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Effects of Spartina alterniflora invasion on the communities of methanogens and sulfate-reducing bacteria in estuarine marsh sediments.

Zeleke J, Sheng Q, Wang JG, Huang MY, Xia F, Wu JH, Quan ZX - Front Microbiol (2013)

Bottom Line: Similar trends were observed for SRB, and they were up to two orders of magnitude higher than the methanogens.Diversity indices indicated a lower diversity of methanogens in the S. alterniflora stands than the P. australis stands.The results showed that in the sediments of tidal salt marsh where S. alterniflora displaced P. australis, the abundances of methanogens and SRB increased, but the community composition of methanogens appeared to be influenced more than did the SRB.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University Shanghai, China.

ABSTRACT
The effect of plant invasion on the microorganisms of soil sediments is very important for estuary ecology. The community structures of methanogens and sulfate-reducing bacteria (SRB) as a function of Spartina alterniflora invasion in Phragmites australis-vegetated sediments of the Dongtan wetland in the Yangtze River estuary, China, were investigated using 454 pyrosequencing and quantitative real-time PCR (qPCR) of the methyl coenzyme M reductase A (mcrA) and dissimilatory sulfite-reductase (dsrB) genes. Sediment samples were collected from two replicate locations, and each location included three sampling stands each covered by monocultures of P. australis, S. alterniflora and both plants (transition stands), respectively. qPCR analysis revealed higher copy numbers of mcrA genes in sediments from S. alterniflora stands than P. australis stands (5- and 7.5-fold more in the spring and summer, respectively), which is consistent with the higher methane flux rates measured in the S. alterniflora stands (up to 8.01 ± 5.61 mg m(-2) h(-1)). Similar trends were observed for SRB, and they were up to two orders of magnitude higher than the methanogens. Diversity indices indicated a lower diversity of methanogens in the S. alterniflora stands than the P. australis stands. In contrast, insignificant variations were observed in the diversity of SRB with the invasion. Although Methanomicrobiales and Methanococcales, the hydrogenotrophic methanogens, dominated in the salt marsh, Methanomicrobiales displayed a slight increase with the invasion and growth of S. alterniflora, whereas the later responded differently. Methanosarcina, the metabolically diverse methanogens, did not vary with the invasion of, but Methanosaeta, the exclusive acetate utilizers, appeared to increase with S. alterniflora invasion. In SRB, sequences closely related to the families Desulfobacteraceae and Desulfobulbaceae dominated in the salt marsh, although they displayed minimal changes with the S. alterniflora invasion. Approximately 11.3 ± 5.1% of the dsrB gene sequences formed a novel cluster that was reduced upon the invasion. The results showed that in the sediments of tidal salt marsh where S. alterniflora displaced P. australis, the abundances of methanogens and SRB increased, but the community composition of methanogens appeared to be influenced more than did the SRB.

No MeSH data available.


Related in: MedlinePlus

Proportions of major dsrB families detected in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands. The sample names are as described as Figure 1.
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Figure 6: Proportions of major dsrB families detected in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands. The sample names are as described as Figure 1.

Mentions: Based on the frequency of nucleotide sequences recovered from the salt marsh, dsrB phylotypes were dominated by Deltaproteobacteria, particularly the families of the order Desulfobacterales (Figure 6), which represented more than 85% of the sequences. Except for the small increase of its relative proportion at PIa and reduction observed at TIIb, Desulfobacteraceae (the most dominant family in the order Desulfobacterales) did not display significant change from the spring to the summer. On the other hand, at the S. alterniflora invaded sediments the mean proportion of Desulfobacteraceae increased from approximately 61 to 54% at locations “a” and “b”, respectively (Figure 6). In contrast, the proportion of Desulfobulbaceae, the second dominant family in the order Desulfobacterales, decreased in the summer (by approximately 45%). However, insignificant change was observed with S. alterniflora invasion. Despite the lower proportions (4.0 ± 2.0%), similar trends were observed for the family Peptococcaceae (Figure 6) within Desulfobulbaceae. Approximately 50% increases were observed from the spring to the summer in the proportions of the novel dsrB cluster (Figure 6).


Effects of Spartina alterniflora invasion on the communities of methanogens and sulfate-reducing bacteria in estuarine marsh sediments.

Zeleke J, Sheng Q, Wang JG, Huang MY, Xia F, Wu JH, Quan ZX - Front Microbiol (2013)

Proportions of major dsrB families detected in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands. The sample names are as described as Figure 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750361&req=5

Figure 6: Proportions of major dsrB families detected in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands. The sample names are as described as Figure 1.
Mentions: Based on the frequency of nucleotide sequences recovered from the salt marsh, dsrB phylotypes were dominated by Deltaproteobacteria, particularly the families of the order Desulfobacterales (Figure 6), which represented more than 85% of the sequences. Except for the small increase of its relative proportion at PIa and reduction observed at TIIb, Desulfobacteraceae (the most dominant family in the order Desulfobacterales) did not display significant change from the spring to the summer. On the other hand, at the S. alterniflora invaded sediments the mean proportion of Desulfobacteraceae increased from approximately 61 to 54% at locations “a” and “b”, respectively (Figure 6). In contrast, the proportion of Desulfobulbaceae, the second dominant family in the order Desulfobacterales, decreased in the summer (by approximately 45%). However, insignificant change was observed with S. alterniflora invasion. Despite the lower proportions (4.0 ± 2.0%), similar trends were observed for the family Peptococcaceae (Figure 6) within Desulfobulbaceae. Approximately 50% increases were observed from the spring to the summer in the proportions of the novel dsrB cluster (Figure 6).

Bottom Line: Similar trends were observed for SRB, and they were up to two orders of magnitude higher than the methanogens.Diversity indices indicated a lower diversity of methanogens in the S. alterniflora stands than the P. australis stands.The results showed that in the sediments of tidal salt marsh where S. alterniflora displaced P. australis, the abundances of methanogens and SRB increased, but the community composition of methanogens appeared to be influenced more than did the SRB.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University Shanghai, China.

ABSTRACT
The effect of plant invasion on the microorganisms of soil sediments is very important for estuary ecology. The community structures of methanogens and sulfate-reducing bacteria (SRB) as a function of Spartina alterniflora invasion in Phragmites australis-vegetated sediments of the Dongtan wetland in the Yangtze River estuary, China, were investigated using 454 pyrosequencing and quantitative real-time PCR (qPCR) of the methyl coenzyme M reductase A (mcrA) and dissimilatory sulfite-reductase (dsrB) genes. Sediment samples were collected from two replicate locations, and each location included three sampling stands each covered by monocultures of P. australis, S. alterniflora and both plants (transition stands), respectively. qPCR analysis revealed higher copy numbers of mcrA genes in sediments from S. alterniflora stands than P. australis stands (5- and 7.5-fold more in the spring and summer, respectively), which is consistent with the higher methane flux rates measured in the S. alterniflora stands (up to 8.01 ± 5.61 mg m(-2) h(-1)). Similar trends were observed for SRB, and they were up to two orders of magnitude higher than the methanogens. Diversity indices indicated a lower diversity of methanogens in the S. alterniflora stands than the P. australis stands. In contrast, insignificant variations were observed in the diversity of SRB with the invasion. Although Methanomicrobiales and Methanococcales, the hydrogenotrophic methanogens, dominated in the salt marsh, Methanomicrobiales displayed a slight increase with the invasion and growth of S. alterniflora, whereas the later responded differently. Methanosarcina, the metabolically diverse methanogens, did not vary with the invasion of, but Methanosaeta, the exclusive acetate utilizers, appeared to increase with S. alterniflora invasion. In SRB, sequences closely related to the families Desulfobacteraceae and Desulfobulbaceae dominated in the salt marsh, although they displayed minimal changes with the S. alterniflora invasion. Approximately 11.3 ± 5.1% of the dsrB gene sequences formed a novel cluster that was reduced upon the invasion. The results showed that in the sediments of tidal salt marsh where S. alterniflora displaced P. australis, the abundances of methanogens and SRB increased, but the community composition of methanogens appeared to be influenced more than did the SRB.

No MeSH data available.


Related in: MedlinePlus