**Author details**

growth revealed none or just very low PCB congener transformation caused probably by the abiotic factors (**Figure 6b**). **Figure 6b** shows also the overall change in the amount of PCB residues in sediment during the duration of remediation process. After 85 days, 27% of the initial PCB amount (40 mg of eight determined PCB congeners per kilogram of dry sediment) remained in sediment treated with a combination of bioaugmentation and biostimulation (with an addition of *O. anthropi* and ivy leaves). Sediment treated only with bioaugmentation (addition of *O. anthropi*) contained 1.5 times higher content of residual PCBs. The performed experiments confirmed the stimulatory effect of ivy leaves toward the bacterial growth and degradation ability of *O. anthropi* as well as on better adaptation to PCBs. The ability of *O. anthropi* to transform higher chlorinated PCB congeners in contaminated river sediment was established as well. These findings could be useful for bioremediation technologies in the

Many responses have been observed and confirmed in bacteria that counteract the effects of toxic environmental organic pollutants. Rigidification of the cell membrane is a consequence of cell adaptation mechanisms. The alterations in cytoplasmic membrane maintain ratio between bilayer and nonbilayer phospholipids (prevention against the environmentally induced formation of interdigitated structure) and keep the optimal phospholipids ordering to stabilize membrane fluidity. Another mechanism to protect bacterial cell is the efflux of toxic compounds from the membrane compartment. Toxic compounds affect not only cytoplasmic lipids but also cell proteins. This results in the development of special protein repair mechanisms by bacteria. Study of these adaptation mechanisms was the first step in selection of appropriate resistant bacterial strains, usually isolated from the contaminated area, and used for bioremediation application. Successful environment decontamination using biological approaches requires bacterial strains that can degrade particular (one or more) contaminants. Moreover, such strains have to be able to survive and adapt to adverse environment. Next step included the study of degradation potential of the most resistant strains. The resistant strain/consortium possessing appropriate degradation enzymes is the essential element of successful bioremediation. Both assisted bioremediation approaches, bioaugmentation and biostimulation, revealed to be perspective and prospective approaches of PCB decontamination. The degradation studies in artificial precisely defined matrices under the laboratory conditions (microcosms) could be applied in macrocosm and then after verification of strain/consortia degradation efficacy and survival ability and characterization of the optimal conditions for the successful decontamination process used in the field

This work was supported by the Scientific Grant Agency of the Ministry of Education, Science, and Sport in the frame of the project VEGA No. 1/0734/12 and by the Slovak Research and

Development Agency under the contract No. APVV-0656-12.

decontamination of PCB polluted environment.

**3. Conclusions**

88 Persistent Organic Pollutants

conditions.

**Acknowledgements**

Dercová Katarína1 \*, Murínová Slavomíra2 , Dudášová Hana3 , Lászlová Katarína1 and Horváthová Hana1

\*Address all correspondence to: katarina.dercova@stuba.sk

1 Faculty of Chemical and Food Technology, Institute of Biotechnology, Slovak University of Technology, Bratislava, Slovakia

