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Novozymes (Denmark)

companyCopenhagen, Denmark

Research output, citation impact, and the most-cited recent papers from Novozymes (Denmark) (Denmark). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
2.2K
Citations
178.6K
h-index
174
i10-index
2.3K
Also known as
Novozymes (Denmark)

Top-cited papers from Novozymes (Denmark)

Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for <i>Fungi</i>
Conrad L. Schoch, Keith A. Seifert, Sabine M. Huhndorf, Vincent Robert +4 more
2012· Proceedings of the National Academy of Sciences5.1Kdoi:10.1073/pnas.1117018109

Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups.

Improvements to the <scp>APBS</scp> biomolecular solvation software suite
Elizabeth Jurrus, Dave Engel, Keith T. Star, Kyle Monson +4 more
2017· Protein Science2.5Kdoi:10.1002/pro.3280

Abstract The Adaptive Poisson–Boltzmann Solver (APBS) software was developed to solve the equations of continuum electrostatics for large biomolecular assemblages that have provided impact in the study of a broad range of chemical, biological, and biomedical applications. APBS addresses the three key technology challenges for understanding solvation and electrostatics in biomedical applications: accurate and efficient models for biomolecular solvation and electrostatics, robust and scalable software for applying those theories to biomolecular systems, and mechanisms for sharing and analyzing biomolecular electrostatics data in the scientific community. To address new research applications and advancing computational capabilities, we have continually updated APBS and its suite of accompanying software since its release in 2001. In this article, we discuss the models and capabilities that have recently been implemented within the APBS software package including a Poisson–Boltzmann analytical and a semi‐analytical solver, an optimized boundary element solver, a geometry‐based geometric flow solvation model, a graph theory‐based algorithm for determining p K a values, and an improved web‐based visualization tool for viewing electrostatics.

Improved Method for Determining Food Protein Degree of Hydrolysis
Per Munk Nielsen, Daphne Elaine Leslie Petersen, C. Dambmann
2001· Journal of Food Science1.7Kdoi:10.1111/j.1365-2621.2001.tb04614.x

ABSTRACT When producing hydrolyzed proteins, it is important to determine the degree of hydrolysis (DH). The trinitro‐benzene‐sulfonic acid (TNBS) method is well established with regard to enzymatic hydrolysis. However, this method is laborious, cannot be used to follow a hydrolysis reaction continuously, and includes hazardous and unstable chemicals. This paper describes a method based on the reaction of primary amino groups with o‐phthaldialdehyde (OPA). The conclusion is that the OPA method of analyzing the DH of protein hydrolyses is more accurate, is easier and faster to carry out, has a broader application range, and is environmentally safer than the TNBS method.

Genome sequencing and analysis of the biomass-degrading fungus Trichoderma reesei (syn. Hypocrea jecorina)
Diego Martinez, Randy M. Berka, Bernard Henrissat, Markku Saloheimo +4 more
2008· Nature Biotechnology1.3Kdoi:10.1038/nbt1403

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.

Insights into the oxidative degradation of cellulose by a copper metalloenzyme that exploits biomass components
R. Jason Quinlan, Matt Sweeney, Leila Lo Leggio, H. Otten +4 more
2011· Proceedings of the National Academy of Sciences1.1Kdoi:10.1073/pnas.1105776108

The enzymatic degradation of recalcitrant plant biomass is one of the key industrial challenges of the 21st century. Accordingly, there is a continuing drive to discover new routes to promote polysaccharide degradation. Perhaps the most promising approach involves the application of "cellulase-enhancing factors," such as those from the glycoside hydrolase (CAZy) GH61 family. Here we show that GH61 enzymes are a unique family of copper-dependent oxidases. We demonstrate that copper is needed for GH61 maximal activity and that the formation of cellodextrin and oxidized cellodextrin products by GH61 is enhanced in the presence of small molecule redox-active cofactors such as ascorbate and gallate. By using electron paramagnetic resonance spectroscopy and single-crystal X-ray diffraction, the active site of GH61 is revealed to contain a type II copper and, uniquely, a methylated histidine in the copper's coordination sphere, thus providing an innovative paradigm in bioinorganic enzymatic catalysis.

Genome sequence of the lignocellulose degrading fungus Phanerochaete chrysosporium strain RP78
Diego Martínez, Luis Larrondo, Nik Putnam, Maarten D. Sollewijn Gelpke +4 more
2004· Nature Biotechnology923doi:10.1038/nbt967

White rot fungi efficiently degrade lignin, a complex aromatic polymer in wood that is among the most abundant natural materials on earth. These fungi use extracellular oxidative enzymes that are also able to transform related aromatic compounds found in explosive contaminants, pesticides and toxic waste. We have sequenced the 30-million base-pair genome of Phanerochaete chrysosporium strain RP78 using a whole genome shotgun approach. The P. chrysosporium genome reveals an impressive array of genes encoding secreted oxidases, peroxidases and hydrolytic enzymes that cooperate in wood decay. Analysis of the genome data will enhance our understanding of lignocellulose degradation, a pivotal process in the global carbon cycle, and provide a framework for further development of bioprocesses for biomass utilization, organopollutant degradation and fiber bleaching. This genome provides a high quality draft sequence of a basidiomycete, a major fungal phylum that includes important plant and animal pathogens.

Stimulation of Lignocellulosic Biomass Hydrolysis by Proteins of Glycoside Hydrolase Family 61: Structure and Function of a Large, Enigmatic Family
Paul V. Harris, Ditte Hededam Welner, K. C. McFarland, Edward Re +4 more
2010· Biochemistry798doi:10.1021/bi100009p

Currently, the relatively high cost of enzymes such as glycoside hydrolases that catalyze cellulose hydrolysis represents a barrier to commercialization of a biorefinery capable of producing renewable transportable fuels such as ethanol from abundant lignocellulosic biomass. Among the many families of glycoside hydrolases that catalyze cellulose and hemicellulose hydrolysis, few are more enigmatic than family 61 (GH61), originally classified based on measurement of very weak endo-1,4-beta-d-glucanase activity in one family member. Here we show that certain GH61 proteins lack measurable hydrolytic activity by themselves but in the presence of various divalent metal ions can significantly reduce the total protein loading required to hydrolyze lignocellulosic biomass. We also solved the structure of one highly active GH61 protein and find that it is devoid of conserved, closely juxtaposed acidic side chains that could serve as general proton donor and nucleophile/base in a canonical hydrolytic reaction, and we conclude that the GH61 proteins are unlikely to be glycoside hydrolases. Structure-based mutagenesis shows the importance of several conserved residues for GH61 function. By incorporating the gene for one GH61 protein into a commercial Trichoderma reesei strain producing high levels of cellulolytic enzymes, we are able to reduce by 2-fold the total protein loading (and hence the cost) required to hydrolyze lignocellulosic biomass.

The complete genome of the crenarchaeon <i>Sulfolobus solfataricus</i> P2
Qunxin She, Rama Kant Singh, Fabrice Confalonieri, Yvan Zivanovic +4 more
2001· Proceedings of the National Academy of Sciences766doi:10.1073/pnas.141222098

The genome of the crenarchaeon Sulfolobus solfataricus P2 contains 2,992,245 bp on a single chromosome and encodes 2,977 proteins and many RNAs. One-third of the encoded proteins have no detectable homologs in other sequenced genomes. Moreover, 40% appear to be archaeal-specific, and only 12% and 2.3% are shared exclusively with bacteria and eukarya, respectively. The genome shows a high level of plasticity with 200 diverse insertion sequence elements, many putative nonautonomous mobile elements, and evidence of integrase-mediated insertion events. There are also long clusters of regularly spaced tandem repeats. Different transfer systems are used for the uptake of inorganic and organic solutes, and a wealth of intracellular and extracellular proteases, sugar, and sulfur metabolizing enzymes are encoded, as well as enzymes of the central metabolic pathways and motility proteins. The major metabolic electron carrier is not NADH as in bacteria and eukarya but probably ferredoxin. The essential components required for DNA replication, DNA repair and recombination, the cell cycle, transcriptional initiation and translation, but not DNA folding, show a strong eukaryal character with many archaeal-specific features. The results illustrate major differences between crenarchaea and euryarchaea, especially for their DNA replication mechanism and cell cycle processes and their translational apparatus.

Lignocellulose degradation mechanisms across the Tree of Life
Simon M. Cragg, Gregg T. Beckham, Neil C. Bruce, Timothy D. H. Bugg +4 more
2015· Current Opinion in Chemical Biology674doi:10.1016/j.cbpa.2015.10.018

Organisms use diverse mechanisms involving multiple complementary enzymes, particularly glycoside hydrolases (GHs), to deconstruct lignocellulose. Lytic polysaccharide monooxygenases (LPMOs) produced by bacteria and fungi facilitate deconstruction as does the Fenton chemistry of brown-rot fungi. Lignin depolymerisation is achieved by white-rot fungi and certain bacteria, using peroxidases and laccases. Meta-omics is now revealing the complexity of prokaryotic degradative activity in lignocellulose-rich environments. Protists from termite guts and some oomycetes produce multiple lignocellulolytic enzymes. Lignocellulose-consuming animals secrete some GHs, but most harbour a diverse enzyme-secreting gut microflora in a mutualism that is particularly complex in termites. Shipworms however, house GH-secreting and LPMO-secreting bacteria separate from the site of digestion and the isopod Limnoria relies on endogenous enzymes alone. The omics revolution is identifying many novel enzymes and paradigms for biomass deconstruction, but more emphasis on function is required, particularly for enzyme cocktails, in which LPMOs may play an important role.

Yield-determining factors in high-solids enzymatic hydrolysis of lignocellulose
Jan B. L. Kristensen, Claus Felby, Henning Jørgensen
2009· Biotechnology for Biofuels644doi:10.1186/1754-6834-2-11

BACKGROUND: Working at high solids (substrate) concentrations is advantageous in enzymatic conversion of lignocellulosic biomass as it increases product concentrations and plant productivity while lowering energy and water input. However, for a number of lignocellulosic substrates it has been shown that at increasing substrate concentration, the corresponding yield decreases in a fashion which can not be explained by current models and knowledge of enzyme-substrate interactions. This decrease in yield is undesirable as it offsets the advantages of working at high solids levels. The cause of the 'solids effect' has so far remained unknown. RESULTS: The decreasing conversion at increasing solids concentrations was found to be a generic or intrinsic effect, describing a linear correlation from 5 to 30% initial total solids content (w/w). Insufficient mixing has previously been shown not to be involved in the effect. Hydrolysis experiments with filter paper showed that neither lignin content nor hemicellulose-derived inhibitors appear to be responsible for the decrease in yields. Product inhibition by glucose and in particular cellobiose (and ethanol in simultaneous saccharification and fermentation) at the increased concentrations at high solids loading plays a role but could not completely account for the decreasing conversion. Adsorption of cellulases was found to decrease at increasing solids concentrations. There was a strong correlation between the decreasing adsorption and conversion, indicating that the inhibition of cellulase adsorption to cellulose is causing the decrease in yield. CONCLUSION: Inhibition of enzyme adsorption by hydrolysis products appear to be the main cause of the decreasing yields at increasing substrate concentrations in the enzymatic decomposition of cellulosic biomass. In order to facilitate high conversions at high solids concentrations, understanding of the mechanisms involved in high-solids product inhibition and adsorption inhibition must be improved.

Plectasin, a Fungal Defensin, Targets the Bacterial Cell Wall Precursor Lipid II
Tanja Schneider, Thomas Kruse, Reinhard Wimmer, Imke Wiedemann +4 more
2010· Science544doi:10.1126/science.1185723

Host defense peptides such as defensins are components of innate immunity and have retained antibiotic activity throughout evolution. Their activity is thought to be due to amphipathic structures, which enable binding and disruption of microbial cytoplasmic membranes. Contrary to this, we show that plectasin, a fungal defensin, acts by directly binding the bacterial cell-wall precursor Lipid II. A wide range of genetic and biochemical approaches identify cell-wall biosynthesis as the pathway targeted by plectasin. In vitro assays for cell-wall synthesis identified Lipid II as the specific cellular target. Consistently, binding studies confirmed the formation of an equimolar stoichiometric complex between Lipid II and plectasin. Furthermore, key residues in plectasin involved in complex formation were identified using nuclear magnetic resonance spectroscopy and computational modeling.

Growing a circular economy with fungal biotechnology: a white paper
Vera Meyer, Evelina Y. Basenko, J. Philipp Benz, Gerhard H. Braus +4 more
2020· Fungal Biology and Biotechnology521doi:10.1186/s40694-020-00095-z

Fungi have the ability to transform organic materials into a rich and diverse set of useful products and provide distinct opportunities for tackling the urgent challenges before all humans. Fungal biotechnology can advance the transition from our petroleum-based economy into a bio-based circular economy and has the ability to sustainably produce resilient sources of food, feed, chemicals, fuels, textiles, and materials for construction, automotive and transportation industries, for furniture and beyond. Fungal biotechnology offers solutions for securing, stabilizing and enhancing the food supply for a growing human population, while simultaneously lowering greenhouse gas emissions. Fungal biotechnology has, thus, the potential to make a significant contribution to climate change mitigation and meeting the United Nation's sustainable development goals through the rational improvement of new and established fungal cell factories. The White Paper presented here is the result of the 2nd Think Tank meeting held by the EUROFUNG consortium in Berlin in October 2019. This paper highlights discussions on current opportunities and research challenges in fungal biotechnology and aims to inform scientists, educators, the general public, industrial stakeholders and policymakers about the current fungal biotech revolution.

Albumin and its application in drug delivery
Darrell Sleep
2014· Expert Opinion on Drug Delivery462doi:10.1517/17425247.2015.993313

INTRODUCTION: Rapid clearance of drugs from the body results in short therapeutic half-life and is an integral property of many protein and peptide-based drugs. To maintain the desired therapeutic effect patients are required to administer higher doses more frequently, which is inconvenient and risks undesirable side effects. Drug delivery technologies aim to minimise the number of administrations and dose-related toxicity while maximising therapeutic efficacy. AREAS COVERED: This review describes albumin's inherent biochemical and biophysical properties, which make it an attractive drug delivery platform and the developmental status of drugs that are associated, conjugated or genetically fused with albumin. Albumin interacts with a number of cell surface receptors including gp18, gp30, gp60, FcRn, cubilin and megalin. The importance of albumin's interaction with the FcRn receptor, the basis for albumin's long circulatory half-life, is described, as are engineered albumins with improved pharmacokinetics. Albumin naturally accumulates at tumours and sites of inflammation, a characteristic which can be augmented by the addition of targeting ligands. The development of albumin drug conjugates which reply upon this property is described. EXPERT OPINION: Albumin's inherent biochemical and biophysical properties make it an ideal drug delivery platform. Recent advances in our understanding of albumin physiology and the improvement in albumin-based therapies strongly suggest that albumin-based therapies have a significant advantage over alternative technologies in terms of half-life, stability, versatility, safety and ease of manufacture. Given the importance of the albumin:FcRn interaction, the interpretation of the pharmacokinetic and pharmacodynamic profiles of albumin-based therapeutics with disturbed albumin:FcRn interaction may have to be reassessed. The FcRn receptor has additional functionality, especially in relation to immunology, antigen presentation and delivery of proteins across mucosal membranes, consequently albumin-based fusions and conjugates may have a future role in oral and pulmonary-based vaccines and drug delivery.

Altered sterol composition renders yeast thermotolerant
Luis Caspeta, Yun Chen, Payam Ghiaci, Amir Feizi +4 more
2014· Science449doi:10.1126/science.1258137

Tricks for boosting yeast's ethanol yields To become a widely used source of fuel, widespread industrial production of ethanol using yeast needs to be simple and efficient. However, two conditions ideal for boosting production—tolerance of higher temperatures and high concentrations of ethanol—have been limiting (see the Perspective by Cheng and Kao). Now, Caspeta et al. have used adaptive laboratory evolution to find yeast strains that can tolerate high temperatures and Lam et al. have identified a route to improve yeast's resistance to high concentrations of ethanol. Science , this issue p. 75 , p. 71 ; see also p. 35

Disclosure of information on intellectual capital in Danish IPO prospectuses
Per Nikolaj Bukh, Christian Nielsen, Peter Gormsen, Jan Mouritsen
2005· Accounting Auditing & Accountability Journal440doi:10.1108/09513570510627685

The purpose of this paper is to examine whether information on intellectual capital (non-financial information on knowledge based resources) is disclosed in Danish IPO prospectuses. Further, to analyse whether this voluntary disclosure has changed in the period from 1999 to 2001 and to analyse what factors can explain the amount of disclosure in the prospectuses. Design/methodology/approach - The paper uses content analysis to compile a measure of disclosure on each prospectus and statistical analysis to test whether there is an association between disclosure and company type, the existence of managerial ownership before the IPO, the size of the company or the age of the firm. Findings - Based on statistical analysis, it is concluded that the extent of managerial ownership prior to the IPO and industry type affects the amount of voluntary intellectual capital disclosure, while company size and age do not affect disclosure. The results are interpreted in the light of the increasing importance of disclosing information on value drivers, strategy and intellectual capital to the capital market and constitute a contribution to the ongoing debate on corporate reporting practices. Practical implications - Since information on intellectual capital is already disclosed in IPO prospectuses this reporting form can be used as inspiration when an intellectual capital report is developed. The results also indicate that companies and their advisers believe that this type of information is important in the capital market's assessment of the company's value. Further, it is suggested that intellectual capital reports should be read in the context of the firm's strategy in the same manner as an prospectus is read. Originality/value - Very few papers have analysed disclosure in prospectuses and it has been from a different perspective from this paper. Further, this paper analyses a time series of data and demonstrates how the amount of disclosure has developed over the years. Finally, the paper contributes to the body of literature on what factors explain disclosure in general.

Complete genome sequence of the industrial bacterium Bacillus licheniformis and comparisons with closely related Bacillusspecies
Michael W. Rey, Preethi Ramaiya, Beth A. Nelson, Shari D Brody-Karpin +4 more
2004· Genome biology391doi:10.1186/gb-2004-5-10-r77

Abstract Background Bacillus licheniformis is a Gram-positive, spore-forming soil bacterium that is used in the biotechnology industry to manufacture enzymes, antibiotics, biochemicals and consumer products. This species is closely related to the well studied model organism Bacillus subtilis , and produces an assortment of extracellular enzymes that may contribute to nutrient cycling in nature. Results We determined the complete nucleotide sequence of the B. licheniformis ATCC 14580 genome which comprises a circular chromosome of 4,222,336 base-pairs (bp) containing 4,208 predicted protein-coding genes with an average size of 873 bp, seven rRNA operons, and 72 tRNA genes. The B. licheniformis chromosome contains large regions that are colinear with the genomes of B. subtilis and Bacillus halodurans , and approximately 80% of the predicted B. licheniformis coding sequences have B. subtilis orthologs. Conclusions Despite the unmistakable organizational similarities between the B. licheniformis and B. subtilis genomes, there are notable differences in the numbers and locations of prophages, transposable elements and a number of extracellular enzymes and secondary metabolic pathway operons that distinguish these species. Differences include a region of more than 80 kilobases (kb) that comprises a cluster of polyketide synthase genes and a second operon of 38 kb encoding plipastatin synthase enzymes that are absent in the B. licheniformis genome. The availability of a completed genome sequence for B. licheniformis should facilitate the design and construction of improved industrial strains and allow for comparative genomics and evolutionary studies within this group of Bacillaceae.

Environmental assessment of enzyme use in industrial production – a literature review
Kenthorai Raman Jegannathan, Per Henning Nielsen
2012· Journal of Cleaner Production391doi:10.1016/j.jclepro.2012.11.005

Enzymatic processes have been implemented in a broad range of industries in recent decades because they are specific, fast in action and often save raw materials, energy, chemicals and/or water compared to conventional processes. A number of comparative environmental assessment studies have been conducted in the past 15 years to investigate whether these properties of enzymatic processes lead to environmental improvements and assess whether they could play a role in moving toward cleaner industrial production. The purpose of this review is to summarize and discuss the findings of these studies and to recommend further developments regarding environmental assessment and implementation of the technology. Life Cycle Assessment (LCA) has been widely used as an assessment tool, while use of the ‘carbon footprint’ concept and Environmental Impact Assessment (EIA) is limited to a few studies. Many studies have addressed global warming as an indicator and several studies have furthermore addressed other impact categories (acidification, eutrophication, photochemical ozone formation, energy and land use). The results show that implementing enzymatic processes in place of conventional processes generally results in a reduced contribution to global warming and also a reduced contribution to acidification, eutrophication, photochemical ozone formation and energy use to the extent that this has been investigated. Agricultural land has been addressed in few studies and land use savings appear to occur in industries where enzymatic processes save agricultural raw materials, whereas it becomes a trade-off in processes where only fossil fuels and/or inorganic chemicals are saved. Agricultural land use appears to be justified by other considerable environmental improvements in the latter cases, and the results of this review support the hypothesis that enzyme technology is a promising means of moving toward cleaner industrial production. LCA gives a more complete picture of the environmental properties of the processes considered than EIA and carbon footprint studies, and it is recommended that researchers move toward LCA in future studies. Tradition, lack of knowledge and bureaucracy are barriers to implementation of enzymatic processes in industry. Education and streamlining of public approval processes etc. are means of overcoming the barriers and accelerating the harvesting of the environmental benefits.

Lipases from <i>Candida </i><i>a</i><i>ntarctica</i>: Unique Biocatalysts from a Unique Origin
Ole Kirk, Morten Würtz Christensen
2002· Organic Process Research & Development375doi:10.1021/op0200165

The specificity of the A-lipase from Candida antarctica (CALA) has been characterized to further clarify the scope of the biocatalyst. The lipase was found to exhibit an almost uniform activity towards various straight-chained primary alcohols and carboxylic acids, only exhibiting a low activity towards very short-chained acids. More interestingly, the enzyme was found to exhibit a high activity towards a surprising diversity of sterically hindered alcohols, including both secondary and tertiary alcohols. These results indicate that CALA can have a unique applicability for the conversion of highly branched substrates where most other lipases fail to display any activity. A new, potentially highly cost-effective, immobilization technology using silica-based granulation has been applied in the immobilization of the B-lipase from the same yeast (CALB). Highly stable particles were obtained with an activity comparable to that of the commercially available immobilized preparations of this enzyme.

Comparative genomics of citric-acid-producing<i>Aspergillus niger</i>ATCC 1015 versus enzyme-producing CBS 513.88
Mikael Rørdam Andersen, Margarita Salazar, Peter J. Schaap, Peter J. I. van de Vondervoort +4 more
2011· Genome Research366doi:10.1101/gr.112169.110

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.

Mechanism and use of the commercially available viability stain, <i>Bac</i>Light
Stuart M. Stocks
2004· Cytometry Part A361doi:10.1002/cyto.a.20069

BACKGROUND: BacLight (Molecular Probes, Eugene, OR, USA) is a popular fluorescence-based two-component stain for determining bacterial cell viability. The main purpose of this work was to fully elucidate the mechanism and to determine why it is sometimes reported that cells stain simultaneously live and dead. METHODS: Solutions of DNA were stained with the two components, propidium iodide (PI) and SYTO9, in different combinations, and fluorescence spectra were collected. RESULTS: K(PI) and K(SYTO9) were approximately 3.7 x 10(5)/M and 1.8 x 10(5)/M. SYTO9 emissions were stronger and overlapped those of PI. Fluorescence resonance energy transfer from SYTO9 to PI was observed. It was, even under normal conditions, possible for DNA bound SYTO9 to have a component in the red region equal to that of DNA bound PI. Potentially confusing emissions were also found to occur when PI was not in sufficient excess to saturate nucleic acid (>0.4 M PI to 1 M DNA base pairs). CONCLUSIONS: The mechanism is a combination of displacement of SYTO9 by PI and quenching of SYTO9 emissions by fluorescence resonance energy transfer. Confusing results can occur if the relative intensities of the stains or the concentration of PI relative to nucleic acid are not properly accounted for.