Fungus Gloeophyllum trabeum (Agaricomytes: Gloeophyllates) is a brown rot wood-decay fungus which produces a vast spectrum of volatile secondary metabolites. Scientific publications state, that one of the metabolites produced by G. trabeum, can be the substance (3Z,6Z,8E)-dodecatrien-1-ol. This chemical substance is also the main component of trail-following pheromone of Rhinotermitidae termite family. In this diploma thesis, I was trying to verify whether various species of G. trabeum are in fact capable of producing the substance (3Z,6Z,8E)-dodecatrien-1-ol. I was also focusing on the effects of saccharides, present in nutrient solutions, on quantitative and qualitative change in composition of volatile secondary metabolites produced by G. trabeum. The saccharides I used for my research were - maltose, fructose, sucrose, xylose, and mannose. The analysis was made by using comprehensive two-dimensional gas chromatography separation technique with time-of-flight mass spectrometric detection (GC×GC-TOFMS). During my research I discovered that one of obtained species of G. trabeum can produce substance (3Z,6Z,8E)-dodecatrien-1-ol, but only under specific conditions. It is produced when cultivating on Petri dishes on agar - cellulose growth media. The measurement was further validated by...

In dieser Arbeit werden die nanoskaligen Partikel von Magnesiumfluorid (MgF2) und Calciumfluorid (CaF2), die als Nano-Metallfluoride (NMFs) bekannt sind, auf ihr Potenzial zur Verbesserung der Beständigkeit von Holz-basierten Materialien untersucht. Ihre besondere Eigenschaft der geringen Wasserlöslichkeit ist Grundlage dafür, einen langanhaltenden Schutz des behandelten Holzes aufrechtzuerhalten, indem die Auslaugung von Fluorid reduziert wird. Die Partikelgröße der synthetisierten NMFs und ihre Verteilung in behandelten Holzproben wurde charakterisiert. Rasterelektronenemikroskopaufnahmen und der zugehörigen energiedispersiven Röntgenspektroskopie zeigen, dass Aggregate dieser Partikel eine homogene verteilung in der untersuchten Holzmatrix von behandelten Proben. Die Fluoridaggregate bilden eine Schutzschicht um die Zellwände und blockieren deren Hoftüpfel, dadurch ist der mögliche Fließweg für die Wasseraufnahme ins Holz eingeschränkt. Dies zeigt sich in erhöhter Hydrophobie des mit Nano-Metallfluorid (NMF)-behandelten Holzproben. Die biozide Wirkung der NMFs wurde gegen Braunfäulepilzen (Coniophora puteana und Rhodonia placenta), am Weißfäulepilz (Trametes versicolor) und den Termiten (Coptotermes formosanus) geprüft. Im Vergleich zu unbehandelten Proben weist das mit Fluorid behandelte Holz eine höhere Beständigkeit gegen Fäulnis und Termitenfraß auf. Obwohl alle NMF-Behandlungen den durch Fäulnis verursachten Masseverlust des Holzes reduzieren, zeigt nur eine kombinierte Behandlung mit MgF2 and CaF2 eine höhere Wirksamkeit gegen Fäulnis und Termitenfraß auf. Die Ergebnisse dieser Arbeit zeigen, dass NMFs robust genug sind für Anwendungen im Freien mit Bodenkontakt. Darüber hinaus stellen sie aufgrund ihrer sehr schlechten Wasserlöslichkeit ein geringeres Risiko für die menschliche Gesundheit und Umwelt dar. Die neuartigen Ergebnisse dieser Arbeit zeigen das Potenzial von NMFs, die Lebensdauer von Baumaterialien aus nicht haltbarem Holz zu erhöhen. / In this study, nanoscopic particles of magnesium fluoride (MgF2) and calcium fluoride (CaF2) also known as nano metal fluorides (NMFs), were evaluated for their potential to improve wood durability. Their distinct property of low-water solubility is proposed to maintain long-lasting protection of treated wood by reducing the leaching of fluoride. Analytical methods were used to characterize the synthesized NMFs and their distribution in treated wood specimens. In nano metal fluoride (NMF) treated specimens, aggregates of these particles are uniformly distributed in the wood matrix as confirmed with scanning electron microscopy images and their corresponding energy-dispersive X-ray spectroscopy maps. The fluoride aggregates form a protective layer around the tracheid walls and block the bordered pits, thus reducing the possible flow path for water absorption into wood. This is reflected in the increased hydrophobicity of NMF treated wood. The biocidal efficacy of NMFs was tested against brown-rot fungi (Coniophora puteana and Rhodonia placenta), white-rot fungus (Trametes versicolor), and termites (Coptotermes formosanus). Compared to untreated specimens, the NMF treated specimens have a higher resistance to decay caused by brown-rot fungi, white-rot fungus, and termites. Although all NMF treatments in wood reduce the mass loss caused by fungal decay and termite attack, only the combined treatment of MgF2 and CaF2 has efficacy against brown-rot fungi and white-rot fungus. Similarly, wood treated with the combined NMF formulation is the least susceptible to attack by C. formosanus. In this thesis, it was proven that NMFs are robust enough for above ground contact outdoor applications of wood in permanent wetness conditions. Also, they pose a low risk to human health and the environment because they are sparingly soluble. Overall, the novel results of this study show the potential of NMFs to increase the service life of building materials made from non-durable wood.

Hierdie studie ondersoek vrae rondom die aard van literêre niefiksie - ook die vierde genre genoem. Die bestaande drieledige genreklassifikasiesisteem maak nie voldoende voorsiening vir tekste waarin die grense tussen feit en fiksie opgehef word nie. Die toename van sodanige hibriede tekste noodsaak dus ‘n uitbreiding van tradisionele genrekategorieë tot ‘n vierde, naamlik dié van literêre niefiksie. Dié ondersoek poog om vrae rondom literêre niefiksie te beantwoord met verwysing na De plaag: het stille knagen van schrijvers, termieten en Zuid-Afrika (2001) van David van Reybrouck. Dié teks dokumenteer Van Reybrouck se ondersoek na die bewering dat Maurice Maeterlinck die termietnavorsing van Eugène Marais sonder erkenning oorgeneem het. Tydens sy navorsingsreis maak Van Reybrouck kennis met die verwikkeldhede van ‘n postapartheid Suid-Afrika en verwoord sy reiservaring met behulp van metafore uit die entomologie. Die resultaat is dat De plaag ‘n hibriede karakter vertoon wat versoenbaar is met die kriteria vir literêr-niefiksionele tekste. / This study attempts to explore the nature of literary nonfiction (the fourth genre). The existing tripartite classification system does not make adequate provision for texts where the borders between nonfiction and fiction are transcended. A marked increase in such texts therefore necessitates an expansion of the traditional genre categories to accommodate a fourth, namely that of literary nonfiction. De plaag: het stille knagen van schrijvers, termieten en Zuid-Afrika (2001) by David van Reybrouck will serve as point of departure to explore the genre of literary nonfiction. The said text documents Van Reybrouck’s investigation into the alleged plagiarism by Maeterlinck of Marais’ research on termites. Van Reybrouck’s travels expose him to the complexities of a post-apartheid South Africa, which he expresses by using metaphors derived from the field of entomology. The result of this process is that De plaag displays a hybrid character which complies with the criteria for literary nonfiction. / Afrikaans and Theory of Literature / M.A. (Afrikaans)

Hierdie studie ondersoek vrae rondom die aard van literêre niefiksie - ook die vierde genre genoem. Die bestaande drieledige genreklassifikasiesisteem maak nie voldoende voorsiening vir tekste waarin die grense tussen feit en fiksie opgehef word nie. Die toename van sodanige hibriede tekste noodsaak dus ‘n uitbreiding van tradisionele genrekategorieë tot ‘n vierde, naamlik dié van literêre niefiksie. Dié ondersoek poog om vrae rondom literêre niefiksie te beantwoord met verwysing na De plaag: het stille knagen van schrijvers, termieten en Zuid-Afrika (2001) van David van Reybrouck. Dié teks dokumenteer Van Reybrouck se ondersoek na die bewering dat Maurice Maeterlinck die termietnavorsing van Eugène Marais sonder erkenning oorgeneem het. Tydens sy navorsingsreis maak Van Reybrouck kennis met die verwikkeldhede van ‘n postapartheid Suid-Afrika en verwoord sy reiservaring met behulp van metafore uit die entomologie. Die resultaat is dat De plaag ‘n hibriede karakter vertoon wat versoenbaar is met die kriteria vir literêr-niefiksionele tekste. / This study attempts to explore the nature of literary nonfiction (the fourth genre). The existing tripartite classification system does not make adequate provision for texts where the borders between nonfiction and fiction are transcended. A marked increase in such texts therefore necessitates an expansion of the traditional genre categories to accommodate a fourth, namely that of literary nonfiction. De plaag: het stille knagen van schrijvers, termieten en Zuid-Afrika (2001) by David van Reybrouck will serve as point of departure to explore the genre of literary nonfiction. The said text documents Van Reybrouck’s investigation into the alleged plagiarism by Maeterlinck of Marais’ research on termites. Van Reybrouck’s travels expose him to the complexities of a post-apartheid South Africa, which he expresses by using metaphors derived from the field of entomology. The result of this process is that De plaag displays a hybrid character which complies with the criteria for literary nonfiction. / Afrikaans and Theory of Literature / M.A. (Afrikaans)