Show simple item record  

dc.contributor.authorJurgens, Joel Allanen_NZ
dc.date.accessioned2010-02-16T20:33:04Z
dc.date.available2010-02-16T20:33:04Z
dc.date.issued2010en_NZ
dc.identifier.citationJurgens, J. A. (2010). Fungal biodiversity in extreme environments and wood degradation potential (Thesis). The University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/3576en
dc.identifier.urihttps://hdl.handle.net/10289/3576
dc.description.abstractThis doctoral thesis reports results from a multidisciplinary investigation of fungi from extreme locations, focusing on one of the driest and thermally broad regions of the world, the Taklimakan Desert, with comparisons to polar region deserts. Additionally, the capability of select fungal isolates to decay lignocellulosic substrates and produce degradative related enzymes at various temperatures was demonstrated. The Taklimakan Desert is located in the western portion of the People's Republic of China, a region of extremes dominated by both limited precipitation, less than 25 mm of rain annually and tremendous temperature variation. The organisms that inhabit this region are required to function in conditions that preclude most forms of life. Fungi are particularly interesting organisms for consideration of life in extreme environments since they absorb nutrients from their surroundings with diffusion taking place through the cell wall and plasma membrane requiring free water. The regions near the poles are another example of areas with extreme environmental conditions, with the north and south polar regions having similarities and differences to each other and to the Taklimakan Desert. All three regions experiences extreme cold but only the Taklimakan Desert has exceedingly warm temperatures. The Taklimakan Desert is diurnal and the polar regions have long periods of light and dark in summer and winter months, respectively. The annual precipitation in the specific polar sites is between 100-200 mm, 5-20 fold more than the Taklimakan Desert. From soil, rock and wood collected in the Taklimakan Desert, 194 independent fungal isolates were generated and identified based on extracted DNA and analysis of the internal transcribed spacer (ITS) region of the rDNA. Dominant taxa were from closely related Thielavia, Embellisia and Alternaria genera. Total DNA extracted directly from environmental samples and subjected to molecular fingerprinting identified 51 consensus sequences almost entirely of taxa not represented by culturing, with the dominant taxa in the Penicillium and Colletotrichum genera. The sequence data from the Taklimakan Desert cultured fungi were phylogenetically investigated by means of neighbor-joining analysis and compared to fungal sequences derived from various substrates collected at sites in Antarctica and the Arctic with wood as the common substrate from which isolates were obtained among all three locations. Based on comparisons of consensus sequences to the polar fungi and fungal databases, 72 isolates appear to represent novel taxa that may be endemic to the Taklimakan Desert and warrant further investigation. Selected fungal isolates from the Taklimakan Desert, Arctic and Antarctic research were investigated to determine and compare their ability to degrade two types of lignocellulose substrates, Pinus resinosa and Populus tremuloides, the latter being a genera of tree identified in some locations of the Taklimakan Desert and the former as a model softwood example. Fungi from all regions were able to degrade these substrates to varying degrees though minimal weight loss was common. These isolates did not produce cellulase or lignin peroxidase concurrent to the temperatures prevalent in the regions from which they were collected, posing interesting possibilities for their wood degradation pathways.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherThe University of Waikatoen_NZ
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectfungien_NZ
dc.subjectdeserten_NZ
dc.subjectTaklimakan Deserten_NZ
dc.subjectpolar regionsen_NZ
dc.subjectlignocellulosicen_NZ
dc.subjectdecayen_NZ
dc.subjectThielavia sp.en_NZ
dc.titleFungal biodiversity in extreme environments and wood degradation potentialen_NZ
dc.typeThesisen_NZ
thesis.degree.disciplineScience and Engineeringen_NZ
thesis.degree.grantorUniversity of Waikatoen_NZ
thesis.degree.levelDoctoral
uow.date.accession2010-01-22T14:11:07Zen_NZ
uow.identifier.adthttp://adt.waikato.ac.nz/public/adt-uow20100122.141107
pubs.place-of-publicationHamilton, New Zealanden_NZ


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record