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Nigel Dunn-Coleman

Bio: Nigel Dunn-Coleman is an academic researcher from Genencor. The author has contributed to research in topics: Trichoderma reesei & Alpha-amylase. The author has an hindex of 25, co-authored 79 publications receiving 3144 citations.


Papers
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Journal ArticleDOI
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

Journal ArticleDOI
TL;DR: In this paper, the authors partially sequenced over 5100 random T. reesei cDNA clones and found that most of the genes encoding known and putative biomass-degrading enzymes were transcriptionally co-regulated.

541 citations

Journal ArticleDOI
TL;DR: Analysis of the superior chymosin producing strains indicated that they have enhanced capabilities to secrete extracellular proteins.
Abstract: We have increased the production of bovine chymosin in Aspergillus niger var. awamori to more than one gram per liter of secreted authentic enzyme by combining a mutagenesis protocol with a novel robotic screening program. Analysis of the superior chymosin producing strains indicated that they have enhanced capabilities to secrete extracellular proteins.

177 citations

Patent
13 Nov 1997
TL;DR: In this paper, an improved method for the production of 1,3-propanediol from a variety of carbon sources is presented, which is an organism comprising DNA encoding protein X of a dehydratase or protein X in combination with at least one of protein 1, protein 2 and protein 3.
Abstract: The present invention provides an improved method for the production of 1,3-propanediol from a variety of carbon sources is an organism comprising DNA encoding protein X of a dehydratase or protein X in combination with at least one of protein 1, protein 2 and protein 3. The protein X may be isolated from a diol dehydratase or a glycerol dehydratase. The present invention also provides host cells comprising protein X that are capable of increased production of 1,3-propanediol.

133 citations

Patent
07 Oct 2005
TL;DR: In this paper, a Trichoderma glucoamylase having the sequence of SEQ ID NO: 4 and biologically functional fragments thereof has been described, which is related to DNA sequences coding for the GluCoAmylases, vectors and host cells incorporating the DNA sequences, enzyme compositions and methods of using the gluCoamylases.
Abstract: The present invention is related to glucoamylases having at least 80% sequence identity to a Trichoderma glucoamylase having the sequence of SEQ ID NO: 4 and biologically functional fragments thereof. The invention is also related to DNA sequences coding for the glucoamylases, vectors and host cells incorporating the DNA sequences, enzyme compositions and methods of using the glucoamylases in various applications.

109 citations


Cited by
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Journal ArticleDOI
M.K. Bhat1
TL;DR: The present article is an overview of the biotechnological state-of-the-art for cellulases and related enzymes.

1,353 citations

Journal ArticleDOI
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

Journal ArticleDOI
TL;DR: A new class introduced in the CAZy database is named “Auxiliary Activities” in order to accommodate a range of enzyme mechanisms and substrates related to lignocellulose conversion and provides a better coverage of the full extent of the lignin degradation machinery.
Abstract: Since its inception, the carbohydrate-active enzymes database (CAZy; http://www.cazy.org ) has described the families of enzymes that cleave or build complex carbohydrates, namely the glycoside hydrolases (GH), the polysaccharide lyases (PL), the carbohydrate esterases (CE), the glycosyltransferases (GT) and their appended non-catalytic carbohydrate-binding modules (CBM). The recent discovery that members of families CBM33 and family GH61 are in fact lytic polysaccharide monooxygenases (LPMO), demands a reclassification of these families into a suitable category. Because lignin is invariably found together with polysaccharides in the plant cell wall and because lignin fragments are likely to act in concert with (LPMO), we have decided to join the families of lignin degradation enzymes to the LPMO families and launch a new CAZy class that we name “Auxiliary Activities” in order to accommodate a range of enzyme mechanisms and substrates related to lignocellulose conversion. Comparative analyses of these auxiliary activities in 41 fungal genomes reveal a pertinent division of several fungal groups and subgroups combining their phylogenetic origin and their nutritional mode (white vs. brown rot). The new class introduced in the CAZy database extends the traditional CAZy families, and provides a better coverage of the full extent of the lignocellulose breakdown machinery.

966 citations

01 Jan 2007
TL;DR: A number of pretreatment technologies are under development and being tested in pilot scale for lignocellulose, which is the largest known renewable carbohydrate source as mentioned in this paper, but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modifi cation of the lignosic structure.
Abstract: The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose and hemicelluloses but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modifi cation of the lignocellulosic structure. A number of pretreatment technologies are under development and being tested in pilot scale. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a number of different cellulases and hemicellulases. The hydrolysis of cellulose is a sequential breakdown of the linear glucose chains, whereas hemicellulases must be capable of hydrolysing branched chains containing different sugars and functional groups. The technology for pretreatment and hydrolysis has been developed to an extent that is close to a commercially viable level. It has become possible to process lignocellulose at high substrate levels and the enzyme performance has been improved. Also the cost of enzymes has been reduced. Still a number of technical and scientifi c issues within pretreatment and hydrolysis remain to be solved. However, signifi cant improvements in yield and cost reductions are expected, thus making large-scale fermentation of lignocellulosic substrates possible. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

957 citations

Journal ArticleDOI
TL;DR: A number of pretreatment technologies are under development and being tested in pilot scale for lignocellulose, which is the largest known renewable carbohydrate source as discussed by the authors, but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modification of the lignosic structure.
Abstract: The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose and hemicelluloses but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modification of the lignocellulosic structure. A number of pretreatment technologies are under development and being tested in pilot scale. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a number of different cellulases and hemicellulases. The hydrolysis of cellulose is a sequential breakdown of the linear glucose chains, whereas hemicellulases must be capable of hydrolysing branched chains containing different sugars and functional groups. The technology for pretreatment and hydrolysis has been developed to an extent that is close to a commercially viable level. It has become possible to process lignocellulose at high substrate levels and the enzyme performance has been improved. Also the cost of enzymes has been reduced. Still a number of technical and scientific issues within pretreatment and hydrolysis remain to be solved. However, significant improvements in yield and cost reductions are expected, thus making large-scale fermentation of lignocellulosic substrates possible. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

942 citations