Open Access Research Article Ismail et al., J Pet Environ Biotechnol 2013, 4:6 DOI: 10.4172/2157-7463.1000163 Volume 4 • Issue 6 • 1000163 J Pet Environ Biotechnol ISSN: 2157-7463 JPEB, an open access journal Abstract The aim of this research was to study the infuence of nanoparticles on the biodegradation of crude oil. Production of biosurfactants was also assessed. Crude oil-utilizing bacteria were isolated from oil felds via enrichment in chemically defned medium with crude oil as a sole carbon source. The isolates could be affliated to the genera Bacillus, Pseudomonas, Achromobacter, and Microbacterium by 16S rRNA gene sequencing and phylogenetic analysis. GC/FID analysis revealed 52 to 98% degradation of the oil saturate fraction within one month. Nanoparticles of ZnO inhibited growth and crude oil biodegradation by one isolate (NBHCO4) in a concentration-dependent manner. Growth of the cultures containing ZnO nanoparticles was relatively slower than that of the nanoparticles-free cultures. Moreover, the oil degradation extent in the nanoparticles-containing cultures (22-50%) was less than that achieved in cultures lacking ZnO nanoparticles (80%). Two strains, NBHCO2 and NCEOW, emulsifed and utilized water-in-oil emulsions (chocolate mousse). Biosurfactant production in only one crude oil culture (I-19) could be confrmed by the observed reduction in surface tension. Some isolates produced biosurfactants from water-soluble substrates such as glucose. The NBHCO2 strain produced a lipopeptide biosurfactant which reduced the surface tension of the growth medium from 72 to 27 mN/m. A gene of catechol dioxygenase was detected in the I-19, NBHCO4, and NCEOW isolates indicating the potential catabolic capabilities of these strains for degradation of the aromatic oil fraction. In conclusion, metal oxide nanoparticles can interfere with crude oil biodegradation. Biosurfactants are not necessarily a prerequisite for crude oil biodegradation. The isolates can be applied for bioaugmentation of petroleum-polluted soil and biosurfactants production. Bacterial Degradation of the Saturate Fraction of Arabian Light Crude oil: Biosurfactant Production and the Effect of ZnO Nanoparticles Wael Ismail 1 *, Noora A Alhamad 1 , Wael S El-Sayed 2,4 , Ashraf M El Nayal 1 , Yin-Ru Chiang 3 , Riyad Y Hamzah 1 1 Biotechnology Program, College of Graduate Studies, Arabian Gulf University, Manama, Kingdom of Bahrain 2 Taibah University, Faculty of Science, Biology Department, Al-Madinah Al-Monawarah, 344, Kingdom of Saudi Arabia 3 Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan 4 Microbiology Department, Faculty of Science, Ain Shams University, Cairo, Egypt Keywords: Bioremediation; Biosurfactant; Emulsifcation; Nanoparticles; Bacillus Introduction Petroleum hydrocarbons are among the most common environmental contaminants [1,2]. Petroleum and its hazardous products can be released into the environment through various production, processing, and consumption operations. Consequently, environmental pollution with petroleum and its products has become an issue of global concern, particularly with the anticipated boost in the production and consumption of fossil fuels [3-5]. Pollution with petroleum hydrocarbons in the Arabian Gulf region has become a serious environmental issue. In deed the Arabian Gulf is one of the most heavily polluted aquatic environments worldwide. It was estimated that ca 60% of the oil transported via the sea is shipped in the Arabian Gulf [5,6]. Furthermore, the Arabian Gulf region has witnessed the largest oil spill to date in terms of the amount of crude oil discharged. During the 1991 Gulf war the release of about 11 million barrels of crude oil has lead to the pollution of all environmental components in the region [7]. In Kuwait, where the situation was the worst, about 190 km of border trenches were flled with 3.5 million barrels of crude oil. Moreover, 400 km 2 of land were polluted because of the fallout from 800 burning wells which released 50 million m 3 of crude oil [8]. Te marine environment and ground water reservoirs were also heavily impacted. Another devastating consequence is the formation of more than 300 oil lakes that covered over 49 km 2 of land with more than 40 million tons of crude oil [9,10]. In addition to land and water pollution with petroleum hydrocarbons, the 1991 Gulf war contributed massively to air pollution [11]. Although more than two decades have elapsed since the catastrophic Gulf war oil spill occurred, the consequences are still apparent today [10]. Following the 1991 Gulf war, some studies have been conducted to evaluate bioremediation as a cleanup technology in the Arabian Gulf territory [9,12,13]. Nonetheless, the work achieved to date is not up to the scale of the massive pollution problem. Most of the research done has focused on the marine environment of the Arabian Gulf. In contrast, a few studies have addressed the crude oil-degrading microbial populations in petroleum-impacted soil. It is well known that one of the factors which ofen impede the biodegradation of hydrophobic substrates like hydrocarbons and crude oil is their low bioavailability [14,15]. Tis is because these substrates have poor aqueous solubility and therefore, are not readily accessible for microbial attack. To circumvent this problem, microbes, which exist predominantly in the aqueous phase, have evolved diferent mechanisms to get access to and utilize hydrophobic compounds. Some *Corresponding author: Wael Ismail, Biotechnology Program, College of Graduate Studies, Arabian Gulf University, Manama, Kingdom of Bahrain, Tel: +97336146948; Fax: +97317239664, E-mail: waelame@agu.edu.bh Received November 05, 2013; Accepted December 20, 2013; Published December 28, 2013 Citation: Ismail W, Alhamad NA, El-Sayed WS, El Nayal AM, Yin-Ru C, et al. (2013) Bacterial Degradation of the Saturate Fraction of Arabian Light Crude oil: Biosurfactant Production and the Effect of ZnO Nanoparticles. J Pet Environ Biotechnol 4: 163. doi:10.4172/2157-7463.1000163 Copyright: © 2013 Ismail W, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Journal of Petroleum & Environmental Biotechnology J o u rn a l o f P et r o l e u m & E n v iro n m en ta l Bi o t e c h n o l o g y ISSN: 2157-7463