Basic and Applied Sciences

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These are scholarly outputs of the Faculty of Basic and Applied Sciences

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Survival of Escherichia Coli in Lagos Lagoon
(1981) Amund, Olukayode O.; Ekundayo, J. A.; Ogunsanya, C. O.; Akpata, T. V. I.
There was a gradual decrease in the population of Escherichia coli incubated in autoclaved and unautoclaved (raw) water samples obtained from three different sampling stations of the Lagos lagoon. The survival period of the bacterium was generally shorter in the unautoclaved than in the autoclaved water sample; and also varied with the season. In November, 1976, the survival periods in unautoclaved (raw) samples were 6 and 8 days respectively; while in February, 1977 they were 12 days for all three water samples. For the autoclaved water samples the survival periods in November 1976 were 12 and 14 days; while in February, 1977 they were 22, 24 and 32 days. The survival period was also affected by seasonal variations in some physic-chemical parameters of the lagoon.
Increased L-ornithine production by an arg mutant of Acinetobacter lwoffi
(Springer-Verlag, 1983-07-01) Amund, Olukayode O.; Mackinnon, G.; Higgins, I. J.
The metabolic production of L-ornithine by an arg mutant of Acinetobacter Iwoffi using n-hexadecane as sole carbon source was studied. Time course experiments under optimised conditions showed that L-ornithine production was growth related, with maximum concentrations (10.5gl-1) accumulating in the late exponential phase of growth.
Observations on the Degradation of Crude Mineral Oil by an Estuarine Microbial Community.
(The Nigerian Society for Microbiology, 1984) Amund, Olukayode O.
An oil-degrading bacterium identified as Acinetobacter lwoffi. S2 was isolated by enrichment on the North Sea Forties oil from a water sample collected from the Medway estuary, Kent, England. This organism metabolises a wide range of long-chain n-alkanes (C8–C28) through the corresponding n-alkan-1-ols and n-alkanoic acids. A mixed microbial population was shown to effect a more extensive degradation of crude oil than single species. Simultaneous growth of five estuarine bacterial isolates on crude oil resulted in the synthesis of novel alkanes of higher molecular weights than those originally founds in the crude oil sample. Results of further investigation however, showed that the novel alkane synthesis could be attributed to the synergistic relationship in the estuarine microbial community.
EVALUATION OF GARLIC EXTRACTS ON CANCER GROWTH IN RATS FED DIETS WITH VARYING LEVELS OF PROTEIN.
(Howard University, 1984) Fakunle, Julius B.
Several aqueous plant extracts of common vegetables were screened for in vitro inhibition of tumor guanylate cyclase activity (the only enzyme known which produces cyclic GMP, a key regulator of cancer cell growth). One hundred and twenty young male rats (100-133g) were assigned to two major groups. One group of sixty animals was injected with transplantable Morris hepatoma (#3924A) one week after they had been placed onto their dietary regimen. Each major group was divided into six minor groups of ten rats each and was fed with three dietary protein levels of either 5%, 15% and 25% (without and with 5% lypholized garlic extract supplement). Non-tumor bearing animals fed 5% or 15% protein ate significantly (p < 0.05) more food than the tumorbearing animals (10.8 vs 9.3g). At the end of four weeks, dietary protein showed a significantly positive correlation with liver weight, kidney weight, tumor weight, tumor area and tumor tissue protein (p < 0.01). Serum and liver protein were significantly decreased in the tumor bearing animals. Low dietary protein significantly decreased tumor growth (p < 0.05) from 60-70%. All diets containing 5% garlic yielded decreased tumor growth from 10-25% (p < 0.05). Results of this study indicate that a decrease in dietary protein and/or a 5% garlic extract dietary supplement caused decreased growth of Morris hepatoma 3924A. It appears that garlic extract supplemented in the diet of experimental animals may help in cancer prevention.
The Degradation of 1-Phenylalkanes by an Oil-Degrading Strain of Alinetobacter Iwoffi
(Kluwer Academic Publishers, 1985-01-01) Amund, Olukayode O.; Higgins, I. J.
An oil-degrading bacterium identified as Acinetobacter lwoffi was isolated by elective culture on North Sea Forties crude oil from an activated sludge sample. It grew on a wide range of n-alkanes (C12 – C28) and 1 –phenylalkanes, including 1-pheny1dodecane, 1-pheny1tridecane and 1-pheny1tetradecane. The organism degraded 1-pheny1dodecane to phenylacetic acid which was further metabolized via homogentisic acid, whilst 1-phenyltridecane was transformed to trans-cin-namic and 3-pheny1propionic acid which were not further metabolized. Evidence is presented for a relationship between aromatic amino acid catabolism and 1-pheny1dodecane degradation in this organism.
A study of bacteria from the digestive system of two advanced termites (Isoptera, Termitidae) in Nigeria
(1986) Amund, Olukayode O.; Yakubu, O. S.; Malaka, S. L. O.
1. The total heterotrophic counts of bacteria present in the digestive system of Macrotermes bellicosus Smeathman and Amitermes evuncifer Silvestri were carried out. 2. The populations of bacteria in the guts of workers were generally higher than in those of soldiers. 3. A total of nineteen bacterial strains belonging to four main genera, namely Cytophaga, Micrococcus, Bacillus and Sarcina were isolated; six of these organisms were capable of producing cellulose-digesting enzymes. 4. The possible role of these cellulolytic bacteria in termite nutrition was discussed.
Occurence and Characteristics of HydroCarbon-Utilizing Bacteria in Nigerian Soils Contaminated with Spent Motor Oil
(1987) Amund, Olukayode O.; Adebowale, A. A.; Ugoji, E. O.
Soil samples were collected from four different oil-contaminated sites in Lagos, Nigeria, Enrichment of soil samples in a mineral salts medium containing SAE 40 motor oil as carbon source resulted in the isolation of eleven bacterial species. These organisms were identified as species of Corynebacterium, Acinetobacter, Pseudomonas, Bacillus, Arthrobacter, Gemella, Flavobacterium and Micrococcus. Substrate specificity tests showed that the organisms could utilize long chain n-alkanes including dodecane, tetradecane and hexadecane. Some species grew on some aromatic hydrocarbons, such as naphthalene, anthracene and phenanthrene. However, all the isolates grew on crude oil as well as motor oil. The growth of a Pseudomonas sp on motor oil resulted in the extensive degradation of the oil and in the synthesis of a new compound.
Extracellular Amylase Production by Cassava-Fermenting Bacteria
(Springer-Verlag, 1987-07-01) Amund, Olukayode O.; gunsina, Olusola A. O.
Fermentation of cassava tubers was accompanied by a gradual decrease in pH, increased amylase activity in the steep liquor, and increased microbial load and lactic acid concentration. Amylase-producing bacterial strains associated with cassava fermentation were isolated and identified as Bacillus subtilis, Bacillus licheniformis and Bacillus cereus. The pH optima for the partially purified enzymes of these organisms were 7.0, 5.5 and 7.5, whilst their temperature optima were 30, 37 and 80 oC. There was no significant difference in amylase activities when starch, dextrin, amylopectin, glucose and maltose were used as growth substrates.
Microbial Rotting and Preservation of Banana Fruits (Musa Sapientum L.) in Nigeria
(The faculty press, Cambridge, 1990) Okonkvvo, Ussana N.; Amund, Olukayode O.; Ogunsanya, Caroline O.
The bacterial and fungal pathogens associated with the watery rot of banana fruits were isolated and identified. The bacterial pathogens were Pediococcus sp., Propionibacterium sp. and Pseudomonas aeruginosa. The fungal pathogens which also showed cellulolytic activities were Botryodiplodia theobromae, Aspergillus niger and Rhizopus sp. These organisms caused rot at room temperature but were unable to cause rot at 5 oC and 10 oC. Banana fruit rot was generally prevented at relative humidities of 10, 50, 80, 90 and 100 %, except that Botryodiplodia theobromae caused rot at 10, 50, and 80% RH. Microbial infection of healthy fruit resulted in a depletion of the total carbohydrate, crude protein, reducing sugar, free fatty acid and ascorbic acid contents. There was an increase in the total lipid and moisture contents of spoilt fruits. Preservation of banana fruits with fungicides and chemical preservatives was investigated. The use of fungicidal wax emulsion was observed to delay fruit ripening and prevented moisture loss thereby controlling the onset of rot.
Purification and properties of a neutral protease produced by Lactobacillus brevis
(Elsevier, 1990-03-01) Amund, Olukayode O.; Omidiji, O.
A proteolytic enzyme was produced by a strain of Lactobacillus brevis isolated from an oriental beverage. The enzyme was extracted and purified 50-fold by gel filtration and ion-exchange chromatography. The optimum pH for the enzyme was 7.0, the optimum temperature 35°C and the molecular weight 34,674 Da. Furthermore, the enzyme was stimulated by cations including Ca2+, Mg2+, Na+ and K+ and inhibited by Zn2+ and Co2+ ions. Other inhibitors were EDTA, ascorbic acid and citric acid. The enzyme is probably a neutral metalloprotease.
Biodegradation of Petroleum Hydrocarbons Under Tropical Estuarine Conditions
(Kluwer Academic Publishers, 1990-09) Amund, Olukayode O.; Igiri, C. O.
The physic-chemical parameters of water samples collected from three points in the Lagos lagoon were studied for 12 months. Salinity varied seasonally but the temperature, pH, dissolved O2, conductivity, NO3 and HPO42- concentrations were relatively constant. There was a direct proportionality between the population density of hydrocarbon-utilizing bacteria and the oil content of water samples. Twelve hydrocarbon-utilizing bacteria were isolated by selective enrichment and characterized as species of Pseudomonas, Alcaligenes, Acinetobacter and Bacillus. The organisms grew mainly on long-chain aliphatic hydrocarbons. Laboratory and field biodegradation studies showed both quantitative and qualitative changes in the hydrocarbon content of crude oil due to microbial degradative activities and a faster rate of oil depletion from the Lagos lagoon during the rainy season. The results obtained could offer a predictive model for estimating the rate of disappearance of petroleum hydrocarbons from the tropical estuarine environment.
Purification and Properties of a Neutral Protease Produced by Lactobaccillus Brevis
(Kluwer Academic Publishers, 1990-09-01) Ilori, Matthew O.; Amund, Olukayode O.; Omidiji, O.
An extracellular glucose-forming amylase was produced by Lactobacillus brevis isolated from ‘Kagasok tea’. The enzyme was purified 70-fold and had optimal activity at 55 oC and pH 6.5. Its Km value for starch was 0.27 mg ml-1 and its M, was approx. 75,900 Da. The activity of the enzyme was enhanced by Ca2+, Mg2+, Na+ or K+ and inhibited by EDTA, KCN, citric acid and L-cysteine.
Occurrence and Distribution of Sulphate-Reducing Bacteria in a Polluted Lagoon
(The faculty press, Cambridge, 1991) Esiobu, N.; Amund, Olukayode O.; Fakile, O. O.; Popoola, O. H.
The presence and distribution of sulphate-reducing bacteria (SRB) in the sediment and water from four strategic points on the Lagos Lagoon were assessed using the most probable number technique. All the samples were positive for the dissimilatory sulphate reducers. The relative occurrence varied markedly with the site and pollution status. The least polluted end of the lagoon recorded the lowest number of SRB in both sediment (4.23x102 SRB/ml) and water (28 SRB/ml) while the most polluted site receiving sewage and domestic wastes harboured numbers as high as 5.71x103 and 7.6x104 SRB/ml for water and sediment sasmples, respectively. The occurrence of sulphate-reducing bacteria in such numbers indicated that this environment favoured biocorrosion of buried and immersed metals. The active involvement of these organisms in the syngenesis of sulphur, metallic sulphides and the general biodegradation of pollutants in this ecosystem is discussed.
Effect of Viscosity on the biodegradability of Automotive Lubricating Oils
(Elsevier, 1991-08-01) Amund, Olukayode O.; Adebiyi, A. G.
Hydrocarbon-utilizing bacteria were isolated by enrichment from water samples collected from the Lagos lagoon and identified as species of Achromobacter, Acinetobacter, Alcaligenes, Arthrobacter, Bacillus, Flavobacterium, Micrococcus and Pseudomonas. The growth potentials of these isolates were evaluated using lubricating oils of different viscosities as substrates. All the organisms grew without lag on oils of low viscosity while they grew with pronounced lag phases on the highly viscous lubricating oil (bright stock). The biodeterioration potential of lubricating oils therefore appears to be closely related to their viscosities.
Hydrocarbon Degradation Potentials of Yeast Isolates from a Polluted Lagoon
(1993) Amund, Olukayode O.; Nwokoye, N.
The population counts of heterotrophic and hydrocarbon-utilising yeasts were monitored at six sampling stations in the Lagos lagoon over a four-week period. Although the population counts were relatively constant in each locality, the highest counts occurred in areas heavily polluted by domestic and industrial effluents. A total of thirty-two hydrocarbon-degrading yeasts were isolated from water at the sampling stations using n-hexadecane as sole carbon source. The isolates were identified as belonging to the genera Candida (25 strains), Endomycopsis (4 strains) and Schizosaccharomyces (3 strains). All the organisms grew on long-chain n-alkane, kerosene, diesel oil and crude oil but failed to grow on short-chain n-alkane, aromatic and alicyclic hydrocarbons. Measurement of growth attributes of the isolates using n-hexadecane, diesel oil oil and crude oil as substrates showed that the Candida species were better utilizers of hydrocarbon substrates relative to Endomycopsis and Schizosaccharomyces species.
Effects of waste engine oil spillage on soil physico-chemical and microbiological properties
(1993) Amund, Olukayode O.; Omole, C. A.; Esiobu, N.; Ugoji, E. O.
Changes in physic-chemical and microbial properties of soils contaminated with waste motor oil were monitored over a 24 week period. Oil application to soils resulted in a decrease in moisture content but brought about increase in organic matter, total nitrogen and available phosphorus contents. There was an initial decrease in microbial counts followed by a subsequent increase in population levels after four weeks. Microbial species diversity was however reduced in oil-contaminated sites relative to the control sites. Hydrocarbon-utilizing bacteria isolated from the experimental sites were identified as Pseudomonas, Acinetobacter, Alcaligenes, Flavobacterium and Corynebacterium. The organisms grew on long-chain n-alkanes, crude oil and fresh engine oil while a few species grew on aromatic hydrocarbons. Laboratory biodegradation studies of fresh engine oil using strains of Pseudomonas, Acinetobacter, and Corynebacterium showed a progressive decrease in oil concentration and pH of the medium due to the production of acidic metabolites.
Microbial Degradation of Four Nigerian Crude Oils in an Estuarine Microcosm.
(Blackwell Publishing Ltd, 1993-03) Amund, Olukayode O.; Akangbou, T. S.
Four Nigerian crude oils (Bonny Light, Bonny Medium, Escravos Light and Forcados Blend) that differ substantially in fractional composition were exposed to the Lagos Lagoon waters in microcosm experiments with oil-impregnated membrane filters. Changes in microbial numbers on the membranes and in the residual oil concentration showed a relationship between the fractional composition and the biodegradation rates of the oils, with the lighter oils disappearing more rapidly. After 10 weeks exposure in the lagoon, only 15 % (w/w) of the Bonny Light crude remained on the filters as compared with 20, 32 and 45 % (w/w) for Escravos Light, Bonny Medium and Forcados Blend respectively. The hydrocarbon-utilizing microbial colonizers of the oil-impregnated membranes were Micrococcus, Bacillus, Pseudomonas, Flavobacterium, Alcaligenes and Aspergillus niger.
Antiprotease and membrane stabilizing activities of extracts of Fagara zanthoxyloides, Olax subscorpioides and Tetrapleura tetraptera
(Taylor & Francis, 1995-01-01) Oyedapo, O. O.; Famurewa, Akindele J.
The saline and alkaline extracts of Fagara zanthoxyloides, Olax subscorpioides and Tetrapleura tetraptera were investigated for antiprotease and membrane stabilizing activities by spectroscopic procedures. Saline extracts of these plants stabilized human red blood cell membrane subjected to hypotonic- and heat-induced lyses. The results revealed that the degree of membrane stabilization was 84% for F. zanthoxyloides while T. tetraptera and O. subscorpioides exhibited 70% and63.2%, respectively. Also, sodium hydroxide extracts of the three plants exhibited antiprotease activity. A 1:5 dilution of F. zanthoxyloides gave 80% inhibition while undiluted extracts of O. subscorpioides and T. tetraptera showed 96% and 73% inhibitions, respectively.
Haematogram and serum iron status of malnourished Nigerian children.
(East African medical journal, 1995-09) Alemnji, G. A.; Thomas, K. D.; Durosinmi, M. A.; Taiwo, O.; Fakunle, Julius B.
Haematological parameters, total serum iron, and total iron binding capacity (TIBC) concentrations were estimated in twenty protein energy malnourished (PEM) children, five kwashiorkor (K), five marasmus (M), five marasmic-kwashiorkor (MK), and five undernourished (U) aged between one and five years on admission and after 18 days hospitalisation at Obafemi Awolowo University Teaching Hospital Complex. The Hospital diet for K and MK consisted of 8% protein and 802 calories per litre while that for M and U consisted of 30% protein and 1350 calories per litre. After the period of 18 days of rehabilitation there was no significant (p> 0.05) difference (Student's t-test) in the weight for age. None of the haematological parameters was significantly different after rehabilitation for all the four types of PEM. Of the four types only Kwashiorkor with mean serum iron values of 15.6+/-1.51 micrograms/100 ml and 21.17+/-0.33 micrograms/100 ml on admission and after rehabilitation respectively was significantly (P< 0.05) different. More attention by the OAUTHC authorities needs to be paid to the management, feeding and diet given to these children so that there will be a greater and more rapid improvement in their rehabilitation.
Genetic Transfer of Auxotrophic Markers in Hydrocarbon-Utilizing Strains of Acinetobacter Lwoffi
(1996) Amund, Olukayode O.
Conjugal transfer of chromosomal genes was shown to occur in oil-degrading strains of Acinetobacter lwoffi. High co-inheritance frequencies of auxotrophic makers inconjugation experiments suggested linkage relationships amongst the, trp and arg loci. The significance of gene transfer in Acinetobacter species was discussed.

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