Remediation of soil contaminated with polycyclic aromatic hydrocarbons from crude oil

The aim of this study was to determine ways of remediating soils contaminated with polycyclic aromatic hydrocarbons (PAHs) associated with crude oil. The study involves the use of planted cowpeas, mushrooms, algae, dead vegetable and live earthworm, and fire-heating of the contaminated garden soil collected from the Niger Delta area of Nigeria. The types and levels of the PAH in the soil before and after three weeks of contamination were determined using gas chromatography. Mushrooms and cowpeas proved to be very adequate phytoremediators. Fire heat was third, algae and dead vegetable with live earthworm showed the least reduction. This study thus recommends that the people of the Niger Delta should engage in planting of mushrooms and cowpeas to regenerate and ameliorate petroleum contaminated land for beneficial farming.Key words: Crude oil, petroleum, contaminated soil, polycyclic aromatic hydrocarbons, mushrooms, cowpeas

Evaluation of maize-soybean flour blends for sour maize bread production in Nigeria

Examination of the functional properties of three different flours/meals and two blends of maize meal and soybean-flour (ratios 9:1 and 8:2, maize:soybean) were carried out. Properties examined included amylose content, bulk density, dispersibility, swelling power, water absorption capacity and viscoelastic properties. The effect of the different flour/meal samples on the properties of sour maize bread were evaluated by baking bread samples with the different flours/meals using a mixed starter culture of Lactobacillus plantarum and Saccharomyces cerevisiae. All flour/meal samples differed, sometimes significantly (p 0.05) in their functional properties. Significant positive correlations existed among the functional properties of the flours at the 1% level (2-tailed). The maize meal/soy flour blends MSA (maize meal and soybean flour mixed in ratio 9:1) and MSB (maize meal and soybean flour mixed in ratio 8:2) did not differ significantly from each other in functional properties except for amylose content. MSA was adjudged the best flour blend for sour maize bread production as its bread had the highest score for overall acceptability (6.1) and other sensory parameters evaluated

A survey of the microflora of Hibiscus sabdariffa (Roselle) and the resulting “Zobo” juice

The dried calyx of Hibiscus sabdariffa (Roselle) is locally processed into a non alcoholic drink known as ‘Zobo’ in Nigeria. This popular drink is quite cheap compared to other bottled soft drinks but its acceptability is still limited because of its very short shelf life (24 h at room temperature). The composition and numbers of the microflora of the dried calyx of the Roselle plant and its resulting juice (Zobo) were examined using standard microbiological methods. The dried calyx obtained from a retail market was processed into juice that was compared with commercially sold (retail) juice. The microorganisms isolated from the dried calyx and the juices included the fungi, Aspergillus niger, Aspergillus flavus, Rhizopus oligosporus, Penicillium citrinum, Mucor spp., Saccharomyces cerevisiae, and Candida krusei, while Bacillus subtilis, Pseudomonas spp., Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Proteus mirabilis, Serratia spp., Lactobacillus brevis and Lactobacillus fermentum represented the bacterial isolates. Viable counts ranged from 0.4 x 104 to 3.2 x 104 cfu/ml. Aerobic and anaerobic bacterial counts were higher in the retail juice (1.1 to 2.2 x104 cfu/ml) than in the laboratory-prepared juice (0.8 to 1.4 x104 cfu/ml) while the dried calyx had the highest fungal counts of 3.2 x 104 cfu/ml. pH of the juices ranged between 2.67 and 2.77 while total titratable acidity values were between 0.02 and 0.08.Keywords: Dried calyx, microflora, viable counts, Zobo juic

Visual acuity and foveal thickness after vitrectomy for macular edema associated with branch retinal vein occlusion: a case series

Abstract Background The mechanism by which vitrectomy improves macular edema in patients with branch retinal vein occlusion remains unclear, although intraocular levels of vascular endothelial growth factor have been suggested to influence the visual prognosis and macular edema. Methods A series of 54 consecutive patients (54 eyes) with branch retinal vein occlusion was studied prospectively. All patients underwent pars plana vitrectomy for treatment of macular edema. Best corrected visual acuity and retinal thickness (examined by optical coherence tomography) were assessed before and after surgery. The level of vascular endothelial growth factor in vitreous fluid harvested at operation was determined. Patients were followed for at least 6 months postoperatively. Results Both the visual acuity and the retinal thickness showed significant improvement at 6 months postoperatively (P = 0.0002 and P Conclusions These results suggest that the vitreous level of vascular endothelial growth factor might influence the visual prognosis and the response of macular edema to vitrectomy in patients with branch retinal vein occlusion.</p

Trace metals and vitamin levels in Nigerian patients with sensory ataxic syndrome

The aetio-pathogenesis of sensory ataxic syndromes is not well understood. Several factors have been implicated ranging from infectious agents to various toxico-nutritional mechanisms. Vitamin deficiencies have been demonstrated in individuals with this disorder. In recent times, the deficiencies of essential trace elements have been implicated, especially zinc, copper, selenium and manganese, in the etiology of ataxic syndromes. We report the levels of essential trace metals and vitamins in the serum and cerebrospinal fluid (CSF) of twelve patients with features of sensory ataxia. The levels of the vitamins and the elements were determined by atomic absorption spectrophotometry. The serum and CSF levels of copper, iron and zinc were significantly reduced when compared to controls, but the levels of magnesium were lower in controls than subjects. The levels of manganese were comparable in both groups. Our obsevation supports the possible role of deficiencies of essential trace metals; specifically copper, iron and zinc; and vitamins in the aetio-pathogenetic mechanism of sensory ataxic syndromes, probably due to defective prevention of oxidative damage to the neurones. The significance of the higher levels of magnesium in the patients is unclear and needs further investigation. Further studies with larger sample sizes are needed to confirm this observation.Keywords: ataxia, trace metals, vitamins, Nigerians Nigerian Journal of Health and Biomedical Sciences Vol. 4(2) 2005: 156–16

Enzymatic Production of Ethanol from Cassava Starch Using Two Strains of Saccharomyces cerevisiae

Cassava starch from TMS 30572 and Idileru were hydrolyzed with ƒ¿-amylase and amylo-glucosidase before fermentation using two strains of Saccharomyces cerevisiae from palm wine and bakersf yeast. The per cent yield of sugars and total dissolved solids were 66 % and 26% respectively while pH was 7. Spectrophotometric measurement of the cell growth revealed steady but insignificant (p . 0.05) increase in cell concentrations up to 48 h fermentation time with a gradual decline by 72 h. Saccharomyces cerevisiae strain from palm wine grew best on TMS 30572 hydrolysate at 20% sugar concentration (optical density 0.663; fermentation time 48 h) while on Idileru hydrolysate it grew best at 25% (optical density 0.698; fermentation time 60 h). The pH values obtained from the fermenting hydrolysates for both yeast strains declined gradually as the fermentation progressed with the lowest pH values (3.01 for S. cerevisiae from palm wine; 3.06 for S. cerevisiae from bakersf yeast) obtained for TMS 30572 cassava variety at 25% sugar concentration. Changes in pH were significant (p . 0.05). The Saccharomyces cerevisiae strain from palm-wine had a higher conversion of available sugar into ethanol. The yield of ethanol was found to vary but the highest ethanol concentration obtained was 5.3% at 10% initial sugar concentration, which gave a sugar conversion efficiency of 37.3%. The results obtained suggestthat Saccharomyces cerevisiae strains from sources other than those used conventionally can serve as good substitutes for bio-conversion processes in the industrial production of ethanol.Keywords: Cassava, enzyme, ethanol, Saccharomyces cerevisiae, starc

Exploitation of Acha (Digitaria exiliis) and Iburu (Digitaria iburua) flours: Chemical characterization and their use for sourdough fermentation

This study aimed at characterizing the chemical and microbiological composition of Acha (Digitariaexiliis) and Iburu (Digitariaiburua) flours and at exploiting their potential for sourdoughfermentation. Both the flours had a gross composition similar to other cereals. As shown by two-dimensional electrophoresis analysis, Acha flour had a higher number of prolamins with respect to Iburu flour. The opposite was found for the number of glutelin spots. The concentration of total free amino acids of Iburu flour was higher than that of Acha flour (1348 ± 34 vs. 100 ± 20 mg/kg). Pediococcus pentosaceus was the dominant species in both the flours. Several isolates were used to ferment Acha or Iburu flours. After 8 h fermentation at 30 °C, pH ranged from 3.41 to 3.83 and from 4.20 to 4.66 for Acha and Iburusourdoughs, respectively. The highest values of TTA and concentration of lactic acid were found in almost all Iburusourdoughs. The synthesis of acetoin and γ-amino butyric acid (GABA) was only found in Iburusourdoughs. Data from the kinetics of acidification, synthesis of lactic and acetic acids, acetoin, and liberation of total free amino acids were elaborated by Principal Component Analysis. Sourdoughs from Acha and Iburu flour were clearly differentiated

Utilization of african grains for sourdough bread making

Acha and Iburu flours were singly subjected to sourdough fermentation with previously selected autochthonous starters. Sourdoughs were used (30%, wt/wt) as aroma carriers and acidifiers during short time fermentation with the addition of baker's yeast. Acha and Iburu sourdough breads were compared to wheat sourdough bread started with the same strains and to breads made with the same formula but using baker's yeast alone. During Acha and Iburu sourdough fermentations, starter lactic acid bacteria reached almost the same cell density found in wheat sourdoughs. Acidification was more intense. Iburu sourdough bread had the highest total titratable acidity, the lowest pH, and contained the highest levels of free amino acids and phytase activity. The values of in vitro protein digestibility did not differ between Acha sourdough and wheat sourdough breads, while Iburu sourdough bread showed a slightly lower value. Acha and Iburu sourdough breads showed lower specific volume and higher density with respect to wheat sourdough breads. Nevertheless, Acha and Iburu sourdough breads were preferred for hardness and resilience. As shown by sensory analysis, Acha and especially Iburu sourdough breads were appreciated for color, acid taste and flavor, and overall acceptability

Ocular morbidities in a targeted high-risk urban population in Benin City, Edo State

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