Limits...
Anthropogenic impact on diazotrophic diversity in the mangrove rhizosphere revealed by nifH pyrosequencing.

Jing H, Xia X, Liu H, Zhou Z, Wu C, Nagarajan S - Front Microbiol (2015)

Bottom Line: The metabolic capacities of these diazotrophs indicate the potential for bioremediation and resiliency of the ecosystem to anthropogenic impact.In heavily polluted locations, the diazotrophic community structures were markedly different and the diversity of species was significantly reduced when compared with those in a pristine location.This, together with the increased abundance of Marinobacterium, which is a bioindicator of pollution, suggests that anthropogenic activity has a negative impact on the genetic diversity of diazotrophs in the mangrove rhizosphere.

View Article: PubMed Central - PubMed

Affiliation: Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences Sanya, China.

ABSTRACT
Diazotrophs in the mangrove rhizosphere play a major role in providing new nitrogen to the mangrove ecosystem and their composition and activity are strongly influenced by anthropogenic activity and ecological conditions. In this study, the diversity of the diazotroph communities in the rhizosphere sediment of five tropical mangrove sites with different levels of pollution along the north and south coastline of Singapore were studied by pyrosequencing of the nifH gene. Bioinformatics analysis revealed that in all the studied locations, the diazotroph communities comprised mainly of members of the diazotrophic cluster I and cluster III. The detected cluster III diazotrophs, which were composed entirely of sulfate-reducing bacteria, were more abundant in the less polluted locations. The metabolic capacities of these diazotrophs indicate the potential for bioremediation and resiliency of the ecosystem to anthropogenic impact. In heavily polluted locations, the diazotrophic community structures were markedly different and the diversity of species was significantly reduced when compared with those in a pristine location. This, together with the increased abundance of Marinobacterium, which is a bioindicator of pollution, suggests that anthropogenic activity has a negative impact on the genetic diversity of diazotrophs in the mangrove rhizosphere.

No MeSH data available.


Related in: MedlinePlus

Unweighted pair group method with arithmetic mean clustering of the diazotrophic community structures for samples collected from the five locations in Singapore based on the total OTUs. Data were square root transformed and the Bray–Curtis similarity was used for clustering analysis.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4612719&req=5

Figure 6: Unweighted pair group method with arithmetic mean clustering of the diazotrophic community structures for samples collected from the five locations in Singapore based on the total OTUs. Data were square root transformed and the Bray–Curtis similarity was used for clustering analysis.

Mentions: Unweighted pair group method with arithmetic mean clustering based on the total OTUs detected in all the samples demonstrated a clear shift among the different geographic locations. SJ and PS had a similar diazotrophic community composition and formed a separate cluster, which was distinct from that in SM and SC (Figure 6). This is in agreement with the fact that SJ and PS were mainly comprised of Cluster III (Desulfovibrio), while there were more γ-Proteobacteria in SM (Pseudomonas sp.) and SC (Marinobacterium) (Figure 5).


Anthropogenic impact on diazotrophic diversity in the mangrove rhizosphere revealed by nifH pyrosequencing.

Jing H, Xia X, Liu H, Zhou Z, Wu C, Nagarajan S - Front Microbiol (2015)

Unweighted pair group method with arithmetic mean clustering of the diazotrophic community structures for samples collected from the five locations in Singapore based on the total OTUs. Data were square root transformed and the Bray–Curtis similarity was used for clustering analysis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4612719&req=5

Figure 6: Unweighted pair group method with arithmetic mean clustering of the diazotrophic community structures for samples collected from the five locations in Singapore based on the total OTUs. Data were square root transformed and the Bray–Curtis similarity was used for clustering analysis.
Mentions: Unweighted pair group method with arithmetic mean clustering based on the total OTUs detected in all the samples demonstrated a clear shift among the different geographic locations. SJ and PS had a similar diazotrophic community composition and formed a separate cluster, which was distinct from that in SM and SC (Figure 6). This is in agreement with the fact that SJ and PS were mainly comprised of Cluster III (Desulfovibrio), while there were more γ-Proteobacteria in SM (Pseudomonas sp.) and SC (Marinobacterium) (Figure 5).

Bottom Line: The metabolic capacities of these diazotrophs indicate the potential for bioremediation and resiliency of the ecosystem to anthropogenic impact.In heavily polluted locations, the diazotrophic community structures were markedly different and the diversity of species was significantly reduced when compared with those in a pristine location.This, together with the increased abundance of Marinobacterium, which is a bioindicator of pollution, suggests that anthropogenic activity has a negative impact on the genetic diversity of diazotrophs in the mangrove rhizosphere.

View Article: PubMed Central - PubMed

Affiliation: Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences Sanya, China.

ABSTRACT
Diazotrophs in the mangrove rhizosphere play a major role in providing new nitrogen to the mangrove ecosystem and their composition and activity are strongly influenced by anthropogenic activity and ecological conditions. In this study, the diversity of the diazotroph communities in the rhizosphere sediment of five tropical mangrove sites with different levels of pollution along the north and south coastline of Singapore were studied by pyrosequencing of the nifH gene. Bioinformatics analysis revealed that in all the studied locations, the diazotroph communities comprised mainly of members of the diazotrophic cluster I and cluster III. The detected cluster III diazotrophs, which were composed entirely of sulfate-reducing bacteria, were more abundant in the less polluted locations. The metabolic capacities of these diazotrophs indicate the potential for bioremediation and resiliency of the ecosystem to anthropogenic impact. In heavily polluted locations, the diazotrophic community structures were markedly different and the diversity of species was significantly reduced when compared with those in a pristine location. This, together with the increased abundance of Marinobacterium, which is a bioindicator of pollution, suggests that anthropogenic activity has a negative impact on the genetic diversity of diazotrophs in the mangrove rhizosphere.

No MeSH data available.


Related in: MedlinePlus