Strain Improvement in Filamentious Fungi-An Overview

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Enzyme production in industrial fungi- molecular genetic strategies for integrated strain improvement

Filamentous fungi have an established and central role in the industrial production of enzymes for various applications ranging from animal feed manufacture to pulp bleaching. Filamentous fungi are also of high interest as efficient expression hosts for a wide range of valuable gene products originating from other organisms. Progress aiming at reaching the full potential of filamentous fungi as production hosts depends on better understanding of gene regulation, protein modification, function of the secretory pathway, genetic and physiological aspects related to product fermentation and studies into functional genomics.19 page(s

Metabolic activity in filamentous fungi can be analysed by flow cytometry

The use of flow cytometry in combination with fluorescent dyes as a technique to rapidly differentiate and enumerate bacterial and yeast cells is well established. We have shown that through the judicial choice of stains, the nondestructive screening and sorting of fungal material is possible. The early stages of growth, from germination through hyphal development of three filamentous fungal species, Penicillium, Phoma and Trichoderma, have been followed using forward- and side-angle scatter on a Becton Dickinson FACSCalibur flow cytometer. By staining isolates with the permeant fluorogenic substrates, dihydroethidium and hexidium iodide metabolic activity in the developing hyphae has been measured. We have been able to demonstrate that there is a 12-13 h window of opportunity during which germination and the early stages of hyphal development of filamentous fungi can be analysed by flow cytometry.9 page(s

Effects of Paecilomyces lilacinus protease and chitinase on the eggshell structures and hatching of Meloidogyne javanica juveniles

A serine protease and an enzyme preparation consisting of six chitinases, previously semi-purified from a liquid culture of Paecilomyces lilacinus strain 251, were applied to Meloidogyne javanica eggs to study the effect of the enzymes on eggshell structures. Transmission electron microscopic studies revealed that the protease and chitinases drastically altered the eggshell structures when applied individually or in combination. In the protease-treated eggs, the lipid layer disappeared and the chitin layer was thinner than in the control. The eggs treated with chitinases displayed large vacuoles in the chitin layer, and the vitelline layer was split and had lost its integrity. The major changes in the eggshell structures occurred by the combined effect of P. lilacinus protease and chitinases. The lipid layer was destroyed; the chitin layer hydrolyzed and the vitelline layer had lost integrity. The effect of P. lilacinus protease and chitinase enzymes on the hatching of M. javanica juveniles was also compared with a commercially available bacterial chitinase. The P. lilacinus protease and chitinase enzymes, either individually or in combination, reduced hatching of M. javanica juveniles whereas a commercial bacterial chitinase had an enhancing effect. Some juveniles hatched when the eggs were exposed to a fungal protease and chitinase mixture. We also established that P. lilacinus chitinases retained their activity in the presence of endogenous protease activity.7 page(s

Application of Genetic Engineering for Strain Improvement in Filamentous Fungi

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Mutagenesis of a thermophilic xylanase using a novel gene shuffling technique

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Molecular Biology of Trichoderma and Biotechnological Applications

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Paecilomyces lilacinus strain Bioact251 is not a plant endophyte

Although Paecilomyces lilacinus is generally considered to be both a soil fungus and a nematode-egg parasitic fungus, it has been reported that jt can also colonise roots and protect the root surface from root-knot nematode attack. When eight crop plant species were challenged with P. lilacinus strain Bioact251, fungal hyphae were never detected within roots, though occasionally colonies arose from the root surface. Examination of the behaviour of P. lilacinus hyphae on root and nematode egg surfaces were compared and found to be very different, with P. lilacinus behaving like a parasitic fungus when growing on a nematode egg but not when on a root surface.6 page(s

Integration of protein Interaction and Metabolic Data for Subcellular Localization Prediction

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Fungal proteomics: initial mapping of biological control strain Trichoderma harzianum

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