft rot fungus Penicillium purpurogenum grows on a variety of natural substrates and secretes various isoforms of xylanolytic enzymes, including three arabinofuranosidases. This work describes the biochemical properties as well as the nucleotide and amino acid sequences of arabinofuranosidase 3 (ABF3). This enzyme has been purified to homogeneity. It is a glycosylated monomer with a molecular weight of 50,700 and can bind cellulose. The enzyme is active with p-nitrophenyl alpha-L-arabinofuranoside and p-nitrophenyl beta-D-xylopyranoside with a K(m) of 0.65 mM and 12 mM, respectively. The enzyme is active on xylooligosaccharides, yielding products of shorter length, including xylose. However, it does not hydrolyze arabinooligosaccharides. When assayed with polymeric substrates, little arabinose is liberated from arabinan and debranched arabinan; however, it hydrolyzes arabinose and releases xylooligosaccharides from arabinoxylan. Sequencing both ABF3 cDNA and genomic DNA reveals that this gene does not contain introns and that the open reading frame is 1,380 nucleotides in length. The deduced mature protein is composed of 433 amino acids residues and has a calculated molecular weight of 47,305. The deduced amino acid sequence has been validated by mass spectrometry analysis of peptides from purified ABF3. A total of 482 bp of the promoter were sequenced; putative binding sites for transcription factors such as CreA (four), XlnR (one), and AreA (three) and two CCAAT boxes were found. The enzyme has two domains, one similar to proteins of glycosyl hydrolase family 43 at the amino-terminal end and a family 6 carbohydrate binding module at the carboxyl end. ABF3 is the first described modular family 43 enzyme from a fungal source, having both alpha-L-arabinofuranosidase and xylobiohydrolase functionalities.
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Affiliation(s)
- María Cristina Ravanal
- Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile, BRIN-USDSSOM Proteomics Facility, University of South Dakota, Vermillion, South Dakota
| | - Eduardo Callegari
- Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile, BRIN-USDSSOM Proteomics Facility, University of South Dakota, Vermillion, South Dakota
| | - Jaime Eyzaguirre
- Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile, BRIN-USDSSOM Proteomics Facility, University of South Dakota, Vermillion, South Dakota
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Vinetsky YP, Rozhkova AM, Chulkin AM, Satrutdinov AD, Sinitsyna OA, Fedorova EA, Bekkarevich AO, Okunev ON, Sinitsyn AP. Regulatory activity of heterologous gene-activator xlnR of Aspergillus niger in Penicillium canescens. BIOCHEMISTRY (MOSCOW) 2009; 74:882-7. [PMID: 19817688 DOI: 10.1134/s0006297909080094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The gene encoding the xlnR xylanolytic activator of the heterologous fungus Aspergillus niger was incorporated into the Penicillium canescens genome. Integration of the xlnR gene resulted in the increase in a number of activities, i.e. endoxylanase, beta-xylosidase, alpha-L-arabinofuranosidase, alpha-galactosidase, and feruloyl esterase, compared to the host P. canescens PCA 10 strain, while beta-galactosidase, beta-glucosidase, endoglucanase, and CMCase activities remained constant. Two different expression constructs were developed. The first consisted of the nucleotide sequence containing the mature P. canescens phytase gene under control of the axhA promoter region gene encoding A. niger (1,4)-beta-D-arabinoxylan-arabinofuranohydrolase. The second construct combined the P. canescens phytase gene and the bgaS promoter region encoding homologous beta-galactosidase. Both expression cassettes were transformed into P. canescens host strain containing xlnR. Phytase synthesis was observed only for strains with the bgaS promoter on arabinose-containing culture media. In conclusion, the bgaS and axhA promoters were regulated by different inducers and activators in the P. canescens strain containing a structural tandem of the axhA promoter and the gene of the xlnR xylanolytic activator.
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Affiliation(s)
- Y P Vinetsky
- Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow, 117545, Russia.
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25
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Akel E, Metz B, Seiboth B, Kubicek CP. Molecular regulation of arabinan and L-arabinose metabolism in Hypocrea jecorina (Trichoderma reesei). EUKARYOTIC CELL 2009; 8:1837-44. [PMID: 19801419 PMCID: PMC2794218 DOI: 10.1128/ec.00162-09] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Accepted: 09/25/2009] [Indexed: 11/20/2022]
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 alpha-L-arabinofuranosidase encoding genes abf1, abf2, and abf3 and also bxl1, which encodes a beta-xylosidase with a separate alpha-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 Deltalad1 strain lacking L-arabinitol dehydrogenase activity and severely impaired in an aldose reductase (Deltaxyl1) strain, suggesting a cross talk between L-arabinitol and the aldose reductase XYL1 in an alpha-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 alpha-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.
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Affiliation(s)
- Eda Akel
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Vienna, Austria
| | - Benjamin Metz
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Vienna, Austria
| | - Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Vienna, Austria
| | - Christian P. Kubicek
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Vienna, Austria
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Abstract
PURPOSE To report 2 cases of keratomycosis caused by Aspergillus tubingensis. METHODS The therapeutic courses were recorded for 2 male patients, 52 and 78 years old, with fungal keratitis caused by black Aspergillus strains. Morphological examination of the isolates was carried out on malt extract agar plates. A segment of the beta-tubulin gene was used for molecular identification. Antifungal susceptibilities were determined by the E test method for molds and the broth microdilution technique National Committee for Clinical Laboratory Standards M38-A. RESULTS A 52-year-old man presented with complaints of pain and redness in the right eye. The patient was successfully treated with natamycin and econazole eyedrops, itraconazole eye ointment, and oral ketoconazole. A 78-year-old man presented with total corneal necrosis in the right eye. A therapeutic keratoplasty was performed, and topical natamycin and econazole were applied. At the postoperative visit after 3 weeks, almost the full corneal graft was clear with formed anterior chamber. Black Aspergillus strains were isolated from the corneal scrapings of both cases and initially identified as Aspergillus niger based on culture characteristics. Sequence analysis of a segment of the beta-tubulin gene revealed that the isolates are representatives of A. tubingensis. CONCLUSIONS Aspergillus tubingensis is closely related with A. niger, the differentiation of these 2 species is difficult by classical morphological criteria. To our knowledge, the presented cases of fungal keratitis are the first reports on ocular infection caused by A. tubingensis.
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Carapito R, Imberty A, Jeltsch JM, Byrns SC, Tam PH, Lowary TL, Varrot A, Phalip V. Molecular basis of arabinobio-hydrolase activity in phytopathogenic fungi: crystal structure and catalytic mechanism of Fusarium graminearum GH93 exo-alpha-L-arabinanase. J Biol Chem 2009; 284:12285-96. [PMID: 19269961 PMCID: PMC2673297 DOI: 10.1074/jbc.m900439200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 02/19/2009] [Indexed: 11/06/2022] Open
Abstract
The phytopathogenic fungus Fusarium graminearum secretes a very diverse pool of glycoside hydrolases (GHs) aimed at degrading plant cell walls. alpha-l-Arabinanases are essential GHs participating in the complete hydrolysis of hemicellulose, a natural resource for various industrial processes, such as bioethanol or pharmaceuticals production. Arb93A, the exo-1,5-alpha-l-arabinanase of F. graminearum encoded by the gene fg03054.1, belongs to the GH93 family, for which no structural data exists. The enzyme is highly active (1065 units/mg) and displays a strict substrate specificity for linear alpha-1,5-l-arabinan. Biochemical assays and NMR experiments demonstrated that the enzyme releases alpha-1,5-l-arabinobiose from the nonreducing end of the polysaccharide. We determined the crystal structure of the native enzyme and its complex with alpha-1,5-l-arabinobiose, a degradation product of alpha-Me-1,5-l-arabinotetraose, at 1.85 and 2.05A resolution, respectively. Arb93A is a monomeric enzyme, which presents the six-bladed beta-propeller fold characteristic of sialidases of clan GHE. The configuration of the bound arabinobiose is consistent with the retaining mechanism proposed for the GH93 family. Catalytic residues were proposed from the structural analysis, and site-directed mutagenesis was used to validate their role. They are significantly different from those observed for GHE sialidases.
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Affiliation(s)
- Raphaël Carapito
- UMR 7175, Ecole Supérieure de Biotechnologie de Strasbourg, Université de Strasbourg-CNRS, Boulevard Sébastien Brandt, BP 10413, 67412 Illkirch-Graffenstaden, France
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28
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Regulation of transcription of cellulases- and hemicellulases-encoding genes in Aspergillus niger and Hypocrea jecorina (Trichoderma reesei). Appl Microbiol Biotechnol 2008; 78:211-20. [PMID: 18197406 DOI: 10.1007/s00253-007-1322-0] [Citation(s) in RCA: 182] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 12/06/2007] [Accepted: 12/08/2007] [Indexed: 10/22/2022]
Abstract
The filamentous fungi Aspergillus niger and Hypocrea jecorina (Trichoderma reesei) have been the subject of many studies investigating the mechanism of transcriptional regulation of hemicellulase- and cellulase-encoding genes. The transcriptional regulator XlnR that was initially identified in A. niger as the transcriptional regulator of xylanase-encoding genes controls the transcription of about 20-30 genes encoding hemicellulases and cellulases. The orthologous xyr1 (xylanase regulator 1-encoding) gene product of H. jecorina has a similar function as XlnR, although at points, the mechanisms seems to be different. Specifically in H. jecorina, the interaction of Xyr1 and the co-regulators Ace1 and Ace2 in the regulation of transcription of xylanases and cellulases has been studied. This paper describes the similarities and differences in the transcriptional regulation of expression of hemicellulases and cellulases in A. niger and H. jecorina.
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Seike K, Sato J, Tomoo K, Ishida T, Yamano A, Ikenishi S, Miyamoto K, Tsujibo H. Crystallization and preliminary X-ray crystallographic analysis of BxlE, a xylobiose transporter from Streptomyces thermoviolaceus OPC-520. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:560-2. [PMID: 17620710 PMCID: PMC2335139 DOI: 10.1107/s1744309107024906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 05/22/2007] [Indexed: 11/10/2022]
Abstract
Together with the integral membrane proteins BxlF and BxlG, BxlE isolated from Streptomyces thermoviolaceus OPC-520 forms an ATP-binding cassette (ABC) transport system that mediates the uptake of xylan. To clarify the structural basis of sugar binding by BxlE at the atomic level, recombinant BxlE was crystallized using the hanging-drop vapour-diffusion method at 290 K. The crystals belonged to the monoclinic space group P2(1), with unit-cell parameters a = 44.63, b = 63.27, c = 66.40 A, beta = 103.05 degrees, and contained one 48 kDa molecule per asymmetric unit (V(M) = 1.96 A3 Da(-1)). Diffraction data collected to a resolution of 1.65 A using a rotating-anode X-ray source gave a data set with an overall R(merge) of 2.6% and a completeness of 91.3%. A data set from a platinum derivative is being used for phasing by the SAD method.
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Affiliation(s)
- Kiho Seike
- Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
| | - Junji Sato
- Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
| | - Koji Tomoo
- Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
| | - Toshimasa Ishida
- Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
| | - Akihito Yamano
- PharmAxess Inc., Biohills 308, 7-7-18 Saitoasagi, Ibaraki, Osaka 567-0085, Japan
| | - Sadao Ikenishi
- Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
| | - Katsushiro Miyamoto
- Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
| | - Hiroshi Tsujibo
- Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan
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Geiser DM, Klich MA, Frisvad JC, Peterson SW, Varga J, Samson RA. The current status of species recognition and identification in Aspergillus. Stud Mycol 2007; 59:1-10. [PMID: 18490947 PMCID: PMC2275194 DOI: 10.3114/sim.2007.59.01] [Citation(s) in RCA: 199] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The species recognition and identification of aspergilli and their teleomorphs is discussed. A historical overview of the taxonomic concepts starting with the monograph of Raper & Fennell (1965) is given. A list of taxa described since 2000 is provided. Physiological characters, particularly growth rates and the production of extrolites, often show differences that reflect phylogenetic species boundaries and greater emphasis should be placed on extrolite profiles and growth characteristics in species descriptions. Multilocus sequence-based phylogenetic analyses have emerged as the primary tool for inferring phylogenetic species boundaries and relationships within subgenera and sections. A four locus DNA sequence study covering all major lineages in Aspergillus using genealogical concordance theory resulted in a species recognition system that agrees in part with phenotypic studies and reveals the presence of many undescribed species not resolved by phenotype. The use of as much data from as many sources as possible in making taxonomic decisions is advocated. For species identification, DNA barcoding uses a short genetic marker in an organism"s DNA to quickly and easily identify it to a particular species. Partial cytochrome oxidase subunit 1 sequences, which are used for barcoding animal species, were found to have limited value for species identification among black aspergilli. The various possibilities are discussed and at present partial beta-tubulin or calmodulin are the most promising loci for Aspergillus identification. For characterising Aspergillus species one application would be to produce a multilocus phylogeny, with the goal of having a firm understanding of the evolutionary relationships among species across the entire genus. DNA chip technologies are discussed as possibilities for an accurate multilocus barcoding tool for the genus Aspergillus.
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Affiliation(s)
- D M Geiser
- Department of Plant Pathology, Pennsylvania State University, University Park 16802, U.S.A
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Sørensen HR, Jørgensen CT, Hansen CH, Jørgensen CI, Pedersen S, Meyer AS. A novel GH43 alpha-L-arabinofuranosidase from Humicola insolens: mode of action and synergy with GH51 alpha-L-arabinofuranosidases on wheat arabinoxylan. Appl Microbiol Biotechnol 2006; 73:850-61. [PMID: 16944135 DOI: 10.1007/s00253-006-0543-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 06/11/2006] [Accepted: 06/11/2006] [Indexed: 10/24/2022]
Abstract
A novel alpha-L-arabinofuranosidase (alpha-AraF) belonging to glycoside hydrolase (GH) family 43 was cloned from Humicola insolens and expressed in Aspergillus oryzae. (1)H-NMR analysis revealed that the novel GH43 enzyme selectively hydrolysed (1-->3)-alpha-L-arabinofuranosyl residues of doubly substituted xylopyranosyl residues in arabinoxylan and in arabinoxylan-derived oligosaccharides. The optimal activity of the cloned enzyme was at pH 6.7 and 53 degrees C. Two other novel alpha-L-arabinofuranosidases (alpha-AraFs), both belonging to GH family 51, were cloned from H. insolens and from the white-rot basidiomycete Meripilus giganteus. Both GH51 enzymes catalysed removal of (1-->2) and (1-->3)-alpha-L-arabinofuranosyl residues from singly substituted xylopyranosyls in arabinoxylan; the highest arabinose yields were obtained with the M. giganteus enzyme. Combinations (50:50) of the GH43 alpha-AraF from H. insolens and the GH51 alpha-AraFs from either M. giganteus or H. insolens resulted in a synergistic increase in arabinose release from water-soluble wheat arabinoxylan in extended reactions at pH 6 and 40 degrees C. This synergistic interaction between GH43 and GH51 alpha-AraFs was also evident when a GH43 alpha-AraF from a Bifidobacterium sp. was supplemented in combination with either of the GH51 enzymes. The synergistic effect is presumed to be a result of the GH51 alpha-AraFs being able to catalyse the removal of single-sitting (1-->2)-alpha-L- arabinofuranosyls that resulted after the GH43 enzyme had catalysed the removal of (1-->3)-alpha-L-arabinofuranosyl residues on doubly substituted xylopyranosyls in the wheat arabinoxylan.
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32
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Sakamoto T. Fungal Exo-acting Enzymes with Novel Catalytic Properties. J Appl Glycosci (1999) 2006. [DOI: 10.5458/jag.53.115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Matsumura K, Obata H, Hata Y, Kawato A, Abe Y, Akita O. Isolation and characterization of a novel gene encoding alpha-L-arabinofuranosidase from Aspergillus oryzae. J Biosci Bioeng 2005; 98:77-84. [PMID: 16233670 DOI: 10.1016/s1389-1723(04)70246-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2004] [Accepted: 05/10/2004] [Indexed: 10/26/2022]
Abstract
We cloned and characterized a novel gene (abfA) encoding alpha-L-arabinofuranosidase (alpha-L-AFase) from Aspergillus oryzae. One clone homologous to the alpha-L-AFase gene of Thermotoga maritima was found in an expressed sequence tag (EST) library of A. oryzae and a corresponding gene was isolated. Molecular analysis showed that the abfA gene carried six exons interrupted by five introns and had an open reading frame encoding 481 amino acid residues. The amino acid sequence similarity at active sites to the alpha-L-AFases from other organisms indicated that the alpha-L-AFase encoded by abfA was classified as a family 51 glycoside hydrolase. When the abfA was overexpressed in the homologous hyperexpression system of A. oryzae, a large amount of alpha-L-AFase was produced as intracellular protein. The apparent molecular mass of the purified enzyme was estimated to be 228,000 by gel filtration and that of its subunit as 55,000 by SDS-PAGE, suggesting that the enzyme is a tetramer. The enzyme hydrolyzed p-nitrophenyl-alpha-L-arabinofuranoside but not other p-nitrophenyl glycosides. These results demonstrated that the abfA gene encodes a functional alpha-L-AFase.
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Affiliation(s)
- Kengo Matsumura
- Research Institute, Gekkeikan Sake Co. Ltd., 300 Katahara-cho, Fushimi-ku, Kyoto 612-8361, Japan.
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Aro N, Pakula T, Penttilä M. Transcriptional regulation of plant cell wall degradation by filamentous fungi. FEMS Microbiol Rev 2004; 29:719-39. [PMID: 16102600 DOI: 10.1016/j.femsre.2004.11.006] [Citation(s) in RCA: 286] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Revised: 10/29/2004] [Accepted: 11/01/2004] [Indexed: 11/22/2022] Open
Abstract
Plant cell wall consists mainly of the large biopolymers cellulose, hemicellulose, lignin and pectin. These biopolymers are degraded by many microorganisms, in particular filamentous fungi, with the aid of extracellular enzymes. Filamentous fungi have a key role in degradation of the most abundant biopolymers found in nature, cellulose and hemicelluloses, and therefore are essential for the maintenance of the global carbon cycle. The production of plant cell wall degrading enzymes, cellulases, hemicellulases, ligninases and pectinases, is regulated mainly at the transcriptional level in filamentous fungi. The genes are induced in the presence of the polymers or molecules derived from the polymers and repressed under growth conditions where the production of these enzymes is not necessary, such as on glucose. The expression of the genes encoding the enzymes is regulated by various environmental and cellular factors, some of which are common while others are more unique to either a certain fungus or a class of enzymes. This review summarises our current knowledge on the transcriptional regulation, focusing on the recently characterized transcription factors that regulate genes coding for enzymes involved in the breakdown of plant cell wall biopolymers.
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Affiliation(s)
- Nina Aro
- VTT Biotechnology, Espoo, Finland.
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Sakamoto T, Fujita T, Kawasaki H. Transglycosylation catalyzed by a Penicillium chrysogenum exo-1,5-α-l-arabinanase. Biochim Biophys Acta Gen Subj 2004; 1674:85-90. [PMID: 15342117 DOI: 10.1016/j.bbagen.2004.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2004] [Revised: 06/03/2004] [Accepted: 06/04/2004] [Indexed: 11/27/2022]
Abstract
Penicillium chrysogenum exo-arabinanase (Abnx), which releases arabinobiose from the nonreducing terminus of alpha-1,5-L-arabinan, was found to possess trans-arabinobiosylation activity on various acceptors, such as aliphatic alcohols, sugars, and sugar alcohols. Abnx was found to prefer primary hydroxyl groups in polyhydric alcohols as acceptors over primary hydroxyl groups in monohydric alcohols. Among the 21 different compounds tested, glycerol was the best acceptor for the enzyme. The transfer product of glycerol was identified as O-alpha-L-arabinosyl-(1-->5)-O-alpha-L-arabinosyl-(1-->1)-glycerol on the basis of the spectral data, fast atom bombardment-mass and 1H- and 13C-NMR. Unlike endo-arabinanases, Abnx catalyzed the hydrolysis of linear arabinan without inverting the anomeric configuration.
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Affiliation(s)
- Tatsuji Sakamoto
- Laboratory of Fermentation Chemistry, Division of Applied Biochemistry, Graduate School of Agriculture and Biological Science, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
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Tsujibo H, Kosaka M, Ikenishi S, Sato T, Miyamoto K, Inamori Y. Molecular characterization of a high-affinity xylobiose transporter of Streptomyces thermoviolaceus OPC-520 and its transcriptional regulation. J Bacteriol 2004; 186:1029-37. [PMID: 14761997 PMCID: PMC344215 DOI: 10.1128/jb.186.4.1029-1037.2004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptomyces thermoviolaceus OPC-520 secretes two types of xylanases (StxI and StxII), an acetyl xylan esterase (StxIII), and an alpha-L-arabinofuranosidase (StxIV) in the presence of xylan. Xylan degradation products (mainly xylobiose) produced by the action of these enzymes entered the cell and were then degraded to xylose by an intracellular beta-xylosidase (BxlA). A gene cluster involved in xylanolytic system of the strain was cloned and sequenced upstream of and including a BxlA-encoding gene (bxlA). The gene cluster consisted of four different open reading frames organized in the order bxlE, bxlF, bxlG, and bxlA. Reverse transcriptase PCR analysis revealed that the gene cluster is transcribed as polycistronic mRNA. The deduced gene products, comprising BxlE (a sugar-binding lipoprotein), BxlF (an integral membrane protein), and BxlG (an integral membrane protein), showed similarity to components of the bacterial ATP-binding cassette (ABC) transport system; however, the gene for the ATP binding protein was not linked to the bxl operon. The soluble recombinant BxlE protein was analyzed for its binding activity for xylooligosaccharides. The protein showed high-level affinity for xylobiose (K(d) = 8.75 x 10(-9) M) and for xylotriose (K(d) = 8.42 x 10(-8) M). Antibodies raised against the recombinant BxlE recognized the detergent-soluble BxlE isolated from S. thermoviolaceus membranes. The deduced BxlF and BxlG proteins are predicted to be integral membrane proteins. These proteins contained the conserved EAA loop (between the fourth and the fifth membrane-spanning segments) which is characteristic of membrane proteins from binding-protein-dependent ABC transporters. In addition, the bxlR gene located upstream of the bxl operon was cloned and expressed in Escherichia coli. The bxlR gene encoded a 343-residue polypeptide that is highly homologous to members of the GalR/LacI family of bacterial transcriptional regulators. The purified BxlR protein specifically bound to a 4-bp inverted sequence overlapping the -10 region of the bxl operon. The binding of BxlR to the site was inhibited specifically by low concentrations of xylobiose. This site was also present in the region located between stxI and stxIV and in the upstream region of stxII. BxlR specifically bound to the regions containing the inverted sequence. These results suggest that BxlR might act as a repressor of the genes involved not only in the uptake system of xylan degradation products but also in xylan degradation of S. thermoviolaceus OPC-520.
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Affiliation(s)
- Hiroshi Tsujibo
- Department of Microbiology, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan.
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37
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Sakamoto T, Ihara H, Shibano A, Kasai N, Inui H, Kawasaki H. Molecular characterization of a Penicillium chrysogenum
exo-1,5-α-L
-arabinanase that is structurally distinct from other arabinan-degrading enzymes. FEBS Lett 2004; 560:199-204. [PMID: 14988022 DOI: 10.1016/s0014-5793(04)00106-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2003] [Accepted: 12/16/2003] [Indexed: 11/17/2022]
Abstract
The nucleotide sequence of the abnx cDNA gene, which encodes an exo-arabinanase (Abnx) of Penicillium chrysogenum 31B, was determined. Abnx was found to be structurally distinct from known arabinan-degrading enzymes based on its amino acid sequence and a hydrophobic cluster analysis. The protein in the protein database with the highest similarity to Abnx was the Neurospora crassa conserved hypothetical protein. The abnx cDNA gene product expressed in Escherichia coli catalyzed the release of arabinobiose from alpha-1,5-L-arabinan. The activity of the recombinant Abnx towards a series of arabino-oligosaccharides, as expressed by k(cat)/K(m) value, was greatest with arabinohexaose.
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Affiliation(s)
- Tatsuji Sakamoto
- Division of Applied Biochemistry, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Osaka 599-8531, Japan.
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38
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Sakamoto T, Kawasaki H. Purification and properties of two type-B alpha-L-arabinofuranosidases produced by Penicillium chrysogenum. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1621:204-10. [PMID: 12726996 DOI: 10.1016/s0304-4165(03)00058-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two distinct extracellular alpha-L-arabinofuranosidases (AFases; EC 3.2.1.55) were purified from the culture filtrate of Penicillium chrysogenum 31B. The molecular masses of the enzymes were estimated to be 79 kDa (AFQ1) and 52 kDa (AFS1) by SDS-PAGE. Both enzymes had their highest activities at 50 degrees C and were stable up to 50 degrees C. Enzyme activities of AFQ1 and AFS1 were highest at pH 4.0 to 6.5 and pH 3.3 to 5.0, respectively. Addition of 10 mg/ml arabinose to the reaction mixture decreased the AFS1 activity but hardly affected AFQ1. Both enzymes displayed broad substrate specificities; they released arabinose from branched arabinan, debranched arabinan, arabinoxylan, arabinogalactan, and arabino-oligosaccharides. AFS1 also showed low activity towards p-nitrophenyl-beta-D-xylopyranoside. An exo-arabinanase, which catalyzes the release of arabinobiose from linear arabinan at the nonreducing terminus, acted synergistically with both enzymes to produce L-arabinose from branched arabinan.
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Affiliation(s)
- T Sakamoto
- Division of Applied Biochemistry, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, Osaka 599-8531, Japan.
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de Groot MJL, van de Vondervoort PJI, de Vries RP, vanKuyk PA, Ruijter GJG, Visser J. Isolation and characterization of two specific regulatory Aspergillus niger mutants shows antagonistic regulation of arabinan and xylan metabolism. MICROBIOLOGY (READING, ENGLAND) 2003; 149:1183-1191. [PMID: 12724380 DOI: 10.1099/mic.0.25993-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper describes two Aspergillus niger mutants (araA and araB) specifically disturbed in the regulation of the arabinanase system in response to the presence of L-arabinose. Expression of the three known L-arabinose-induced arabinanolytic genes, abfA, abfB and abnA, was substantially decreased or absent in the araA and araB strains compared to the wild-type when incubated in the presence of L-arabinose or L-arabitol. In addition, the intracellular activities of L-arabitol dehydrogenase and L-arabinose reductase, involved in L-arabinose catabolism, were decreased in the araA and araB strains. Finally, the data show that the gene encoding D-xylulose kinase, xkiA, is also under control of the arabinanolytic regulatory system. L-Arabitol, most likely the true inducer of the arabinanolytic and L-arabinose catabolic genes, accumulated to a high intracellular concentration in the araA and araB mutants. This indicates that the decrease of expression of the arabinanolytic genes was not due to lack of inducer accumulation. Therefore, it is proposed that the araA and araB mutations are localized in positive-acting components of the regulatory system involved in the expression of the arabinanase-encoding genes and the genes encoding the L-arabinose catabolic pathway.
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Affiliation(s)
- Marco J L de Groot
- Section Molecular Genetics of Industrial Micro-organisms, Wageningen University, Dreijenlaan 2, NL-6703HA Wageningen, The Netherlands
| | - Peter J I van de Vondervoort
- Section Molecular Genetics of Industrial Micro-organisms, Wageningen University, Dreijenlaan 2, NL-6703HA Wageningen, The Netherlands
| | - Ronald P de Vries
- Section Molecular Genetics of Industrial Micro-organisms, Wageningen University, Dreijenlaan 2, NL-6703HA Wageningen, The Netherlands
| | - Patricia A vanKuyk
- Section Molecular Genetics of Industrial Micro-organisms, Wageningen University, Dreijenlaan 2, NL-6703HA Wageningen, The Netherlands
| | - George J G Ruijter
- Section Molecular Genetics of Industrial Micro-organisms, Wageningen University, Dreijenlaan 2, NL-6703HA Wageningen, The Netherlands
| | - Jaap Visser
- Section Molecular Genetics of Industrial Micro-organisms, Wageningen University, Dreijenlaan 2, NL-6703HA Wageningen, The Netherlands
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Lee RC, Hrmova M, Burton RA, Lahnstein J, Fincher GB. Bifunctional family 3 glycoside hydrolases from barley with alpha -L-arabinofuranosidase and beta -D-xylosidase activity. Characterization, primary structures, and COOH-terminal processing. J Biol Chem 2003; 278:5377-87. [PMID: 12464603 DOI: 10.1074/jbc.m210627200] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
An alpha-l-arabinofuranosidase and a beta-d-xylosidase, designated ARA-I and XYL, respectively, have been purified about 1,000-fold from extracts of 5-day-old barley (Hordeum vulgare L.) seedlings using ammonium sulfate fractional precipitation, ion exchange chromatography, chromatofocusing, and size-exclusion chromatography. The ARA-I has an apparent molecular mass of 67 kDa and an isoelectric point of 5.5, and its catalytic efficiency during hydrolysis of 4'-nitrophenyl alpha-l-arabinofuranoside is only slightly higher than during hydrolysis of 4'-nitrophenyl beta-d-xyloside. Thus, the enzyme is actually a bifunctional alpha-l-arabinofuranosidase/beta-d-xylosidase. In contrast, the XYL enzyme, which also has an apparent molecular mass of 67 kDa and an isoelectric point of 6.7, preferentially hydrolyzes 4'-nitrophenyl beta-d-xyloside, with a catalytic efficiency approximately 30-fold higher than with 4'-nitrophenyl alpha-l-arabinofuranoside. The enzymes hydrolyze wheat flour arabinoxylan slowly but rapidly hydrolyze oligosaccharide products released from this polysaccharide by (1 --> 4)-beta-d-xylan endohydrolase. Both enzymes hydrolyze (1 --> 4)-beta-d-xylopentaose, and ARA-I can also degrade (1 --> 5)-alpha-l-arabinofuranohexaose. ARA-I and XYL cDNAs encode mature proteins of 748 amino acid residues which have calculated molecular masses of 79.2 and 80.5 kDa, respectively. Both are family 3 glycoside hydrolases. The discrepancies between the apparent molecular masses obtained for the purified enzymes and those predicted from the cDNAs are attributable to COOH-terminal processing, through which about 130 amino acid residues are removed from the primary translation product. The genes encoding the ARA-I and XYL have been mapped to chromosomes 2H and 6H, respectively. ARA-I transcripts are most abundant in young roots, young leaves, and developing grain, whereas XYL mRNA is detected in most barley tissues.
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Affiliation(s)
- Robert C Lee
- Department of Plant Science, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia
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41
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de Vries RP, Jansen J, Aguilar G, Parenicová L, Joosten V, Wülfert F, Benen JAE, Visser J. Expression profiling of pectinolytic genes from Aspergillus niger. FEBS Lett 2002; 530:41-7. [PMID: 12387863 DOI: 10.1016/s0014-5793(02)03391-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The expression of 26 pectinolytic genes from Aspergillus niger was studied in a wild type strain and a CreA derepressed strain, under 16 different growth conditions, to obtain an expression profile for each gene. These expression profiles were then submitted to cluster analysis to identify subsets of genes with similar expression profiles. With the exception of the feruloyl esterase encoding genes, all genes were expressed in the presence of D-galacturonic acid, polygalacturonate, and/or sugar beet pectin. Despite this general observation five distinct groups of genes were identified. The major group consisted of 12 genes of which the corresponding enzymes act on the pectin backbone and for which the expression, in general, is higher after 8 and 24 h of incubation, than after 2 or 4 h. Two other groups of genes encoding pectin main chain acting enzymes were detected. Two additional groups contained genes encoding L-arabinose and D-galactose releasing enzymes, and ferulic acid releasing enzymes, respectively. The genes encoding beta-galactosidase and the L-arabinose releasing enzymes were not only expressed in the presence of D-galacturonic acid, but also in the presence of L-arabinose, suggesting that they are under the control of two regulatory systems. Similarly, the rhamnogalacturonan acetylesterase encoding gene was not only expressed in the presence of D-galacturonic acid, polygalacturonate and sugar beet pectin, but also in the presence of L-rhamnose. The data presented provides indications for a general pectinolytic regulatory system responding to D-galacturonic acid or a metabolite derived from it. In addition, subsets of pectinolytic genes are expressed in response to the presence of L-arabinose, L-rhamnose or ferulic acid.
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Affiliation(s)
- Ronald P de Vries
- Molecular Genetics of Industrial Microorganisms, Wageningen University, The Netherlands.
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Hernández A, Copa-Patiño JL, Soliveri J. xln23 from Streptomyces chattanoogensis UAH23 encodes a putative enzyme with separate xylanase and arabinofuranosidase catalytic domains. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 2002; 12:167-77. [PMID: 11762192 DOI: 10.3109/10425170109080771] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The xylanase gene xysA of Streptomyces halstedii JM8 was used to isolate a DNA fragment from a gene library of Pstl-digested chromosomal DNA of the lignocellulolytic actinomycete Streptomyces chattanoogensis CECT-3336. Nucleotide sequence analysis revealed a gene (xln23) encoding a bifunctional multimodular enzyme bearing two independent xylanase and alpha-L-arabinofuranosidase domains separated by a Ser/Gly-rich linker. The N terminus of the predicted protein showed high homology to family F xylanases. The C terminus was homologous to amino acid sequences found in enzymes included in the glycosyl hydrolase family 62 and, in particular, to those of alpha-L-arabinofuranosidase AbsB from Streptomyces lividans. PCR and RT-PCR experiments showed that the nucleotide sequences corresponding to each domain are arranged as expected on the chromosomal DNA and that they are cotranscribed. To our knowledge, this is the first description of xylanase and arabinofuranosidase domains in a same open reading frame.
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Affiliation(s)
- A Hernández
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Alcalá, 28871-Alcalá de Henares, Spain
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Hasper AA, Dekkers E, van Mil M, van de Vondervoort PJI, de Graaff LH. EglC, a new endoglucanase from Aspergillus niger with major activity towards xyloglucan. Appl Environ Microbiol 2002; 68:1556-60. [PMID: 11916668 PMCID: PMC123852 DOI: 10.1128/aem.68.4.1556-1560.2002] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel gene, eglC, encoding an endoglucanase, was cloned from Aspergillus niger. Transcription of eglC is regulated by XlnR, a transcriptional activator that controls the degradation of polysaccharides in plant cell walls. EglC is an 858-amino-acid protein and contains a conserved C-terminal cellulose-binding domain. EglC can be classified in glycoside hydrolase family 74. No homology to any of the endoglucanases from Trichoderma reesei was found. In the plant cell wall xyloglucan is closely linked to cellulose fibrils. We hypothesize that the EglC cellulose-binding domain anchors the enzyme to the cellulose chains while it is cleaving the xyloglucan backbone. By this action it may contribute to the degradation of the plant cell wall structure together with other enzymes, including hemicellulases and cellulases. EglC is most active towards xyloglucan and therefore is functionally different from the other two endoglucanases from A. niger, EglA and EglB, which exhibit the greatest activity towards beta-glucan. Although the mode of action of EglC is not known, this enzyme represents a new enzyme function involved in plant cell wall polysaccharide degradation by A. niger.
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Affiliation(s)
- Alinda A Hasper
- Molecular Genetics of Industrial Microorganisms Section, Wageningen University, NL-6703 HA Wageningen, The Netherlands
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44
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de Vries RP, Visser J. Aspergillus enzymes involved in degradation of plant cell wall polysaccharides. Microbiol Mol Biol Rev 2001; 65:497-522, table of contents. [PMID: 11729262 PMCID: PMC99039 DOI: 10.1128/mmbr.65.4.497-522.2001] [Citation(s) in RCA: 542] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a more and more attractive alternative to chemical and mechanical processes. Over the past 15 years, much progress has been made in elucidating the structural characteristics of these polysaccharides and in characterizing the enzymes involved in their degradation and the genes of biotechnologically relevant microorganisms encoding these enzymes. The members of the fungal genus Aspergillus are commonly used for the production of polysaccharide-degrading enzymes. This genus produces a wide spectrum of cell wall-degrading enzymes, allowing not only complete degradation of the polysaccharides but also tailored modifications by using specific enzymes purified from these fungi. This review summarizes our current knowledge of the cell wall polysaccharide-degrading enzymes from aspergilli and the genes by which they are encoded.
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Affiliation(s)
- R P de Vries
- Molecular Genetics of Industrial Microorganisms, Wageningen University, 6703 HA Wageningen, The Netherlands.
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Shofiqur Rahman AK, Kawamura S, Hatsu M, Hoq MM, Takamizawa K. Physicochemical properties of a novel alpha-L-arabinofuranosidase from Rhizomucor pusillus HHT-1. Can J Microbiol 2001; 47:767-72. [PMID: 11575504 DOI: 10.1139/w01-064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The zygomycete fungus Rhizomucor pusillus HHT-1, cultured on L(+)arabinose as a sole carbon source, produced extracellular alpha-L-arabinofuranosidase. The enzyme was purified by (NH4)2SO4 fractionation, gel filtration, and ion exchange chromatography. The molecular mass of this monomeric enzyme was 88 kDa. The native enzyme had a pI of 4.2 and displayed a pH optimum and stability of 4.0 and 7.0-10.0, respectively. The temperature optimum was 65 degrees C, and it was stable up to 70 degrees C. The Km and Vmax for p-nitrophenyl alpha-L-arabinofuranoside were 0.59 mM and 387 micromol x min(-1) x mg(-1) protein, respectively. Activity was not stimulated by metal cofactors. The N-terminal amino acid sequence did not show any similarity to other arabinofuranosidases. Higher hydrolytic activity was recorded with pnitrophenyl alpha-L-arabinofuranoside, arabinotriose, and sugar beet arabinan; lower hydrolytic activity was recorded with oat-spelt xylan and arabinogalactan, indicating specificity for the low molecular mass L(+)-arabinose containing oligosaccharides with furanoside configuration.
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Affiliation(s)
- A K Shofiqur Rahman
- Department of Bioprocessing, Faculty of Agriculture, Gifu University, Yanagido, Japan
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Tsukagoshi N, Kobayashi T, Kato M. Regulation of the amylolytic and (hemi-)cellulolytic genes in aspergilli. J GEN APPL MICROBIOL 2001; 47:1-19. [PMID: 12483563 DOI: 10.2323/jgam.47.1] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Filamentous fungi produce high levels of polysaccharide-degrading enzymes and are frequently used for the production of industrial enzymes. Because of the high secretory capacity for enzymes, filamentous fungi are effective hosts for the production of foreign proteins. Genetic studies with Aspergillus nidulans have shown pathway-specific regulatory systems that control a set of genes that must be expressed to catabolize particular substrates. Besides the pathway-specific regulation, wide domain regulatory systems exist that affect a great many individual genes in different pathways. A molecular analysis of various regulated systems has confirmed the formal models derived from purely genetic data. In general, many genes are subject to more than one regulatory system. In this article, we describe two transcriptional activators, AmyR and XlnR, and an enhancer, Hap complex, in view of their regulatory roles in the expression of the amylolytic and (hemi-)cellulolytic genes mainly in aspergilli. The amyR gene has been isolated as a transcriptional activator involved in the expression of amylolytic genes from A. oryzae, A. niger, and A. nidulans, and the xlnR gene, which has been isolated from A. niger and A. oryzae, activates the expression of xylanolytic genes as well as some cellulolytic genes in aspergilli. Both AmyR and XlnR have a typical zinc binuclear cluster DNA-binding domain at their N-terminal regions. Hap complex, a CCAAT-binding complex, enhances the overall promoter activity and increases the expression levels of many fungal genes, including the Taka-amylase A gene. Hap complex comprises three subunits, HapB, HapC, and HapE, in A. nidulans and A. oryzae as well as higher eukaryotes, whereas HAP complex in Saccharomyces cerevisiae and Kluyveromyces lactis has the additional subunit, Hap4p, which is responsible for the transcriptional activation. Hap complex is suggested to enhance transcription by remodeling the chromatin structure. The regulation of gene expression in filamentous fungi of industrial interest could follow basically the same general principles as those discovered in A. nidulans. The knowledge of regulation of gene expression in combination with traditional genetic techniques is expected to be increasingly utilized for strain breeding. Furthermore, this knowledge provides a basis for the rational application of transcriptional regulators for biotechnological processes in filamentous fungi.
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Affiliation(s)
- Norihiro Tsukagoshi
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
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Abstract
Interest in the alpha-L-arabinofuranosidases has increased in recent years because of their application in the conversion of various hemicellulosic substrates to fermentable sugars for subsequent production of fuel alcohol. Xylanases, in conjunction with alpha-L-arabinofuranosidases and other accessory enzymes, act synergistically to degrade xylan to component sugars. The induction of alpha-L-arabinofuranosidase production, physico-chemical characteristics, substrate specificity, and molecular biology of the enzyme are described. The current state of research and development of the arabinofuranosidases and their role in biotechnology are presented.
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Affiliation(s)
- B C Saha
- Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, U.S. Department of Agriculture, Agricultural Research Service, Peoria, IL 61604, USA.
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Hasper AA, Visser J, de Graaff LH. The Aspergillus niger transcriptional activator XlnR, which is involved in the degradation of the polysaccharides xylan and cellulose, also regulates D-xylose reductase gene expression. Mol Microbiol 2000; 36:193-200. [PMID: 10760176 DOI: 10.1046/j.1365-2958.2000.01843.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Screening of an Aspergillus niger differential cDNA library, constructed by subtracting cDNA fragments of a xlnR loss-of-function mutant from wild-type cDNA fragments, resulted in the cloning of the gene encoding D-xylose reductase (xyrA). Northern blot analysis using an A. niger wild-type strain, a xlnR multiple-copy strain and a xlnR loss-of-function mutant confirmed that the xyrA gene is regulated by XlnR, the transcriptional activator of the xylanolytic enzyme system in A. niger. D-xylose reductase catalyses the NADPH-dependent reduction of D-xylose to xylitol, which is the first step in D-xylose catabolism in fungi. Until now, XlnR was shown to control the transcription of genes encoding extracellular hydrolytic enzymes involved in cellulose and xylan degradation. In the present study, we show that A. niger is able to harmonize its sugar metabolism and extracellular xylan degradation via XlnR by regulating the expression of XyrA.
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Affiliation(s)
- A A Hasper
- Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, NL-6703 HA Wageningen, The Netherlands
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Kimura I, Yoshioka N, Kimura Y, Tajima S. Cloning, sequencing and expression of an α-l-Arabinofuranosidase from Aspergillus sojae. J Biosci Bioeng 2000; 89:262-6. [PMID: 16232740 DOI: 10.1016/s1389-1723(00)88830-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/1999] [Accepted: 12/02/1999] [Indexed: 11/21/2022]
Abstract
The arabinofuranosidase gene was cloned from the cDNA of Aspergillus sojae. It was found to contain an open reading frame composed of 984 base pairs (bp) and to encode 328 amino acid residues (aa). The cDNA sequence suggested that the mature enzyme is preceded by a 26-aa signal sequence and the molecular mass was predicted to be 32,749 Da. The A. sojae arabinofuranosidase consists of a single catalytic domain; it does not have a specific substrate-binding domain such as the xylan-binding domain reported in an arabinofuranosidase from Streptomyces lividans (Vincent, P. et al.: Biochem. J., 322, 845-852, 1997). The deduced amino acid sequence of the catalytic domain of the mature enzyme exhibits extensive identity with the catalytic domains of Streptomyces coelicolor (74%), Aspergillus niger (75%), S. lividans (74%), and Aspergillus tubingensis (75%), which are enzymes that belong to family 62 of the glycosyl hydrolases. The cloned AFdase gene was expressed in Escherichia coli BL21 (DE3) pLysS as a cellulose-binding domain tag fusion protein. The specific activity of the purified recombinant enzyme was 18.6 units/mg protein, which is one-fourth that of the enzyme purified from a solid-state culture of A. sojae.
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Affiliation(s)
- I Kimura
- Kagawa Prefectural Fermentation and Food Experimental Station, 1351-1 Nouma, Uchinomi-cho, Shouzu-gun, Kagawa 761-4421, Japan
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Gielkens MM, Dekkers E, Visser J, de Graaff LH. Two cellobiohydrolase-encoding genes from Aspergillus niger require D-xylose and the xylanolytic transcriptional activator XlnR for their expression. Appl Environ Microbiol 1999; 65:4340-5. [PMID: 10508057 PMCID: PMC91575 DOI: 10.1128/aem.65.10.4340-4345.1999] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/1999] [Accepted: 07/30/1999] [Indexed: 11/20/2022] Open
Abstract
Two cellobiohydrolase-encoding genes, cbhA and cbhB, have been isolated from the filamentous fungus Aspergillus niger. The deduced amino acid sequence shows that CbhB has a modular structure consisting of a fungus-type cellulose-binding domain (CBD) and a catalytic domain separated by a Pro/Ser/Thr-rich linker peptide. CbhA consists only of a catalytic domain and lacks a CBD and linker peptide. Both proteins are homologous to fungal cellobiohydrolases in family 7 of the glycosyl hydrolases. Northern blot analysis showed that the transcription of the cbhA and cbhB genes is induced by D-xylose but not by sophorose and, in addition, requires the xylanolytic transcriptional activator XlnR.
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Affiliation(s)
- M M Gielkens
- Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, NL-6703 HA Wageningen, The Netherlands
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