Solomon E Omonigho | University of Benin, Benin City , Nigeria. (original) (raw)

Papers by Solomon E Omonigho

Annals of Microbiology, Nov 13, 2021

Incidence of foodborne diseases and growing resistance of pathogens to classical antibiotics is a... more Incidence of foodborne diseases and growing resistance of pathogens to classical antibiotics is a major concern in the food industry. Consequently, there is increasing demand for safe foods with fewer chemical additives but natural products which are not harmful to the consumers. Bacteriocins, produced by lactic acid bacteria (LAB), is of interest because they are active in a nanomolar range, do not have toxic effects, and are readily available in fermented food products. Methods: In this research, LAB were isolated from fufu, gari, kunu, nono, and ogi using De Mann, Rogosa, and Sharpe agar. Cell-free supernatants were prepared from 18-24 h LAB culture grown on MRS broth. Effect of organic acid was eliminated by adjusting the pH of the supernatants to 7.0 with 1M NaOH while the effect of hydrogen peroxide was eliminated by treating with Catalase enzyme. The supernatant was then filter-sterilized using a membrane filtration unit with a 0.2-μm pore size millipore filter and subjected to agar well diffusion assay against foodborne antibiotic-resistant bacteria. Result: A total of 162 isolates were obtained from the food samples. The antimicrobial sensitivity test yielded positive results for 45 LAB isolates against Staphylococcus aureus ATCC 25923 while 52 LAB isolates inhibited Escherichia coli ATCC 25922. On confirmation of the bacteriocinogenic nature of the inhibitory substance, 4 of the LAB isolates displayed a remarkable degree of inhibition to Leuconostoc mesenteroides, Salmonella typhimurium, and Bacillus cereus. Agar well diffusion assay was also performed against antibiotic-resistant foodborne pathogens using the cell-free supernatant (CFS) obtained from Lactobacillus fermentum strain NBRC15885 (Limosilactobacillus fermentum), Lactobacillus fermentum strain CIP102980 (Limosilactobacillus fermentum), Lactobacillus plantarum strain JCM1149 (Lactiplantibacillus garii), and Lactobacillus natensis strain LP33 (Companilactobacillus nantensis). The foodborne pathogens exhibited a notable level of resistance to antibiotics, with B. cereus exhibiting a resistance profile of 40%, S. aureus (50%), K. pnuemoniae (70%), E. coli (60%), and S. typhi (40%). The (CFS) was able to inhibit the growth of B. cereus, Klebsiella pneumonia, S. typhimurium, S. aureus, and E. coli. Conclusion: Therefore, it portends that the bacteriocins produced by the LAB isolated from these food products could act as probiotics for effective inhibition of the growth of antibiotic-resistant foodborne pathogens.

Food Chemistry, Feb 1, 2000

The eects of dierent preservative treatments on the chemical changes of pounded white yam (Diosco... more The eects of dierent preservative treatments on the chemical changes of pounded white yam (Dioscorea rotundata) upon storage were investigated. Preservative treatments adopted include steaming at 100 C for 30 min, addition of 0.1% sodium benzoate, treating with 0.1% sodium benzoate plus heating at 85 C for 30 min and ®nally the samples at room temperature (282 C). Changes occurred in the chemical composition of stored untreated pounded yam samples with the product becoming staled. The pH value (6.00), total solids content (30.88%) and crude protein content (5.56%) of fresh untreated samples initially increased before decreasing to 4.80, 25.60% and 5.50%, respectively, after storage for 8 days. Titratable acidity, moisture content and reducing sugars content of fresh samples initially decreased but subsequently increased. Extractable fat, crude ®bre and ash contents continually increased from 1.25, 1.20 and 1.90% to 4.10, 2.90 and 8.60% respectively. The rate of change in chemical properties/ composition of treated pounded yam samples was aected by the preservation method adopted and time of storage. Samples treated with 0.1% sodium benzoate plus heating at 85 C for 30 min had stable chemical compositions over 8-day periods of storage and possibly longer.

Food Chemistry, Nov 1, 2000

... The initial pH-value (6.00±0.00) of fresh untreated pounded yam makes the product vulnerable ... more ... The initial pH-value (6.00±0.00) of fresh untreated pounded yam makes the product vulnerable to bacterial spoilage. Jay (1978) and Frazier and Westhoff (1978) have noted that foods with ultimate pH of about 5.60 and above are more susceptible to bacterial spoilage. ...

Research Journal of Medicinal Plant, Apr 1, 2007

Journal of Advances in Microbiology

Citric acid production using agro-waste as cheap carbon source helps in waste management and redu... more Citric acid production using agro-waste as cheap carbon source helps in waste management and reduction in cost of production. The study was aimed at optimizing citric acid production from corncobs as substrate was amended with copper ions. Corncobs were collected, air dried, milled and pretreated with acid hydrolysis. The pretreated corncob media were inoculated with 106 spores/ml of Aspergillus niger and fermented for 10 d at 28 \(\pm\) 2 °C. Effect of corncob concentrations of 5 – 25 % w/v on citric acid production was examined. The concentration with highest yield of citric acid was optimized using copper ions concentration of 0 – 0.4 g/l. All through the fermentation processes samples analyzed were citric acid produced, fungal biomass, and changes in pH. The supplemented corncob medium had the highest citric acid production and fungal biomass after 8 d of fermentation. Studies on corncob concentrations showed that 25 %w/v of corncobs had the highest citric acid production and fu...

BMJ Global Health, 2021

BackgroundWith reports of surges in COVID-19 case numbers across over 50 countries, country-level... more BackgroundWith reports of surges in COVID-19 case numbers across over 50 countries, country-level epidemiological analysis is required to inform context-appropriate response strategies for containment and mitigation of the outbreak. We aimed to compare the epidemiological features of the first and second waves of COVID-19 in Nigeria.MethodsWe conducted a retrospective analysis of the Surveillance Outbreak Response Management and Analysis System data of the first and second epidemiological waves, which were between 27 February and 24 October 2020, and 25 October 2020 to 3 April 2021, respectively. Descriptive statistical measures including frequencies and percentages, test positivity rate (TPR), cumulative incidence (CI) and case fatality rates (CFRs) were compared. A p value of <0.05 was considered statistically significant. All statistical analyses were carried out in STATA V.13.ResultsThere were 802 143 tests recorded during the study period (362 550 and 439 593 in the first an...

Libyan Journal of Medical Sciences, 2020

Background: The aim is to determine the pattern of cytokines secretion by assessing interleukins ... more Background: The aim is to determine the pattern of cytokines secretion by assessing interleukins (IL-1, IL-6, and tumor necrosis factor-alpha (TNF-α) in pulmonary tuberculosis patients. Materials and Methods: A cross-sectional study was conducted on 146 consecutive (54 males and 92 females) sputum positive for tuberculosis and 38 apparently healthy age- and sex-matched sputum negative for tuberculosis as control were recruited between May 2016 and June 2017. A volume of 5 mL of blood samples was collected for the determination of serum IL-1, IL-6 and TNF-α using the ELISA method. Results: There was a higher cytokine mean ± standard error of the mean for tuberculosis subjects (95.77 ± 6.68 pg/mL; 107.54 ± 14.76 pg/mL, 122.09 ± 16.55 pg/ml) and controls (79.88 ± 3.53 pg/ml; 78.35 ± 6.82 pg/ml; 94.11 ± 14.08 pg/ml) for interleukin-1, interleukin-6, and TNF-α, respectively, when compared. There was strong correlation between mean values of IL-6 and TNF-α (r = 0.72315, P < 0.05). There was significance difference (P < 0.05) observed in the mean serum concentrations of cytokines among the genders (P < 0.05). Conclusion: The study revealed that IL-1, IL-6, TNF-α are important biological markers for tuberculosis disease.

Indian journal of traditional knowledge

Microbiological analysis was carried out on samples of 20 medicinal plants obtained from open mar... more Microbiological analysis was carried out on samples of 20 medicinal plants obtained from open markets in Benin and her environs. The standard plate count technique on Nutrient agar (NA) was used to determine the total aerobic bacterial count, mannitol salt agar and Baird-Parker agar for staphylococcal count, MacConkey agar for coliform count and potato dextrose agar for fungal counts. The purified bacterial and fungal isolates were then characterized and identified. All the samples examined contained microorganisms. The bacterial count ranged from 1.0×10 3 cfu/g to 9.8×10 4 cfu/g with Aframomum meleguata, Onyokea gore and Khaya ivorensis having the highest count of 9.8 × 10 4 cfu/g; 9.4 × 10 3 cfu/g and 8.8×10 3 cfu/g, respectively and Justicia flava had the lowest count of 1.0 × 10 3 cfu/g. The fungal counts were high in all the samples examined. The bacterial isolates were identified as Staphylococcus aureus (50.0%), Staphylococcus epidermidis (25.0%), Escherichia coli (10.0%) and...

Food Control, 2002

The microbiological quality of garri obtained from open markets and traditional processing indust... more The microbiological quality of garri obtained from open markets and traditional processing industry in Benin City with reference to staphylococcal contamination was investigated. Enumeration of the total heterotrophic bacteria, total fungal propagules and Staphylococcus aureus in food samples was carried out using appropriate media. The staphylococcal thermonuclease activity determination was used as an indicator of previous (substantial) growth of S. aureus and possible presence of staphylococcal enterotoxins. The total heterotrophic bacterial count of the open marketsÕ samples was 7:75 AE 2:87 Â 10 3 cfu/g with corresponding staphylococcal count of 1:65 AE 0:82 Â 10 3 and fungal propagule count of 2:50 AE 1:14 Â 10 2 cfu/g. Samples obtained immediately after processing from the traditional garri industry revealed total heterotrophic bacterial count of 5:00 Â 10 1 cfu/ g; staphylococcal count of 5:00 Â 10 0 cfu/g and no fungal count. The zone diameter of thermonuclease activity was 8:13 AE 0:52 mm for open marketsÕ samples while traditional processing industry samples have 7:83 AE 0:54 mm. From the study, it was found that there was contamination and growth of S. aureus and possibly the presence of staphylococcal enterotoxin in the product. The public health significance of the microorganisms with the production of thermonuclease and enterotoxins by S. aureus are discussed.

Trends in Medical Research, 2007

Tropical Journal of Natural Product Research

Waste generation demands that measures must be put in place in order to avert their detrimental e... more Waste generation demands that measures must be put in place in order to avert their detrimental effect to the environment. Bioconversion of agricultural waste to useful products like enzyme is a welcome development. Amylase production by Aspergillus niger via submerged fermentation of fruit wastes such as pineapple, orange, banana, cucumber and watermelon was investigated. Biomass of A. niger, amylase produced and pH of the fermenting fruit waste media were determined using standard techniques during submerged fermentation. From the data obtained Banana waste medium produced the highest yield of A. niger amylase (259.00 ± 1.23 U/mL) compared to other waste media at 4 d of fermentation. Amylase yield from Banana waste medium was significantly higher compared with the other fruit wastes (p < 0.05). Among the various supplemented nitrogen sources in the Banana waste medium, ammonium nitrate gave the highest amylase yield of 881.00 ± 16.97 U/mL while the least (549.5 ± 20.51 U/mL) was from potassium nitrate medium. Thus, the study revealed that A. niger can be used for amylase production from fruit waste and optimal yield can be enhanced by supplementing the medium with ammonium nitrate.

African Scientist, Jun 3, 2021

The edaphic enzyme profiles associated with compounded top herbicide; Glyphosate impacted and con... more The edaphic enzyme profiles associated with compounded top herbicide; Glyphosate impacted and control soils sourced from a commercial farm setting and a fallow land were determined using routine methodologies. The commercial farm establishment and the fallow farm were sited in Amukpe and Adavware communities both located in Sapele Local Government Area, Delta State, Nigeria. The amylase and invertase content of the soils ranged from 11.43 µg glucose/g soil ± 0.24 to 52.15 µg glucose/g soil ± 0.68 and 55.46 µg sucrose/g soil ± 1.25 to 548.13 µg sucrose/g soil ± 15.56 respectively. The mean protease, urease, and dehydrogenase activities varied from 59.24 µg tyrosine/g soil ± 1.59 to 122.65 µg tyrosine/g soil ± 0.59, 6.34 µg NH4 + /g soil ± 0.22 to 25.63 µg NH4 + /g soil ± 0.46 and 5.61 µg TPF/g soil ± 0.18 to 13.86 µg TPF/g soil ± 0.26. The differences in soil enzymatic activity amongst the glyphosate exposed soils and the control soil were statistically significant (p<0.001). The usage of glyphosates impacted negatively on the analyzed soil invertase, protease, amylase, and urease activities but had no observable effect on dehydrogenase activity.

1 Assessment of the in-vitro activity and in-vivo preventive efficacy of phyto-fabricated silver ... more 1 Assessment of the in-vitro activity and in-vivo preventive efficacy of phyto-fabricated silver nanoparticles and silver nanoparticle/mancozeb combination against Fusarium wilt of Lycopersicon esculentum mill Godfrey O. Oribhabor *, Solomon E. Omonigho 1 Department of Microbiology, Faculty of Life Sciences, University of Benin, PMB 1154 Benin City, Edo State, Nigeria. *Corresponding author: Godfrey O. Oribhabor., Email: godfrey.oribhabor@uniben.edu Received: August 22, 2020, Accepted: September 29, 2020, Published: September 29, 2020. ABSTRACT: The antifungal activity of phyto-fabricated silver nanoparticle (AgNP) alone and in combination with the fungicide, mancozeb, against F. oxysporum f. sp. lycopersici were investigated in-vitro and under field trial. Treatments were applied at different concentrations (5.0, 7.5, 10.0, 12.5 %) while media without the treatments served as control. AgNP alone demonstrated an insignificant mycelial radial growth inhibitory effect (p > 0.05) on...

Journal of Applied Sciences and Environmental Management, Nov 29, 2017

The effect of disposing municipal waste on soil was evaluated by analyzing the microbiological an... more The effect of disposing municipal waste on soil was evaluated by analyzing the microbiological and enzyme activity of soil samples at three different locations, from five municipal waste dumpsites and compared with soil samples from a farmland which serves as the control. Soil microbial load, physicochemical parameters and enzyme activities were determined using standard procedure. The highest heterotrophic bacterial count (1.02 ± 0. 4 × 10 7 cfu/g) was recorded from New Benin market Dumpsite (sampling point A) while the least (3.25 ± 0.4 ×10 4 cfu/g) was from the control (sampling point C). The result obtained showed that there was significant difference (p> 0.05) in the Heterotrophic bacteria and fungi count between the control and the soil samples from the various locations of the dumpsites. The bacteria identified were Acinetobacter species, Micrococcus luetus, Pseudomonas aeruginosa, Serratia species, Bacillus subtilis, Klebsiella species, Staphylococcus aureus, Arthrobacter species, Escherichia coli and Streptococcus feacalis, while fungi identified were Aspergillus niger, Trichoderma species, Penicillium species, Fusarium species, Mucor species, Saccharomyces species, Rhizopus species. Pseudomonas aeruginosa was the most prevalent bacterial isolate (20.3 %) while Streptococcus feacalis was the least isolate (3.1 %). Aspergillus niger was the most prevalent fungi isolate and Fusarium species the least isolated fungi. The enzymatic profile revealed that Oba market and Satana market had the highest Dehydrogenase and Urease activities with the values of 23.70 ± 16.32 mg/g/6h and 97.90 ± 14.93 mg/g/24h respectively. The physicochemical parameter measured in this study showed that the soil samples were acidic (5.60 ± 0.17-6.23 ± 0.35) and sandy (72.20 ± 4.11-90.60 ± 0.00 %). Trace amount of zinc (0.10 ± 0.00-1.53 ± 1.02 mg/kg), lead (< 0.01-1.23 ± 0.17 mg/kg) and copper (0.01 ± 0.00-0.80 ± 0.10 mg/kg) was observed in both the control soil and the test samples. The result showed that although municipal waste dump is an unsustainable practice, it has a positive impact on the quality of the soil samples examined. © JASEM

The frequent discharge of used petroleum products from automobiles has become a major source of c... more The frequent discharge of used petroleum products from automobiles has become a major source of concern due to unguided discharge into the soil environment, hence the need for biodegradation of the products. Bacterial species were isolated from contaminated soil in mechanic workshops and screened for their for hydrocarbon degradation potentials using standard microbiological procedures. Physicochemical properties of the contaminated soil were also analysed using standard techniques. The highest and lowest heterotrophic bacterial counts of 2.82 ± 0.16 ×10 and 2.09 ± 0.32 ×10 cfu/g were from the control soil and site 1 respectively. For hydrocarbon utilizing bacterial, Site 2 had the highest load of 8.33 ± 2.55 ×10 while the control had the least 1.35±0.33× 10 cfu/g. The bacterial isolates from the contaminated soil were found to be Corynebacterium kutsceri, Escherichia coli, Bacillus licheniformis, Bacillus subtilis, Bacillus megaterium, Klebsiella oxytoca, Staphylococcus aureus, Pse...

Broiler feed was formulated from fermented cashew apple residue (CAR) and its effect on the intes... more Broiler feed was formulated from fermented cashew apple residue (CAR) and its effect on the intestinal microflora balance of the birds was evaluated. CAR was subjected to fermentation by Lactobacillus plantarum before being incorporated into the feed. The feeds were formulated by substituting maize with CAR at three levels: 100:0 (Diet A), 50:50 (Diet B), and 70:30 (Diet C) maize to CAR. Forty Day-old chicks were placed on the formulated feed for 6 weeks until they reached table size weight (2.2-2.5 Kg). The results indicated a slight difference in the colour and formation of the faeces of the experimental birds and there were no significant differences in the feed intake of the treatment groups and the control during the trial period. There were no significant differences in the feed conversion ratio (1.531±0.02 to 1.710±0.01) and the total weight gain (2.226±0.08 to 2.355±0.10) of the experimental groups and the control. Further, there was a higher level of lactic acid bacteria in...

Article history: Received 03 May 2019 Revised 11 May 2019 Accepted 15 May 2019 Available online 1... more Article history: Received 03 May 2019 Revised 11 May 2019 Accepted 15 May 2019 Available online 12 June 2019 Soil quality has been known to have a strong effect on cocoa tree growth and the interactions of plant and microbe in the rhizosphere influence plant health, productivity and soil fertility. In this study, the rhizospheres of cocoa seedlings were analyzed for bacterial density population after soil amendment. Cocoa seedlings were self-grown in nursery located at the Orchard of the Faculty of Agriculture, University of Benin and Amelonado variety Tc1-Tc8 pods were used. The seeds were prepared, pre-germinated and planted in bags containing 5 kg top soil. Organic fertilizers (compost poultry manure and cow dung) and inorganic fertilizer was applied to the soil surrounding the seedlings at one month after planting. The sowing soil and the rhizosphere of the cocoa seedlings at one month to four month were collected and analyzed. Serial dilution method was used for culturing and b...

Pakistan Journal of Biological Sciences, 2007

Purpose: To evaluate the microbial load on 17 randomly selected plant samples from 60 ethnobotani... more Purpose: To evaluate the microbial load on 17 randomly selected plant samples from 60 ethnobotanically collected medicinal plants from five local markets in Abeokuta, Ogun State, Nigeria. Method: The pour plate method was used to cultivate serially diluted portions of the medicinal plant samples investigated. Enumeration of bacteria was carried out on nutrient agar (NA) while that of fungi was effected on Sabouraud agar (SA). Results: The identified microbial isolates include 12 bacterial and 6 fungal genera. The mean heterotrophic bacteria counts of the different herbal samples ranged from 1.3 × 105 cfu/g (Cnestis ferruginea) to 6.7 × 106 cfu/g (Daniellia oliveri), while total fungal propagule counts ranged from 0.0 × 101 cfu/g (Terminalia superba, Cola gigantea, Rauwolfia vomitoria, Zingiber officinale and Argemone mexicana) to 7.1 × 106 cfu/g (Nesogordonia papaverifera). The synopsis and frequency (prevalence rate) of microbial species isolation showed that Bacillus spp. (82.4 %)...

Journal of Applied Sciences and Environmental Management

The dominant bacteriological and archaeal phyla of compounded soils sourced from a commercial far... more The dominant bacteriological and archaeal phyla of compounded soils sourced from a commercial farm estate located in Amukpe town and a nearby control in Adavware community both in Delta State, were evaluated with the aid of Next Generation Sequencing (NGS) protocols. The residual herbicide and pesticide composition of the bulked soils were also determined using gas chromatography (GC) and electron capture detector (ECD). Total concentrations of the extracted DNA were 6.83 and 6.65 ng/µl for the control and experimental soils. Nine (9) bacterial phyla; Proteobacteria,