Charles O . Nwuche | University of Nigeria, Nsukka (original) (raw)

Papers by Charles O . Nwuche

Research paper thumbnail of Recent advances in biotechnological valorization of agro-food wastes (AFW): Optimizing integrated approaches for sustainable biorefinery and circular bioeconomy

Bioresource technology reports, Jun 1, 2024

Research paper thumbnail of Bioremediation of pharmaceutical waste waters

Research paper thumbnail of Biological elements as important tools in the detection/monitoring of drug compounds in organic and environmental samples

Research paper thumbnail of Production, Partial Purification, and Characterization of Lipase from <i>Aspergillus niger</i> and Its Application in Treatment of Vegetable Oil Effluent

Chemical and biomolecular engineering, 2022

Research paper thumbnail of Micro and nanoplastics ravaging our agroecosystem: A review of occurrence, fate, ecological impacts, detection, remediation, and prospects

Research paper thumbnail of Animal Waste: An Environmentally Sustainable Management Approach

Climate Changes Mitigation and Sustainable Bioenergy Harvest Through Animal Waste, 2023

Research paper thumbnail of Silicon-based nanoparticles for mitigating the effect of potentially toxic elements and plant stress in agroecosystems: A sustainable pathway towards food security

Science of The Total Environment

Due to their size, flexibility, biocompatibility, large surface area, and variable functionality ... more Due to their size, flexibility, biocompatibility, large surface area, and variable functionality nanoparticles have enormous industrial, agricultural, pharmaceutical and biotechnological applications. This has led to their widespread use in various fields. The advancement of knowledge in this field of research has altered our way of life from medicine to agriculture. One of the rungs of this revolution, which has somewhat reduced the harmful consequences, is nanotechnology. A helpful ingredient for plants, silicon (Si), is well-known for its preventive properties under adverse environmental conditions. Several studies have shown how biogenic silica helps plants recover from biotic and abiotic stressors. The majority of research have demonstrated the benefits of siliconbased nanoparticles (Si-NPs) for plant growth and development, particularly under stressful environments. In order to minimize the release of brine, heavy metals, and radioactive chemicals into water, remove metals, nonmetals, and radioactive components, and purify water, silica has also been used in environmental remediation. Potentially toxic elements (PTEs) have become a huge threat to food security through their negative impact on agroecosystem. Si-NPs have the potentials to remove PTEs from agroecosystem and promote food security via the promotion of plant growth and development. In this review, we have outlined the various sources and ecotoxicological consequences of PTEs in agroecosystems. The potentials of Si-NPs in mitigating PTEs were extensively discussed and other applications of Si-NPs in agriculture to foster food security were also highlighted.

Research paper thumbnail of Silicon-based nanoparticles for mitigating the effect of potentially toxic elements and plant stress in agroecosystems: A sustainable pathway towards food security

Science of The Total Environment, 2023

Due to their size, flexibility, biocompatibility, large surface area, and variable functionality ... more Due to their size, flexibility, biocompatibility, large surface area, and variable functionality nanoparticles have
enormous industrial, agricultural, pharmaceutical and biotechnological applications. This has led to their
widespread use in various fields. The advancement of knowledge in this field of research has altered our way of
life from medicine to agriculture. One of the rungs of this revolution, which has somewhat reduced the harmful
consequences, is nanotechnology. A helpful ingredient for plants, silicon (Si), is well-known for its preventive
properties under adverse environmental conditions. Several studies have shown how biogenic silica helps plants
recover from biotic and abiotic stressors. The majority of research have demonstrated the benefits of siliconbased nanoparticles (Si-NPs) for plant growth and development, particularly under stressful environments. In
order to minimize the release of brine, heavy metals, and radioactive chemicals into water, remove metals, nonmetals, and radioactive components, and purify water, silica has also been used in environmental remediation.
Potentially toxic elements (PTEs) have become a huge threat to food security through their negative impact on
agroecosystem. Si-NPs have the potentials to remove PTEs from agroecosystem and promote food security via the
promotion of plant growth and development. In this review, we have outlined the various sources and ecotoxicological consequences of PTEs in agroecosystems. The potentials of Si-NPs in mitigating PTEs were extensively
discussed and other applications of Si-NPs in agriculture to foster food security were also highlighted.

Research paper thumbnail of Biogas from Manure: The Future of Renewable Natural Gas and Its Implications

Climate Changes Mitigation and Sustainable Bioenergy Harvest Through Animal Waste, 2023

Research paper thumbnail of Transfer of Multidrug Resistance among Bacteria Isolated from Industrial Wastes

Bio-Research, 2011

Objectives: Sewage effluent from the sewage treatment plant of the University of Nigeria, Nsukka,... more Objectives: Sewage effluent from the sewage treatment plant of the University of Nigeria, Nsukka, was analyzed for the presence of metal and non-metal ions and for the presence of metal tolerant and drug resistant bacteria. Methods: Plasmid mediation of metal tolerance and multiple drug resistance was demonstrated by sodium dodecyl sulphate (SDS) curing and direct cell transfer experiments. Results: Ions found present (in mgL-1) include, among others, Mercury (50.148), Lead (41.906), Sodium (907.240), and Potassium (700.00). Bacterial populations isolated from the effluent were members of the genera Enterobacter (n = 15), Escherichia (n = 18), Achromobacter (n = 18), Acinetobacter (n = 25) Klebsiella (n = 12), Pseudomonas (n = 08), Proteus (n = 20) and Serratia (n = 10). Enterobacter spp showed high percentage tolerance of 73% to Lead. Species of Acinetobacter and Pseudomonas showed, to varying degrees, across-the-board tolerance to all the individual salts. Also an across-the-board resistance of between 25-75% and 8.3-41.7% to the test drugs was exhibited by Pseudomonas and Klebsiella spp respectively. Sixty per cent each of Acinetobacter and Klebsiella spp lost both metal tolerance and drug resistance attributes simultaneously following the SDS curing protocol. Overall percentage loss of both characteristics was 57.1%. Acquisition of metal tolerance and multidrug resistance by recipients was total (100%) and so was the subsequent loss of these capabilities following SDS treatment of these recipients. Discussion: The public health hazard derivable from these findings is discussed.

Research paper thumbnail of Amylase Production by Aspergillus niger immobilized in Microporous Calcium Alginate Gel Beads

Romanian Biotechnological Letters, 2021

Microporous calcium alginate gel beads were investigated as potential solutions to mass transfer ... more Microporous calcium alginate gel beads were investigated as potential solutions to mass transfer limitations in immobilized cultures. The beads were prepared by gelling mixtures of sodium alginate and fillers (starch or granulated sugars) in calcium chloride solution. The resulting beads were cured in the same solution, during which the fillers leached out of the beads thereby creating micro-pores in the beads (microporous beads). The effectiveness of the microporous beads in improving amylase production by Aspergillus niger LC 269109 was investigated. Spores of A. niger were immobilized in the microporous beads and used for batch alpha amylase and gluco amylase production. Amylase production by the A. niger immobilized in the microporous beads were significantly higher (p<0.01) than the values obtained with the conventional calcium alginate gel beads. Under all the conditions investigated, gluco-amylase activities were significantly (p<0.01) higher than the alpha-amylase acti...

Research paper thumbnail of Co-production of parasporal crystal toxins and antimicrobial substances by <i>Bacillus thuringiensis</i> BAR 3

Nigerian Journal of Biotechnology, 2017

Co-production of parasporal crystal toxins and antimicrobial substances by Bacillus thuringiensis... more Co-production of parasporal crystal toxins and antimicrobial substances by Bacillus thuringiensis BAR 3

Research paper thumbnail of Comparative Studies on the Kinetic Properties of Lipases Purified from Aspergillus nidulans and Aspergillus niger LC 269109

Biochemistry & Molecular Biology Journal, 2020

Lipases are enzymes with potential industrial applications but their supply is not sufficient for... more Lipases are enzymes with potential industrial applications but their supply is not sufficient for efficient utilization. The present work focused on lipase from two fungal isolates (Aspergillus niger LC 269109 and Aspergillus nidulans). The effects of pH, temperature and substrate concentration on lipase activity, as well as some kinetic parameters were determined. The lipase from Aspergillus nidulans was optimally active at pH 7 and temperature of 40°C, while the lipase from Aspergillus niger LC 269109 was found to be optimally active at pH 6 and temperature of 50°C. Lipase from Aspergillus nidulans was found to have a larger K m (17.54 mg/ml) than the lipase from Aspergillus niger LC 269109 (9.71 mg/ml) and a higher V max (769. 23 µmol/min) compared to that of lipase from Aspergillus niger LC 269109 (714.29 µmol/min). Hence, these isolates of Aspergillus nidulans as well as the Aspergillus niger, LC 269109 may be exploited as cheap source of lipase.

Research paper thumbnail of Alginate microporous beads promote higher ethanol productivity than the normal beads in a repeated-batch ethanolic process involving Saccharomyces cerevisiae LC 269108

African Journal of Biotechnology, 2019

Mass transfers pose significant challenge in fermentation due to wide diffusion gradient existing... more Mass transfers pose significant challenge in fermentation due to wide diffusion gradient existing between the culture broth and the immobilized cells. In the present study, Saccharomyces cerevisiae LC 269108 was immobilized in a recently described microporous alginate beads. The new method was compared with the conventional calcium alginate gel beads in a repeated batch process for the production of ethanol. The fermentation conditions implemented were 110 rpm, pH 5.5 and temperature of 30°C for 60 h. The bead diameters were 3 mm while the calcium chloride concentration was 2.0%. In separate batch experiments conducted by the simultaneous saccharification and fermentation (SSF) method, the free cells maintained plateau at peak ethanol concentration of 7.50±0.33% after 36 h. In the conventional alginate (6.51±0.05%) and microporous beads (7.06±0.10%), ethanol dropped in concentration until reaching final volumes of 5.65±0.33 and 6.56±0.64%, respectively. In the repeated batch experiments, five fermentation batches or runs were conducted over a 12 h period each. The concentrations of ethanol produced in batches with the cells immobilized in calcium alginate were 2.91±0.34, 5.80±0.22, 5.01±0.39, 4.41±0.14 and 3.77±0.21%, respectively. Cells immobilized in microporous beads had higher ethanol output with concentrations 2.33±0.07, 6.62±0.04, 6.16±0.32, 5.90±0.2 and 4.70±0.26% obtained after five respective batches. Glucose metabolism was found to be lower with cells immobilized in alginate beads. From initial glucose concentration of 14.30±0.2%, residual glucose was detected after the first (3.61±2.11%), fourth (3.18±0.98%) and fifth (5.30±0.86%) batches of fermentation. In the batches containing microporous beads, residual glucose (5.36±0.29%) was confirmed after the first batch only. The present study demonstrates the feasibility of using microporous beads in the production of ethanol.

Research paper thumbnail of Experimental and In-Silico Investigation of Anti-Microbial Activity of 1-Chloro-2-Isocyanatoethane Derivatives of Thiomorpholine, Piperazine and Morpholine

PloS one, 2017

The Antibiogram properties of 1-chloro-2-isocyanatoethane derivatives of thiomorpholine (CTC), pi... more The Antibiogram properties of 1-chloro-2-isocyanatoethane derivatives of thiomorpholine (CTC), piperazine (CPC) and morpholine (CMC) were evaluated by the approved agar well diffusion, the minimum inhibitory concentration (MIC) and in silico techniques. A total of fourteen microbial cultures consisting of ten bacteria and four yeast strains were used in the biological study while affinity of the compounds for DNA gyrase, a validated antibacterial drug target, was investigated by docking method. Results indicate that both thiomorpholine and piperazine had zero activity against the Gram negative organisms tested. With morpholine, similar result was obtained except that cultures of Escherichia coli (ATCC 15442) and Salmonella typhi (ATCC 6539) presented with weak sensitivity (7-8 mm) as shown by the inhibition zone diameter (IZD) measurement. The Gram positive organisms were more sensitive to morpholine than the other compounds. The highest IZD values of 15-18 mm were achieved except f...

Research paper thumbnail of Assessment of heavy metal contamination of rice grains (Oryza sativa) and soil from Ada field, Enugu, Nigeria: Estimating the human healtrisk

Human and Ecological Risk Assessment: An International Journal, 2016

ABSTRACT The concentrations of heavy metals in rice grains and soils from Ada cultivated fields w... more ABSTRACT The concentrations of heavy metals in rice grains and soils from Ada cultivated fields were investigated. Rice and soil samples were digested and the heavy metal concentrations determined using atomic absorption spectrophotometer. The results showed the following concentrations of metals (mg/kg): soil—Pb (4.64 ± 2.18), Cd (0.83 ± 0.83), Zn (20.26 ± 18.60), Mn (68.90 ± 19.91), Ni (3.46 ± 2.42), and Cr (21.41 ± 14.6); rice—Pb (3.99 ± 1.43), Cd (1.10 ± 0.53), Zn (65.37 ± 58.09), Mn (37.81 ± 5.82), Ni (3.12 ± 1.49), and Cr (10.87 ± 6.47). The Canadian, Nigerian and Chinese maximum allowable concentration for cadmium in soil were exceeded by 15%, 30%, and 85% of the soil samples, respectively. Heavy metals in all the rice samples evaluated were found to be above the World Health Organization (WHO) maximum permissible limit for lead, cadmium, and chromium. Strong positive and significant correlations were observed between some metal pairs in soil and rice indicating the similarity in origin. The estimated daily intakes of Pb and Cd from rice grown on the fields were higher than the safety levels established by WHO and the Joint FAO/WHO Expert Committee Food Additive, respectively. Hazard quotients and total hazard index for Pb and Cd were greater than 1. This indicates that consumption of rice from these fields will likely induce adverse health effects arising largely from Pb and Cd exposure.

Research paper thumbnail of The impact of Palm Oil Mill Effluent (POME) application on the rhizosphere heterotrophic population, nitrogen fixing bacteria and enzyme activity of an agricultural soil

Nigerian Journal of Biotechnology

Research paper thumbnail of Isolation of bacteriocin - producing lactic acid bacteria from 'Ugba' and 'Okpiye', two locally fermented nigerian food condiments

Brazilian Archives of Biology and Technology, 2013

Research paper thumbnail of Bioethanol production under multiple stress condition by a new acid and temperature tolerant Saccharomyces cerevisiae strain LC 269108 isolated from rotten fruits

Process Biochemistry

Abstract Milled pulp flour from spoilt Dioscorea rotundata tubers was investigated as potential f... more Abstract Milled pulp flour from spoilt Dioscorea rotundata tubers was investigated as potential feedstock for bioethanol production using a new isolate of Saccharomyces cerevisiae strain LC 269108 displaying both thermotolerant and acid-tolerant properties. Fermentation was implemented by simultaneous saccharification and fermentation (SSF) for 60 h at pH 5.5 and temperatures of 30 °C and 40 °C. The results showed that the isolate metabolized a narrow range of carbon compounds, showed capacity to ferment many sugars (with gas evolution) and exhibited tolerance to acidification (up to 70 mM of acetic acid) under high temperature conditions. The time course of fermentation showed that the peak ethanol concentrations were 7.15 ± 0.08% at 30 °C and 7.29 ± 0.53% at 40 °C after 12 h and 48 h, respectively. In batches spiked with 50 mM acetic acid, the final ethanol concentration decreased to 6.30 ± 0.10% at 30 °C and to 5.50 ± 0.26% at 40 °C. No significant difference (P > .05) was found between the concentrations of ethanol produced at 30 °C and 40 °C. However, the ethanol concentration obtained from a culture containing 50 mM acetic acid was significantly lower (P

Research paper thumbnail of Nanoparticles, Biosurfactants and Microbes in Bioremediation

Research paper thumbnail of Recent advances in biotechnological valorization of agro-food wastes (AFW): Optimizing integrated approaches for sustainable biorefinery and circular bioeconomy

Bioresource technology reports, Jun 1, 2024

Research paper thumbnail of Bioremediation of pharmaceutical waste waters

Research paper thumbnail of Biological elements as important tools in the detection/monitoring of drug compounds in organic and environmental samples

Research paper thumbnail of Production, Partial Purification, and Characterization of Lipase from &lt;i&gt;Aspergillus niger&lt;/i&gt; and Its Application in Treatment of Vegetable Oil Effluent

Chemical and biomolecular engineering, 2022

Research paper thumbnail of Micro and nanoplastics ravaging our agroecosystem: A review of occurrence, fate, ecological impacts, detection, remediation, and prospects

Research paper thumbnail of Animal Waste: An Environmentally Sustainable Management Approach

Climate Changes Mitigation and Sustainable Bioenergy Harvest Through Animal Waste, 2023

Research paper thumbnail of Silicon-based nanoparticles for mitigating the effect of potentially toxic elements and plant stress in agroecosystems: A sustainable pathway towards food security

Science of The Total Environment

Due to their size, flexibility, biocompatibility, large surface area, and variable functionality ... more Due to their size, flexibility, biocompatibility, large surface area, and variable functionality nanoparticles have enormous industrial, agricultural, pharmaceutical and biotechnological applications. This has led to their widespread use in various fields. The advancement of knowledge in this field of research has altered our way of life from medicine to agriculture. One of the rungs of this revolution, which has somewhat reduced the harmful consequences, is nanotechnology. A helpful ingredient for plants, silicon (Si), is well-known for its preventive properties under adverse environmental conditions. Several studies have shown how biogenic silica helps plants recover from biotic and abiotic stressors. The majority of research have demonstrated the benefits of siliconbased nanoparticles (Si-NPs) for plant growth and development, particularly under stressful environments. In order to minimize the release of brine, heavy metals, and radioactive chemicals into water, remove metals, nonmetals, and radioactive components, and purify water, silica has also been used in environmental remediation. Potentially toxic elements (PTEs) have become a huge threat to food security through their negative impact on agroecosystem. Si-NPs have the potentials to remove PTEs from agroecosystem and promote food security via the promotion of plant growth and development. In this review, we have outlined the various sources and ecotoxicological consequences of PTEs in agroecosystems. The potentials of Si-NPs in mitigating PTEs were extensively discussed and other applications of Si-NPs in agriculture to foster food security were also highlighted.

Research paper thumbnail of Silicon-based nanoparticles for mitigating the effect of potentially toxic elements and plant stress in agroecosystems: A sustainable pathway towards food security

Science of The Total Environment, 2023

Due to their size, flexibility, biocompatibility, large surface area, and variable functionality ... more Due to their size, flexibility, biocompatibility, large surface area, and variable functionality nanoparticles have
enormous industrial, agricultural, pharmaceutical and biotechnological applications. This has led to their
widespread use in various fields. The advancement of knowledge in this field of research has altered our way of
life from medicine to agriculture. One of the rungs of this revolution, which has somewhat reduced the harmful
consequences, is nanotechnology. A helpful ingredient for plants, silicon (Si), is well-known for its preventive
properties under adverse environmental conditions. Several studies have shown how biogenic silica helps plants
recover from biotic and abiotic stressors. The majority of research have demonstrated the benefits of siliconbased nanoparticles (Si-NPs) for plant growth and development, particularly under stressful environments. In
order to minimize the release of brine, heavy metals, and radioactive chemicals into water, remove metals, nonmetals, and radioactive components, and purify water, silica has also been used in environmental remediation.
Potentially toxic elements (PTEs) have become a huge threat to food security through their negative impact on
agroecosystem. Si-NPs have the potentials to remove PTEs from agroecosystem and promote food security via the
promotion of plant growth and development. In this review, we have outlined the various sources and ecotoxicological consequences of PTEs in agroecosystems. The potentials of Si-NPs in mitigating PTEs were extensively
discussed and other applications of Si-NPs in agriculture to foster food security were also highlighted.

Research paper thumbnail of Biogas from Manure: The Future of Renewable Natural Gas and Its Implications

Climate Changes Mitigation and Sustainable Bioenergy Harvest Through Animal Waste, 2023

Research paper thumbnail of Transfer of Multidrug Resistance among Bacteria Isolated from Industrial Wastes

Bio-Research, 2011

Objectives: Sewage effluent from the sewage treatment plant of the University of Nigeria, Nsukka,... more Objectives: Sewage effluent from the sewage treatment plant of the University of Nigeria, Nsukka, was analyzed for the presence of metal and non-metal ions and for the presence of metal tolerant and drug resistant bacteria. Methods: Plasmid mediation of metal tolerance and multiple drug resistance was demonstrated by sodium dodecyl sulphate (SDS) curing and direct cell transfer experiments. Results: Ions found present (in mgL-1) include, among others, Mercury (50.148), Lead (41.906), Sodium (907.240), and Potassium (700.00). Bacterial populations isolated from the effluent were members of the genera Enterobacter (n = 15), Escherichia (n = 18), Achromobacter (n = 18), Acinetobacter (n = 25) Klebsiella (n = 12), Pseudomonas (n = 08), Proteus (n = 20) and Serratia (n = 10). Enterobacter spp showed high percentage tolerance of 73% to Lead. Species of Acinetobacter and Pseudomonas showed, to varying degrees, across-the-board tolerance to all the individual salts. Also an across-the-board resistance of between 25-75% and 8.3-41.7% to the test drugs was exhibited by Pseudomonas and Klebsiella spp respectively. Sixty per cent each of Acinetobacter and Klebsiella spp lost both metal tolerance and drug resistance attributes simultaneously following the SDS curing protocol. Overall percentage loss of both characteristics was 57.1%. Acquisition of metal tolerance and multidrug resistance by recipients was total (100%) and so was the subsequent loss of these capabilities following SDS treatment of these recipients. Discussion: The public health hazard derivable from these findings is discussed.

Research paper thumbnail of Amylase Production by Aspergillus niger immobilized in Microporous Calcium Alginate Gel Beads

Romanian Biotechnological Letters, 2021

Microporous calcium alginate gel beads were investigated as potential solutions to mass transfer ... more Microporous calcium alginate gel beads were investigated as potential solutions to mass transfer limitations in immobilized cultures. The beads were prepared by gelling mixtures of sodium alginate and fillers (starch or granulated sugars) in calcium chloride solution. The resulting beads were cured in the same solution, during which the fillers leached out of the beads thereby creating micro-pores in the beads (microporous beads). The effectiveness of the microporous beads in improving amylase production by Aspergillus niger LC 269109 was investigated. Spores of A. niger were immobilized in the microporous beads and used for batch alpha amylase and gluco amylase production. Amylase production by the A. niger immobilized in the microporous beads were significantly higher (p<0.01) than the values obtained with the conventional calcium alginate gel beads. Under all the conditions investigated, gluco-amylase activities were significantly (p<0.01) higher than the alpha-amylase acti...

Research paper thumbnail of Co-production of parasporal crystal toxins and antimicrobial substances by <i>Bacillus thuringiensis</i> BAR 3

Nigerian Journal of Biotechnology, 2017

Co-production of parasporal crystal toxins and antimicrobial substances by Bacillus thuringiensis... more Co-production of parasporal crystal toxins and antimicrobial substances by Bacillus thuringiensis BAR 3

Research paper thumbnail of Comparative Studies on the Kinetic Properties of Lipases Purified from Aspergillus nidulans and Aspergillus niger LC 269109

Biochemistry & Molecular Biology Journal, 2020

Lipases are enzymes with potential industrial applications but their supply is not sufficient for... more Lipases are enzymes with potential industrial applications but their supply is not sufficient for efficient utilization. The present work focused on lipase from two fungal isolates (Aspergillus niger LC 269109 and Aspergillus nidulans). The effects of pH, temperature and substrate concentration on lipase activity, as well as some kinetic parameters were determined. The lipase from Aspergillus nidulans was optimally active at pH 7 and temperature of 40°C, while the lipase from Aspergillus niger LC 269109 was found to be optimally active at pH 6 and temperature of 50°C. Lipase from Aspergillus nidulans was found to have a larger K m (17.54 mg/ml) than the lipase from Aspergillus niger LC 269109 (9.71 mg/ml) and a higher V max (769. 23 µmol/min) compared to that of lipase from Aspergillus niger LC 269109 (714.29 µmol/min). Hence, these isolates of Aspergillus nidulans as well as the Aspergillus niger, LC 269109 may be exploited as cheap source of lipase.

Research paper thumbnail of Alginate microporous beads promote higher ethanol productivity than the normal beads in a repeated-batch ethanolic process involving Saccharomyces cerevisiae LC 269108

African Journal of Biotechnology, 2019

Mass transfers pose significant challenge in fermentation due to wide diffusion gradient existing... more Mass transfers pose significant challenge in fermentation due to wide diffusion gradient existing between the culture broth and the immobilized cells. In the present study, Saccharomyces cerevisiae LC 269108 was immobilized in a recently described microporous alginate beads. The new method was compared with the conventional calcium alginate gel beads in a repeated batch process for the production of ethanol. The fermentation conditions implemented were 110 rpm, pH 5.5 and temperature of 30°C for 60 h. The bead diameters were 3 mm while the calcium chloride concentration was 2.0%. In separate batch experiments conducted by the simultaneous saccharification and fermentation (SSF) method, the free cells maintained plateau at peak ethanol concentration of 7.50±0.33% after 36 h. In the conventional alginate (6.51±0.05%) and microporous beads (7.06±0.10%), ethanol dropped in concentration until reaching final volumes of 5.65±0.33 and 6.56±0.64%, respectively. In the repeated batch experiments, five fermentation batches or runs were conducted over a 12 h period each. The concentrations of ethanol produced in batches with the cells immobilized in calcium alginate were 2.91±0.34, 5.80±0.22, 5.01±0.39, 4.41±0.14 and 3.77±0.21%, respectively. Cells immobilized in microporous beads had higher ethanol output with concentrations 2.33±0.07, 6.62±0.04, 6.16±0.32, 5.90±0.2 and 4.70±0.26% obtained after five respective batches. Glucose metabolism was found to be lower with cells immobilized in alginate beads. From initial glucose concentration of 14.30±0.2%, residual glucose was detected after the first (3.61±2.11%), fourth (3.18±0.98%) and fifth (5.30±0.86%) batches of fermentation. In the batches containing microporous beads, residual glucose (5.36±0.29%) was confirmed after the first batch only. The present study demonstrates the feasibility of using microporous beads in the production of ethanol.

Research paper thumbnail of Experimental and In-Silico Investigation of Anti-Microbial Activity of 1-Chloro-2-Isocyanatoethane Derivatives of Thiomorpholine, Piperazine and Morpholine

PloS one, 2017

The Antibiogram properties of 1-chloro-2-isocyanatoethane derivatives of thiomorpholine (CTC), pi... more The Antibiogram properties of 1-chloro-2-isocyanatoethane derivatives of thiomorpholine (CTC), piperazine (CPC) and morpholine (CMC) were evaluated by the approved agar well diffusion, the minimum inhibitory concentration (MIC) and in silico techniques. A total of fourteen microbial cultures consisting of ten bacteria and four yeast strains were used in the biological study while affinity of the compounds for DNA gyrase, a validated antibacterial drug target, was investigated by docking method. Results indicate that both thiomorpholine and piperazine had zero activity against the Gram negative organisms tested. With morpholine, similar result was obtained except that cultures of Escherichia coli (ATCC 15442) and Salmonella typhi (ATCC 6539) presented with weak sensitivity (7-8 mm) as shown by the inhibition zone diameter (IZD) measurement. The Gram positive organisms were more sensitive to morpholine than the other compounds. The highest IZD values of 15-18 mm were achieved except f...

Research paper thumbnail of Assessment of heavy metal contamination of rice grains (Oryza sativa) and soil from Ada field, Enugu, Nigeria: Estimating the human healtrisk

Human and Ecological Risk Assessment: An International Journal, 2016

ABSTRACT The concentrations of heavy metals in rice grains and soils from Ada cultivated fields w... more ABSTRACT The concentrations of heavy metals in rice grains and soils from Ada cultivated fields were investigated. Rice and soil samples were digested and the heavy metal concentrations determined using atomic absorption spectrophotometer. The results showed the following concentrations of metals (mg/kg): soil—Pb (4.64 ± 2.18), Cd (0.83 ± 0.83), Zn (20.26 ± 18.60), Mn (68.90 ± 19.91), Ni (3.46 ± 2.42), and Cr (21.41 ± 14.6); rice—Pb (3.99 ± 1.43), Cd (1.10 ± 0.53), Zn (65.37 ± 58.09), Mn (37.81 ± 5.82), Ni (3.12 ± 1.49), and Cr (10.87 ± 6.47). The Canadian, Nigerian and Chinese maximum allowable concentration for cadmium in soil were exceeded by 15%, 30%, and 85% of the soil samples, respectively. Heavy metals in all the rice samples evaluated were found to be above the World Health Organization (WHO) maximum permissible limit for lead, cadmium, and chromium. Strong positive and significant correlations were observed between some metal pairs in soil and rice indicating the similarity in origin. The estimated daily intakes of Pb and Cd from rice grown on the fields were higher than the safety levels established by WHO and the Joint FAO/WHO Expert Committee Food Additive, respectively. Hazard quotients and total hazard index for Pb and Cd were greater than 1. This indicates that consumption of rice from these fields will likely induce adverse health effects arising largely from Pb and Cd exposure.

Research paper thumbnail of The impact of Palm Oil Mill Effluent (POME) application on the rhizosphere heterotrophic population, nitrogen fixing bacteria and enzyme activity of an agricultural soil

Nigerian Journal of Biotechnology

Research paper thumbnail of Isolation of bacteriocin - producing lactic acid bacteria from 'Ugba' and 'Okpiye', two locally fermented nigerian food condiments

Brazilian Archives of Biology and Technology, 2013

Research paper thumbnail of Bioethanol production under multiple stress condition by a new acid and temperature tolerant Saccharomyces cerevisiae strain LC 269108 isolated from rotten fruits

Process Biochemistry

Abstract Milled pulp flour from spoilt Dioscorea rotundata tubers was investigated as potential f... more Abstract Milled pulp flour from spoilt Dioscorea rotundata tubers was investigated as potential feedstock for bioethanol production using a new isolate of Saccharomyces cerevisiae strain LC 269108 displaying both thermotolerant and acid-tolerant properties. Fermentation was implemented by simultaneous saccharification and fermentation (SSF) for 60 h at pH 5.5 and temperatures of 30 °C and 40 °C. The results showed that the isolate metabolized a narrow range of carbon compounds, showed capacity to ferment many sugars (with gas evolution) and exhibited tolerance to acidification (up to 70 mM of acetic acid) under high temperature conditions. The time course of fermentation showed that the peak ethanol concentrations were 7.15 ± 0.08% at 30 °C and 7.29 ± 0.53% at 40 °C after 12 h and 48 h, respectively. In batches spiked with 50 mM acetic acid, the final ethanol concentration decreased to 6.30 ± 0.10% at 30 °C and to 5.50 ± 0.26% at 40 °C. No significant difference (P > .05) was found between the concentrations of ethanol produced at 30 °C and 40 °C. However, the ethanol concentration obtained from a culture containing 50 mM acetic acid was significantly lower (P

Research paper thumbnail of Nanoparticles, Biosurfactants and Microbes in Bioremediation