Mucoralean fungi present in soil from arid regions in South Africa
| dc.contributor.advisor | Botha, A. | |
| dc.contributor.advisor | Viljoen, B. C. | |
| dc.contributor.author | Seabi, Buti Oscar | |
| dc.date.accessioned | 2018-04-05T12:10:25Z | |
| dc.date.available | 2018-04-05T12:10:25Z | |
| dc.date.issued | 1999-11 | |
| dc.description.abstract | English: The aim of the first part of the study was to investigate the ecological niche of mucoralean fungi in arid soil, with specific reference to the position these fungi occupy in the biogeochemical cycle of nitrogen. Consequently, selected mucoralean taxa occurring frequently in soil habitats, including strains from culture collections, as well as isolates obtained from a soil sample from arid Upper Nama Karoo, were used to evaluate in vitro growth to determine nitrogen sources and aw tolerances. Nine mucoralean fungal genera including 18 species were examined for the ability to utilise a series of nitrogen containing compounds and to grow at an aw of 0.955 on solid media. The nitrogen concentration in the media was 0.1 g.r1 and the series of nitrogen containing compounds were ammonium chloride, asparagine, sodium glutamate, sodium nitrite and potassium nitrate. The genera were Actinomucor Schostak., Backusella Hesselt. & J.J. Ellis, Cunningha'fnella Matr., GongronelIa Ribaldi, MortierelIa Coem., Mucor Fresen., Rhizomucor Lucet & Costantin., Rhizopus Ehrenb. and Thamnostylum Arx & H. P. Upadhyay. Thirty-nine fungal strains obtained from culture collections (CBS, MUFS and PPRI), as well as 12 soil isolates from the Karoo, were tested. All the species and strains tested in this study were able to utilise asparagine and glutamate. Strains belonging to CunninghamelIa, Mucor racemosus Fresen., Rhizopus microsporus Tiegh. and Rhizopus stolonifer (Ehrenb.: Fr.) VuilI. were unable to utilise ammonium chloride. Strains of CunninghamelIa, MortierelIa, Rhizomucor, Rhizopus microsporus and Rhizopus stolonifer were unable to grow on nitrate as sole nitrogen source. Nitrite was found to be toxic to species belonging to CunninghamelIa, MortierelIa, Rhizomucor, Rhizopus and Thamnostylum. Members of GongronelIa, MortierelIa, Mucor racemosus, Rhizomucor and Thamnostylum were unable to grow at an a, of 0.955. The aim of the second part of the study was firstly to get an indication whether the mucoralean diversity of the Karoo, as observed in the first part of the study and in the records obtainable from literature, differs from data on mucoralean diversity from other arid regions. The latter included data from literature and what could be found in a soil sample taken from Kimberley Thorn Bushveld. Secondly, the aim was to test the isolates obtained from the Kimberley Thorn Bushveld soil sample in order to further explore the ability of mucoralean fungi to utilise the above mentioned series of nitrogen sources and to grow at an a, of 0.955. In addition, selected mucoralean taxa occurring frequently in soil habitats were tested for the ability to survive elevated temperatures in soil. It was found that the following species of the Mucorales may be encountered in the arid soil of the Karoo; Actinomucor elegans, CunninghamelIa echinulata, MortierelIa isabellina, Mucor circinelloides, Rhizomucor species, Rhizopus oryzae Went. Prins. Geerl. and Rhizopus stolonifer. Future surveys would reveal if genera like Absidia, GongronelIa and Zygorrhynchus, which have been isolated from arid regions, also occur in Karoo soil. Representatives of mucoralean taxa occurring in arid Karoo soil were able to utilise organic as well as inorganic oxidised nitrogen sources. However, at the concentration tested in this study, nitrite was found to be toxic to representatives of CunninghamelIa, Mortierell8, Rhizomucor and Rhizopus. Nitrate could not be utilised by CunninghamelIa, MortierelIa, Rhizomucor and Rhizopus stolonifer. Whether this inability to utilise inorganic nitrogen sources would prevail 'during oligotrophic growth in soil, remains a question to be addressed by future research. Representatives of the above mucoralean taxa occurring in arid soil were able to survive 55°C for 14 h in soil. | en_ZA |
| dc.description.abstract | Afrikaans: Afrikaans: Die doel van die eerste gedeelte van hierdie studie was om die ekologiese nis van mucoraliese fungi in droë grond te bestudeer, met spesifieke verwysing na die posisie van hierdie fungi in die biogeochemiese siklus van stikstof. Uitgesoekte mucoraliese taksa wat gereeld in grondhabitatte voorkom, insluitend stamme vanuit kultuurversamelings en isolate verkry uit Ongrondmonster van die droë Boonste Nama-Karoo, is gevolglik gebruik om in vitro groei vas te stel, ten einde stikstofbronne en aw toleransies te bepaal. Nege mucoraliese fungusgenera, wat 18 species insluit, is ondersoek vir hul vermoë om ‘n reeks stikstofbevattende verbindings te benut en by ‘n aw van 0.955 op soliede media te groei. Die stikstofkonsentrasie in die media was 0.1 g.l-1 en die reeks stikstofbevattende verbindings was ammoniumchloried, asparagien, natriumglutamaat, natriumnitriet en kaliumnitraat. Die genera was Actinomucor Schostak., Backusella Hesselt. & J.J. Ellis, CunninghamelIa Matr., GongronelIa Ribaldi, MortierelIa Coem., Mucor Fresen., Rhizomucor Lucet & Costantin., Rhizopus Ehrenb. en Thamnostylum Arx & H. P. Upadhyay. Nege-en-dertig fungusstamme wat uit kultuurversamelings (CBS, MUFS and PPRI) verkry is, asook 12 grondisolate uit die Karoo, is getoets. AI die species en stamme wat in hierdie studie getoets is, kon asparagien en glutamaat benut. Stamme wat tot CunninghamelIa, Mucor racemosus Fresen., Rhizopus microsporus Tiegh. en Rhizopus stolonifer (Ehrenb.: Fr.) Vuill. behoort het, was nie in staat om ammoniumchloried te benut nie. Stamme van CunninghamelIa, MortierelIa, Rhizomucor, Rhizopus microsporus en Rhizopus stolonifer kon nie op nitraat as enigste stikstofbron groei nie. Nitriet is gevind om toksies te wees vir species wat behoort tot CunninghamelIa, MortierelIa, Rhizomucor, Rhizopus en Thamnostylum. Lede van GongronelIa, MortierelIa, Mucor racemosus, Rhizomucor en Thamnostylum kon nie by Ona, van 0.955 groei nie. Die doel van die tweede deel van die studie was eerstens om ‘n aanduiding te kry of die mucoraliese diversiteit van die Karoo, soos waargeneem in die eerste gedeelte van die studie en ook uit verslae wat uit die literatuur beskikbaar is, verskil van data oor mucoraliese diversiteit in ander droë streke. Laasgenoemde sluit data in uit die literatuur en wat gevind kon word in Ongrondmonster wat geneem is in Kimberley Doring-Bosveld. Die doel was tweedens om die isolate wat uit die Kimberley Doring-Bosveld monster verkry is, te toets ten einde die vermoë van mucoralies fungi om die bogenoemde reeks stikstofbronne te benut en by 'n a, van 0.955 te groei verder te ondersoek. Mucoraliese taksa wat dikwels in grondhabitatte voorkom, is verder getoets vir hul vermoë om verhoogde grondtemperature te oorleef. Dit is gevind dat die volgende Mucorales-species in die droë grond van die Karoo aangetref mag word; Actinomucor elegans, CunninghamelIa echinulata, Morlierella isabellina, Mucor circinelloides, Rhizomucor species, Rhizopus oryzae (Went. Prins. Geerl.) en Rhizopus stolonifer. Toekomstige opnames salonthul of genera soos Absidia, GongronelIa en Zygorrhynchus, wat ook uit droë streke geïsoleer is, ook in Karoogrond voorkom. Verteenwoordigers van mucoraliese taksa wat in droë Karoo-grond voorkom, was in staat om organiese asook anorganiese geoksideerde stikstofbronne te benut. Teen die konsentrasie wat in hierdie studie getoets is, is nitriet egter gevind om toksies te wees vir verteenwoordigers van CunninghamelIa, Morlierella, Rhizomucor en Rhizopus. Nitraat kon nie deur CunninghamelIa, Morliere lle, Rhizomucor en Rhizopus stolonifer benut word nie. Of hierdie onvermoë om anorganiese stikstofbronne te benut standhou tydens oligotrofiese groei in grond, is 'n vraag wat deur toekomstige navorsing aangespreek moet word. Verteenwoordigers van bogemelde mucoraliese taksa wat in droë grond voorkom, was in staat om vir 14 h in grond met 'n temperatuur van 55°C te oorleef. | af |
| dc.description.sponsorship | National Research Foundation (NRF) | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/8116 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Mucorales | en_ZA |
| dc.subject | Soil | en_ZA |
| dc.subject | Arid regions | en_ZA |
| dc.subject | Karoo | en_ZA |
| dc.subject | Nitrogen utilisation | en_ZA |
| dc.subject | Fungi | en_ZA |
| dc.subject | Water activity | en_ZA |
| dc.subject | Kimberley Thorn Bushveld | en_ZA |
| dc.subject | Mucorales -- South Africa | en_ZA |
| dc.subject | Soil fungi | en_ZA |
| dc.subject | Nitrogen | en_ZA |
| dc.subject | Dissertation (M.Sc. (Microbiology and Biochemistry))--University of the Free State, 1999 | en_ZA |
| dc.title | Mucoralean fungi present in soil from arid regions in South Africa | en_ZA |
| dc.type | Dissertation | en_ZA |