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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

Abundance of (A) methanogens and (B) SRB in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands of the Dongtan salt marsh located in the Yangtze River estuary. The error bars represent the standard deviation of three replicate reaction tubes. The sample names are as described in Figure 1.
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Figure 2: Abundance of (A) methanogens and (B) SRB in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands of the Dongtan salt marsh located in the Yangtze River estuary. The error bars represent the standard deviation of three replicate reaction tubes. The sample names are as described in Figure 1.

Mentions: To understand the overall relative abundances of methanogens and SRB, SYBR Green I-based quantification of total archaeal and bacterial 16S rRNA genes were determined from the samples used to investigate methanogens and SRB. As revealed from the copy numbers of mcrA and dsrB genes, the abundances of methanogens and SRB varied with the invasion and growth of S. alterniflora (Figures 2A,B). In spring, the mean abundance of methanogens were approximately 2.4 ± 1.3 × 105, 1.1 ± 0.9 × 106 and 1.2 ± 0.4 × 106 copies per g of dried soil in the P. australis, transition and S. alterniflora stands, respectively, indicating there were approximately 5 times more methanogens in the S. alterniflora stands than in the P. australis stands. Furthermore, higher abundances of methanogens were observed in the summer (4.8 ± 0.1 × 105, 1.2 ± 0.1 × 106 and 3.6 ± 0.6 × 106 copies per g of dried soil in the P. australis, transition and S. alterniflora stands, respectively), representing a dramatic increase of methanogens in the S. alterniflora stands (approximately 7.5-fold higher than the P. australis stands). In terms of the changes associated with S. alterniflora invasion, similar trends were observed for the abundance of archaeal 16S rRNA gene copies in both sampling seasons (Figure 2A). The mean abundance proportions of methanogens (copies of mcrA to 16S rRNA gene of total archaea) were also higher in the S. alterniflora-impacted stands than in the P. australis stands. In the spring, the mean abundance proportions of methanogens were approximately 31, 53, and 63% in the P. australis, transition and S. alterniflora stands, respectively, whereas they slightly changed to 30, 32 and 71%, respectively, in the summer.


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)

Abundance of (A) methanogens and (B) SRB in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands of the Dongtan salt marsh located in the Yangtze River estuary. The error bars represent the standard deviation of three replicate reaction tubes. The sample names are as described in Figure 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Abundance of (A) methanogens and (B) SRB in sediments from P. australis (P), S. alterniflora (S) and transition (T) stands of the Dongtan salt marsh located in the Yangtze River estuary. The error bars represent the standard deviation of three replicate reaction tubes. The sample names are as described in Figure 1.
Mentions: To understand the overall relative abundances of methanogens and SRB, SYBR Green I-based quantification of total archaeal and bacterial 16S rRNA genes were determined from the samples used to investigate methanogens and SRB. As revealed from the copy numbers of mcrA and dsrB genes, the abundances of methanogens and SRB varied with the invasion and growth of S. alterniflora (Figures 2A,B). In spring, the mean abundance of methanogens were approximately 2.4 ± 1.3 × 105, 1.1 ± 0.9 × 106 and 1.2 ± 0.4 × 106 copies per g of dried soil in the P. australis, transition and S. alterniflora stands, respectively, indicating there were approximately 5 times more methanogens in the S. alterniflora stands than in the P. australis stands. Furthermore, higher abundances of methanogens were observed in the summer (4.8 ± 0.1 × 105, 1.2 ± 0.1 × 106 and 3.6 ± 0.6 × 106 copies per g of dried soil in the P. australis, transition and S. alterniflora stands, respectively), representing a dramatic increase of methanogens in the S. alterniflora stands (approximately 7.5-fold higher than the P. australis stands). In terms of the changes associated with S. alterniflora invasion, similar trends were observed for the abundance of archaeal 16S rRNA gene copies in both sampling seasons (Figure 2A). The mean abundance proportions of methanogens (copies of mcrA to 16S rRNA gene of total archaea) were also higher in the S. alterniflora-impacted stands than in the P. australis stands. In the spring, the mean abundance proportions of methanogens were approximately 31, 53, and 63% in the P. australis, transition and S. alterniflora stands, respectively, whereas they slightly changed to 30, 32 and 71%, respectively, in the summer.

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