Obinna A Oje
@funai.edu.ng
Biochemistry / Biological Sciences
Alex Ekwueme Federal University Ndufu Alike
I hold a Ph.D in Environmental Biochemistry and an M.Sc in Industrial BIochemistry
EDUCATION
University of Nigeria
RESEARCH INTERESTS
Industrial Biochemistry, Environmental Biochemistry
Scopus Publications
Scopus Publications
Arinze I. Onwurah, Obinna A. Oje, Victor Okpashi, Angela C. Udebuani, Chidiebere E. Ugwu, and Ikechukwu N. Onwurah
Springer Science and Business Media LLC
Anthony C. Ekennia, Dickson N. Uduagwu, Njemuwa N. Nwaji, Olawale J. Olowu, Obianuju L. Nwanji, Miracle Ejimofor, Christopher U. Sonde, Obinna O. Oje, and David O. Igwe
Informa UK Limited
Abstract We report on biosynthesis of silver nanoparticles using aqueous leaf extract of Euphorbia sanguinea and its photocatalytic degradation of Congo red dye and melanogenesis inhibition activity of mushroom tyrosine enzyme. Surface Plasmon resonance bands obtained from UV-Vis spectra were within the range 430–436 nm. FT-IR studies reveal the presence of functional groups of the plant metabolites used as stabilizing agents of nanoparticles. The shape of silver nanoparticles is spherical with size ranges about 20–28.8 nm as confirmed by SEM. XRD patterns displayed well-defined crystalline peaks corresponding to the face-centred cubic structures of metallic silver nanoparticles. The results of photocatalysis showed high photocatalytic efficiency of 86% and 90% within 5 min and 60 min, respectively at a rate of solar radiation of in the degradation of Congo red dye. The AgNPs gave dose dependent melanogenesis inhibition activity with IC50 of 71.96 µg/ml, showing non competitive mode of inhibition. Highlights Rapid formation of silver nanoparticles using 0.5 mL extract of Euphorbia sanguinea. AgNPs are spherical, monodispersed and with sizes in the range of 20–29 nm. High photocatalytic efficiency of 86% was obtained within 5 min of solar radiation of AgNPs in the degradation experiment of Congo red dye. First order kinetics with a correlation coefficient of 0.9472 and a rate of 0.0063 min−1 was established for the photocatalytic process. AgNPs showed dose dependent melanogenesis inhibition activity of IC50 71.96 µg/ml .
Israel Godwin Nwovu, Ike Oluka, Omaka N. Omaka, and Obinna A. Oje
Springer Science and Business Media LLC
Anthony Ekennia, Dickson Uduagwu, Olawale Olowu, Obianuju Nwanji, Obinna Oje, Blessing Daniel, Sandra Mgbii, and Chimerem Emma-Uba
Elsevier BV
Anthony C. Ekennia, Dickson N. Uduagwu, Njemuwa N. Nwaji, Obinna O. Oje, Chimerem O. Emma-Uba, Sandra I. Mgbii, Olawale J. Olowo, and Obianuju L. Nwanji
Springer Science and Business Media LLC
Azubuike Peter Ebokaiwe, Omaka Ndukaku Omaka, Uchechukwu Okorie, Obinna Oje, Chima Egedeigwe, Amobi Ekwe, and Nnaemeka Joshua Nnaji
Informa UK Limited
ABSTRACT This study investigated changes in kidney, liver and erythrocyte of male rats after exposure to ground water samples collected in the studied areas and treated water sample. Results reveal high levels of heavy metals in water from studied areas and a concomitant accumulation of metals in liver, kidney and blood of rats. Heavy metal contaminated underground water (HMCUW) caused a significant increase in levels of malondialdehyde (MDA) and decreased activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), including glutathione (GSH) levels. Principal component analysis implicated geogenic and anthropogenic factors for underground water contamination by heavy metals in the areas. However, activities of gamma-glutamyl transferase (γ-GT), 51 nucleotidase (51NT), glutathione peroxidase (GSH-Px), and myeloperoxidase (MPO) significantly increased in kidney, liver and erythrocytes of rats compared with control group (p < 0.001). We observed significant (p < 0.001) increase in serum electrolytes, urea and creatinine levels compared to control. Heavy metals in HMCUW are above ambient levels and possess significant decrease in triiodothyronine (T3) and thyroxine (T4) levels. Histology revealed alterations in architecture of the kidney and liver. Prolonged exposure to HMCUW could induce oxidative damage in kidney, liver and erythrocyte which could elicit liver and kidney dysfunctions.
A. D. Okenyi, C. S. Ubani, O. A. Oje, and I. N. E. Onwurah
Springer Science and Business Media LLC
Obinna A. Oje, Victor E. Okpashi, Jane C. Uzor, Ugochukwu O. Uma, Anthony O. Irogbolu, and Ikechukwu N.E. Onwurah
Science Alert
This study was designed to determine the effect of acid and alkaline pretreatment of rice husk on the production of biosurfactant using Mucor indicus. Rice husk was pretreated at 120°C in a mineral nutrient medium at variable pH of 2, 7 and 12. The media were adjusted to pH7 after pretreatment to provide suitable environmental pH for microbial growth. Mucor indicus isolated from the rice husk dump site was used to inoculate the pretreated rice rusk media and the set-up was allowed to stand for 28 days with intermittent shaking. At the expiration of 28 days, the broth was filtered and centrifuged to remove all suspended cells. The cell free broth was collected for the extraction of biosurfactant using a mixture of chloroform/methanol at ratio 2:1 (mixture/broth). The results revealed that the biosurfactants yield were 0.59±0.078, 0.40±0.042 and 0.78±0.050 g in 100 mL of broth for pH 2, 7 and 12 pretreated rice husk, respectively. The biosurfactants produced showed highest emulsification index for automotive gas oil and lowest for premium motor spirit. The results also suggested that the biosurfactants produced have glycolipids properties. Therefore, it will be correct to suggest that for the conversion of rice husk into useful material such as biosurfactant, the heat pretreatment should be carried out at an alkaline pH.
Obinna A. Oje, Arinze L. Ezugwu, Chibuike S. Ubani, Izunna F. Agbazue, and Ikechukwu N.E. Onwurah
Science Alert
This study was aimed at the production of cellulase from the degradation of rice husk using a fungi species isolated from rice husk dump site. Rice husk was pre-treated at 120°C in a mineral nutrient medium at different pH 2, 7 and 12. After the pre-treatment the pH of the different media was adjusted to 7 which was suitable for microbial growth. Mucor indicus isolated from the rice husk dump site was inoculated into the pre-treated husk media and the set-up was allowed to stand for 28 days with periodic shaking. At the expiration of the 28 days, the broth was filtered and centrifuged at 4000 rpm for 20 min to remove all cell suspension. Cellulase was isolated using 90% ammonium sulfate saturation. The yield of cellulase produced were 14.81, 13.43 and 26.74% with specific activity 1.415, 23.237 and 15.524 m mgG for pH 2, 7 and 12, respectively. After gel filtration the yield of cellulase produced was 0.71, 6.01 and 12.10% with specific activity of 0.114, 22.365 and 19.320 m mgG for pH 2, 7 and 12, respectively. The Vmax of crude cellulase produced were 0.81, 2.10 and 2.84 μmol minG while the Km were 46.30, 42.21 and 47.72 mg mLG 1 for pH 2, 7 and 12, respectively. The Vmax: Km ratio were 0.0176, 0.0497 and 0.0594 mL mgG 1 for pH 2, 7 and 12, respectively, which showed that the cellulase produced at pH 12 will be more efficient in the hydrolysis of cellulose to glucose. This was also demonstrated by the catalytic efficiency of the enzyme at pH 12 (3.57×10G). The result also showed that cellulase extracted from rice husk pretreated at pH 12 possesses high catalytic efficiency when compared with other pHs.
Obinna A. Oje, Peter N. Uzoegwu, Ikechukwu N. E. Onwurah, and Uchechukwu U. Nwodo
Springer Science and Business Media LLC