Mette Lübeck

Aalborg University · Department of Chemistry and Bioscience

Green biomass from leguminous and gramineous forage crops, such as alfalfa and grass-clover, has been proposed as a potential new source of feed protein concentrates for non-ruminant livestock. However, the efficient separation of the protein fraction from the non-digestible cell components, primarily comprising cell walls (fiber) and starch, prese...

The infection biology of Bipolaris oryzae and the defence responses of its host rice were studied using the rice cv. MTL 189 inoculated with two isolates of B5 (highly compatible with MTL 189) and K2 (less compatible). In the former interaction, the hyphal progress was accompanied by tissue degradation and extensive sporulation after 8 days, wherea...

Nowadays, cassava leaves are mostly treated as a byproduct of cassava root production, yet this readily available biomass is rich in protein with a balanced content of amino acids. Cassava leaves therefore represent a promising, underutilized biomass for extraction of proteins. The purpose of this study was to provide updated information on the fea...

Alfalfa has a high potential as a novel food protein and can contribute to meet the increasing food demand. To facilitate food grade quality, protein extraction is essential. In this study, different extractions with isoelectric focusing the protein were compared; acid precipitation (citric and lactic acids) and fermentation (endogenous and Lactoba...

Slurry acidification is effective for reducing gaseous emissions during slurry storage. However, an alternative to sulfuric acid traditionally used is needed. This study investigated the efficiency of slurry bio-acidification treatment by adding different types and amounts of fermentable substrates to initiate and sustain the fermentation process....

Filamentous fungi are a large and diverse taxonomically group of microorganisms found in all habitats worldwide. They grow as a network of cells called hyphae. Since filamentous fungi live in very diverse habitats, they produce different enzymes to degrade material for their living, for example hydrolytic enzymes to degrade various kinds of biomass...

Alfalfa has a high potential as a novel food protein and can contribute to meet the increasing food demand. To facilitate food grade quality, protein extraction is essential. In this study, different extractions with isoelectric focusing the protein were compared; acid precipitation (citric and lactic acids) and fermentation (endogenous and Lactoba...

Background Succinic acid has great potential to be a new bio-based building block for deriving a number of value-added chemicals in industry. Bio-based succinic acid production from renewable biomass can provide a feasible approach to partially alleviate the dependence of global manufacturing on petroleum refinery. To improve the economics of biolo...

Nutrient recovery from organic green biomass after processing in a green biorefinery concept for the production of protein feed, biogas and fertilizer for organic farming was investigated. Mass balances in terms of wet weight, TS, VS, C, N, P, K and S were evaluated for processing red clover and clover grass into protein concentrate, press cake and...

The production of L-lactic acid was investigated in combination with the production of protein concentrates in the frame of a green biorefinery for efficient utilization of grasses and legume crops. Alfalfa green juice was the sole substrate utilized for initial lactic acid fermentation with Lactobacillus salivarius, Lactobacillus paracasei or Baci...

Photosynthetic active green leaves from grasses, legumes and other plants contain in general high amounts of protein, which can be utilized by ruminants or in many cases is wasted. Extraction of proteins from leaves represents an attractive solution to the increasing demand for protein-rich feed for monogastric animals, while decreasing the depende...

Aspergillus carbonarius is an efficient producer of organic acids with great potential for bio-based production of organic acids. In this study, we identified a gene f2kp encoding the enzyme 6-phosphofructo-2-kinase known as an allosteric regulator of the glycolytic flux and investigated its role in the production of organic acid. The strategy was...

In integrated biorefineries, physical and mechanical, thermochemical, chemical as well as biotechnological processes are applied in order to simultaneously obtain various products belonging to the classes: Food, feed, materials, chemicals, and energy, from various biogenic feedstocks. The focus on the production of more than one product is also exp...

Background: In filamentous fungi, transport of organic acids across the mitochondrial membrane is facilitated by active transport via shuttle proteins. These transporters may transfer different organic acids across the membrane while taking others the opposite direction. In Aspergillus niger, accumulation of malate in the cytosol can trigger produ...

Lactic acid bacteria (LAB) have extensive industrial applications as producers of lactic acid, as probiotics, as biocontrol agents and as biopreservatives. LAB play a large role in food fermentation and in silage processes, where crops such as grass, legumes, cereals or corn are fermented into high-moisture feed that is storable and can be used to...

Lactic acid bacteria (LAB) have extensive industrial applications as producers of lactic acid, as probiotics, as biocontrol agents and as biopreservatives. LAB play a large role in food fermentation and in silage processes, where crops such as grass, legumes, cereals or corn are fermented into high-moisture feed that is storable and can be used to...

There is an increasing interest in green biorefineries for the utilization of green biomass to provide a variety of valuable products. Proteins can be extracted from green biomasses such as alfalfa, clover, or grass and separated into protein‐rich concentrates suitable for feeding to monogastric animals. Press cake suitable for feeding ruminant ani...

Filamentous fungi are among the microorganisms that most efficiently are able to degrade plant biomass by secreting cell wall-degrading enzymes and they are therefore used extensively in the industry as workhorses for the production of enzymes, including cellulases for the use in second-generation biorefinery concepts. Fungi are therefore of intere...

Among cellulases, β-glucosidases play a key role in the final conversion of cellulose into glucose as well as they boost the performance of the other cellulases, in particular cellobiohydrolases in relieving product inhibition. This chapter serves as case example from screening for novel fungal cellulases focusing on β-glucosidases to identifying a...

This volume discusses the latest research and techniques used to study novel cellulases. The chapters in this book explore topics such as the role of cellulases in lignocellulose deconstruction for generation of a sugar platform for biofuel; screening for novel fungal b-glucosidases in a variety of fungal strains; discovery of novel enzymes in bact...

Nowadays, the organic farming sector is growing at a fast pace in Europe while needs to face the lack of organic protein sources and in particular, feeding monogastric animals is becoming more and more urgent. Green biorefinery concepts might become the suitable solution for the production of organic protein-rich feeds from green crops. In this con...

Background C4-dicarboxylic acids, including malic acid, fumaric acid and succinic acid, are valuable organic acids that can be produced and secreted by a number of microorganisms. Previous studies on organic acid production by Aspergillus carbonarius, which is capable of producing high amounts of citric acid from varieties carbon sources, have reve...

The biogas potential of the residual fractions of four organically grown green crops after protein extraction was studied. The protein extraction method involved screw pressing of freshly harvested biomass to obtain a plant juice, followed by precipitation of the proteins. After protein extraction, 95% of organic matter was still present in the res...

In recent years, versatile genetic tools have been developed and applied to a number of filamentous fungi of industrial importance. However, the existing techniques have limitations when it comes to achieve the desired genetic modifications, especially for efficient gene targeting. In this study, we used Aspergillus carbonarius as a host strain due...

Filamentous fungi from the genus Aspergillus are of high importance for biobased organic acid production. So far, a number of Aspergillus strains belonging to phylogenetically distantly related species have been successfully applied in industrial production of organic acids due to their excellent capabilities of secreting high amounts of desired or...

The global regulatory protein LaeA is known for regulating the production of many kinds of secondary metabolites in Aspergillus species, as well as sexual and asexual reproduction, and morphology. In Aspergillus carbonarius, it has been shown that LaeA regulates production of ochratoxin. We have investigated the regulatory effect of LaeA on product...

Aspergillus carbonarius exhibits excellent abilities to utilize a wide range of carbon sources and to produce various organic acids. In this study, wheat straw hydrolysate containing high concentrations of glucose and xylose was used for organic acid production by A. carbonarius. The results indicated that A. carbonarius efficiently co-consumed glu...

Aspergillus saccharolyticus exhibits great potential as a cell factory for industrial production of dicarboxylic acids. In the analysis of the organic acid profile, A. saccharolyticus was cultivated in an acid production medium using two different pH conditions. The specific activities of the enzymes, pyruvate carboxylase (PYC), malate dehydrogenas...

The most important challenges for conversion of lignocellulosic plant biomass into bioproducts are to overcome its recalcitrance and to reduce steps needed for its biorefining. Conventionally, conversion is carried out using pretreatment followed by the hydrolysis of biomass to monomer sugars that are fermented into different bioproducts. Fungi are...

Organically grown green biomass (red clover, clover grass) was investigated as a resource for organic feed and organic fertilizer by combination of proteins extraction and anaerobic digestion of the residues. Extraction of proteins from both crops revealed very favourable amino acid composition for the use as animal feed. The residual 90% of organi...

Aspergillus carbonarius has a potential as a cell factory for production of various organic acids. In this study, the organic acid profile of A. carbonarius was investigated under different cultivation conditions. Moreover, two heterologous genes, pepck and ppc, which encode phosphoenolpyruvate carboxykinase in Actinobacillus succinogenes and phosp...

Difficulties with the supply of organic protein feed; low crop yields and low value of leguminous forage crops and a lack of organic fertilisers are nowadays some of the major challenges faced in organic farming with monogastric animals. Thus, organic farmers are forced to import feed and manure from conventional farms. In order to overcome these c...

Aspergillus carbonarius has potential as a cell factory for the production of different organic acids. At pH 5.5, A.carbonarius accumulates high amounts of gluconic acid when it grows on glucose based medium whereas at low pH, it produces citric acid. The conversion of glucose to gluconic acid is carried out by secretion of the enzyme, glucose oxid...

Unlabelled: Fermentation by filamentous fungi in Erlenmeyer flasks is a favoured method for comparing different fermentation conditions. However, significant inter-flask variation often occurs when using Erlenmeyer flasks, which makes the comparison of fermentation product levels less reliable. We have investigated the use of a 24-well plate metho...

Aspergillus carbonarius accumulates xylitol when it grows on D-xylose. In fungi, D-xylose is reduced to xylitol by the NAD(P)H-dependent xylose reductase (XR). Xylitol is then further oxidized by the NAD(+)-dependent xylitol dehydrogenase (XDH). The cofactor impairment between the XR and XDH can lead to the accumulation of xylitol under oxygen-limi...

We present two novel methods for DNA cloning that have been developed for the rapid construction of vectors used for insertion of genes in filamentous fungi. These two cloning methods are based on the USER (uracil-specific excision reagent) cloning method. The simpleUSER cloning method proposed in this paper varies from USER cloning by substituting...

Profitable biomass conversion processes are highly dependent on the use of efficient enzymes for lignocellulose degradation. Among the cellulose degrading enzymes, beta-glucosidases are essential for efficient hydrolysis of cellulosic biomass as they relieve the inhibition of the cellobiohydrolases and endoglucanases by reducing cellobiose accumula...

The newly discovered fungal species Aspergillus saccharolyticus was found to produce a culture broth rich in β-glucosidase activity. In this present work, the main β-glucosidase of A. saccharolyticus responsible for the efficient hydrolytic activity was identified, isolated, and characterized. Ion exchange chromatography was used to fractionate the...

Volutella colletotrichoides is shown to belong to the Plectosphaerellaceae rather than the Hypocreales where other species of that genus reside. The new genus Lectera is described for V. colletotrichoides, and for a further, previously undescribed species with slightly longer conidia and differences in rDNA ITS and glyc-eraldehyde 3-phosphate dehyd...

β-Glucosidase activity plays an essential role for efficient and complete hydrolysis of lignocellulosic biomass. Direct use of fungal fermentation broths can be cost saving relative to using commercial enzymes for production of biofuels and bioproducts. Through a fungal screening program for β-glucosidase activity, strain AP (CBS 127449, Aspergillu...

Plasmodiophora brassicae is an obligate, biotrophic pathogen causing the club-root disease of crucifers. Despite its importance as a plant pathogen, little is known about P. brassicae at the molecular level as most of its life cycle takes place inside the plant host, and axenic culturing is impossible. Discovery of genes expressed during infection...

Figures that illustrate selected aspects of the main text. Figure S1 provides a phylogeny of Trichoderma NPRSs. Figure S2 compares the numbers of epoxide hydrolase genes in Trichoderma with that in other fungi. Figure S3 compares the codon usage in genes from syntenic and nonsyntenic regions of the genomes of Trichoderma reesei, T. atroviride and T...

Comparative properties and gene inventory of T. reesei, T. virens and T. atroviride. This file contains additional information on genomic properties and selected gene families from the three Trichoderma species comprising 19 tables. Table S1 summarizes the satellite sequences identified in the Trichoderma genomes and four other fungal genomes. Tabl...

Additional information on selected gene groups of Trichoderma, methods used for genome sequencing, and legends for the figures in Additional file 3. Chapter 1: Carbohydrate-Active enzymes (CAZymes). Chapter 2: Aegerolysins and other toxins. Chapter 3: Small secreted cysteine rich proteins (SSCPs). Chapter 4: EST sequencing and analysis. Chapter 5:...

Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus, has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma. Here we report an analysis of the genome sequence...

A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite profiles) and molecular (β-tubulin, internal transc...

Downy mildew is an economically important and widespread disease in quinoa (Chenopodium quinoa) growing areas. Although in many studies Peronospora farinosa is most commonly regarded as the causal agent of the disease, identification and classification of the pathogen remain still uncertain due to its taxonomic confusion. Thirty-six Peronospora iso...

Until now, molecular and biochemical methods have only been used to show whether or not Plasmodiophora brassicae is present in plant or soil samples but not to what extent. Here, in planta quantification of P. brassicae by whole-cell fatty acid (WCFA) measurements and real- time polymerase chain reaction (PCR) was evaluated. Arachidonic acid (ARA,...

To identify rhizobacteria from the Mekong Delta of Vietnam, which can systemically protect watermelon against Didymella bryoniae and elucidate the mechanisms involved in the protection conferred by isolate Pseudomonas aeruginosa 23(1-1). Bacteria were isolated from watermelon roots and their antagonistic ability tested in vitro. Of 190 strains, 68...

In the Andean region of South America downy mildew, caused by Peronospora farinosa, is the most important disease of quinoa (Chenopodium quinoa). Peronospora farinosa, a highly polyphyletic species, occurs on quinoa and wild relatives on all continents. However, very little is known about the geographic diversity of the pathogen. As the interest in...

African and Asian populations of Fusarium spp. (Gibberella fujikuroi species complex) associated with Bakanae of rice (Oryzae sativa L.) were isolated from seeds and characterized with respect to ecology, phylogenetics, pathogenicity and mycotoxin production. Independent of the origin, Fusarium spp. were detected in the different rice seed samples...

The effect of an extract of Yucca schidigera on the control and infection process of the apple scab pathogen, Venturia inaequalis, was examined and compared with the chemical resistance inducer, acibenzolar-S-methyl (ASM). In seedling assays, both materials significantly reduced apple scab symptoms and pathogen sporulation on leaves and both showed...

A protocol involving PCR, shot-gun cloning and sequencing was developed as a pre-diagnostic screening tool working directly on disease symptoms. The method was used to show the presence of biotrophic and non-biotrophic eukaryotic plant pathogens in leaves and fruits.

Although intensively investigated for biological control of insect pests, little is known about the ecology of the fungal entomopathogenic genus Beauveria in natural or agricultural habitats. In this study, we used molecular phylogenetic and genotypic information to infer species diversity, reproductive potential and genetic structure of Beauveria...