Australian Journal of Basic and Applied Sciences, 5(12): 2218-2226, 2011 ISSN 1991-8178 Corresponding Author: Ismail Saadoun, Department of Applied Biology, College of Sciences, University of Sharjah, P.O. Box 27272, Sharjah, United Arab Emirates E-mail: isaadoun@sharjah.ac.ae; Tel: 971-6-503807; Fax: 971-6-3814 2218 Selection of Bacteria and Plant Seeds to Grow on Phenol to be Used in Remediation of Phenol Contaminated Soils Ismail Saadoun Department of Applied Biology, College of Sciences, University of Sharjah, P.O. Box 27272, Sharjah, United Arab Emirates Abstract: Tolerance of various plant seeds to different concentrations of phenol, and growth of bacteria on phenol as a sole carbon source has been investigated. Three different types of bacterial colonies have been recovered on the agar plates. Biochemical and culture morphology examination of the recovered bacteria revealed that they mainly belonged to the genus Pseudomonas, Micrococcus and Streptomyces. O.D. reading at 600 nm and UV absorbance at 273 nm determined the growth and/or phenol degradation by the tested bacteria. Incubation of 4 tested Pseudomonas spp. and 1 Streptomyces sp. in mineral salts medium (MSM) supplemented with 0.2% (w/v) of phenol for 14 days and at 28 °C indicated the removal of 124 mg/l of phenol by Streptomyces sp. (strain 3A 13 ) as compared to 42, 84, 90 and 102 mg/l by P. putrefaciense, P. fluorescense, P. cepacia and P. acidovorans, respectively. Streptomyces sp. (strain 3A 13 ) seems to play a significant role in decomposition of toxic compounds such as phenol. A noticeable decline in Jew’s mallow (Cochorus olitorius) and Alfaalfa (Medicago sativa) seed germination of 62.5% and 86.4% was shown at 500 and 1000 mg/kg phenol or higher, respectively. Seeds of barley (Hordeum vulgare) showed more resistant to phenol with a decline of 40 and 76% at 1000 and 1500 mg/kg phenol, respectively. However, seeds of solid Horani wheat (Triticum durum) were the most resistant to phenol which showed a percentage decline of 43.5% at 1500 mg/kg phenol. The effect of different phenol concentrations was also reflected on the length of sprouts of the tested plants with severe decline (> 75%) of C. olitorius sprouts' length at 500 mg/kg phenol as compared to the most resistant plant sprouts (T. durum) that showed < 45% decline of sprouts' length. It appears that the local seed plants (T. durum and Hordeum vulgare) have the ability to germinate with 40 % or more at 1500 mg/kg phenol. Careful selection of plant species to be used at a particular polluted sites should be cautiously approached based on the actual soil and climate conditions and other characteristics of the site. Key words: Bacteria, Germination, Plant seeds, Phenol. INTRODUCTION The pollution with petroleum, heavy metals, xenobiotics, organic compounds and other contaminants is a growing environmental concern that harms both terrestrial and aquatic ecosystems. Bioremediation as a cleanup method and through the exploitation of the activities of microorganisms would degrade or attenuate such contaminants. Phytoremediation as one of the developed and implemented technologies of bioremediation is another option for cleaning up environmental pollution which, focuses on the use of living green plants (trees, grasses and aquatic plants) for the removal of contaminants and metals from soil, although some phytoremediation applications are believed to work through stimulation of rhizosphere bacteria by the growing plant root (Glass, 2005). Because phenolic compounds are widely distributed in the environment from various industrial as well as natural sources, bacteria with a potential to grow on toxic compounds such as phenol as a sole source of carbon and energy were tested here. Several aerobic microorganisms that degrade phenol have been isolated (Ahamad and Kunhi 1996; Folsom, et al., 1990; Futamata, et al., 2001; Macros, et al., 1997; Tobajas, et al., 2007; Yang, and Humphrey, 1975) with the Pseudomonads were the most widely distributed bacteria known for the biodegradation of phenolic compounds. Degradation of phenol by other bacteria such as Ochrobactrum sp. and Streptomyces setonii (Antai and Crawford, 1983; EL-Sayed, et al., 2003), molds (Alexieva, et al., 2007) and filamentous fungi (Stoilova, et al., 2007) were reported. For hydrocarbon contamination, terrestrial, aquatic and wetland plants and algae can be used for the phytoremediation process under specific cases and conditions (Nedunuri, et al., 2000; Radwan, et al., 2000; Siciliano, et al., 2000). The specific mechanisms involved in phytoremediation include: enhanced rhizosphere activity and subsequence biodegradation; phytodegradation; phytoextraction; phytovolatilization, and hydraulic pumping (USACOE, 1997). An inventory of plant species in terrestrial and wetland environments in western Canada with a demonstrated potential to phytoremediate or tolerate petroleum hydrocarbons was developed by (Farrell, et al.,