Author
Albert J. J. van Ooyen
Other affiliations: DSM
Bio: Albert J. J. van Ooyen is an academic researcher from Wageningen University and Research Centre. The author has contributed to research in topics: Astaxanthin & Aspergillus niger. The author has an hindex of 16, co-authored 24 publications receiving 2696 citations. Previous affiliations of Albert J. J. van Ooyen include DSM.
Papers
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DSM1, Delft University of Technology2, University of Nottingham3, Technical University of Denmark4, Wageningen University and Research Centre5, University of Sheffield6, Utrecht University7, Biomax Informatics AG8, CLC bio9, University of Liverpool10, Ghent University11, University of Manchester12, University of Provence13, University of Groningen14, Pasteur Institute15, University of Amsterdam16, University of Angers17, Leiden University18, Radboud University Nijmegen19, University of Szeged20
TL;DR: The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid, and the sequenced genome revealed a large number of major facilitator superfamily transporters and fungal zinc binuclear cluster transcription factors.
Abstract: The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level of synteny was observed with other aspergilli sequenced. Strong function predictions were made for 6,506 of the 14,165 open reading frames identified. A detailed description of the components of the protein secretion pathway was made and striking differences in the hydrolytic enzyme spectra of aspergilli were observed. A reconstructed metabolic network comprising 1,069 unique reactions illustrates the versatile metabolism of A. niger. Noteworthy is the large number of major facilitator superfamily transporters and fungal zinc binuclear cluster transcription factors, and the presence of putative gene clusters for fumonisin and ochratoxin A synthesis.
1,161 citations
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TL;DR: It is succeeded in constructing an S. cerevisiae strain capable of producing high levels of β-carotene, up to 5.9 mg/g (dry weight), which was accomplished by the introduction of an additional copy of crtI and tHMG1 into carotenoid-producing yeast cells.
Abstract: To determine whether Saccharomyces cerevisiae can serve as a host for efficient carotenoid and especially β-carotene production, carotenogenic genes from the carotenoid-producing yeast Xanthophyllomyces dendrorhous were introduced and overexpressed in S. cerevisiae. Because overexpression of these genes from an episomal expression vector resulted in unstable strains, the genes were integrated into genomic DNA to yield stable, carotenoid-producing S. cerevisiae cells. Furthermore, carotenoid production levels were higher in strains containing integrated carotenogenic genes. Overexpression of crtYB (which encodes a bifunctional phytoene synthase and lycopene cyclase) and crtI (phytoene desaturase) from X. dendrorhous was sufficient to enable carotenoid production. Carotenoid production levels were increased by additional overexpression of a homologous geranylgeranyl diphosphate (GGPP) synthase from S. cerevisiae that is encoded by BTS1. Combined overexpression of crtE (heterologous GGPP synthase) from X. dendrorhous with crtYB and crtI and introduction of an additional copy of a truncated 3-hydroxy-3-methylglutaryl-coenzyme A reductase gene (tHMG1) into carotenoid-producing cells resulted in a successive increase in carotenoid production levels. The strains mentioned produced high levels of intermediates of the carotenogenic pathway and comparable low levels of the preferred end product β-carotene, as determined by high-performance liquid chromatography. We finally succeeded in constructing an S. cerevisiae strain capable of producing high levels of β-carotene, up to 5.9 mg/g (dry weight), which was accomplished by the introduction of an additional copy of crtI and tHMG1 into carotenoid-producing yeast cells. This transformant is promising for further development toward the biotechnological production of β-carotene by S. cerevisiae.
328 citations
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Technical University of Denmark1, DSM2, Pacific Northwest National Laboratory3, Biomax Informatics AG4, Novozymes5, University of Göttingen6, University of Seville7, Concordia University8, Chr. Hansen9, United States Department of Energy10, Stanford University11, Vienna University of Technology12, Los Alamos National Laboratory13
TL;DR: In this article, the authors performed whole-genome sequencing of the Aspergillus niger wild-type strain (ATCC 1015) and produced a genome sequence of very high quality.
Abstract: The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compel additional exploration. We therefore undertook whole-genome sequencing of the acidogenic A. niger wild-type strain (ATCC 1015) and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence, and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was used to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 Mb of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis supported up-regulation of genes associated with biosynthesis of amino acids that are abundant in glucoamylase A, tRNA-synthases, and protein transporters in the protein producing CBS 513.88 strain. Our results and data sets from this integrative systems biology analysis resulted in a snapshot of fungal evolution and will support further optimization of cell factories based on filamentous fungi.
308 citations
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TL;DR: Addition of phytase-transgenic seeds to animal feed obviates the need for inorganic phosphorus supplementation, and is environmentally desirable because of the reduced excretion of phosphorus.
Abstract: Phytate is the main storage form of phosphorus in many plant seeds, but bound in this form it is a poor nutrient for monogastric animals Its availability can be significantly increased by addition of the enzyme phytase, which releases phosphate from the substrate, phytate We have engineered a phytase from Aspergillus niger in tobacco seeds, providing a stable and convenient packaging of the enzyme that is directly applicable in animal feed The enzyme was expressed as 1 percent of the soluble protein in mature seeds In in vitro tests that simulated chicken crop and stomach conditions, release of phosphate from feed by addition of transgenic seeds was demonstrated Supplementation of broiler diets with transgenic seeds resulted in an unproved growth rate, comparable to diets supplemented with fungal phytase or phosphorus Addition of phytase-transgenic seeds to animal feed thus obviates the need for inorganic phosphorus supplementation, and is environmentally desirable because of the reduced excretion of phosphorus
242 citations
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TL;DR: The various strains, genetic techniques and molecular tools currently available for the use of K. lactis as a host for protein expression are reviewed and data illustrating the recent use of proteomics studies to identify cellular bottlenecks that impede heterologous protein expression is presented.
Abstract: Kluyveromyces lactis is both scientifically and biotechnologically one of the most important non-Saccharomyces yeasts. Its biotechnological significance builds on its history of safe use in the food industry and its well-known ability to produce enzymes like lactase and bovine chymosin on an industrial scale. In this article, we review the various strains, genetic techniques and molecular tools currently available for the use of K. lactis as a host for protein expression. Additionally, we present data illustrating the recent use of proteomics studies to identify cellular bottlenecks that impede heterologous protein expression.
216 citations
Cited by
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University of New Mexico1, Los Alamos National Laboratory2, Novozymes3, University of Provence4, VTT Technical Research Centre of Finland5, Pacific Northwest National Laboratory6, Joint Genome Institute7, United States Department of Agriculture8, Vienna University of Technology9, Pontifical Catholic University of Chile10, Oregon State University11, Genencor12
TL;DR: This work assembled 89 scaffolds to generate 34 Mbp of nearly contiguous T. reesei genome sequence comprising 9,129 predicted gene models, providing a roadmap for constructing enhanced T.Reesei strains for industrial applications such as biofuel production.
Abstract: Trichoderma reesei is the main industrial source of cellulases and hemicellulases used to depolymerize biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. We assembled 89 scaffolds (sets of ordered and oriented contigs) to generate 34 Mbp of nearly contiguous T. reesei genome sequence comprising 9,129 predicted gene models. Unexpectedly, considering the industrial utility and effectiveness of the carbohydrate-active enzymes of T. reesei, its genome encodes fewer cellulases and hemicellulases than any other sequenced fungus able to hydrolyze plant cell wall polysaccharides. Many T. reesei genes encoding carbohydrate-active enzymes are distributed nonrandomly in clusters that lie between regions of synteny with other Sordariomycetes. Numerous genes encoding biosynthetic pathways for secondary metabolites may promote survival of T. reesei in its competitive soil habitat, but genome analysis provided little mechanistic insight into its extraordinary capacity for protein secretion. Our analysis, coupled with the genome sequence data, provides a roadmap for constructing enhanced T. reesei strains for industrial applications such as biofuel production.
1,085 citations
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TL;DR: Through analysis of the current advances in production of citric, lactic and succinic acid production, guidelines for future developments in this fast-moving field are presented.
750 citations
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TL;DR: This review summarizes the current strategies that have been successfully applied during the last years to activate silent gene clusters in filamentous fungi, especially in the genus Aspergillus, and attempts to simulate the natural habitat by co-cultivation of microorganisms from the same ecosystem.
622 citations
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TL;DR: The current review discusses the relevance of several engineering strategies, such as rational and inverse metabolic engineering, evolutionary engineering, and global transcription machinery engineering, in yeast strain improvement and summarizes existing tools for fine-tuning and regulating enzyme activities and thus metabolic pathways.
Abstract: Summary: The traditional use of the yeast Saccharomyces cerevisiae in alcoholic fermentation has, over time, resulted in substantial accumulated knowledge concerning genetics, physiology, and biochemistry as well as genetic engineering and fermentation technologies. S. cerevisiae has become a platform organism for developing metabolic engineering strategies, methods, and tools. The current review discusses the relevance of several engineering strategies, such as rational and inverse metabolic engineering, evolutionary engineering, and global transcription machinery engineering, in yeast strain improvement. It also summarizes existing tools for fine-tuning and regulating enzyme activities and thus metabolic pathways. Recent examples of yeast metabolic engineering for food, beverage, and industrial biotechnology (bioethanol and bulk and fine chemicals) follow. S. cerevisiae currently enjoys increasing popularity as a production organism in industrial (“white”) biotechnology due to its inherent tolerance of low pH values and high ethanol and inhibitor concentrations and its ability to grow anaerobically. Attention is paid to utilizing lignocellulosic biomass as a potential substrate.
603 citations
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TL;DR: W Whole-genome analyses indicate that the genome structures of these two species are highly syntenic and suggest that the genus Metarhizium evolved from plant endophytes or pathogens, andTranscriptional analysis of both fungi during early infection processes provided further insights into the genes and pathways involved in infectivity and specificity.
Abstract: Metarhizium spp. are being used as environmentally friendly alternatives to chemical insecticides, as model systems for studying insect-fungus interactions, and as a resource of genes for biotechnology. We present a comparative analysis of the genome sequences of the broad-spectrum insect pathogen Metarhizium anisopliae and the acridid-specific M. acridum. Whole-genome analyses indicate that the genome structures of these two species are highly syntenic and suggest that the genus Metarhizium evolved from plant endophytes or pathogens. Both M. anisopliae and M. acridum have a strikingly larger proportion of genes encoding secreted proteins than other fungi, while ∼30% of these have no functionally characterized homologs, suggesting hitherto unsuspected interactions between fungal pathogens and insects. The analysis of transposase genes provided evidence of repeat-induced point mutations occurring in M. acridum but not in M. anisopliae. With the help of pathogen-host interaction gene database, ∼16% of Metarhizium genes were identified that are similar to experimentally verified genes involved in pathogenicity in other fungi, particularly plant pathogens. However, relative to M. acridum, M. anisopliae has evolved with many expanded gene families of proteases, chitinases, cytochrome P450s, polyketide synthases, and nonribosomal peptide synthetases for cuticle-degradation, detoxification, and toxin biosynthesis that may facilitate its ability to adapt to heterogenous environments. Transcriptional analysis of both fungi during early infection processes provided further insights into the genes and pathways involved in infectivity and specificity. Of particular note, M. acridum transcribed distinct G-protein coupled receptors on cuticles from locusts (the natural hosts) and cockroaches, whereas M. anisopliae transcribed the same receptor on both hosts. This study will facilitate the identification of virulence genes and the development of improved biocontrol strains with customized properties.
575 citations