Studies on the diversity, abundance and succession of hydrocarbon utilizing micro organisms in tropical soil polluted with oily sludge

A research was carried out in a tropical region to study the population of hydrocarbon utilizers in soil polluted with oily sludge. Plots were prepared to receive treatments with neat and emulsified oilysludge. These plots were further treated with fertilizer and bioaugmented with a consortium of hydrocarbon utilizers for six months. Results obtained indicated that, the presence of oily sludge in soilcaused the growth of diverse genera of oil degraders. The major genera of bacteria active in polluted soil were Pseudomonas, Bacillus and Acinetobacter, while fungal general were Aspergillus, Penicillium,and Mucor. Abundant microbial growth was observed during the first 60 days. Some organisms such as Pseudomonas, Bacillus, Penicillium, and Aspergillus were present in polluted soil throughout the experimental period, while others including Candida, Sporobolomyces and Rhizopus were found only during the first two months. Further analysis revealed that, succession of the hydrocarbon utilizers in polluted soil was subject to seasonal variations and depended primarily on the fraction of the oil being utilized at a specific time and also on the physiology of the micro organisms involved. In addition, the selective appearance and succession of hydrocarbon utilizers in the polluted soil were affected only by the presence of neat and emulsified oil in soil as compare to other treatment parameters. The practical implication of these findings suggests that reloading of oil in some treated plots could be carried outafter the first 90 days. Molecular techniques are underway to provide a more comprehensive study on this successional trend

Extracellular protease produced by Bacillus subtilis isolated from contaminated paracetamol oral preparation

In a study to evaluate the microbiological safety of some paracetamol oral solutions sold in some Nigerian drug stores, 40.0% of the samples examined was contaminated with protease-producing Bacillus subtilis. The production of extracellular protease was induced by casein in the minimal medium and was found to be the major enzyme in the growth medium. The enzyme was partially purified by ammonium sulphate precipitation technique and the specific activity determined. The quantitative assay revealed that the produced enzyme exhibited proteolytic activity at different assay conditions. The level of enzyme production increased with increase in cell density. The enzyme was stable at the pH and temperature ranges 7.5-10 and 45-60°C, respectively, indicating proteolysis over a wide range of environmental conditions.Keywords: microbiological safety, paracetamol oral solutions, Bacillus subtilis, extracellular protease, proteolysis Global Journal of Pure and Applied Sciences Vol. 12(1) 2006: 55-6

Variation in microbial density and physico-chemical properties of kerosene-polluted soil

No Abstract. Global Journal of Pure and Applied Sciences Vol. 12 (4) 2006: 465-47

Crude oil degrading potential of freshwater bacterial isolates from slow running freshwater system located in Cross River state, Nigeria

No Abstract.Global Journal of Pure and Applied Sciences Vol. 13 (3) 2007: pp.403-40

EVALUATION OF SEASONAL VARIATION IN THE MICROBIAL AND HEAVY METAL CONCENTRATIONS OF IMO RIVER ESTUARY OF THE NIGER DELTA MANGROVE ECOSYSTEM Cross River State Nigeria

ABSTRACT: Evaluation of seasonal variation in the microbial and heavy metal content in Imo River estuary of the Niger Delta mangrove ecosystem using standard analytical methods was carried out on samples collected. The study was conducted during the wet and dry seasons (August and November). The results obtained showed that the sediment samples had a significantly (P < 0.05) higher counts of total heterotrophic bacteria (THB) than the surface and sub-surface water samples. However, the sediment samples during the dry season had a significantly (P < 0.05) higher counts of THB than the wet season (2.55 ± 2.34 × 107 cfug-1 and 2.46 ± 2.20 × 107 cfug-1) respectively. There was no significant difference (P > 0.05) in the population of THB in the surface water during the wet and dry seasons (2.23 ± 2.23 × 106 cfuml-1 and 2.39 ±1.63 × 106 cfuml-1) respectively, while there was a significant difference (P < 0.05) in the population of total heterotrophic bacteria (THB) in the sub-surface water during the dry and the wet seasons (2.27 ±2.00 × 106 cfuml-1 and 2.13 ± 1.84 × 106 cfuml-1) respectively. The total fungal (TF) densities in the surface water were 1.17 ± 0.93 x 105 cfuml-1 and 1.38 ± 0.63 x 105 cfuml-1 during the wet and dry seasons respectively, the mean densities of 1.15 ± 0.63 x 105 cfuml-1 and 1.30 ± 0.48 x 105 cfuml-1 were observed in the sub-surface water during the wet and dry seasons respectively, while in the sediments, the mean densities observed were 1.42 ± 1.19 x 106 cfug-1 and 1.60 ± 1.05 x 106 cfug-1 during the wet and dry seasons respectively. The results obtained also indicate that the water and sediment samples show a remarkable variation in the concentrations of heavy metals during the wet and dry seasons