The depletion of petroleum and other platform chemical resources are a global concern; therefore alternative substrates must be identified to replace these current sources. Thus allowing research in fungal biotechnology to prosper, as filamentous fungi can utilize second-generation feedstocks or agricultural waste to produce these petroleum derived platform chemicals. This research focuses on the ability of filamentous fungi to use different second-generation feedstocks such as wheat bran and sugar cane bagasse to generate platform chemicals of interest, namely being itaconic acid (IA) and other organic acids of interest, such as citric acid. This study focused on the metabolite producing capabilities of Aspergillus terreus, initially in a shake flask fermentation environment and then in an Airlift Bioreactor environment utilizing hydrolyzed wheat bran and sugar cane bagasse as a substrate source to produce metabolites of interest. The initial shake flask fermentation experiment involved inoculation and incubating A. terreus in hydrolyzed wheat bran with additional minerals at 30°C for 5 days at a pH range of between 3-4. The result yielded itaconic acid and citric acid concentrations of 1.01g/l and 6.23g/l at their peaks, respectively. The airlift bioreactor was run for 16 days with a constant pH range between 3-4, at a temperature of 30°C with a dissolved oxygen level of 20g/l. The result of the study yielded a high itaconic acid and citric acid concentration peaking at 59.4 g/l and 59.2 g/l, respectively.

Typescript. / Digitized by Kansas Correctional Industries

Fungi are well-known to produce a tremendous variety of bioactive secondary metabolites which play important roles as pharmaceuticals and agrochemicals. In contrast to random-screening approaches utilized in industry, our research applies ecology-based strategy to the selection of fungi for chemical studies. The research described here involves the chemical investigation of freshwater and fungicolous fungi as producers of novel metabolites with potential practical value. Freshwater fungi, as a distinctive ecological group, have only recently been studied in any depth, and remain underexplored in comparison with other fungal niche groups. Chemical studies of freshwater fungal isolates in our research group have led to the discovery of a variety of new bioactive metabolites, suggesting significant untapped potential among these organisms. Studies in this area described in this thesis led to the discovery of twenty-two new metabolites, many of which display significant antibacterial and/or antifungal activities. Some of these compounds possess novel structural features, such as new ring systems. Mycoparasitic and fungicolous fungi are those that colonize other fungi and could be viewed as potential producers of antifungal agents because of the negative effects they often exert on their hosts. Bioassay-guided fractionation of extracts from cultures of selected mycoparasitic and fungicolous fungal isolates afforded twenty-five new compounds representing diverse structural types. Most of these compounds display biological activity, with some showing antifungal and/or antiinsectan effects. The new secondary metabolites isolated during these studies represent a variety of different biosynthetic classes, including cyclic depsipeptides, nucleosides, polyketides, macrolides, terpenoids, and compounds with mixed biogenetic origin. Their structures were established by analysis of MS and NMR data, chemical degradation or derivatization reactions, and/or X-ray diffraction analysis data. Absolute configuration assignments were achieved by application of different strategies, such as Mosher's method, Marfey's method, or CD spectral analysis. Details of the isolation, structure elucidation, and biological activity of these new compounds are presented in this thesis.

In spite of significant shortcomings among existing clinical antifungal agents, the rate of development of new therapeutics has been sluggish, and the mortality rate caused by fungal diseases has remained almost unchanged. Natural products have provided useful templates for the development of several of the most important therapeutic antifungal agents. In particular, fungi have been rich sources of antifungal natural products, and many fungal species remain chemically underexplored. Our research program has focused on fungicolous and coprophilous fungal niche groups. These types of fungi often show antagonistic effects toward host or competitor fungi—a phenomenon hypothesized to be associated in part with the production of antifungal metabolites. Earlier results reported from our research program have shown that studies of such fungi can be effective approaches to the discovery of new bioactive natural products, including antifungal agents. During our continued efforts to discover new antifungal and antiinsectan natural products, diverse fungal metabolites were obtained from complex fermentation extracts by use of various chromatographic methods. In addition to previously known compounds and simple analogues thereof, structurally interesting new metabolites were encountered. Those isolated from fungicolous fungi include ten new caryophyllene-type sesquiterpenoids from a Pestalotiopsis sp., three of which contain previously undescribed ring systems or new skeletons. The remainder are oxidized analogues of punctaporonins. Seven new polyketide-derived metabolites were obtained from another Pestalotiopsis isolate, in this case, P. disseminata, and two unusual ring systems were identified. A distinctive biosynthetic pathway was proposed for these seven polyketides. Members of another class of polyketides (pyrenocines), which contain pyrone or thiopyran units, were encountered from Penicillium paxilli. One of the three new pyrenocine analogues obtained contains an adenine unit—a rare feature among fungal secondary metabolites. Chemical investigation of another Penicillium sp., P. lanosum, afforded a new fumiquinazoline analogue, as well as a compound previously described in a thesis of a member of our research group. In work described here, the original stereochemical assignment was revised, and the compound was renamed as lanosindole. Metabolites isolated from this fungicolous Penicillium isolate have amino acid origins in common, and two of them showed antiinsectan activity. Seven new polyketide alcohols were obtained from the coprophilous fungus Podospora appendiculata. Two of them contain a tetrahydropyran unit and three are acyclic, differentiating them from other known members of this class. Finally, funiculosin B, an antifungal metabolite of mixed biogenetic origin containing a rare tetrahydroxycyclopentanyl moiety, was isolated from a flower-colonizing isolate of Capnodium sp. The structures of the compounds described above were determined mainly by analysis of NMR and MS data. Synthetic modification, X-ray crystallographic analysis, and ECD data analysis in conjunction with molecular modeling were applied to their stereochemical assignments. The results described in this thesis indicate that fungicolous and coprophilous fungi are prolific producers of new natural products, some of which display activity in assays of medical and agricultural relevance. Although most of the new compounds described here were inactive against pathogenic fungi, the rich diversity of chemistry encountered suggests potential for this ecology-based approach in the discovery of new bioactive natural products.

Pisolithus is an ectomycorrhizal (ECM) fungal genus that exists in native and plantation forests worldwide. Despite many aspects of the genus having been studied over the years, there is limited knowledge of the genetic population structure of Pisolithus spp. The major aim of this study was to begin to elucidate the genetic structure of populations of Pisolithus native to the eastern states of Australia. Initially, the number of species represented in the University of Western Sydney Pisolithus culture collection was investigated using ITS-RFLP and previously developed simple sequence repeat (SSR) markers. From these analyses, two clear groupings emerged with the RFLP groups corresponding to the SSR groups identified. To study genetic population structure, appropriate markers were required and SSR markers were considered to be most suited to this end. The developed SSR markers were successfully used to amplify P. microcarpus and P. albus DNA from ECM root tips and soil samples. Therefore, these markers will be a useful tool for future investigations into the population structure of above and below-ground structures of P. microcarpus and P. albus populations. / Doctor of Philosophy (PhD)

"November 2002" / Includes bibliographical references (leaves 128-153) / xviii, 153 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002

Bibliography: leaves 138-160. The 152 species of mycorrhizal fungi can be difficult to identify and quantify because the taxonomy of these fungi is based on the description of spores, which is time consuming, requires considerable expertise and cannot be assumed to reflect the situation within the root. Few attempts have been made to identify the species which are present in roots. Several approaches have been identified in previous work and the development of sensitive molecular methods for identification and quantification of two species of arbuscular mycorrhizal (AM) fungi are described in this study. Mycorrhizal fungal communities were sampled in both natural and agricultural ecosystems at two sites in South Australia. The combination of spore identification from trap culture and field-collected soil promises to be an effective means to study diversity of AM fungi in a particular system. PCR primers for Glomus mosseae and Gigaspora margarita were designed from the internal transcribed spacer (ITS) sequences of field-collected spores, with the aim of providing tools for field diagnosis.

Graduation date: 1991

Thesis (M.S.)--Southern Oregon University, 2002. / Includes bibliographical references (leaves 37-43). Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.

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