Browsing by Author "Ademakinwa, Adedeji Nelson"
Now showing 1 - 14 of 14
Results Per Page
Sort Options
Item Biochemical and biophysical characterisation of a small purified lipase from Rhizopus oryzae ZAC3(Taylor and Francis Online, 2021-02-08) Ayinla, Zainab Adenike; Ademakinwa, Adedeji Nelson; Gross, Richard A.; Agboola, Femi K.The characteristics of a purified lipase from Rhizopus oryzae ZAC3 (RoL-ZAC3) were investigated. RoL-ZAC3, a 15.8 kDa protein, which was optimally active at pH 8 and 55 °C had a half-life of 126 min at 60 °C. The kinetic parameters using p-nitrophenylbutyrate as substrate were 0.19 ± 0.02 mM, 126 ± 5.6 U/ml and 122 s−1 for Km , V max and k cat respectively. RoL-ZAC3 showed stability in methanol and isopropanol with Na+ enhancing the activity. p-nitrophenyloleate and castor oil were the best preferred substrates among the p-nitrophenyl esters and vegetable oils tested respectively. About 43% residual activity was observed after incubation for 30 min at 75 °C. Circular dichroism thermal scan showed that the lipase displayed intense negative ellipticities even at high temperature. Perturbation of the tertiary structure with increasing temperature caused the exposure of hydrophobic side chains to the aqueous environment as revealed by tryptophan fluorescence, with a t−Tm of 50 °C. Differential scanning calorimetry analysis showed melting temperature and calorimetric enthalpy of 55.5 °C and 444 kJ/mol respectively. Dynamic light scattering analysis indicated that the lipase was prone to aggregation upon unfolding at high temperature. It can be concluded that RoL-ZAC3 possesses promising potential for numerous biotechnological applications.Item Biodegradation of cyanide in cassava wastewater using a novel thermodynamically-stable immobilized rhodanese(Taylor and Francis Online, 2020-11-18) Ademakinwa, Adedeji Nelson; Agunbiade, Mayowa Oladele; Fagbohun, OladapoExtracellular rhodanese obtained from Aureobasidium pullulans was employed in both free and immobilized forms for the biodegradation of cyanide present in cassava processing mill effluent (CPME). Crosslinking with glutaraldehyde (at an optimum concentration of 5% v/v) before entrapment in alginate beads resulted in the highest immobilization yield of 94.5% and reduced enzyme leakage of 1.8%. Rhodanese immobilized by cross-linking before entrapment (cbe) retained about 46% of its initial activity after eight cycles of catalysis compared to the entrapment in alginate alone (eaa) which lost more than 79% after the fifth catalytic cycle. A cross-examination of thermodynamic (DG d, DS d, DH d) kinetic (kd, t1=2, D and z values) parameters at 30–70 C showed that cbe displayed a higher resistance to thermal inactivation when compared to the free enzyme (fe) and (eaa). The efficiency of cyanide biodegradation from the CPME by the fe, eaa and cbe were 55, 62, and 74% respectively after 6 h. Biodegradation of cyanide using the cbe was monitored using FTIR spectroscopy. Rhodanese immobilized via cbe had a higher resistance to thermal denaturation over other enzyme forms. Hence, this makes cbe adaptable for large-scale detoxification of cyanide from CPME.Item Bioremediation of textile dye solutions, textile dye mixtures and textile effluents by laccase from Aureobasidium pullulans (de Bary) G. Arnaud (1918) (Fungi: Ascomycota)(Brazilian Journal of Biological Sciences, 2015-12-15) Ademakinwa, Adedeji Nelson; Agboola, Femi KayodeThe environmental impact of textile waste water is detrimental to all living species in such habitat and hence there is the need to seek novel bioremediation alternative means to alleviate the effect of these dyes on aquatic life. This study investigated the potentials of Aureobasidium pullulans (de Bary) G. Arnaud (1918) (Fungi: Ascomycota) in bioremediation of waste water through its production of laccase. Both the fungi and its secreted laccase (crude and purified) were used to decolorize textile dyes, textile dye mixtures and textile waste-water effluent. A. pullulans laccase was able to decolorize malachite green (79.9%), allura red (57.5%), tartrazine (21.5%) and methylene blue (4.5%) after 2 h of incubation. The crude A. pullulans laccase was able to decolorize the textile waste water up to 35% after 3 h incubation and it was able to decolorize the blue + green + red dye mixtures more specifically. The purified laccase was able to specifically decolorize malachite green. The fungi was able to absorb the textile dyes when it was inoculated into a laccase culture medium containing the dyes or textile waste water effluent. There was approximately 91% decolorization of malachite green, 71% decolorization of allura red, 23% methylene blue and 38% tartazine after three day incubation A. pullulans when inoculated into the textile water effluent was able to decolorize the textile waste water effluent up to 80% after 5 days of incubation. Manganese peroxidase played additional role in the decolorization as it was detected in the crude filtrate (1.2 units/mL/min) but no lignin peroxidase activity was detected. It can be deduced that A. pullulans is a potential fungi useful for bioremediation of textile waste-water polluted environment.Item Fungal α-amylase entrapped in agar-agar organic matrix “beads” enhances fabric starch-desizing potentials and α-amylase-detergent compatibility(Research Square, 2021-08-05) Ademakinwa, Adedeji Nelson; Ayinla, Zainab Adenike; Agboola, Femi KayodeAureobasidium pullulans α-amylase (ApAmy) mixed with melted agar-agar solution and drop-wisely added to a mixture of organic solvent solution allowed for the entrapment of the α-amylase in the agaragar organic matrix as beads. The immobilized ApAmy’s characteristics and wash performance were elucidated in comparison with the soluble ApAmy. Agar-agar at 2.0 % (w/v) and toluene: chloroform at 3:1 resulted in the highest immobilization yield retaining about 98% residual activity after ten catalytic cycles. The optimum temperature and pH for the immobilized enzyme were 60ºC and 6.5 respectively. The immobilized ApAmy hydrolysed branched and linear substrates thus establishing its broad substrate specificity. Relatively, the immobilized ApAmy (iApAmy) was more tolerant to organic solvents than the free enzyme. The iApAmy was mildly inhibited by cobalt but metals such as zinc, manganese, calcium and sodium enhanced the free and immobilized ApAmy activity. The iApAmy had a higher washing efficiency (77%) in the presence of detergents than the free enzyme (68%) and control (36%). The iApAmy showed good potentials as a detergent additive and from its characteristics, it could be useful in other industrial applications.Item Kinetic and thermodynamic investigations of cell-wall degrading enzymes produced by Aureobasidium pullulans via induction with orange peels: application in lycopene extraction(Taylor and Francis Online, 2019-08-09) Ademakinwa, Adedeji Nelson; Agboola, Femi KayodeThe production of cell-wall degrading enzymes (CWDE) such as cellulase and pectinase by Aureobasidium pullulans NAC8 through induction using orange peels was investigated for the potential application of these enzymes in the extraction of lycopene from tomato skin, waste, and paste (SWP). The CWDE was then immobilized via entrapment in alginate beads for lycopene extraction and the kinetic/thermodynamic properties of the free and immobilized CWDE investigated. The optimum production of CWDE occurred at pH, temperature, and orange peel concentration of 6.0, 50 C, and 2.0% (w/v), respectively. The values obtained for some kinetic and thermodynamic parameters such as E d; t1=2; DG d; and DH d indicate that both free and immobilized cellulase and pectinase were thermostable between 40 and 50 C. Maximum lycopene extracted from the tomato SWP was 80 ± 2.4 mg/kg, 42 ± 1.3 mg/kg and 60 ± 1.2 mg/kg, respectively, using the immobilized CWDE. The entrapped CWDE was able to extract lycopene with yields of 58 ± 4.2, 51 ± 1.2 and 57 ± 4.2% for tomato SWP respectively after the fifth cycle. Using orange peels for the induction of CWDE by A. pullulans offers a unique and cheaper approach to obtaining thermostable multi-enzyme complexes employable for easy lycopene extraction from tomato SWP.Item Laccase immobilization via cross-linked aggregate preparation: Characterization, thermodynamic/kinetic properties and application in removal of bisphenol A from solutions(Springer, 2021-03) Ademakinwa, Adedeji NelsonFungal laccase from Aureobasidium pullulans was immobilized via cross-linked enzyme aggregate (CLEA) preparation under statistically optimized conditions. The stability of the CLEA to heat inactivation was studied via investigation of its thermodynamic and kinetic parameters. The immobilized enzyme was then deployed in the biodegradation of a bisphenol-A (BPA). The optimum conditions for CLEA preparation resulting in the highest immobilization yield were ammonium sulphate (60% v/v), glutaraldehyde (30 mM), pH (4.5), time (6 h) and temperature (55ºC). The CLEA retained about 51% of its activity after eight catalytic cycles. The optimum pH and temperature of the laccase CLEA were 5.5 and 60ºC respectively. The SEM indicated that the laccase CLEA was type II (unstructured). The data obtained from the heat inactivation kinetics and thermodynamic characterization indicated that the CLEA was stable to heat denaturation than the free enzyme. The kinetic parameters obtained for the CLEA with ABTS as substrate were 101.3 µM, 2.94 µmols-1mg-1 and 0.03 dm3s-1mg-1 for the Km, Kcat and Kcat/Km respectively. The optimum conditions for BPA biodegradation using the CLEA were temperature (55ºC), time (2 h), CLEA (1.0 mg) and BPA concentration (40 mg/L). After the 7th cycle, laccase CLEA retained about 63 ± 2.3% biodegradation efficiency. A heat-resistant laccase CLEA was able to remove BPA from solutions under statistically optimized conditions. The laccase CLEA has properties for other futuristic applications.Item Marine Actinobacteria Bioflocculant: A Storehouse of Unique Biotechnological Resources for Wastewater Treatment and Other Applications(MDPI, 2020-10-30) Awolusi, Oluyemi Olatunji; Ademakinwa, Adedeji Nelson; Ojo, Abidemi; Erasmus, Mariana; Bux, Faizal; Agunbiade, Mayowa OladeleThe bioactive compounds produced by actinobacteria have played a major role in antimicrobials, bioremediation, biofuels, enzymes, and anti-cancer activities. Biodegradable microbial flocculants have been produced by bacteria, algae, and fungi. Microbial bioflocculants have also attracted biotechnology importance over chemical flocculants as a result of degradability and environmentally friendly attributes they possess. Though, freshwater actinobacteria flocculants have been explored in bioflocculation. Yet, there is a paucity of information on the application of actinobacteria flocculants isolated from the marine environment. Similarly, marine habitats that supported the biodiversity of actinobacteria strains in the field of biotechnology have been underexplored in bioflocculation. Hence, this review reiterates the need to optimize culture conditions and other parameters that a ect bioflocculant production by using a response surface model or artificial neural network.Item Partial Purification and Characterization of Cellulolytic Enzyme from Bacillus pantothenticus Isolated from a Dumpsite(Research & Reviews: Journal of Microbiology and Biotechnology, 2017-04-27) Quadri, Hafsat Omolabake; Ademakinwa, Adedeji Nelson; Adejumo, Ayoade Lateef; Agboola, Femi KayodeCellulose hydrolyzing organism, Bacillus pantothenticus, was isolated from a dumpsite soil. Partial purification of the enzyme with precipitation with 60% chilled acetone and on Biogel P-100 gel filtration yielded an enzyme with specific activity of 253.50, 10.40% yield and purification fold of 2.41. The apparent Km and Vmax for Carboxymethylcellulose (CMC) hydrolysis was 1.167 mg/ml and 0.833 μg of glucose/ml/min respectively. The native molecular weight of the enzyme from B. pantothenticus was estimated as 51.48 kDa. The cellulase produced showed activity over broad range of temperature (30-70°C) with maximum activity at 60°C. The enzyme also showed activity in a wide pH range of 4-11 with optimum activity at pH 4.5. At concentration of 10 mM, KCl, MgCl2, NaCl and NiCl2 inhibited the enzyme while CoCl2 activated the enzyme. The enzyme showed highest activity with microcrystalline cellulose as substrate followed by CMC. Significant activity was also observed with organic substrates such as sugarcane bagasse, orange bagasse and corn cub. The study concluded that the cellulose enzyme obtained had suitable catalytic properties for use in biodegradation of waste and other industrial applications.Item Production of Laccase by Auerobasidium Pullulans and Cladosporium Werneckii under Optimized Conditions: Applications in Decolourization of Textile Dyes.(RESEARCH AND REVIEWS: JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY, 2014-06-30) Ademakinwa, Adedeji Nelson; Agboola, Femi KayodeTextile dye waste-water presents an enormous task in its disposal. This present study aims to identify fungus capable of producing extracellular laccases that under optimized conditions can decolourize textile dyes. Auerobasidium pullulans and Cladosporium werneckii isolated from soil and decayed wood respectively were identified as laccase producing fungi. Physiological conditions for maximal laccase production were investigated. The fungal biomass was determined to correlate laccase production and its growth. The optimized culture broth was used in decolourization of several textile dyes. A. pullulans had maximum laccase activity of 19.18 U/ml on the ninth day of incubation; it utilized glucose, maximum laccase activity was observed at 37 ˚C and pH 6.0 whereas C. werneckii preferred galactose, produced maximum activity of 1.53 U/ml on the twelfth day, had optimum activity at 30 ˚C and pH 5.0. Both fungal isolates preferred tryptophan as nitrogen source and utilized inoculum size of 24 mm and 0.3 mM of CuSO4 for optimal laccase production. A. pullulans laccase is constitutive whereas C. werneckii is inducible. The increase or decrease in laccase activity is in direct proportion to the rate of fungal growth. Optimized culture broth from A. pullulans and C. werneckii had 1.25 and 2.03 fold increase in laccase activity respectively and they were both able to decolourize malachite green specifically i. e 73% and 35% and had least decolourizing abilities on methylene blue in the absence of inducers and after three hours of incubation. The ability of these newly isolated fungal strains to produce laccase extracellularlly and also decolourize dyes would serve as a way to eliminate industrial textile waste water.Item Properties of Rhodanese from the Liver of Tilapia Oreochromis Niloticus, in Asejire Lake, Nigeria(Academic Journals, 2014-02-20) ATERE, TOPE GAFAR; Agboola, Femi Kayode; Ademakinwa, Adedeji NelsonThe study investigates the purification and characterisation of rhodanese from the liver of the tilapia fish (Oreochromis niloticus) collected from Asejire Lake in Nigeria. This was with a view to understanding the biochemical basis of the survival of the fish in cyanide polluted water. Rhodanese was isolated and purified from liver tissue homogenate of tilapia using CM-Sephadex ion exchange chromatography and Sephadex G-75 gel filtration. The specific activity of the enzyme was 56.86 U/mg. The Km values for KCN and Na2S2O3 as substrates were 0.1240 ± 0.0021 mM and 0.0516 ± 0.0097 mM, respectively. The apparent molecular weight was estimated by gel filtration on a Sephacyl S-400 column to be 35,460 Da. The optimal activity was found at pH 6.5 and the temperature optimum was 40°C. The rhodanese enzyme showed that the activity of the enzyme was not affected by MgCl2, KCl, NH4Cl, MnCl2 and CaCl2 while AlCl3, inhibited the enzyme.Item Purification and biochemical characterization of a β-cyanoalanine synthase expressed in germinating seeds of Sorghum bicolor (L.) moench(De Gruyter : Turkish Journal of Biochemistry, 2018-02-06) Amiola, Ruth Ololade; Ademakinwa, Adedeji Nelson; Ayinla, Zainab Adenike; Ezima, Esther Nkechi; Agboola, Femi KayodeBackground: β-Cyanoalanine synthase plays essential roles in germinating seeds, such as in cyanide homeostasis. Methods: β-Cyanoalanine synthase was isolated from sorghum seeds, purified using chromatographic techniques and its biochemical and catalytic properties were determined. Results: The purified enzyme had a yield of 61.74% and specific activity of 577.50 nmol H2S/min/mg of protein. The apparent and subunit molecular weight for purified β-cyanoalanine synthase were 58.26 ± 2.41 kDa and 63.4 kDa, respectively. The kinetic parameters with sodium cyanide as substrate were 0.67 ± 0.08 mM, 17.60 ± 0.50 nmol H2S/mL/min, 2.97 × 10−1 s−1 and 4.43 × 102 M−1 s−1 for KM, Vmax, kcat and kcat/KM, respectively. With L-cysteine as substrate, the kinetic parameters were 2.64 ± 0.37 mM, 63.41 ± 4.04 nmol H2S/mL/min, 10.71 × 10−1 s−1 and 4.06 × 102 M−1 s−1 for KM, Vmax, kcat and kcat/KM, respectively. The optimum temperature and pH for activity were 35°C and 8.5, respectively. The enzyme retained more than half of its activity at 40°C. Inhibitors such as HgCl2, EDTA, glycine and iodoacetamide reduced enzyme activity. Conclusion: The biochemical properties of β-cyanoalanine synthase in germinating sorghum seeds highlights its roles in maintaining cyanide homeostasisItem Some biochemical, catalytic, thermodynamic and kinetic properties of purified fructosyltransferase from wild and improved mutant-type Aureobasidium pullulans NAC8(Taylor and Francis Online, 2019-09-15) Ademakinwa, Adedeji Nelson; Agboola, Femi KayodeA low molecular weight intracellular and extracellular fructosyltransferase was purified from the wild (Wt) and improved mutant-type (Mt) Aureobasidium pullulans and its characteristics and thermodynamic properties determined. The Wt had been previously genetically modified by chemical mutagenesis. The purified fructosyltransferases from the Wt and Mt had subunit molecular weights between 13.4 and 17.0 kDa, respectively. The pH of the purified fructosyltransferase from the Wt and Mt were within 4.0–5.5. From the KM values, the fructosyltransferase from Mt showed higher affinity for sucrose than Wt fructosyltransferase. The optimum temperature obtained for the Mt intracellular and extracellular fructosyltransferase were 80 and 70 C, respectively, while the Wt extracellular and intracellular fructosyltransferase was 60 C. Most metals enhanced fructosyltransferase activity in a concentration-dependent manner except for mercury. Triton X-100 and Tween-80 enhanced the fructosyltransferase activity. Organic solvents such as acetone, ethanol, methanol, toluene and dichloromethane enhanced the enzyme activity while dimethylformamide inhibited the enzyme. From the thermodynamic and kinetic parameters (t1=2, DH , DS , DG Þ Mt fructosyltransferase was more stable to thermal inactivation than the Wt fructosyltransferase. Hence, it can be concluded that, after strain improvement of the Wt, the purified Mt fructosyltransferase was more stable to organic solvents, surfactants, and thermal denaturation, etc. compared to the Wt. This makes Mt fructosyltransferase more useful mostly in the food industry than the Wt.Item Strain improvement and statistical optimization as a combined strategy for improving fructosyltransferase production by Aureobasidium pullulans NAC8(Elsevier, 2017-07-04) Ademakinwa, Adedeji Nelson; Ayinla, Zainab Adenike; Agboola, Femi KayodeStrain improvement of a low fructosyltransferase-producing Aureobasidium pullulans NAC8 (Accession No. KX023301) was carried out using chemical mutagens such as ethidium bromide and ethyl methane sulfonate. The wild-type and mutant strain were distinguished using Random amplified polymorphic DNA PCR and DNA fingerprinting analysis. Plackett-Burman and Box Behnken design were statistical tools used to determine important media parameters and optimization, respectively. Phenotypically and genetically, the new improved strain was different from the wild-type. The most important media parameters from PDB influencing fructosyltransferase production were ammonium chloride, sucrose and yeast extract at p<0.05. Some significant parameters obtained with the BBD exhibited quadratic effects on FTase. The F values (35.37 and 32.11), correlation coefficient (0.98 and 0.97) and the percent coefficient of variation (2.53% and 2.40%) were obtained for extracellular and intracellular FTase respectively. The validation of the model in the improved strain resulted in an overall 6.0 and 2.0-fold increase in extracellular and intracellular FTase respectively compared to the wild-type. A relatively low FTase-producing strain of Aureobasidium pullulans NAC8 was enhanced for optimum production using a two-pronged approach involving mutagenesis and statistical optimization. The improved mutant strain also had remarkable biotechnological properties that make it a suitable alternative than the wild-typeItem Studies on the Optimization of Lipase Production by Rhizopus sp. ZAC3 Isolated from the Contaminated Soil of a Palm Oil Processing Shed(Journal of Applied Biology & Biotechnology, 2017-03-20) Ayinla, Zainab Adenike; Ademakinwa, Adedeji Nelson; Agboola, Femi KayodeThis study investigated the screening, production and optimization of an extracellular lipase from a fungus isolated from the contaminated soil of a palm oil processing shed. This was with a view to obtaining a strain that can secrete lipase with biochemical properties exploitable for biotechnological applications such as bioremediation of oil contaminated sites. Soil samples were collected from palm oil contaminated sites in Gbogan, Osun State, Nigeria (Latitude N 7°29.1481´ and Longitude E 4°20.7587´). The isolated fungal strains were screened on tributyrin agar for exogenous lipolytic activity. Molecular identification was carried out by amplifications of ITS-1, 5.8S and ITS-2 regions. The effects of incubation time, inducers, pH, temperature, carbon and nitrogen sources were varied for optimal lipase production using one factor at a time approach. Rhizopus oryzae ZAC3 (NCBI accession No: KX035094) was identified as the highest lipase-producing strain. Maximum lipase production was observed on the fourth day, pH 5.0 and a temperature of 45 oC. Olive oil, xylose and yeast extract were the best inducer, carbon and nitrogen sources respectively for lipase production. There was a 2.02 fold increase in lipase production under these optimized conditions. In conclusion, Rhizopus oryzae ZAC3 lipase has properties exploitable for industrial and biotechnological applications