Mucoralean fungi present in soil from arid regions in South Africa

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 indicatio
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
National Research Foundation (NRF)