As the initiative for establishing a yeast culture collection began in the early 1980âs in
the department of Microbial, Biochemical and Food Biotechnology, research pertaining
to the identification of isolates became the main focus. Yeasts such as Candida
shehatae and Pichia stipitis claimed potential applications in the fermentation industry
and received the most research attention. This research area and others reflected the
potential of the culture collection as one of the sources of microbial diversity. As a
result, this granted this culture collection a Microbial Resources Centre by the United
Nations Educational, Scientific and Cultural Organization (UNESCO) in 1996. Isolation,
preservation, identification and determination of taxanomic affinities of yeasts are some
of the important aspects of this culture collection in addition to others such as
bioprospecting and elucidation of biotechnological applications of strains. As a general
practice, these isolates must be identified reliably and rapidly using techniques such as
polymerase chain reaction (PCR) and sequencing of the ribosomal DNA.
Polymerase chain reaction (PCR) and sequenceing of the ribosomal DNA was mainly
used in this study to identify isolates present in the UNESCO-MIRCEN Biotechnological
Yeast Culture Collection. Ribosomal DNA was amplified and sequenced, followed by
analysis of sequence data that was searched against available sequences on National
Center for Biotechnology Information (http://www.ncbi.nlm.nih.gov/). In the case of new
species, verification of novelty was performed by sequencing the internal transcribed
spacers and doing phylogenetic analysis based on multigenic approach. New species were assigned to their phylogenetic groups and described using standardized traditional
techniques.
It was apparent from this study that using molecular identification methods, the number
of identified ascomycetes and basidiomycetes as well as yeast-like taxa, with possible
applications in the industrial, clinical, pharmaceutical, environmental and agricultural
settings can be rapidly identified in great numbers. In this study, three basidiomycete
strains representing new species in the genus Cryptococcus, with potential applications
in cyanide bioremediation, were identified and described. These strains represent a new
species which form part of a small group of yeasts (including Cryptococcus humicolus
strain) with the ability to utilize inorganic cyanide as sole carbon and nitrogen source.
Some of the applications and importance of strains representing known ascomycetes,
basidiomycetes and yeast-like taxa are also highlighted here. Not only was the
identification of isolates achieved in this study, but also full description of new yeasts
present in the UNESCO-MIRCEN Biotechnological Yeast Culture Collection with
possible applications in bioremediation. However, the applications of species such as
Trichosporon africanensis sp. nov. will be elucidated elsewhere.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-10192011-122707 |
| Date | 19 October 2011 |
| Creators | Eric, Motaung Thabiso |
| Contributors | Prof JLF Kock, Prof J Albertyn, Dr C-H Pohl-Albertyn |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-10192011-122707/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0091 seconds