Time filter

Source Type

Madukasi E.I.,Harbin Institute of Technology | Madukasi E.I.,Federal Institute of Industrial Research | Chunhua H.,Harbin Institute of Technology | Zhang G.,Harbin Institute of Technology
International Journal of Environmental Science and Technology | Year: 2011

A new photosynthetic bacterium isolate was morphologically identified as a non-motile rod-shape gram-negative bacterium. It produced a dark red culture under phototrophic condition, reproduced by budding and formed a lamellar intracytoplasmic membrane system parallel to cytoplasmic membrane, which contained bacteriochlorophyll a and caratenoids. It's physiological and nutrient requirement tests gave indication that the isolate thrived and multiplied in varied environmental conditions. It was consequently named Z08 and identified as Rhodobacter sphaeroides by 16SrDNA. Adaptation of Z08 to biodegradation of two environmentally concerned wastewaters, i.e. soybean and pharmaceutical wastewaters, attested its potential in wastewater bioremediation. Z08 adaptation in a suspended batch photobioreactor treating pharmaceutical wastewater at 3500lx radiation recorded best result after wastewater dilution of 1:4 with concomitant chemical oxygen demand reduction, biomass yield and specific growth of 50 %, 780 mg/L and 0.015/h, respectively at the lowest hydraulic retention time of three days. Furthermore, gas chromatography mass spectra analyses of treated and raw pharmaceutical wastewater indicated that high molecular weight recalcitrant compounds found in the pharmaceutical wastewater were transformed to less toxic and acceptable lower molecular weight substances through biodegradation. Whilst Z08 treatment of soybean wastewater under natural light intensity radiation recorded 80 % reduction, 1540 mg/L and 0.025/h for chemical oxygen demand, biomass and specific growth rate respectively regardless of the food to microorganism ratio. This preliminary investigation showed that isolate Z08 has some toxic tolerance level which could detoxify refractory substances with great potential for cell protein recovery in high organic strength wastewater. Therefore, strain Z08 could be employed in biodegradation of contaminated wastewater streams. © IRSEN, CEERS, IAU.

Orji F.A.,Federal Institute of Industrial Research | Ibiene A.A.,University of Port Harcourt | Okerentugba P.O.,University of Port Harcourt
American Journal of Environmental Sciences | Year: 2013

Laboratory-scale studies were carried out using a nutrient formula produced from Eicchornia crassipes plant to achieve bioremediation of crude oil impacted mangrove soil. In a 70 day study, the culturable heterotrophic bacterial population of the Eichhornia crassipes recipe increased from 6.26×05 Cfu/g to 2.69×107 Cfu/g. The control set-up had its total culturable bacterial count increased from 5.76×05 Cfu/g to 1.24×106 Cfu/g. Statistical analyses showed significant difference for the two conditions (p > 0.05). The total culturable heterotrophic fungal count in the Eichhornia crassipes recipe treatment increased from 5.36×105 Cfu/g to 2.50×107 Cfu/g respectively. The total culturable hydrocarbon utilising bacteria in Eichhornia crassipes treated polluted mangrove soil increased from 2.52×104 Cfu/g to 3.81×107 Cfu/g. Statistical analyses showed significant difference at p > 0.05 level for the two conditions (Eicchornia crassipes nutrient treated soil and control). The conductivity value of the Eichhornia crassipes recipe treated soil decreased progressively. Phosphate, nitrate, %total organic carbon, Total Hydrocarbon Content (THC). Studies using Gas chromatographic analyses showed that in the Eichhornia crassipes recipe treated polluted mangrove soil, 0, 58.92 and 75.36% were lost at zero hour, 28th day and 70th day respectively. In addition, in the control experimental set-up, 0, 7.14 and 13.42% of TPH were lost at zero hour, 28th day and 70th day respectively. There was no significant difference between the control experiment and Eichhornia crassipes (p = 0.054). The use of organic nutrient sources such Eichhornia crassipes recipe/nutrient powder is of good use as source of limiting nutrient needed for bioremediation of crude oil impacted medium. © 2013 Science Publication.

Oluwole O.B.,Federal Institute of Industrial Research | Olapade A.A.,University of Ibadan | Awonorin S.O.,Abeokuta Federal University of Agriculture | Henshaw F.O.,Abeokuta Federal University of Agriculture
International Agrophysics | Year: 2013

This study was conducted to investigate effects of extrusion conditions on physicochemical properties of blend of yam and bambara nut flours. A blend of white yam grit (750 μm) and Bambara nut flour (500 μm) in a ratio of 4:1, respectively was extrusion cooked at varying screw speeds 50-70 r.p.m., feed moisture 12.5-17.5% (dry basis) and barrel temperatures 130-150°C. The extrusion variables employed included barrel temperature, screw speed, and feed moisture content, while the physicochemical properties of the extrudates investigated were the expansion ratio, bulk density, and trypsin inhibition activity. The results revealed that all the extrusion variables had significant effects (p<0.05) on the product properties considered in this study. The expansion ratio values ranged 1.55-2.06, bulk density values ranged 0.76-0.94 g cm-3, while trypsin inhibition activities were 1.01-8.08 mg 100 g-1 sample. © 2013 Institute of Agrophysics.

Kuforiji O.O.,Bells University of Technology | Kuboye A.O.,Federal Institute of Industrial Research | Odunfa S.A.,University of Ibadan
International Journal of Plant Biology | Year: 2010

Orange (pulp) and pineapple wastes were used as substrates for citric acid production by two strains of Aspergillus niger. A. niger strains NRRL 567 and 328 produced the maximum amount of citric acid (57.6% and 55.4%, respectively) at a moisture content of 38.9% in orange waste and the highest yields of 46.4% and 45.4% citric acid in pineapple waste at moisture contents of 54.4% and 63.4 %, respectively. The addition of 1-3% methanol to the substrates resulted in reduction in yield in both cases. © Kuforiji Olubukola et al.

Ahmed A.S.,University of Pretoria | Ahmed A.S.,Federal Institute of Industrial Research | McGaw L.J.,University of Pretoria | Eloff J.N.,University of Pretoria
BMC Complementary and Alternative Medicine | Year: 2013

Background: Microbial infections and resulting inflammation and oxidative stress are common pathogenesis of gastrointestinal tract (GIT) disorders. In South Africa, several species of the genus Maytenus are used in traditional medicine to treat various infectious diseases. Most of the previous work on this genus was focused on nonpolar extracts from the root and bark. In this study, leaf extracts of polar extracts of Maytenus peduncularis, Maytenus procumbens, Maytenus senegalensis and Maytenus undata were evaluated for antimicrobial, anti-inflammatory and antioxidant activities to determine their efficacy as therapeutic agents in GIT disorders.Methods: Phenolic-enriched leaf extracts and fractions were prepared by extracting with acidified 70% methanol and solvent-solvent fractionation. The activities of the fractions against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis as well as clinical isolates of Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans were determined using a serial microplate dilution method. Antioxidant activities were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH) radical scavenging and linoleic acid peroxidation inhibitory assays. The phenolic composition as well as the cytotoxicity against Vero cell lines of the crude extracts was evaluated using various standard protocols.Results: The antimicrobial activities were concentrated in the non-polar fractions of hexane, dichloromethane and ethyl acetate (MICs 19-312 μg/ml). The crude extracts and polar fractions (butanol and water) had moderate to poor antimicrobial activity (MICs 312 to above 2500 μg/ml). The crude extracts and polar fractions had good antioxidant activity (EC50 values varied from 1.22 to 607 μg/ml, 1.71 to 312 μg/ml and 23 to 284 μg/ml for DPPH, ABTS and OH respectively. Linoleic acid peroxidation inhibition EC50 values of the crude extracts ranged between 27 and 39 μg/ml with relatively low toxicity against Vero cell lines (IC50 values 87 to 187 μg/ml). Fractionation of a crude extract with low activity could lead to fractions with more potent activity.Conclusion: This study justifies the traditional use of leaf crude extracts and fractions from these four plants to remedy gastrointestinal disorders resulting from infection, inflammation and oxidative stress complications. The study also provides rationale for the use of leaf extracts with same beneficial effects in place of unsustainable root and bark harvest. © 2013 Ahmed et al.; licensee BioMed Central Ltd.

Discover hidden collaborations