Browsing by Author "Chike I. C. Ogbonna"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Growth assessment and amylase production by Aspergillus niger and A. terreus isolated from soils of Artemisia annua l. Plantation
    (European Journal of Biotechnology and Bioscience, 2015) Abigail I. Ogbonna; Isaac A. Onyimba; Aleruchi Chuku; Patience O. Nwadiaro; Chike I. C. Ogbonna; Festus C. Onwuliri
    Fungi associated with soils of decomposing Artemisia annua L. process waste in an A. annua Plantation were studied. Two of the isolates, A. niger and A. terreus which had high frequencies of occurrence were assessed for their growth rates over an incubation period of 168hrs using Czapek Dox and Sabouraud Dextrose Agar media. Their abilities to produce glucoamylase of biotechnological importance using submerged fermentation (SmF) were studied. The two isolates grown in basal medium containing starch as sole source of carbon and were harvested at 24 hour intervals over a period of 168hours. A. niger and A. terreus were found to have colony diameters of 5.2cm and 5cm after the 7th day of incubation. The highest glucoamylase potential at pH 5.03 was demonstrated by A. terreus, with peak enzyme activity of 0.375mmol-L while that of A. niger was 0.281mmol-L on the 6th day of incubation. These two fungal species could be useful in the degradation of biological wastes.
  • No Thumbnail Available
    Item
    OCCURRENCE OF POTENTIALLY HAZARDOUS FUNGI IN EXPOSED BREWERY SPENT SORGHUM GRAINS
    (European scientific journal, 2014-03) Isaac A. Onyimba; Chike I. C. Ogbonna; Chukwu, O. O. Chukwu; Collins C. E. Odu
    Samples of environmentally exposed spent sorghum grains (SSG), commonly used as feedstuff in Nigeria, were obtained from the Jos International Brewery and screened for potentially harzardous fungi associated with them. A total of three samples, one per week, were used in the study. Truly colonizing fungi of the SSG were further determined by assessing the abilities of the fungal isolates to grow on specially formulated spent sorghum grain agar (SSGA). Fourteen fungal species belonging to nine genera were isolated from the SSG. Frequently occurring fungi included Aspergillus niger (89%), A. fumigatus (56%), A. flavus (78%), Rhizopus, oryzae (78%) and R. stolonifer (56%). The genus Aspergillus had the highest number of species (28.6%) among the isolates. The true fungal colonizers of SSG were found to include A. flavus, A. fumigatus, A. niger, A. ochraceus, Curvularia lunata, Geotrichum candidum, Humicola grisea, Penicillium sp, R. oryzae, R. stolonifer and Trichoderma harzianum. Among the fungal isolates were species that have been known to contain either pathogenic or toxigenic strains. The findings from the experiments showed that exposed SSG can be colonized by potentially hazardous fungi and as such, caution should be exercised in its use as a feedstuff.