Background: With increasing demands of fossil fuel energy, extensive exploration of natural sources has caused a number of large scale accidental spills of crude oil and resulted in environmental disasters. The consequence of oil pollution to environment and human health has brought a serious challenge to environmental scientists. The aim of the present study is to evaluate the biodegradation of petrolum compound by Bacillus subtilis isolated from automobile workshops. Methods: Soil samples were collected from petrol bunks and workshops and subjected to serial dilution and plating. From the developed bacterial colonies, one was selected and identified as Bacillus subtilis based on the biochemical tests. The isolated strain was able to grow in minimal broth along with 2.5, 5, 7.5 and 10% concentrations of petrol which indicated the capability of the organism in degrading petrol and utilizing it as a source for growth. Results: The isolated strain's efficiency was determined by analysing the parameters pH, optical density and CO 2 released during petrol degradation. HPLC analysis also confirmed the degradation of petrol by Bacillus subtilis. Conclusion: The isolate Bacillus subtilis has the ability to tolerate the petrol concentrations and grow on them. Hence, this strain can be used in cleaning oil polluted sites.

Background: Oil spills are considered as one of the critical problems which cause a decline in environmental health. Currently the biological solutions have become more familiar to remove hazardous substances from the environment. Methods: Soil samples were collected from petrol bunks and automobile workshops at Madurai and used for the isolation of fungi. The isolated fungus was identified as Penicillium sp. using lacto phenol cotton blue staining method and cultural characteristics. The efficiency of the fungal strain on the degradation of different concentrations of petrol was studied using 2.5, 5, 7.5 and 10% of petrol in minimal medium. Results: The parameters, pH, optical density and CO released were determined. HPLC analysis exhibited a difference in the pattern of peaks between control and the 2 treated sample confirming petrol degradation. Conclusion: The ability of Penicillium sp. to tolerate oil pollutants and grow on them, suggest that it can be employed as bioremediation agent and can be used in restoring the ecosystem when contaminated by oil.

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Through this investigation, we establish the mechanism and physical characterization of zinc (II) sequestration by Morganella morganii ACZ05 strain, which was isolated and characterized from soil polluted by effluents from electroplating industries. As far as we know, there is very little literature concerning zinc biosorption using an environmental strain of Morganella morganii. The SEM analysis shows the dark porous gaps in the aggregated cell-matrix of test bacterial biomass which is inferred as water channels usually seen in biofilms, as compared to metal-unexposed control. Morganella morganii is not known to produce biofilms unless in the rare nosocomial conditions. Here, SEM analysis shows the production of biofilms after exposure to zinc (II) at 500 ppm, which has not been previously reported. EDX analysis of bacterial biomass also specified the sorption of zinc (II) by the bacterial cells and the presence of new peaks for zinc in contrast to control. Both XRD and FTIR analysis observations strongly implicate the potential of physical adsorption as a mechanism for heavy metal resistance. Analysis of the cell surface by Atomic force microscopy and examination of the topography revealed cell aggregation occurs during biofilm production after zinc biosorption. Unlike other reports, regular models such as Langmuir isotherm and Freundlich isotherm were found insufficient to explain the physisorption of zinc (II) metal ions on the complex multicomponent adsorbents such as the exopolymeric surface of the bacterial cells. However, adsorption kinetics of zinc (II) to the bacterial biomass was most effectively elucidated by a pseudo-second-order kinetic model, suggesting a certain kind of chemisorption that requires further study.