Using of biosurfactant and bacterial enzymes for treatment of the oily polluted soils

Biosurfactants are valuable microbial amphiphilic molecules (consisting of molecules having a polar water-soluble group attached to a water-insoluble hydrocarbon chain) with effective surface-active and biological properties applicable to several industries and processes. In recent years natural biosurfactants had attracted attention because of their low toxicity, biodegradability, and ecological acceptability. This work includes eighteen spore-former isolates belong to Bacillus genus that were isolated from twenty five samples of oily polluted soil. Eight strains were showed the ability to produced biosurfactants by spotting over the blood agar plates, and six isolates specifically 15ASA was showed a good lipase and biosurfactant producing, when grown in mineral salt medium at 30°C, with lower surface tension of water from 72 to 32.25mN/m. The best results were obtained when using olive oil and sodium nitrate as carbon and nitrogen sources respectively. Emulsifying index E24 was done and showed that benzene and olive oil were the best substrates (59.2%), while engine oil, vegetable oil and crude oil were less good substrates for emulsification (55.5, 55.5 and 37.03)% respectively. Test of displacing the oil (engine oil, vegetable oil, benzene, olive oil and crude oil) showed that zones of displacement with (30, 40, 35, 15 and 25)mm respectively. Results showed that 70% of the initial concentration of engine oil (1gm) was degraded after 72h of incubation