A META-ANALYSIS OF THE BACTERIAL AND ARCHAEAL DIVERSITY OBSERVED IN WETLAND SOILS - Salt Marshes - page 16

Genbank and RDP database were analyzed no matter their previously assigned taxonomic
information or other analyses.
To address the long-term question of understanding microorganisms from wetland soil
habitats, this study first aimed at characterizing prokaryotic communities inhabiting wetland
soils. The prokaryotic microorganisms from wetland soil habitats drive the biogeochemical
cycles of elements and may be a source of novel halophilic enzymes. Thus, we studied the
diversity of prokaryotic microorganisms from wetland soils with meta-analysis approach.

3.1. Data Summary

In total, 14318 sequences longer than 250 bp were retrieved from Genbank and RDP
databases. The sequences were mostly about 800 bp long, followed by approximate 600 bp
(Figure 1). Interestingly, there are a small submit of sequence length between 1400 bp and
1600 bp. The 12583 bacterial sequences were assigned to 6383 OTUs, while the 1735
archaeal sequences were assigned to 521 OTUs (Table 1 and Figure 1). The most abundant
bacterial and archaeal OTU contained 143 sequences and 113 sequences, respectively. Over
90% bacterial sequences were classified within five phyla namely Proteobacteria,
Bacteroidetes, Acidobacteria, Firmicutes and Actinobacteria (Figure 2). The remaining
sequences were classified within 26 ‗minor' phyla, of which Chloroflexi, Planctomycetes,
Cyanobacteria and Verrucomicrobia were the only ‗minor' phyla with a representation of 1%
of all bacterial sequences.
Of the archaeal sequences analyzed, all of them were classified within two phyla:
Euryarchaeota and Crenarchaeota, representing 925 and 810 sequences, respectively.

Table 1. Diversity statistics for Archaea, Bacteria, and 'Major' phylum groups.
Coverage = #OTUs/rarefaction estimate; OTU and abundance were calculated
using a 0.03 dissimilarity cut-off

Group Total

sequences

Unclassified
to phylum

# of
OTUs

ACE Chao1 Rarefaction

estimation

Current
coverage
(%)

Bacteria 12583 none 6383 30581 17176 15768

41

Pro 5763 2791 12472 7245 6811

40

Act 783 418 2280 1088 1033

46

Aci 1345 731 2972 1693 1602

28

Fir 973 540 3595 1856 1915

54

Bact 2244 868 2700 1887 1601

59

Archaea 1735 none 521 1131 884 883

83

Eur 925 418 681 505 504

62

Cre 810 197 442 311 320

41