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Item MODELLING OF HEAVY METAL BIOACCUMULATION OF Eichhornia crassipes [MART.] SOLMS AND Pistia stratiotes L. IN OLOGE LAGOON, LAGOS, NIGERIA(2016-03) NDIMELE, C. C.Macrophytes such as Eichhornia crassipes and Pistia stratiotes are known bioaccumulators found in the Ologe Lagoon which receives effluents mainly from Agbara Industrial Estate. However, the mechanism of heavy metal bioaccumulation by these macrophytes has not been fully understood. This study was designed to determine the mechanism of heavy metal bioaccumulation and model the phytoremediation capabilities of the macrophytes. Five sampling stations: Owo (before the point of discharge of effluent as control), Agbara, Otto Jetty, Morogbo and Etegbin (after the point of effluent discharge) were selected for the study. Water samples, sediments, E. crassipes and P. stratiotes were collected using standard procedures in these stations from July, 2013 to December, 2014 from the lagoon and analysed for heavy metals using standard methods. Temperature, pH, Conductivity, Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Dissolved Oxygen (DO) were determined according to APHA methods. Selected heavy metals: Zn, Fe, Cu, Pb and Cd in water, sediments and the two macrophytes were determined in accordance with FAO/SIDA method. Eichhornia crassipes and P. stratiotes were grown in three different concentrations (10, 15 and 20 mg/L) of CuSO4.5H2O; ZnSO4; FeSO4.7H2O and Pb(NO3)2 in three replicates for six weeks. Thereafter, plant leaves, stems and roots were harvested and analysed for metal bioaccumulation and translocation. Time evolution of pollution was determined using first and second-order kinetic models. Data were analysed using descriptive statistics, ANOVA and Fisher’s LSD test (α0.05). Water temperature ranged from 28.7±0.37-29.4±0.69°C, pH (6.7±0.1-6.9±0.1), Conductivity (1565±784.7-3088±1478.6 µS/cm), TSS (10.4±0.5-20.6±1.2 mg/L), TDS (89.2±1.8-1739±872.2 mg/L), BOD (2.9±0.7-3.7±0.2 mg/L), COD (13.8±0.8-23.9±1.0 mg/L) and DO (4.2±0.2-4.9±0.2 mg/L). The concentration of Zn (30±2.0 µg/L) in water sample was higher than the USEPA limit (6 µg/L at 45 mg/L hardness) for the protection of aquatic ecosystems. The highest {Fe (2310±613 mg/kg) and Cu (38.20±10.21 mg/kg)} and lowest {Fe (1305±848 mg/kg) and Cu (2.92±0.37 mg/kg)} concentrations in sediment were recorded in Agbara and Etegbin respectively. The concentration (mg/kg) of heavy metals in E. crassipes and P. stratiotes from Agbara was significantly higher (Fe=1368±236.12; Zn=42.60±5.62) than values obtained from other sampling stations (Fe=470±55.96-642.58±303.26; Zn=11.14±1.83-20.41±4.31). In the laboratory experiment, metals were accumulated through the roots to the shoot (phytoextraction) via a concentration gradient (for E. crassipes pots spiked with 10, 15 and 20 mg/L of Zn, the average quantity of the metal absorbed were 5.56±0.09, 8.89±0.60 and 15.58±0.15 mg/L respectively). The bioaccumulation factor in E. crassipes varied from 10 (Pb) to 9000 (Fe) while in P. stratiotes, it varied from 9 (Pb) to 8500 (Cu). Translocation factors were higher in root/stem (7.06±1.09 for Pb) than stem/leaf (5.42±1.12 for Pb). Iron accumulation in different parts of E. crassipes {(mg/kg) was: {leaf (0.45±0.06-15.58±0.15); stem (0.33±0.05-16.48±0.44); root (0.40±0.07-18.50±3.16)} and P. stratiotes was: {leaf (0.36±0.06-6.67±1.17) and root (0.45±0.08-7.49±1.78)}. Pots seeded with Fe maintained green colouration for a longer time than those seeded with Cu, Zn and Pb. The time evolution of pollution was best described by first-order kinetic model. Eichhornia crassipes and Pistia stratiotes bioaccumulated heavy metals and the mechanism of bioaccumulation is a function of time and level of concentration of the heavy metals.Item MYCOTOXIN PRODUCTION AND MOLECULAR CHARACTERISATION OF Penicillium SPECIES ISOLATED FROM MILLET GRAINS (Pennisetum glaucum) (L.) R. Br.) IN SOUTHWESTERN NIGERIA(2017-01) KOTUN, B. C.Millet, a widely consumed food crop, is subject to fungal contamination during storage. These fungi produce mycotoxins in stored food products. Mycotoxins such as citrinin and ochratoxin produced by Penicillium species have been reported to be injurious to consumers. Knowledge of the fungi involved in the production of these mycotoxins will help in the control of its spread in food products. However, there is dearth of information on the mycotoxins produced by Penicillium on millet grain and the species characterisation with molecular technique in Nigeria. Hence, this study was designed to investigate the distribution of Penicillium species and determine the presence of mycotoxins in the millet grains with molecular techniques. Samples of millet grains were purchased from three randomly selected markets each in Lagos, Ogun, Ondo, Oyo and Ekiti states all in southwestern Nigeria. One hundred grains from each of the millet samples were employed for isolation of fungi using Dichloran rose bengal chloramphenicol agar. Morphological identification of the fungal isolates was done using Pitt`s manual. The DNA of the Penicillium species were isolated using standard procedures. Similarities between species were determined by amplifying their internal transcribed spacer (ITS1, ITS4) region and partial beta tubulin gene (Bt2a, Bt2b). Physiological assessment of the Penicillium isolates which includes optimum pH, carbon and nitrogen sources, temperature and incubation time for mycelial growth were carried out using standard methods. Toxigenic screenings of the isolates were carried out by amplifying the genes pksCT, ctnA, orf3 and otanps responsible for citrinin and ochratoxin production. The effects of pH and temperature on mycotoxin production were determined and quantified using Enzyme linked immunosorbent assay. Data were analysed using descriptive statistics. Thirty-four isolates were obtained, out of which twenty-three were identified as Penicillium citrinum (17), P. capsulatum (1), P. simplicissimum (1), P. oxalicum (1), P. steckii (2) and P. chrysogenum (1). Distributions among the states were Ondo: Penicillium citrinum, P. simplicissimum and P. oxalicum, Ogun: Penicillium citrinum and P. chrysogenum while only Penicillium citrinum was obtained from Lagos, Oyo and Ekiti states. Twenty-one isolates showed amplification to the beta tubulin gene with a uniform amplicon size of 500 base pair, while P. simplicissimum and P. oxalicum exhibited variation in amplicon fragement sizes (450 and 550 base pair), respectively. Physiological assessment of the isolates showed optimum growth at pH 8 having 2.51 g Mycelia Weight (MW) and starch as carbon source having (2.14 g MW), (NH4)2SO4 as nitrogen source having (0.86 g MW), optimum temperature was at 30 °C having (0.96 g MW) and 14 days as best incubation time with 0.94 g as dry MW. Toxigenic genes ctnA (678-679 base pair), orf3 (428-447 base pair) and otanps (788 base pair) was detected in six Penicillium (26%) isolates. Ochratoxin production was highest at pH 8 with 7.0 ppb, and at 25 °C with 5.0 ppb. Distribution of Penicillium on millet grain across the study area was determined, the isolates were characterised and mycotoxin from Penicillium citrinum was found to be above the standard permissible limit of ochratoxin.Item EVALUATION OF RHIZOBIUM AND MYCORRHIZA INTERACTIONS IN SUSTAINABLE MAIZE (Zea mays L.) AND SOYABEAN (Glycine max L.) PRODUCTION(2014-09) AMUSAT, M.A.Maize and soyabean are among the staples in the world. Their sustainable production through the use of synthetic fertilizer causes soil degradation and ground water contamination. An alternative means of boosting and sustaining the production of these staples through the use of rhizobium and mycorrhiza have been reported but there are contradictory reports on interactions between the two organisms. Therefore, the objective of this study was to assess the influence of Rhizobium japonicum and Glomus etunicatum on maize and soyabean production. Three farmlands in Oyo town were purposively selected. In the first and second farmlands were planted sole maize and soyabean respectively and were rotated the following season while both crops were intercropped on the third farmland. The experimental layout was randomised complete block design in split plot with three replications. The treatments were mycorrhizal, rhizobium, combined inoculations and uninoculated (controls). Maize was inoculated with Glomus etunicatum, while soyabean was inoculated with Glomus etunicatum and broth of Rhizobium japonicum. The plants’ population densities were 66,667 and 266,667 respectively. Growth parameters were measured using established methods at two weeks interval. The plants’ biomass, yield, proximate and nutrient analyses were determined usin g standard methods. Data were analysed using descriptive statistics and ANOVA at p = 0.05. The average heights (cm) of mycorrhiza, rhizobium and combined inoculated plants were 59.8±3.0, 68.3 ±1.8 and 63.7±1.2 respectively while that of their uninoculated counterparts was 52.7±3.4 in both sole and intercropped soyabean. Similarly, significant differences in biomass production were obtained between inoculated (3.7, 3.9, 3.9 g) and uninoculated (2.9 g) soyabean. Sole and rotated soyabean had significant biomass values which were 34.7 and 23.4 % respectively higher than the intercropped soyabean. There was no significant difference in nutrient contents of soyabean; its percentage proximate contents showed significant effects of rhizobium (4.5), mycorrhiza (4.0) or combined inoculation (4.2) in relation to uninoculated treatments (3.1). In intercropped and rotated maize, higher values of number of leaves and plant height were obtained in the mycorrhizal inoculated treatments compared with uninoculated counterparts. Biomass values of the intercropped and rotated maize were 15.5 and 12.5 % respectively higher than that of sole maize. There was significant main effect of mycorrhizal inoculation on nutrient contents of maize in intercropped and rotated farmlands. The grain yields of sole and combined inoculated soyabean ranged between 648.1–738.7 kgha-1 and significantly outweighed that of the uninoculated counterparts (524.6–584.9 kgha-1). There were no significant differences in grain yield of sole and intercropped maize, however, grain yield of rotated maize (585 kgha-1) was significantly higher than that of sole maize (512.9 kgha-1). Interactions between R. japonicum and G. etunicatum stimulated growth of both crops, while intercropping enhanced growth and biomass production of maize but had negative effects on soyabean. Interaction between Rhizobium japonicum and Glomus etunicatum had synergistic effects on growth of maize and soyabean. The combination of the two organisms and the systems of farming favoured the yield of both crops. The use of both microsymbionts combined with the cultural farming systems is therefore recommended to boost soyabean and maize production.Item STUDIES ON THE INFLUENCE OF VESICULAR ARBUSCULAR MYCORRHIZA AND FERTILIZATION ON CHILI PEPPER (Capsicum annuum L.) IN DIFFERENT CROPPING SYSTEMS(2011-11) ADETUNJI, J. A.Investigations were conducted with four pot and two field experiments on the influence of vesicular arbuscular mycorrhiza (VAM), and fertilization on chili pepper, Capsicum annuum var. tatase (Yoruba) in different cropping systems. All experiments were factorial in a randomized complete block design (RCBD) and each treatment was replicated three times. The first two pot experiments carried out in the Department of Botany and Microbiology, University of Ibadan under natural solar illumination and daily temperature, consisted of three types of VAM inoculation (Glomus mosseae, Glomus etunicatum and control), two levels of cropping systems (sole chili pepper and chili pepper intercropped with cowpea) and two levels of single superphosphate (0kg P/ha and 60kg P/ha) simultaneously in sterile and non-sterile soils. The third pot experiment consisted of three types of VAM inoculation (Glomus fasciculatum. Glomus mosseae and control), three levels of cropping systems (sole chili pepper, chili pepper with soybean intercrop and chili pepper with cowpea intercrop) and two levels of rock phosphate supplement (0kg P/ha and 60kg P/ha) in sterile. Finally the fourth pot experiment consisted of three species of VAM (Glomus mosseae, Glomus etunicatum and Glomus fasciculatum) three levels of organic fertilization (control, soybean intercrop and 5% organic manure) and three levels of rock P (0kg P/ha, 30kg P/ha and 60kg P/ha) also in sterile soil. The latter two pot experiments and the field experiments were located at National Horticultural Research Institute Ibadan, a derived savanna and transition zone between a tropical rain forest and southern guinea savanna. The first field experiment consisted of three types of VAM inoculation (Glomus mosseae, Glomus fasciculatum and control) three levels of cropping systems (sole chili pepper, chili pepper with cowpea intercrop and chili pepper with soya bean intercrop) and two levels of rock P (0kg P/ha and 60kg P/ha). The second field experiment consisted of three species of VAM fungi (Glomus mosseae, Glomus fasciculatum and Glomus etunicatum), three levels of organic fertilization (control, soya bean intercrop and 5% organic manure) and three levels of rock P (0kg P/ha, 30kg P/ha and 60kg P/ha). The soil pH (6.5) was significantly (P<0.05) reduced with Glomus mosseae inoculation while there was significantly (P<0.05) higher %C and Ca at 60kg P/ha than 0kg P/ha inorganic P supplement in non-sterile soil. Apart from P, the uptake of N, K, Ca, Mg, Zn and Fe were significantly (P<0.05) improved by mycorrhizal inoculation. The dry matter yield of mycorrhizal plant was significantly (P<0.05) higher than non-mycorrhizal plant with Glomus mosseae performing best in sterile soil. However, there was a significant drop (16%) in dry matter yield with the addition of 60kg P/ha single superphosphate. Mycorrhizal inoculated pepper plants had a twofold increase in fruit weight over uninoculated-mycorrhizal pepper plants. The use of rock P with organic manure in the presence of VAM enhanced fruit yield for chili pepper. There were significant (P<0.05) variations in the performance of mycorrhizal species in both pot and field experiments subject to soil environment and cropping systems. The experiment has provided the basis for the recognition of the fact that mycorrhizal activity is not only a component of plant system but also a soil-plant system improver.Item Studies on antimicrobial potentials of three ganoderma species(2010-05) Jonathan, S. G.; Awotona, F. EThe fruit bodies of three Ganoderma species namely G. lucidium, G. applanatum and G. australe were collected from the decaying logs within the University of Ibadan Botanical Gardens .Invitro antagonistic effect of the ethanol, methanol and distilled water extracts of these macro fungi were tested against some disease causing microorganisms. Both crude and pure extracts of these Ganoderma species exhibited various degree of inhibition against the test organisms. The widest inhibitory zone (20.3mm) were obtained with the crude methanolic extract of G. lucidium against Proteus mirabilis while the highest in-vitro antifungal activity (24.3mm) was observed in the crude ethanolic extracts of G. lucidium against Aspergillus niger. The lowest zone of inhibition (2.3mm) was demonstrated with the aqueous extract of G. australe against Escherichia coli and 2.7mm with purified extract of G. australe against Penicillum oxalium . The minimum inhibitory concentration (MIC) for the ethanol extract ranged between 1.7 and 5.0mg/ml for bacteria and between 2.0 and 6.0mg/ml for fungi. The implications of these findings were discussed.Item Comparative study of antibacterial activities of ethanol extracts of the bark and seeds of garcinia kola and caricapapaya(2011-05) Ogunjobi, A. A.; Ogunjobi, T. E.A comparative study of the antimicrobial activities of the bark and seed extracts of Garcinia kola and Carica papaya were tested using the Agar well diffusion method on eight bacterial strains - Staphylococcus aureus; Salmonella typhi B; Shigelladysenteria; Pseudomonas aeruginosa; Serratiamarcescens; Pseudomonas fluorescens; Proteus vulgaris; and Bacillus subtillis. Phytochemical screening shows that both bark and seed of the two plants contain reducing sugars, phenols and alkaloids whereas the pawpaw extracts contained tannins which were absent in the bitter kola plant part. Garcinakola on the other hand has saponin that was not present in Caricapapaya. The Garcinia seed ethanol extract manifested the best inhibitory activities against the test bacteria, producing inhibition zones ranging from 12–23mm. There was no resistance from any of the test bacteria. The pawpaw seed extract was also effective against the test bacteria. The inhibition zone observed ranged from 11-16mm. The ethanol extract of both plants were active against Staphylococcus aureus, Shigelladysenteria, Pseudomonas fluorescens; and Salmonella typhi B. Pawpaw leaf ethanolic extract significantly inhibited Pseudomiasaeruginosa, while Garcinia seeds ethanolic extract also inhibited Bacillus substilis. The activity index of ethanol extract of Garcinia kola seed was higher than that of pawpaw seed when both gentamicin and tetracycline were used as a standard antibiotics. The aqueous extract of both plant parts were not as effective as the ethanol extract. The activities of these medicinal plants against the tested bacterial species in this study justified their common use in African traditional medicine in the treatment of various ailments.Item Antibacterial activities of daldina concentrica(2011-01) Jonathan, S. G.; Olawuyi, O. J.; Popoola, O. O.; Aina, D. A.Activities of the distilled water, ethanolic and chloroform extracts of Daldina concentrica an ascomycetous fungus was investigated on Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus) using agar well diffusion method. Ethanolic extract of Daldina concentrica showed significantly antibacterial activity against all the test microorganisms except Bacilllus cereus (P ≤0.05). Staphylococcus aureus was the most sensitive organism to the extracts of this fungus with 17.0mm zone of inhibition with ethanol extract. It was also shown that chloroform extract of Daldinia concentrica possessed higher anti-bacterial activity against the five tested microorganisms. The effect of fresh tissues of the fungus on test bacteria indicated that Proteus mirabilis was the only sensitive organism with 5.0mm zone of inhibition while other bacteria were resistant. The implications of these findings were discussed.