Qualitative and quantitative determination of PCB congeners by using a HT-5 GC column and an efficient quadrupole MS

Büthe, Annegret; Denker, Eckhard

doi:10.1016/0045-6535(94)00440-6

Cited by 32 publications

(11 citation statements)

References 37 publications

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“…PCBs were extracted by washing the slides with n-hexane using a modified method described previously (7). The extracts were concentrated under a gentle stream of N 2 to about 200 l and filled up to 1,000 l with hexane.…”

Section: Methodsmentioning

confidence: 99%

Three Stages of a Biofilm Community Developing at the Liquid-Liquid Interface between Polychlorinated Biphenyls and Water

Macêdo

Kuhlicke

Neu

et al. 2005

Appl Environ Microbiol

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Soil contaminated with polychlorinated biphenyls (PCB) was used as an inoculum to grow a complex biofilm community on PCB oil (Aroclor 1242) on a substratum (Permanox). The biofilm was monitored for 31 days by confocal laser scanning microscopy, community fingerprinting using single-strand conformational polymorphism (SSCP), amplicons of the 16S rRNA genes, and chemical analyses of the PCB congeners. SSCP analysis of the young biofilm revealed a rather diverse microbial community with species of the genera Herbaspirillum and Bradyrhizobium as dominant members. The biofilm developing on the PCB droplets displayed pronounced stages of PCB degradation and biofilm development not described before from pure-culture experiments. The first step was the colonization of the substratum while the PCB oil was hardly populated. When a certain density of bacteria was reached on the Permanox, the PCB was colonized, but soon the degradation of the congeners was markedly reduced and many cells were damaged, as seen by LIVE/DEAD staining. Finally, the biofilm formed aggregates and invaded the PCB oil, showing lower numbers of damaged cells than before and a dramatic increase in PCB degradation. This sequence of biofilm formation is understood as a maturation process prior to PCB oil colonization. This is followed by a thin biofilm on the PCB droplet, an aggregation process forming pockets in the PCB, and finally an invasion of the biofilm into the PCB oil. Only the mature biofilm showed degradation of pentachlorinated PCB congeners, which may be reductively dechlorinated and the resulting trichlorobiphenyls then aerobically metabolized.

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Section: Methodsmentioning

confidence: 99%

Three Stages of a Biofilm Community Developing at the Liquid-Liquid Interface between Polychlorinated Biphenyls and Water

Macêdo

Kuhlicke

Neu

et al. 2005

Appl Environ Microbiol

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“…Therefore the results do not represent the contamination of the benthos at the feeding sites in general. All samples were frozen at -18°C and analysed according to the method described by Büthe & Denker (1995). The preparation of the egg samples was carried out according to Heidmann (1986), the food samples were prepared according to Denker (1996).…”

Section: Methodsmentioning

confidence: 99%

Organochlorines in Eggs and Food Organisms of Avocets ( Recurvirostra avosetta )

Dietrich

Büthe

Denker

et al. 1997

Bulletin of Environmental Contamination and Toxicology

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“…PCBs were extracted using a modified procedure (Macedo et al, 2005) as described by Buthe & Denker (1995). Briefly, three pieces of Permanox slide (eight for the control without inoculation with the soil sample) for each microcosm, each bearing one PCB droplet, were cut off the slides and were separately extracted with nhexane, the extracts were cooled to 0 • C, and concentrated under a gentle stream of N 2 , the residues were dissolved in 1 ml hexane.…”

Section: Pcb Analysismentioning

confidence: 99%

Adaptation of microbial communities in soil contaminated with polychlorinated biphenyls, leading to the transformation of more highly chlorinated congeners in biofilm communities

et al. 2006

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A site polluted for many years with polychlorinated biphenyls (PCB) was used to elucidate the metabolic adaptation of microbial communities to these xenobiotics. Soil samples taken along a gradient of PCB-pollution at this site were used to grow biofilm communities on PCB oil. The biofilm communities originating from the non-polluted soil formed rather uniform and thin bacterial layers on PCB oil, while the biofilms originating from contaminated soil samples formed agglomerated structures on the PCB droplets. Biofilm communities were very diverse but those from highly polluted soil were dominated byBurkholderiaspecies, a genus known for degrading several PCBs. All biofilm communities could transform low to medium chlorinated PCB congeners but a strong increase in the rate and degree of PCB transformation in communities from heavily polluted soil was observed. Notably, pentachlorinated congeners were transformed only by biofilms derived from the highly polluted soil but at the same time the content of trichlorinated congeners did not decrease. It is assumed that biofilms from the highly contaminated soil reductively dechlorinated PCB, converting pentachlorinated congeners to trichlorinated congeners in the spherical biofilm aggregates by diffusing to the surface of the aggregates, where aerobic transformation took place.

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Qualitative and quantitative determination of PCB congeners by using a HT-5 GC column and an efficient quadrupole MS

Cited by 32 publications

References 37 publications

Three Stages of a Biofilm Community Developing at the Liquid-Liquid Interface between Polychlorinated Biphenyls and Water

Three Stages of a Biofilm Community Developing at the Liquid-Liquid Interface between Polychlorinated Biphenyls and Water

Organochlorines in Eggs and Food Organisms of Avocets ( Recurvirostra avosetta )

Adaptation of microbial communities in soil contaminated with polychlorinated biphenyls, leading to the transformation of more highly chlorinated congeners in biofilm communities

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