Anaerolineae Betaproteobacteria Gammaproteobacteria Deltaproteobacteria Alphaproteobacteria Clostridia (a) Caldilineae Nitrospira Acidobacteria GQ396871 Gemmatimonadetes EU686603 Bacteroidia Solibacteres HM748667 Sphingobacteria SS Chloracidobacterium CS AB240310 NC

0 5 10 15 20 25 30 Relative abundance of class (%) 1.5

Actinobacteria CS-3 HM748667 CS-2 (b) EU686603 Rubrobacteria CS-1 Nitrospira

Anaerolineae HQ645210 Deltaproteobacteria Betaproteobacteria Caldilineae SS-1 Clostridia GQ396871 Planctomycetacia SS-3 Gammaproteobacteria Sphingobacteria Gemmatimonadetes SS-2 PC2 (11.7%)PC2 NC-3 Chloracidobacterium NC-2 Alphaproteobacterria Ignavibacteria Acidobacteria NC-1 Bacteroidia Solibacteres AB240310 Bacilli -1.5 -1.5 1.5 PC1 (82.9%)

Fig. S1. Correlation between samples and soil bacterial communities at class level (a) Taxonomic compositions of bacterial communities. The bars mean averages, and error bars mean standard deviations of relative portions. (b) Principal component analysis (PCA) based on the relative abundance.

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Anaerolinaeles Methylococcales Thiobacillus Rhizobiales Burkholderiales (a) Desulfuromonadales Clostridiales Myxococcales Acidobacteriales GQ396871 Gemmatimonadales Gallionellales EU686603 EU786132 Bacteroidales Caldilineales Thermodesulfovibrio Solibacterales Xanthomonadales Methylophilales AB308366 Sterolibacterium Sphingobacteriales Steroidobacter Sphingomonadales Legionellales Chromatiales Rhodospirillales FM253572 AF234694 SS AB240310 EF516615 CS Blastocatella NC

0 5 10 15 20 Relative abundance of order (%) 1.5

EF516615 Micrococcales CS-3 (b) CS-2 Methylophilales Legionellales Steroidobacter Xanthomonadales EU686603 Thermodesulfovibrio CS-1 AB308366 Gallionellales Caldilineales Sphingomonadales Myxococcales Chromatiales Clostridiales Thiobacillus SS-1 GQ396871 Anaerolinaeles EU786132 SS-3 Sterolibacterium Methylococcales Gemmatimonadales Sphingobacteriales

PC2 (13.2%)PC2 SS-2 Rhizobiales NC-3 AF234694 NC-2 NC-1 FM253572 Rhodospirillales Blastocatella Solibacterales Desulfuromonadales Bacteroidales Burkholderiales Acidobacteriales AB240310 -1.5 -1.5 1.5 PC1 (80.2%) Fig. S2. Correlation between samples and soil bacterial communities at order level (a) Taxonomic compositions of bacterial communities. The bars mean averages, and error bars mean standard deviations of relative portions. (b) Principal component analysis (PCA) based on the relative abundance.

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Anaerolinaceae Methylomonas Thiobacillus Geobacteraceae Bradyrhizobiaceae AM745150 Acidobacteriaceae Gallionellaceae GQ396871 (a) EU786132 EU686603 FN563196 Thermodesulfovibrio Clostridiaceae Solibacteraceae AY234747 Xanthomonadaceae Anaeromyxobacteraceae Methylophilaceae HQ014645 Gemmatimonadaceae EU881211 Sterolibacterium Oxalobacteraceae DQ404819 GU454901 Sphingomonadaceae Acidiferrobacter EU399673 SS Comamonadaceae CS Chitinophagaceae NC AB240310

0 2 4 6 8 10 12 14 16 18 Relative abundance of family (%) 1.5

CS-3 Micrococcaceae

Xanthomonadaceae CS-2 Methylophilaceae AM745150 (b) Thermodesulfovibrio CS-1 EU686603 Gallionellaceae HQ014645 FN563196 Sphingomonadaceae Thiobacillus SS-1 Acidiferrobacter Anaerolinaceae EU786132 GQ396871 Sterolibacterium SS-3 EU881211 Comamonadaceae Oxalobacteraceae Methylomonas Clostridiaceae Anaeromyxobacteraceae SS-2 PC2 (13.7%)PC2 EU399673 Gemmatimonadaceae NC-3 AY234747 Chitinophagaceae NC-1 Bradyrhizobiaceae NC-2 Acidobacteriaceae GU454901 Solibacteraceae AB240310 Geobacteraceae DQ404819 -1.5 -1.5 1.5 PC1 (79.2%) Fig. S3. Correlation between samples and soil bacterial communities at family level (a) Taxonomic compositions of bacterial communities. The bars mean averages, and error bars mean standard deviations of relative portions. (b) Principal component analysis (PCA) based on the relative abundance.

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M. tundripaludum T. thioparus (a) Anaerolinaceae_uc A. oryzae AM745150 Thiobacillus_uc FN563196 GQ500701 4P005625 Geobacter_uc FJ810576 AY221611 HQ697693 HQ178913 EU662349 AB186832 EU937836 NC CS Koribacter_uc SS

0 2 4 6 8 10 12 14 16 Relative abundance of species (%) 1.5

Arthrobacter oryzae CS-3 (b) CS-2 HQ697693

AM745150 CS-1 SS-1 FJ810576 Thiobacillus_uc AY221611 FN563196 EU662349 Thiobacillus thioparus Methylobacter tundripaludum GQ500701 SS-3 AB186832 HQ178913

PC2 (8.0%)PC2 Anaerolinaceae_uc NC-3 SS-2 4P005625 NC-2 Geobacter_uc NC-1 EU937836 Koribacter_uc -1.5 -1.5 1.5 PC1 (86.4%) Fig. S4. Correlation between samples and soil bacterial communities at species level (a) Taxonomic compositions of bacterial communities. The bars mean averages, and error bars mean standard deviations of relative portions. The Methylobacter tundripaludum is dominant species in stabilized soil (red arrow). (b) PCA based on the relative abundance. The samples from stabilized soil are grouped with Methylobacter tundripaludum (red arrows).

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