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.


Identity and distribution of the 20 most abundant OTUs (with 95% similarity as the cutoff value) among all samples collected from the five mangrove locations in Singapore.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 2: Identity and distribution of the 20 most abundant OTUs (with 95% similarity as the cutoff value) among all samples collected from the five mangrove locations in Singapore.

Mentions: The distribution of the 20 most abundant OTUs was highly varied among the different samples with the 12 top OTUs occurring in SM. OTU1 and 2 accounted respectively for 29 and 25% of the total OTUs in SJ, and showed a high similarity with Marinobacterium lutimaris DSM22012 and Scytonema sp. LEGE07189, respectively. The abundance of the remaining OTUs was less than 6% for each, except for OTU3, which accounted for 11% in SM showing close affiliation with Klebsiella sp. (Figure 2). In addition, a BLAST search provided the identities of the 10 most abundant OTUs in each sample, and these were shown to vary considerably such that the top OTUs in SC and PS were both closely affiliated with Marinobacterium lutimaris DSM22012 with different levels of similarities; whereas in PRP and SJ, they were affiliated with Desulfovibrio gigas and Desulfovibrio magneticus, respectively, and in SM, they were affiliated with Klebsiella sp. (Supplementary Figure S2).


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)

Identity and distribution of the 20 most abundant OTUs (with 95% similarity as the cutoff value) among all samples collected from the five mangrove locations in Singapore.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 2: Identity and distribution of the 20 most abundant OTUs (with 95% similarity as the cutoff value) among all samples collected from the five mangrove locations in Singapore.
Mentions: The distribution of the 20 most abundant OTUs was highly varied among the different samples with the 12 top OTUs occurring in SM. OTU1 and 2 accounted respectively for 29 and 25% of the total OTUs in SJ, and showed a high similarity with Marinobacterium lutimaris DSM22012 and Scytonema sp. LEGE07189, respectively. The abundance of the remaining OTUs was less than 6% for each, except for OTU3, which accounted for 11% in SM showing close affiliation with Klebsiella sp. (Figure 2). In addition, a BLAST search provided the identities of the 10 most abundant OTUs in each sample, and these were shown to vary considerably such that the top OTUs in SC and PS were both closely affiliated with Marinobacterium lutimaris DSM22012 with different levels of similarities; whereas in PRP and SJ, they were affiliated with Desulfovibrio gigas and Desulfovibrio magneticus, respectively, and in SM, they were affiliated with Klebsiella sp. (Supplementary Figure S2).

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.