History

This study included the diagnosis of Staphylococcus lentus bacteria obtained from the laboratories of the Department of Biology in the College of Education for Pure Sciences and testing the efficiency of this bacterial species for the first time in Iraq in the analysis of motor oil used as a single source of carbon and energy and production of protein-rich biomass. The liquid BHM mineral salts and submerged culture technology were used to determine the optimum conditions for biodegradation of used motor oil and (SCP) production. Different numbers were used for the pH (6, 7, 8, 9, 10) and different temperatures (25, 30, 35, 40, 45) °C, as well as different concentrations of the carbon source represented by the used motor oil (1.5, 3, 4.5, 6,7.5) ml per 100 ml BHM medium, and bacterial Inoculum was added (0.5, 1, 1.5, 2, 2.5, 3) ml / 100 ml BHM medium. We also used two nitrogen sources, ammonium sulfate (NH₄)₂SO₄ and urea  CO (NH₂)₂ separately, and added Pepton to support the BHM medium.  The jugs incubated for a period of (24, 72, 120, 168,216) hours, the results showed that Staph. lentus has the potential to grow in solid, liquid BHM medium with added (3%) of motor oil used as the only carbon and energy source. The amount of oil gradually faded from the BHM medium until it disappeared completely. The results showed that the best biomass production was (18.4 g / l) at pH (7), temperature (35 °C) and carbon source concentration (3%) for used motor oil and bacterial Inoculum size (1%) and by using ammonium sulfate as a source of nitrogen after incubate period  (216) In an hour in a incubator shaker at a speed of 100 rpm, the crude protein ratio was (33.9%) of the dry biomass of Staph. lentus, carbohydrate (15.7%), nucleic acid ratio, DNA and RNA (2.042%) and (1.591%), respectively, the results also showed that the (SCP) product contains mineral elements such as phosphorus at (1.9831%) and copper by (0.0036%) while The percentage of potassium (0.8325%), iron (0.0271%), zinc (0.002%) and sodium (4.308%).