Browse

You are looking at 1 - 10 of 29 items for :

  • Analytical Chemistry x
Clear All
Open access

Anthony M. Ugbenyen, John J. Simonis and Albertus K. Basson

Abstract

Flocculants are chemicals that mediate flocculation process, by aggregating colloids from suspension to form floc. Chemical flocculants are hazardous to the environment, which inform the search for safer and eco-friendly alternatives from microorganisms. Bacterial strains were isolated from water and sediment samples collected from Sodwana Bay, South Africa, and physiological properties of the bacterial strains were observed. Flocculation test using kaolin clay suspension was done on all isolates and the ones that showed flocculating activity were identified molecularly using 16 rRNA gene sequence analysis. Forty marine bacteria isolates were gotten from sediments and water samples collected from Sodwana Bay. Most of the isolates exhibited a range of colony pigmentation (pink, creamy, yellow, and white). After purification of individual isolates, they were screened for their potential to produce bioflocculant. The result revealed that isolates marked SOD3, SOD10, SOD12, SOD26, SOD27, SOD28, SOD32, SOD33 and SOD34 produced bioflocculants as shown by the flocculating activities from their crude extract. All these isolates showed good flocculation of kaolin clay suspension above 60% (flocculating activity) except SOD12. These bioflocculant producing isolates were identified as Pseudoalteromonas sp, Alcaligenes faecalis, Bacillus subtilis, Bacillus cereus, Bacillus stratosphericus. The results showed Sodwana Bay, South Africa as a reservoir of bacteria with potential to produce flocculants. However, further studies on the optimisation of culture conditions for bioflocculant production, extraction, characterisation and application of isolates is on the way to underscore the biotechnological importance of these microbes as producers of substitutes to harmful chemical flocculants commonly used in water and wastewater treatment.

Open access

Olatunji M. Kolawole, Ajibola O. Ayodeji and Jeremiah I. Ogah

Abstract

Rift Valley fever virus (RVFV) is a zoonotic virus classified as category A priority pathogen. Rift Valley fever (RVF) has been poorly investigated in Nigeria with the infection among Nigerians last reported in 1996. Two hundred (200) febrile subjects with symptoms of malaria attending local hospitals in Ilorin, Nigeria were investigated for malaria, malaria positive subjects were investigated for the presence of RVF. Malaria screening was done using Carestart TM malaria HRP2(pf), while RVF antibodies were tested for using anti-RVF IgM ELISA. Molecular identification of the viral genome was carried out using RNA extraction (QIAGEN) and quantitative Polymerase Chain Reaction (qPCR). Of the 200 subjects tested for malaria infection, 93 (46.5%) were positive, while 20 (21.5%) of the 93 subjects were seropositive for RVF. RVF virus genome was found in 5 (25%) of the 20 positive subjects. The high prevalence of RVF among malaria positive subjects show that there is a risk of a RVF outbreak if its prevalence remains unchecked.

Open access

Oladipupo R. Akolade, Alaribe S. Chinwe, Balogun T. Olalekan, Akere T. Halima, Ayanda A. Fatima, Toye T. Emuejevoke and Coke A.B. Herbert

Abstract

Phytochemical constituents of plants extracts have been well investigated as leads for drug discovery and development. However, aside their immense medicinal properties, their safety is also of paramount importance, therefore evaluating the toxicity of plants extracts and their phytochemicals is an important aspect of quality measures to meet the requirements for consumption.This study was done to identify the volatile phytochemical compounds present in n-hexane extract of Uvaria chamae stems (UCSH) with the aid of gas chromatography-mass spectrometry (GC-MS) and to evaluate the effects of this non-polar extract on DNA using diphenylamine (DPA) and agarose gel electrophoresis assays, also to investigate the haematological parameters using an auto Haematology Analyzer.The GC-MS analysis of UCSH identified some compounds which include; squalene, lupeol, stigmasterol, β-sitosterol, and Benzyl benzoate with excellent medicinal properties. Genotoxicity assays results showed significant reductions in DNA fragmentation in liver and testis cells of mice as against the DNA biomarker and vehicle control group. Haematological results showed significant increase in white blood cells (WBC), red blood cell (RBC), platelets (PLT) and lymphocytes (LYMP) but significant reduction in mean corpuscular - volume (MCV), haemoglobin (MCH), and haemoglobin concentration (MCHC).The present study showed that the phytochemicals present in the n-Hexane extract of Uvaria chamae stems may play protective role in the genomic DNA of liver and testis tissues and also may induce hematological changes which may enhance the immune system.

Open access

Elijah A. Adebayo, Musibau A. Azeez, Olusola N. Majolagbe and Julius K. Oloke

Abstract

Genetic diversity in nineteen strains of Pleurotus was studied using morphometric traits and growth factors. Ability of the isolates of these strains to tolerate different ranges of temperature and pH were evaluated. Highest mycelial growth rates were obtained at 25 °C (mutants and hybrids) and 30 °C (wild type), while LAU 90 (mutant) performed satisfactorily at all evaluated temperature ranges (15-35 °C). Highest mycelial yields (dry weight) were produced by LAU 90 at different pH regimes (4.0 - 9.0), while hybrids LN 97 and LN 98 maximally produced mycelial yield at pH 5.0 and 7.0, respectively. Analysis od Principal component (PC) revealed that components of these strains accounted for 86.1% of total variations among the strains with first PC recording 44.6%. The dendrogram discriminated nineteen Pleurotus genotypes into two major genetic groups with mutants and hybrid strains in Cluster A, separated distinctly from wild parents in Cluster B, indicating genetic diversity. The expression of heterosis can be maximized by information obtained among the hybrid strains and mutant (LAU90) strain. The hybrid (LN98) strain with superior performance may be selected for adoption in commercial mushroom production.

Open access

Tolulope A. Oyedeji, Chibuzor I. Akobi, Daniel O. Onireti and Olufunso O. Olorunsogo

Abstract

Mitochondrial dysfunction (MD) and impaired apoptotic pathways cause irreversible opening of the Mitochondrial Permeability Transition (MPT) pore, resulting in several pathological conditions e.g. cancer, ageing and neurodegenerative diseases. Many bioactive compounds from plants have been identified as modulators of the MPT pore which makes them possible drugs for the management of MD associated diseases. Adenopus breviflorus (A.breviflorus) is a tropical medicinal plant used in folkore medicine as an abortifacient and in treating gonorrhoea. In this study, the effects of ethylacetate and methanol fractions of A.breviflorus were assessed on rat liver MPT pore and Mitochondrial ATPase (mATPase). The fruit of A.breviflorus was extracted with water to obtain the aqueous Extract (AEAB), which was fractionated using vacuum liquid chromatography (VLC) to obtain ethylacetate and methanol fractions of A.breviflorus (EFAB, and MFAB). The extent of MPT pore opening and mATPase by EFAB and MFAB were assayed spectrophotometrically. The results obtained showed that EFAB and MFAB have no significant inductive effect on the MPT pore in the absence of Ca2+. However, in the presence of Ca2+, EFAB inhibited calcium-induced MPT pore opening in a non-concentration dependent manner. Maximum inhibition of MPT pore opening was 57.1% at 50 μg/ml. Interestingly, MFAB potentiated calcium ion effect by opening the pore further. Specifically, MFAB opened the MPT pore by 11, 10, 17 and 9% at 50, 150, 250 and 350 μg/ml, respectively. Furthermore, EFAB and MFAB inhibited mATPase activity in rat liver mitochondria at 62.5, 187.5, 312.5 and 437.5 μg/ml by 2.6, 18.8, 37.3, 52.6% and 41.8, 6.8, 24.3, 8.4%, respectively. The ethylacetate and methanol fractions of Adenopus breviflorus possess potential phytochemicals that can modulate opening of the mitochondrial permeability transition pore and inhibit mitochondrial ATPase activity in rat liver. These fractions may find use in drug development against diseases where excessive apoptosis takes place.

Open access

Temitope O. Olomola, Tawakalit O. Kelani, Mojisola C. Cyril-Olutayo and Joseph M. Agbedahunsi

Abstract

Some salicylaldehyde-derived Baylis-Hillman adducts and 3-(chloromethyl)coumarins have been synthesised and evaluated in vitro for their antisickling activities. The compounds were screened for inhibitory and reversal activity against mutated haemoglobin (HbSS) in red blood cells at four different concentrations (4 mg/mL, 2 mg/mL, 1 mg/mL and 0.5 mg/mL) as a measure of their antisickling potentials. Among the synthesized compounds, 6-chloro-3-(chloromethyl)coumarin 4d showed the highest inhibitory activity (83.75±1.90%), followed by 6-chlorocoumarin-3-methylsulfinic acid 5d (80.90 ±0.91%) and the least was tert-butyl-3-hydroxy- 3-(2-hydroxyphenyl)-2-methylenepropanoate 3a (33.33±1.86%). The results obtained from the reversal antisickling experiment showed that the percentage of sickle cells able to revert to the normal biconcave shape was dose dependent. Compound 5d had the highest reversal activity (66.49±1.39%) followed by 6-bromo-3- (chloromethyl)coumarin 4c (59.66±2.95) and 4d (55.50±1.95%) at 4 mg/mL. Compound 4c had higher reversal activity than the standard p-hydroxybenzoic acid at 2 mg/mL, 1 mg/mL and at 0.5 mg/mL. The 3-substituted coumarins 4a-d, and 5d had higher inhibitory antisickling activities than their Baylis-Hillman precursors 3a-d. Effect of 4a-d and 5d on the rate of polymerization of sickle cell heamoglobin was further studied spectrophotomerically using hemolysate of HbSS. The considerable inhibitory and reversal activities of these compounds make them good candidates for further antisickling studies.

Open access

Olusola N. Majolagbe, Elijah A. Adebayo, Abiodun Ayandele and Louis Ezediuno

Abstract

Microbes play significant roles in remediation of heavy metal polluted industrial effluent using the mechanisms of biosorption and bioaccumulation. In the present study, six heavy metal resistant autochthonous bacteria species namely Bacillus cereus, B. megaterium, B. subtilis, Flavobacterium aquatile, Pseudomonas flourescens and Pseudomonas putida were isolated from effluent samples collected from Paper-mill industry (PMI), Paints and Chemicals Industry (PCI), and Steel-rolling Industry (SRI). The isolates were studied for their heavy metal tolerant capacities at different aqueous salt concentrations. Elemental analysis of the industrial effluent samples collected indicated the presence of heavy metals such as Copper (Cu2+), Manganese (Mn2+), Iron (Fe2+) and Lead (Pb2+) at varying concentrations in μg/ml. Generally, there were variations in the minimum inhibitory concentrations (MIC) of the heavy metal salt to each of the bacteria understudy. The MIC value of each of the bacterial isolates to aqueous solution of Cu2SO4 showed that B. megaterium, B. subtilis, Pseudomonas flourescens and Pseudomonas putida had the same MIC value of 20 ± 1.5 μg/mL while Bacillus cereus and Flavobacterium aquatile had MIC values of 13 ± 1.3 μg/mL and 25 ± 2.1 μg/mL respectively. This variation was also noticeable in aqueous salts of Mn2SO4, Fe2SO4 and Pb2SO4. The bacteria isolates showed sensitivity to heavy metals with increasing zone of inhibition as concentration increased with each isolate showing varying degree of metalotolerance. The effectiveness of the autochthonous bacteria as a means to bio-augment the remediation of heavy metal polluted industrial effluent was further proven and recommended.

Open access

A Adetoro, S.O. Idris, A.D. Onu and F.G Okibe

Abstract

Kinetics of oxidation of Lysine (Lys) and mechanisms by μ-peroxo bis[bis(ethylenediamine)succinimidato-dicobalt(III)]dinitratedihydrate; [LCo(μ-O2)CoL](NO3)2.2H2O (L = suc(en)2), hereafter the complex, was investigated at 420 nm wavelength of maximum absorption of the complex under the conditions hydrogen ions concentration = 1.8 × 10-2 mol dm-3, temperature = 24 ± 1 °C, [LCo(μ-O2)CoL2+] = 1.4 × 10-4 mol dm-3 and ionic strength = 0.5 mol dm-3. First order in [LCo(μ- O2)CoL2+] and [Lys] were obtained but inverse first order in [H+]. The proposed overall rate equation is as shown:

Rate of the reaction decreases when hydrogen ions concentration increase and exhibited converse effect with increase in concentration of ionic strength from 0.1 - 1.3 mol dm-3. Added cations and anions affected the reaction rate and the Michaelis-Menten plot passed through the origin indicating no absence of intermediate complex in the electron transfer processes. Putting all the results obtained together, the most probable reaction mechanism is in favour of outer-sphere and an appropriate rate law is established using steady state approximation.

Open access

Olusola N. Majolagbe, Elijah A. Adebayo, Abiodun Ayandele and Louis Ezediuno

Abstract

Microbes play significant roles in remediation of heavy metal polluted industrial effluent using the mechanisms of biosorption and bioaccumulation. In the present study, six heavy metal resistant autochthonous bacteria species namely Bacillus cereus, B. megaterium, B. subtilis, Flavobacterium aquatile, Pseudomonas flourescens and Pseudomonas putida were isolated from effluent samples collected from Paper-mill industry (PMI), Paints and Chemicals Industry (PCI), and Steel-rolling Industry (SRI). The isolates were studied for their heavy metal tolerant capacities at different aqueous salt concentrations. Elemental analysis of the industrial effluent samples collected indicated the presence of heavy metals such as Copper (Cu2+), Manganese (Mn2+), Iron (Fe2+) and Lead (Pb2+) at varying concentrations in μg/ml. Generally, there were variations in the minimum inhibitory concentrations (MIC) of the heavy metal salt to each of the bacteria understudy. The MIC value of each of the bacterial isolates to aqueous solution of Cu2SO4 showed that B. megaterium, B. subtilis, Pseudomonas flourescens and Pseudomonas putida had the same MIC value of 20 ± 1.5 μg/mL while Bacillus cereus and Flavobacterium aquatile had MIC values of 13 ± 1.3 μg/mL and 25 ± 2.1 μg/mL respectively. This variation was also noticeable in aqueous salts of Mn2SO4, Fe2SO4 and Pb2SO4.The bacteria isolates showed sensitivity to heavy metals with increasing zone of inhibition as concentration increased with each isolate showing varying degree of metalotolerance. The effectiveness of the autochthonous bacteria as a means to bio-augment the remediation of heavy metal polluted industrial effluent was further proven and recommended.

Open access

Ahmed Adetoro, Suleiman O. Idris, Ameh D. Onu and Friday G. Okibe

Abstract

Kinetics of oxidation of Lysine (Lys) and mechanisms by μ-peroxo bis[bis(ethylenediamine)succinimidato-dicobalt(III)]dinitratedihydrate; [LCo(μ-O2)CoL](NO3)2.2H2O (L = suc(en)2), hereafter the complex, was investigated at 420 nm wavelength of maximum absorption of the complex under the conditions hydrogen ions concentration = 1.8 × 10−2 mol dm−3, temperature = 24 ± 1 °C, [LCo(μ-O2)CoL2+] = 1.4 × 10−4 mol dm−3 and ionic strength = 0.5 mol dm−3. First order in [LCo(μ-O2)CoL2+] and [Lys] were obtained but inverse first order in [H+]. The proposed overall rate equation is as shown:

Rate=(k1k2+K1k3k41[H+])[LCo(μO2)CoL2+][Lys]

Rate of the reaction decreases when hydrogen ions concentration increase and exhibited converse effect with increase in concentration of ionic strength from 0.1 – 1.3 mol dm−3. Added cations and anions affected the reaction rate and the Michaelis-Menten plot passed through the origin indicating no absence of intermediate complex in the electron transfer processes. Putting all the results obtained together, the most probable reaction mechanism is in favour of outer-sphere and an appropriate rate law is established using steady state approximation.