Browsing by Author "Kareem Sarafadeen Olateju"

Now showing 1 - 12 of 12
  • Thumbnail Image
    Item
    Ascorbic Acid Production by Aspergillus flavus and Aspergillus tamarii; Kinetic and Thermodynamic Study
    (Springer, 2020) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Adeogun Abideen Idowu
    This study investigated the fermentation kinetics and thermodynamics of ascorbic acid production from Brewery Spent Grain (BSG) using Aspergillus flavus and Aspergillus tamarii. Ascorbic acid fermentation of A. flavus and A. tamarii was performed at a temperature of 30 °C, agitation speed of 100 rpm and pH 5.0 at 96 h of fermentation. The thermodynamics, kinetics of the growth parameters and ascorbic acid production were studied using Monod, Contois and Teisser models. Teisser model gave the best fit as it obtained the highest maximum specific growth rate (μmax) and correlation coefficient of 0.184 h−1 and 0.997, respectively, at 40 °C, pH 5.0 and 0.6 g of BSG. The result showed that Teisser model gave a better description of each growth parameter. Hence, the production of ascorbic acid by A. flavus and A. tamarii is growth-associated.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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; 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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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; Temitope Popoola; 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.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Optimization of Biodiesel Production from Spent Cooking Oil by Fungal Lipase Using Response Surface Methodology
    (Nigerian Journal of Biotechnology, 2018) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Adio Olayinka Quadri; Osho Michael Bamitale; Omeike Sunday Osaizua
    This study evaluated the potential of optimizing Spent Cooking Oil (SCO) transesterification for biodiesel production using Response Surface Methodology (RSM). Potential biodiesel yield from transesterification was optimized using a three-level four factor Response Surface Central Composite Design (RSCCD) with methanol oil ratio (1:1 to 3:1), temperature range 35-45 °C, agitation speed range 100-200 rpm and enzyme load 10-20%. Biodiesel properties including fatty acid methyl ester (FAME), Flash Point (FP), Pour Point (PP) and kinematic viscosity were compared with American (ASTM D6751) and European Union (EN 14214) standards. Biodiesel production was optimum at 3:1 methanol to oil ratio, temperature of 35 °C, agitation speed of 150 rpm and 20% enzyme load. 9-octadecanoic acid hydroxyl methyl ester (33.83%) was the prominent FAME produced, while the viscosity (6 mm2/s), density (893 kg/m3), FP (260 °C) and PP (- 0.5 °C) all met both American and European standards. This study showed that RSM is a viable methodology which could be used for optimization of biodiesel production from biological sources.
  • Thumbnail Image
    Item
    Optimization of Biodiesel Production from Spent Cooking Oil by Fungal Lipase Using Response Surface Methodology
    (Nigerian Journal of Biotechnology, 2018) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Adio Olayinka Quadri; Osho Michael Bamitale; Omeike Sunday Osaizua
    transesterification for biodiesel production using Response Surface Methodology (RSM). Potential biodiesel yield from transesterification was optimized using a three-level four factor Response Surface Central Composite Design (RSCCD) with methanol oil ratio (1:1 to 3:1), temperature range 35-45 °C, agitation speed range 100-200 rpm and enzyme load 10-20%. Biodiesel properties including fatty acid methyl ester (FAME), Flash Point (FP), Pour Point (PP) and kinematic viscosity were compared with American (ASTM D6751) and European Union (EN 14214) standards. Biodiesel production was optimum at 3:1 methanol to oil ratio, temperature of 35 °C, agitation speed of 150 rpm and 20% enzyme load. 9-octadecanoic acid-hydroxyl methyl ester (33.83%) was the prominent FAME produced, while the viscosity (6 mm2/s), density (893 kg/m3), FP (260 °C) and PP (- 0.5 °C) all met both American and European standards. This study showed that RSM is a viable methodology which could be used for optimization of biodiesel production from biological sources.
  • Thumbnail Image
    Item
    Production and characterization of amylase by mixed cultures of Aspergilllus flavus and Aspergillus tamarii
    (Biokemistri, 2014) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Akpan Inyang
    This study evaluated the potentials of mixed cultures of Aspergillus flavus and A. tamarii used for enhanced amylase production. Amylase producing moulds were screened from the soil by plating on Remazol Brillant Blue-Starch agar. Out of the 800moulds screened, studies were conducted on amylase production of monocultures and mixed cultures of non-aflatoxigenic Aspergillus flavus(A) and Aspergillus tamarii(C) by growing them on rice bran solid media at 30°C for 72h. The synergy between the two moulds was pronounced at 70°C and pH 6.0, 7.0 where the enzyme activity of the mixed culture(E) was 2.5times higher than that of the monocultures. Storage stability with Cassava starch and Soyabean flour showed that the maximal enzyme stability of 95% was obtained with 3% (w/v) of Cassava starch at 4°C while 96% enzyme stability was achieved with 4% (w/v) Soyabean flour at 30°C over a period of 8weeks. Thin Layer Chromatography of starch hydrolysates showed a mixture of glucose and maltose from extracts of A with only maltose from C suggesting that A produced glucoamylase and α- amylase while C produced only α-amylase. This study shows that extracts of the mixed cultures contain enzyme complex that can be of high importance in the starch industry.
  • Thumbnail Image
    Item
    Production Of Ascorbic Acid By Blastoschizomyces spp and Kluyveromyces marxianus From Corn Straw Waste Using Submerged Fermentation
    (Crawford Journal of Natural & Applied Sciences, 2019) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Omisore A. E.
    Corn Straw Waste (CSW) as a novel substrate for the production of ascorbic acid by yeasts using submerged fermentation. Cells of Blastoschizomyces spp and Kluyveromyces marxianus were cultured in a liquid fermentation medium containing CSW (0.6 % w/v) for ascorbic acid production. Optimization studies of the ascorbic acid fermentation process was carried out at pH range 4 - 8, temperature range 30 - 45 °C, agitation speed range 50 - 200 rpm for 120 h. Ascorbic acid produced was quantified by titration using 2, 6-Dichlorophenol Indophenol (DCPIP) dye. The statistical analysis of the effects of different concentrations of carbon and nitrogen sources, pH, temperature and agitation speed on ascorbic acid production showed no significant difference at p<0.05. Optimum ascorbic acid yields of 6.5 g/L and 5.5 g/L were produced by Blastoschizomyces spp and Kluyveromyces marxianus respectively at pH 5, temperature (35 °C) and agitation speed of 100 rpm at 120 h of fermentation. This study shows the potential of Corn straw waste as a novel and economical substrate for ascorbic acid production.
  • Thumbnail Image
    Item
    Simultaneous Production of Glucose and Ascorbic Acid from Cassava Starch by Mixed Culture of Aspergilllus Flavus and Aspergillus Tamarii
    (Nigerian Journal of Microbiology, 2016) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Omemu Adebukunola Mobolaji; Akpan Inyang
    The study evaluated simultaneous production of glucose and ascorbic acid from cassava starch by fungal amylases of Aspergillus flavus and Aspergillus tamarii grown on rice bran solid medium at 30oC for 72 h. Partially purified amylase of Aspergillus flavus (A), Aspergillus tamarii (C), and partially purified amylase extracted from the mixed cultures of A. flavus and A. tamarii (B), hydrolyzed cooked cassava starch to glucose optimally at 70oC, pH 6.0 with 90%, 70% and 85% conversion efficiency respectively. On the contrary, bioconversion of cassava starch by enzyme extracts of the three cultures A, B, and C to ascorbic acid occurred mainly at 65oC, pH 4.5. Enzyme extracts of A and C converted cooked cassava starch to ascorbic acid in a two-step reaction at 65oC, pH 4.5 after 6 h of fermentation to yield 15 mg/ml and 25 mg/ml ascorbic acid respectively. The synergy between Aspergillus flavus and Aspergillus tamarii in the mixed culture resulted in an increased ascorbic acid production of 43 mg/ml at 6 h. Glucose production was inversely proportional to ascorbic acid production indicating a direct conversion of glucose to ascorbic acid by enzyme extracts of Aspergillus flavus, Aspergillus tamarii and mixed cultures of A. flavus and A. tamarii. This shows that enzyme of the mixed cultures contain enzyme complex that can be useful in the direct conversion of cassava starch to ascorbic acid
  • Thumbnail Image
    Item
    Strain improvement of Aspergillus flavus for enhanced ascorbic acid production by physical and chemical mutagenesis
    (Nigerian Journal of Biotechnology, 2018) Banjo Temitope Temitayo; Kareem Sarafadeen Olateju; Banjo Temitope Oluwabunmi; Abayomi O. S.
    The demand for ascorbic acid in the food and pharmaceutical industry led to the search for hyper ascorbic acid producing strains by physical and chemical mutagenesis. Spores of Aspergillus flavus were subjected to Ultraviolet (UV) radiation (240 nm) and Ethidium Bromide (EB) (25, 50, 75 and 100 μg/ml) to develop hyper-producing mutants. The selected mutants were cultured in a liquid fermentation medium containing Brewery Spent Grain (0.6 % w/v) at pH range 4 - 8, temperature range 30 - 45 °C, agitation speed range 60 - 160 rpm for 96 h. Ascorbic acid produced was quantified by titration techniques and with High Performance Liquid Chromatography (HPLC). The UV and EB mutant strains of A. flavus gave increased ascorbic acid yields of 6.99 g/L and 7.28 g/L respectively when compared to the parental strain with ascorbic acid yield of 3.92 g/L. Optimum ascorbic acid yields were produced at 40 °C, pH 5.0 and 100 rpm at 96 h of fermentation. This study shows the potential of strain improvement for enhanced ascorbic acid production.