Browsing by Author "Popoola Temitope"

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    Biosynthesis of Ascorbic Acid by Aspergillus Flavus and Aspergillus Tamarii Immobilized in Afzelia Africana Matrix.
    (Food and Applied Bioscience Journal, 2018) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Akinloye Oluseyi Adeboye; Popoola Temitope
    A novel matrix for the immobilization of ascorbic acid produced by Aspergillus flavus and Aspergillus tamarii was reported. Spores of A. flavus and A. tamarii were immobilized on Afzelia africana matrix cross-linked with glutaraldehyde (2.5%) and the effects of Afzelia africana gel concentration (9–13%), spore load (100–500 mg/100 ml), bead size (2–7 mm) and bead number (2–10) on ascorbic acid yield were determined. The immobilized fungi were cultured in a liquid fermentation medium containing BSG (0.6% w/v) for ascorbic acid production for 144 h. The ascorbic acid produced was quantified titrimetrically. The statistical analysis of the effects of gel concentration, spore load and bead size on ascorbic acid production showed no significant difference at p>0.05. However, there was significant difference in the effect of bead number on ascorbic acid production at p<0.05. Ascorbic acid yield of 8.5 g/L and 7.5 g/L was produced by Aspergillus tamarii and Aspergillus flavus respectively using 9 beads at 96 h of fermentation. The immobilized Aspergillus tamarii and Aspergillus flavus retained activities of 72% and 70% respectively after five repeated cycle and also exhibited increased activities over the free cells. This study shows the potential of Afzelia africana as a novel matrix for enhanced ascorbic acid production.
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    Microbial Production of Ascorbic Acid from Brewery Spent Grain (BSG) by Aspergillus flavus and Aspergillus tamarii
    (Food and Applied Bioscience Journal, 2018) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Popoola Temitope; Akinloye Oluseyi Adeboye
    This study evaluated the use of Brewery Spent Grain (BSG) as a novel substrate for the production of ascorbic acid using Aspergillus flavus and Aspergillus tamarii. Spores of Aspergillus flavus and Aspergillus tamarii were cultured in a liquid fermentation medium containing BSG (0.6% w/v) for ascorbic acid production. The process was studied at pH 4–8, temperature range 30–45°C, agitation speed range 60–160 rpm for 168 h. Stability studies and the effects of Ethylenediaminetetraacetic Acid (0.5–4.0 g/ml) on ascorbic acid production were studied. Ascorbic acid produced was quantified by titration techniques and with High Performance Liquid Chromatography (HPLC). The statistical analysis of the effects of temperature and agitation speed on ascorbic acid production showed no significant difference at p<0.05. However, there was significant difference in the effect of pH on ascorbic acid production at p<0.05. Optimum ascorbic acid yields of 7.25 g/L and 6.25 g/L were produced by A. tamarii and A. flavus respectively at pH 5.0, temperature (40°C) and agitation speed of 100 rpm at 96 h of fermentation. High Performance Liquid Chromatography (HPLC) showed that 6.248 g/L and 7.246 g/L of ascorbic acid were produced by A. flavus and A. tamarii, respectively. Ascorbic acid production by A. flavus and A. tamarii was completely inhibited at 4 g/ml of EDTA. This study shows the potential of BSG as a novel substrate for ascorbic acid production.
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    Optimization and production of ascorbic acid by fusant cell of Aspergillus flavus and Aspergillus tamarii
    (Journal of King Saud University – Science, 2019) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Akinduti Akinniyi Paul; Popoola Temitope; Akinloye Oluseyi Adeboye
    Ascorbic acid is an essential vitamin for the optimal growth of most animals including humans. The complexity and expensive nature of ascorbic acid production necessitates the development of a relatively simple and cost-effective method for its production. Hence, this study explored the potential of a somatic hybrid (fusant cell) of Aspergillus flavus and Aspergillus tamarii for enhanced production of ascorbic acid. Optimization studies of the ascorbic acid fermentation processes were performed at pH range of 4–8, temperature range of 30–45 C and agitation speed range 60–160 rpm for 96 h of fermentation. Quantification of the ascorbic acid produced was done titrimetrically. There was significant difference (P < 0.05) in the ascorbic acid production of the fusant cell and the parental cells. The ascorbic acid produced by the somatic hybrid was 8.85 g/L compared to its parental strains (3.92 g/L and 4.57 g/L). However, pH, temperature and agitation speed had no significant effects (P > 0.05) on ascorbic acid production. The study revealed that maximal ascorbic acid production of 9.95 g/L was obtained at pH 5.0, temperature 40 C and agitation speed of 100 rpm at 96 h of fermentation. This study shows the potential of fusant cell for enhanced ascorbic acid production.