Naslov
The effect of secondary plant metabolites, carvone and tannin, on PCB-degradation by mixed bacterial cultures

Autori
Petrić, Ines ; Hršak, Dubravka ; Fingler, Sanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XII. International Congress of Bacteriology and Applied MIcrobiology (IUMS 2008) : Abstract Book / - , 2008, 335-335

Skup
International Congress of Bacteriology and Applied MIcrobiology (12 ; 2008)

Mjesto i datum
Istanbul, Turska, 05.08.2008. - 09.08.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
PCB; carvone; tannin; mixed cultures

Sažetak
Despite the fact that different biphenyl-utilizing bacteria have shown to promote degradation of polychlorinated biphenyls (PCBs), their use as bioaugmentation agents has been hindered by the inability of applying biphenyl as an inducer of bph genes due to its adverse health effects, cost and poor water solubility. Considering that certain natural compounds may also serve as inducers, in this study we selected two secondary plant metabolites, carvone and tannin, and investigated their impact on the degradation of selected PCB congeners in the mixture Aroclor 1248. For comparison, the experiment with biphenyl was performed as well. Four mixed bacterial cultures used in this study (TSZ7, CONZ, BH1 and BH2) were enriched from different heavily PCB-contaminated soils by applying a microcosm approach and stimulating the growth of biphenyl-utilizing bacteria. Reduction of PCB congeners was monitored by GC-MS analyses. The obtained results suggested that the addition of both carvone and tannin supported PCB-degradation and that all cultures showed degrading capability toward the selected congeners ranging from three- to penta-chlorobiphenyls. However, the effect of tested plant metabolites on PCB-degradation was culture dependent. Thus, the cultures TSZ7 and CONZ, demonstrating a similar degrading potential, showed to be the most effective in the presence of biphenyl, reducing the selected PCB congeners in the range 60-99%. For comparison, in the presence of tannin and carvone, PCB-reduction was in the range 40-70% and 17%-53%, respectively. Cultures BH1 and BH2 showed no preference regarding biphenyl and the tested plant metabolites ; BH1 degraded the selected PCB congeners in the range 39-71% and BH2 in the range 55-80%. Further evidence for PCB degradation is the fact that the genes bphA (encoding the first enzyme of the bph pathway) and bphC (encoding ring-cleavage enzyme) have been identified in all the cultures. The present study demonstrated that the selected secondary plant metabolites, carvone and tannin, may induce bph catabolic pathway in some biphenyl-utilizing bacteria, which opens the possibility to develop new approaches for bioremediation of PCB-contaminated enviroment.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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