acta satech Journal of the Life & Physical Sciences Babcock

Fungal diversity and antagonistic interactions of Stachybotrys chartarum In Soils within Babcock University
*1 Ezekiel C. N., 2 C. C. Nwangburuka , 3 C. P. Anokwuru , 1 F. A. Adesioye, 1 O. B. Olaoye & 1 N. C. Okonkwo
1 Department of Biosciences & Biotechnology, 2 Department of Agriculture & Industrial Technology, 3Department of Chemical & Environmental Sciences, Babcock University, Ilisan –Remo. Ogun State, Nigeria.

Soil samples from 10 randomly selected locations within Babcock University were characterized based on texture and their fungal species diversity determined. The antagonistic activity of one of the isolates, Stachybotrys chartarum, was also studied using the diffusible metabolite bioassay method. The soils are composed mainly of sand particles and ranged from sandy through sandy-clay to the loamy-sand texture with varying pH values ranging from 5.91 to 7.56. The moisture contents of the soils ranged from 2.5% (lowest) to 12.3% (highest). Mycological analyses of the soils revealed a total of 57 isolates belonging to 14 identified genera while 9 isolates were unidentified. The identified genera are Aspergillus, Penicillium, Curvularia, Chaetomium, Fusarium, Rhizopus, Trichothecium, Trichoderma, Verticillium, Phoma, Stachybotrys, Cladosporium, Alternaria and Mucor. The Horticultural Garden soil (BUHG) emerged as the community with the highest species richness (10 species) while soils around the University Cafeteria (BUCF) were the least (3 species) with diversity index value (H’) of 2.209 and 1.001, respectively. S. chartarum liberated diffusible metabolite with antagonistic activity against all tested isolates except Clad. cladosporioides (HG3) and A. niger (SQ1). The Maximum Antagonistic Rate (MAR) (mm/day) was highest for A. flavus (MC2) with a value of 1.10 but least for P. shaze (SQ2) at 0.87, as both MARs were reached within 6 d. This is the first report of P. shaze occurrence in Nigerian soil.
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