hnolo

S692 Abstracts / Journal of Biotec

Combined bioremediation with nonionic surfactant flushing sys-tem is identified to be a successful in situ process to removemany PAH-contaminated sites (Harwell et al., 1999). A num-ber of chemical reactions occurring among PAH, surfactant andsoil might affect biodegradation so it is difficult to integratethe two processes. In previous study we found that cohesiveenergy density can determine the biodegradation rates of PAHsin aqueous solution (Chang et al., 2007). Thus, the objectiveof this study is to continuously evaluate the effects of chem-ical interactions on naphthalene (NAP) biodegradation in thesurfactant-soil/water systems. Results presented are the additivenonionic surfactants (TX-100 and Brij35) used as the concentrationof monomer (MN) or micelle (CMC) can influence NAP biodegra-dation. The pseudo first-order kinetics of NAP are found as thefollowing order: NAP–Brij35–MN > NAP–Brij35–CMC > NAP–TX-100–MN > NAP–TX-100–CMC. It is indicated that the surfactantsadsorbed on the two soils (clay and TCS) could increase their organicmatter, leading to the changes in the distribution coefficients ofNAP in the surfactant-soil/water systems. Log Koc values for NAPare obtained as the following order: NAP–TX-100–MN > NAP–TX-100–CMC > NAP–Brij35–MN > NAP–Brij35–CMC. Higher Koc valuesof NAP–TX-100 generate a strong partition effect to inhibit micro-bial activity in aqueous solution. Besides, NAP biodegradation wasaffected as PAH dissolved in the MN or CMC surfactant bulk.PAH–MN biodegradation is faster than PAH–CMC because bacte-ria are able to directly attack the exposed PAH structure. Bacterialcommunity illustrates that domain Bacteria reach to 42.96–53.21%during the biodegradation process; and mainly consist of threephyla such as alpha-, beta- and grama-Proteobacteria. The percent-age of free-living and attached bacterial communities in specificspecies is obviously disparate. Representative species included Bre-vundimonas (Pseudomonas) diminuta, Caulobacter sp., Mycoplanabullata, Acidovorax sp. and Pseudomonas aeruginosa take advantagein free-living state in soil/water systems, ranged from 20.65% to29.67%.

References

Chang, Y.-T., Lee, J.-F., Hung, C.-H., 2007. PAH biodegradation in surfactant-watersystems based on the theory of cohesive energy density (CED). J. Chem. Technol.Biotechnol. 82, 442–452.

Harwell, J.H., Sabatini, D.A., Knox, R.C., 1999. Surfactants for ground water remedia-tion. Colloid Surf. A 151, 255–268.

doi:10.1016/j.jbiotec.2008.07.1605

VII5-P-029

Enhancing Fenton-biological treatment for PAH-contaminatedsoil by acidophilic bacteria

Yi-tang Chang a,∗, Ming-Chin Chang b, Hung-Yang Kang b

a Department of Microbiology, Soochow University, Shih-Lin, Taipei222, Taiwanb Department of Environmental Engineering, Hung Kung University,Sha Lu, Taichung 443, Taiwan

E-mail address: timchang08@gmail.com (Y.-t. Chang).

PAHs in contaminated soil and groundwater are of particularconcern because of the mutagenic, teratogenic and carcinogeniccharacteristics threatening human health and ecological environ-ment. Hence, the effective remediation technologies are urgentlyrequired such as in situ treatment. Previous our study presentedbiodegradation following the Fenton’s oxidation as pretreatmentwas a successful integrated technology removing high-molecular-weight PAHs in soil (Chang et al., 2007). A disadvantage was found

gy 136S (2008) S678–S707

most microorganisms may degrade PAHs were inhibited in such anacidic environment according to declining pH about 3 by increas-ing [H+] during Fenton reaction (Stapleton et al., 1998). In thisexperiment, an innovation to save time and cost was developedto enhance this treatment by acidophilic bacteria. Pyrene was con-ducted by preparing the initial concentration of 50 mg/soil kg in asoil/water system during 28 days. The conditions of Fenton’s oxi-dation by 14.4 mM of [Fe]2+ and 206 mM of [H2O2] over 30 minfollowing the biodegradation by mix-cultural acidophilic bacteria.As a result, using the acidophilic bacteria in the acidic substrate canbiodegrade pyrene more effectively than using PAH-biodegradersin the neutral substrate that the pseudo first-order kinetic con-stants of 0.120 day−1 and 0.079 day−1, respectively. Moreover, theintermediates from Fenton’s oxidation were to obtain the hydro-carbons with less benzene rings or containing oxygen. Differentproducts are found in aqueous solution and in soil phase underpyrene biotransformation by free-living and attached bacteria andtheir by-products. For bacterial community, the percentage of Bac-teria was 59.23–65.71%. The five subclasses of Bacteria includingalpha-, beta-, grama-Proteobacteria, High G + C DNA content andLow G + C DNA content were ranged from 54.70% to 63.42%. Per-centages of the Acetobacter sp. were 8.21% in free-living state and29.98% in attached state. Pseudomonas sp. presented in the rangeof 16.42–19.33%. From the experimental results suggest the aci-dophilic bacteria can improve the integrated chemical/biologicalprocess for PAH treatment in soil.

References

Chang, Y.-T., Chang, M.-C., Kang, H.-Y., 2007. Integration of bioremediation and Fen-ton reaction for high molecular weight (HMW) PAH removal from contaminatedsoil. In: 2nd International Conference on Environmental, Industrial and AppliedMicrobiology, Seville, Spain.

Stapleton, R.D., Savage, D.C., Sayler, G.S., Stacey, G., 1998. Biodegradation of aromatichydrocarbons in an extremely acidic environment. Appl. Environ. Microbiol. 64,4180–4184.

doi:10.1016/j.jbiotec.2008.07.1606

VII5-P-031

Development of transgenic plants with cytochrome P4502E1gene and glutathione-S-transferase gene for degradation oforganic pollutants

Prachy Dixit ∗, Sudhir Singh, Prasun K. Mukherjee, Susan Eapen

Nuclear Agriculture and Biotechnology Division, Bhabha AtomicResearch Centre, Mumbai 400085, India

E-mail address: prachy dixit@rediffmail.com (P. Dixit).

Rapid industrialization coupled with increased urbanization hasincreased the levels of organic pollutants in soil and solutions. Phy-toremediation, the use of green plants to extract, sequester anddetoxify pollutants is recognised as a useful and aesthetically pleas-ing method for cleaning up of pollutants. Although some plantshave the inherent ability to phytodegrade some of the organicchemicals, in general, they lack the complete catabolic pathway fordegradation/mineralization. Organic chemicals are first convertedinto lipophilic compounds by oxidation, reduction and hydrolysisand later in the next phase, they get conjugated to an endoge-nous molecule like glutathione, sugars and amino acids (Eapenet al., 2007).In the present work, two genes namely cytochromeP4502E1, a monooxygenase from human involved in phase I oforganic pollutant degradation and glutathione-S-transferase gene(GST) from fungus Trichoderma virens involved in phase II werecloned and introduced individually into plant expression vector