Petroleum products are complex mixtures of hundreds of hydrocarbon compounds. Petroleum has been recognized as a potential environmental contaminant. This research was undertaken to evaluate the effect of petroleum hydrocarbon on soil characteristics and seeds germination in arid lands. Results indicated that bulk density and real density of the polluted samples are relatively higher and lower respectively then the corresponding values of the unpolluted soils. Percent ages of the clay fraction obtained with and without removing the cementing agents showed high and low values for % clay fraction respectively. Low calcium carbonate content was found in the polluted samples as a result of solubilization effects of the petroleum products on calcium carbonate particles. ECe values were very high in the polluted samples (ECe = 28.6 - 82.5 dS/m) and very low in the unpolluted samples (ECe = 2.75 - 2.79 dS/m). Soluble calcium and sulphat ions were the dominant ions in the saturation extract of unpolluted soil samples. Organic matter contents were high (4.94%) in the polluted soil and Low in the unpolluted soil (0.54%). Soil polluted with hydrocarbon was very high (7.13-7.5%) in the unpolluted soil and very low (0.63-0.71%) in the polluted soil. Total elemental contents shows that the most important metals with regard to potential hazards in the contaminated soils, are Cr, Pb, and Ni. Other heavy metals indicated low to medium concentration either in petroleum polluted or the non polluted soils. The concentration of toxic elements in the tested soils could be derived from petroleum pollution and/or from it's chemical weathering particularly under the relatively low pH of the polluted soils. Results indicated no barley seed emergence after 14 days in the polluted soil even after several leaching to alleviate the high level of salt concentrations in the polluted soil. The data reflect the serious effects of petroleum products on the deterioration of soil characteristics which reflected on the emergence of barley seeds.

The nine most frequent bacterial strains out of 127 were isolated form ten drinking water samples collected from tap water and bottled water in sharqia governorate. The nine isolates were purified and examined for their resistance to increasing concentrations of two heavy metal ions, lead (Pb+2) and iron (Fe+3). Four stains out of the nine isolates encoded I, II, IV, and VIII showed the highest efficiency of both Pb+2 and Fe +3 uptake from nutrient broth media containing 100 ppm of the heavy metal ions. The four bacteria were preliminary identified and then confirmed by the Biolog examination as Corynebacterium jeikeium, Pseudomonas putida biotype A, Acinetobacter calcoaceticus and Acidovorax delafieldii. The increased concentrations of Pb+2 ions (from 100 to 500 ppm) in nutrient broth media had deleterious effect on the process of heavy metal uptake (biosorption) by all the four selected isolates. Whereas percentage of Pb+2 uptake decreased from 42.9 to 24%; from 72.6 to 42%, from 78.9 to 37% and from 68.8 to 45%, for the four selected isolates, respectively. Meanwhile there was slight decrease change in Fe+3 uptakes percentage accompanying the increase in heavy metal ion concentration. Optimization of the cultural conditions releaved maximum uptake op pb+2 and Fe+3 by the four tested strains in presence of 100 ppm heavy metal concentration when incubated at 25oC except for Acinetobacter calcoaceticus at 35oC in case of Pb+2 uptake, when pH, was adjusted at 5 under static conditions. Upon addition of 50 ppm Cu+2 ions to broth media supplemented with 100 ppm Pb+2 ions, the percentage of metal biosorption by the four tested isolated decreased between 41.11% and 48.45% according to type of strain. Similarly presence of Cu+2 ions caused decrease in Fe+2 uptake by the four isolates ranging between 29.14-45.1%. Percentage of Pb+2 ions uptake by the tested bacteria sharply decreased when a sterile tap water sample was used as natural medium for cell-metal contact. The percentage of uptake inhibition of Pb+2 ranged between 57-65.23% and between 75.1-84.27% for Fe+3 ions. Cell hydrolysate of three tested bacteria appeared to be free from plasmid DNA proving that the genetic character of heavy metal resistance is plasmidless and related to chromosmal DNA in case of Cory. jeikeium, P. putida and A. delafieldii. On the other hand, Acinet. Calcoaceticus contained plasmid of size 23.130 kb. Examining Acientobacter calcoaceticus using transmission electron microscope revealed the accumulation of Pb+2 ions on bacterial cell surface and the intracellular absorption of Fe+3 ions.