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Degradation of 4-n-nonylphenol under nitrate reducing conditions.

De Weert JP, Viñas M, Grotenhuis T, Rijnaarts HH, Langenhoff AA - Biodegradation (2010)

Bottom Line: Biodegradation of NP can reduce its toxicological risk.The largest change in diversity was observed between the enrichments of the third and fourth generation, and further enrichment did not affect the diversity.Phenol was degraded in all cases, but did not affect the linear NP degradation under denitrifying conditions and did not initiate the degradation of tNP and linear NP under the other tested conditions.

View Article: PubMed Central - PubMed

Affiliation: Deltares, Utrecht, The Netherlands. jasperien.deweert@deltares.nl

ABSTRACT
Nonylphenol (NP) is an endocrine disruptor present as a pollutant in river sediment. Biodegradation of NP can reduce its toxicological risk. As sediments are mainly anaerobic, degradation of linear (4-n-NP) and branched nonylphenol (tNP) was studied under methanogenic, sulphate reducing and denitrifying conditions in NP polluted river sediment. Anaerobic bioconversion was observed only for linear NP under denitrifying conditions. The microbial population involved herein was further studied by enrichment and molecular characterization. The largest change in diversity was observed between the enrichments of the third and fourth generation, and further enrichment did not affect the diversity. This implies that different microorganisms are involved in the degradation of 4-n-NP in the sediment. The major degrading bacteria were most closely related to denitrifying hexadecane degraders and linear alkyl benzene sulphonate (LAS) degraders. The molecular structures of alkanes and LAS are similar to the linear chain of 4-n-NP, this might indicate that the biodegradation of linear NP under denitrifying conditions starts at the nonyl chain. Initiation of anaerobic NP degradation was further tested using phenol as a structure analogue. Phenol was chosen instead of an aliphatic analogue, because phenol is the common structure present in all NP isomers while the structure of the aliphatic chain differs per isomer. Phenol was degraded in all cases, but did not affect the linear NP degradation under denitrifying conditions and did not initiate the degradation of tNP and linear NP under the other tested conditions.

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Principal component analysis score plot of denaturing gradient gel electrophoresis profiles (Fig. 4) of a 4-n-NP degrading enrichments of various generations and dilutions originating from samples with 4-n-NP, and with 4-n-NP and phenol. The marker is equal to fourth generation 109 sample originating with 4-n-NP and phenol
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Fig5: Principal component analysis score plot of denaturing gradient gel electrophoresis profiles (Fig. 4) of a 4-n-NP degrading enrichments of various generations and dilutions originating from samples with 4-n-NP, and with 4-n-NP and phenol. The marker is equal to fourth generation 109 sample originating with 4-n-NP and phenol

Mentions: Changes in microbial composition were monitored by principal-component analysis (PCA). The PCA score plot (Fig. 5) shows that the NP enrichments and the NP + P enrichments form two different clusters. The loadings of the different excised dominated bands of the NP and NP + P enrichments are given in Table 3. Within a cluster can be seen that transfer to a new generation had a larger effect on the population than making dilutions series. Dilution of inocula did not change the population significantly in both types of enrichments. However, the population change between the enrichments and dilutions from the batch originating with 4-n-NP and phenol was larger compared to the samples originating with 4-n-NP, mainly on the first component (PC1) which explains 48.3% of the variation in the data.Fig. 5


Degradation of 4-n-nonylphenol under nitrate reducing conditions.

De Weert JP, Viñas M, Grotenhuis T, Rijnaarts HH, Langenhoff AA - Biodegradation (2010)

Principal component analysis score plot of denaturing gradient gel electrophoresis profiles (Fig. 4) of a 4-n-NP degrading enrichments of various generations and dilutions originating from samples with 4-n-NP, and with 4-n-NP and phenol. The marker is equal to fourth generation 109 sample originating with 4-n-NP and phenol
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3008940&req=5

Fig5: Principal component analysis score plot of denaturing gradient gel electrophoresis profiles (Fig. 4) of a 4-n-NP degrading enrichments of various generations and dilutions originating from samples with 4-n-NP, and with 4-n-NP and phenol. The marker is equal to fourth generation 109 sample originating with 4-n-NP and phenol
Mentions: Changes in microbial composition were monitored by principal-component analysis (PCA). The PCA score plot (Fig. 5) shows that the NP enrichments and the NP + P enrichments form two different clusters. The loadings of the different excised dominated bands of the NP and NP + P enrichments are given in Table 3. Within a cluster can be seen that transfer to a new generation had a larger effect on the population than making dilutions series. Dilution of inocula did not change the population significantly in both types of enrichments. However, the population change between the enrichments and dilutions from the batch originating with 4-n-NP and phenol was larger compared to the samples originating with 4-n-NP, mainly on the first component (PC1) which explains 48.3% of the variation in the data.Fig. 5

Bottom Line: Biodegradation of NP can reduce its toxicological risk.The largest change in diversity was observed between the enrichments of the third and fourth generation, and further enrichment did not affect the diversity.Phenol was degraded in all cases, but did not affect the linear NP degradation under denitrifying conditions and did not initiate the degradation of tNP and linear NP under the other tested conditions.

View Article: PubMed Central - PubMed

Affiliation: Deltares, Utrecht, The Netherlands. jasperien.deweert@deltares.nl

ABSTRACT
Nonylphenol (NP) is an endocrine disruptor present as a pollutant in river sediment. Biodegradation of NP can reduce its toxicological risk. As sediments are mainly anaerobic, degradation of linear (4-n-NP) and branched nonylphenol (tNP) was studied under methanogenic, sulphate reducing and denitrifying conditions in NP polluted river sediment. Anaerobic bioconversion was observed only for linear NP under denitrifying conditions. The microbial population involved herein was further studied by enrichment and molecular characterization. The largest change in diversity was observed between the enrichments of the third and fourth generation, and further enrichment did not affect the diversity. This implies that different microorganisms are involved in the degradation of 4-n-NP in the sediment. The major degrading bacteria were most closely related to denitrifying hexadecane degraders and linear alkyl benzene sulphonate (LAS) degraders. The molecular structures of alkanes and LAS are similar to the linear chain of 4-n-NP, this might indicate that the biodegradation of linear NP under denitrifying conditions starts at the nonyl chain. Initiation of anaerobic NP degradation was further tested using phenol as a structure analogue. Phenol was chosen instead of an aliphatic analogue, because phenol is the common structure present in all NP isomers while the structure of the aliphatic chain differs per isomer. Phenol was degraded in all cases, but did not affect the linear NP degradation under denitrifying conditions and did not initiate the degradation of tNP and linear NP under the other tested conditions.

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