Biodegradation of Bonny light crude oil in soil microcosm by some bacterial strains isolated from crude oil flow stations saver pits in Nigeria

In an effort at developing an active indigenous bacterial consortium that could be of relevance in bioremediation of petroleum contaminated systems in Nigeria, four hydrocarbon degrading bacteria strains were isolated. Partial sequencing of the 16S rDNA of the isolates suggests that they are all strains of Pseudomonas aeruginosa. Axenic cultures of the isolates biodegraded Bonny light crude oil in soil microcosm. Amount of crude oil biodegraded in 15 days ranged significantly (P < 0.05) from 4.9% to 29.6%. Degradation rates and specific growth rates varied significantly (P < 0.05) between 0.049 and 0.351 day-1 and 0.017 and 0.028 hour-1 respectively. Major peak components of the oil were reduced by between 6.5% and 70.6%. It would appear that oil degradation capability of axenic cultures of at least three of these isolates was not different from that of their consortium. Also, the multiple antibiotic resistance observed in the isolates is an important factor to consider in their eventual use in bioremediation exercises. (African Journal of Biotechnology: 2003 2(5): 1014-108

Developing an ionospheric map for South Africa

The development of a map of the ionosphere over South Africa is presented in this paper. The International Reference Ionosphere (IRI) model, South African Bottomside Ionospheric Model (SABIM), and measurements from ionosondes in the South African Ionosonde Network, were combined within their own limitations to develop an accurate representation of the South African ionosphere. The map is essentially in the form of a computer program that shows spatial and temporal representations of the South African ionosphere for a given set of geophysical parameters. A validation of the map is attempted using a comparison of Total Electron Content (TEC) values derived from the map, from the IRI model, and from Global Positioning System (GPS) measurements. It is foreseen that the final South African ionospheric map will be implemented as a Space Weather product of the African Space Weather Regional Warning Centre

Flocculating Properties of a Bioflocculant Produced by Bacillus sp. Isolated from a Marine Environment in South Africa

We assessed the bioflocculant production by a bacteria isolated from a marine environment in South Africa. The 16S rDNA nucleotide sequence analyses revealed the bacteria to have a 99 % similarity to Bacillus sp. A-5A and the sequence was deposited in the Genbank as Bacillus sp. MAYA (accession number JF799093). Bioflocculant production by the bacteria was optimal when glucose (95.6 % flocculating activity) and ammonium nitrate (83.3 % flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 2 % (v/v); initial pH 6; and Ca2+ as coagulant aid. Chemical analysis of the purified bioflocculant shows that it is composed of uronic acid, neutral sugar and protein. FTIR analysis reveals the presence of methoxyl, hydroxyl, carboxyl and amino-groups in the compound bioflocculant. The bioflocculant is thermostable with about 65.6 % residual flocculating activity retained after heating the bioflocculant at 100 °C for 25 minutes

Commensal Staphylococcus spp., Acinetobacter spp. and Stenotrophomonas maltophilia as reservoirs of antibiotic resistance genes

Staphylococcus species, Acinetobacter species and Stenotrophomonas maltophilia are of particular importance as they sometimes reside as flora on the intact skin and nasal passages of man and farm animals. Studies around the globe have shown them as “friends and foes” especially in immunocompromised individuals as they occur as commensals but sometimes as pathogens that infect, causing morbidity and consequently higher therapeutic cost. The occurrence of antibiotic resistance gene(s) in their genomes and their phenotypic display of resistance make them difficult to control and places a high demand on the assessment of such genes in the bacteria. In doing this, the less considered (commensals) have been described more recently as a reservoir for antibiotic resistance genes. The transfer of heavy metal and antibiotic resistance genes from Staphylococcus spp., a Gram positive bacterium to S. maltophilia and Acinetobacter species, Gram negative bacteria confer the resilience to control measures that is peculiar with the former on the latter. This attribute in Acinetobacter spp. and S. maltophilia have encouraged their inclusion in drug screening research. Intermittent assessment of resistance genes in the ecosystem should be embraced to foster appropriate measures against their spread.Keyword: Commensal, resistance genes, Staphylococcus, Acinetobacter, Stenotrophomonas maltophili

Assessment of water quality of Obueyinomo River, Ovia North East Local Government Area, Edo State, Southern Nigeria

This study was carried out to assess the water quality of Obueyinomo River using water quality index. Ambient and water temperatures were determined in-situ while total dissolved solids (TDS), total suspended solids (TSS), total solids (TS), turbidity, pH, conductivity, hardness, alkalinity, dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), chloride, nitrate, phosphate, calcium and magnesium levels were analyzed in the laboratory using standard techniques. With the exception of DO, the other physicochemical parameters showed no significant difference (p&gt;0.05) across the stations. Distribution patterns of physicochemical parameters in stations 1, 2 and 3 were analyzed using PCA. There was a strong association for stations 1, 2 and 3 which was also highly associated with nitrates. Hardness, magnesium calcium and phosphate formed a cluster showing the contributions of these ions to water hardness. Alkalinity, suspended solids and chloride formed a cluster suggesting that the suspended solids are largely composed of chlorides. Turbidity, pH, BOD and DO at all the stations exceeded the Federal Ministry of Environment standards for surface water. The water quality index (WQI) values at stations 1, 2 and 3 were 138.45, 122.70 and 170.01 respectively. The parameters responsible for the high values of WQI as indicated by the water quality rating include turbidity, pH, dissolved oxygen and biochemical oxygen demand. The high WQI values in all the stations studied which exceeded the benchmark of 100 showed that the water from this river is unfit for drinking purposes and should be treated before consumption by inhabitants of the area.Keywords:  Physicochemical parameters, River, Water quality index, Contaminatio

Moisture Sorption Isotherms of the Wood and Inner Bark of Ten Southern U.S. Hardwoods

The adsorption isotherms of the woods and inner barks of ten hardwoods, measured at 25 C and atmospheric pressure, were essentially identical, but the desorption isotherms for the barks were consistently lower than those for the woods. Three fundamental constants were required to evaluate the isotherms in terms of the Dent (1977) model, a modification of the classical BET surface model, and of the Hailwood-Horrobin (1946) single-hydrate solution model. Two of these constants are identical for the two models, but the third is somewhat lower for the Dent model. Both models divide the sorbed water into two components, one strongly bonded and the other more weakly bonded to the wood or bark substrate. Also both models predict an identical parabolic relationship giving the ratio of the relative humidity to the moisture content as a function of relative humidity

Leasing as an Alternative Source of Finance: The Nigerian Experience

The Nigerian economy is at present beset with multi-dimensional socio-political-economic problems. Globalization, deregulation, and the instability of the value of the naira have crippling effects on business organizations. Fiscal and monetary policies put in place to nurse the economy back to buoyancy have tended to squeeze and curtail credit expansion. This paper advocates that leasing is an alternative of finance that could be used to assist companies in particular and the Nigerian economy in general to the path of economic growth and development

Undergraduates' Perception of Causes of Youth Restiveness in Delta State of Nigeria

This study investigated undergraduates' perception of causes of youth. restiveness in Delta State of Nigeria. Four research questions were asked and four hypotheses formulated to guide the study. The study employed a descriptive survey design. A sample of 275 undergraduates drawn through multi-stage random sampling technique was used. A thirty item questionnaire titled "Undergraduates' Perception of the Causes of Youth Restiveness Inventory" UPCOYR was designed by the researchers and used for the study. The instrument had a Cronbach alpha co-efficient value of 0.76. The data were analyzed using descriptive statistics, t-test and Analysis of Variance (ANOVA). The results revealed the following: that there was no significant difference between the perception of male and female undergraduates of the causes of youth restiveness in Delta State, there was no significant difference between younger and older undergraduates in their perception of the causes of youth restiveness. But there was significant difference between the perception of younger and older undergraduates of the causes of youth restiveness. Lastly, there was significant difference among undergraduates in their perception of the causes of youth restiveness based on discipline. Recommendations were made based on the findings. Keywords: Undergraduates, Youth Restiveness, Causes of Youth Restiveness

Petroleum Hydrocarbon Fingerprints of Water and Sediment Samples of Buffalo River Estuary in the Eastern Cape Province, South Africa

. Surface water and sediment samples were collected from five points in the estuary and extracted using standard methods. The extracts were subsequently analyzed by gas chromatography-flame ionization detection. Results showed that total petroleum hydrocarbon (TPH) varied from 7.65 to 477 g/L in the water and 12.59 to 1,100 mg/kg in the sediments, with mean values of 146.50 ± 27.96 g/L and 209.81 ± 63.82 mg/kg, respectively. Concentrations of TPH in the sediments correlated significantly with organic carbon (OC) in both seasons. TPH and OC levels were slightly lower in summer than in autumn in the two environmental matrices, and the average amount of TPH in the water samples collected from all the sampling stations was generally lower than the EU standard limit of 300 g/L. However, the levels in the sediments exceeded the EGASPIN target value (50 mg/kg) for mineral oil but were below the intervention value (5,000 mg/kg), indicating a serious impact of industrial growth and urbanization on the area, although the n-alkane ratios and indexes used for source tracking revealed excessive flow from both natural and anthropogenic sources