Table S1 Geochemical Parameters of the Investigated Hot Springs in This Study

Table S1 Geochemical parameters of the investigated hot springs in this study

- - 2- - + Cl NO2 SO4 Br NO3 Li Na NH4 K Mg Ca Sample (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) (mg L-1) -1 156.8 50.2 83.4 15.9 32.8 9.2 658.7 16.7 55.9 11.3 51.3 DG-4 155.9 36.3 76.5 9.9 27.7 10.6 772.3 16.7 74.1 5.1 49.7 DG-5 167.9 60.5 47.9 9.6 27.5 12.6 1055.7 35.2 126.0 8.9 91.9 DG-14 156.2 29.8 8.4 n.a. 26.6 9.6 659.3 5.4 70.7 3.6 20.4 DG-16 160.1 38.1 62.4 9.5 27.2 11.8 817.7 16.6 90.0 3.5 21.9 QZM-4 277.7 24.3 327.8 n.d. 28.8 3.9 291.2 28.5 47.9 38.3 316.1 QZM-5 273.7 28.0 492.3 11.7 30.3 3.9 284.0 28.0 60.0 48.3 536.5 QZM-6 282.1 62.9 460.6 n.d. 28.6 3.9 297.2 43.4 63.5 47.7 431.8 QZM-7 285.9 54.6 431.9 12.1 29.9 3.7 292.4 58.7 65.9 38.1 142.9 QZM-9 212.5 23.8 461.2 n.d. 30.0 2.6 187.9 3.0 21.2 33.7 264.6 QZM-10 128.6 19.6 252.7 n.d. 31.1 1.7 128.3 1.3 17.5 18.4 138.3 QZM-11 214.2 28.2 417.9 n.d. 30.8 2.8 202.1 3.2 24.5 39.6 328.0 QZM-12 208.8 31.1 381.5 n.d. 30.7 2.8 210.3 6.6 30.5 30.9 252.8 QZM-13 105.9 41.1 350.2 n.d. 32.7 1.3 112.6 8.2 23.8 39.8 259.1 QZM-14 208.4 21.8 354.7 n.d. 32.4 2.4 162.0 0.8 19.8 26.6 188.9

Table S2 The dsrB gene clones from the investigated hot springs and their closest relatives in the GenBank

GenBank accession QZM QZM QZM QZM Identity OTU ID QZM-9 QZM-10 QZM-11 QZM-12 QZM-13 QZM-14 DG-1 DG-4 DG-5 DG-14 DG-16 No. of the closest -4 -5 -6 -7 (%) reference OTU1 12 5 4 5 3 1 11 8 2 4 12 2 0 0 0 AWH63881.1 93% OTU2 13 12 10 10 3 0 0 1 0 0 0 0 0 0 0 AGJ00858.1 95% OTU3 0 4 7 6 2 0 0 0 0 0 0 0 0 0 0 AFK32735.1 95% OTU4 0 7 4 8 7 0 0 0 0 0 0 0 0 0 0 AWH64713.1 93% OTU5 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 APA21667.1 91% OTU6 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 AHZ11304.1 94% OTU7 0 0 1 2 0 0 0 0 0 0 0 0 0 0 0 AWH63868.1 87% OTU8 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 WP_018086255.1 99% OTU9 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 AGR84841.1 92% OTU10 0 0 3 2 0 0 0 0 0 0 0 0 0 0 0 ACO35898.1 97% OTU11 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 AWH64381.1 90% OTU12 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 ABX65363.1 96% OTU13 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 AHZ11364.1 97% OTU14 0 0 0 0 14 3 6 5 3 4 0 0 0 0 0 AWW01246.1 93% OTU15 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 AWH64232.1 94% OTU16 0 0 0 0 20 13 7 4 11 18 0 0 0 0 0 AWH63823.1 93% OTU17 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 ACQ73016.1 93% OTU18 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 AWH64728.1 96% OTU19 0 0 0 0 2 0 0 1 3 4 0 0 0 0 0 AAO61660.1 95% OTU20 0 0 0 0 9 6 1 7 0 0 0 0 0 0 0 BAF34624.1 93% OTU21 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 AWH63978.1 92%

Table S2 The dsrB gene clones from the investigated hot springs and their closest relatives in the GenBank (Continued)

GenBank accession QZM QZM QZM QZM Identity OTU ID QZM-9 QZM-10 QZM-11 QZM-12 QZM-13 QZM-14 DG-1 DG-4 DG-5 DG-14 DG-16 No. of the closest -4 -5 -6 -7 (%) reference OTU22 0 0 0 0 0 1 0 6 0 2 0 0 0 0 0 BAF34624.1 90% OTU23 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 AWH64728.1 94% OTU24 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 KUK12289.1 94% OTU25 0 1 0 2 0 0 0 0 0 0 0 0 0 0 0 AWH63881.1 94% OTU26 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 AWH63938.1 95% OTU27 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 WP_088553243.1 82% OTU28 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 ACP30533.1 94% OTU29 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 APA21669.1 94% OTU30 0 0 0 0 0 0 0 0 0 0 44 21 10 8 2 AFK32735.1 95% OTU31 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 AWH64662.1 94% OTU32 0 0 0 0 0 0 0 0 0 0 0 0 14 0 0 AHZ11384.1 99% OTU33 0 0 0 0 0 0 0 0 0 0 0 0 0 13 3 AFK32735.1 98% OTU34 0 0 0 0 0 0 0 0 0 0 0 0 0 12 3 ABK90639.1 98% OTU35 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 AWW01163.1 88% OTU36 0 0 0 0 0 0 0 0 0 0 0 0 0 2 9 AFK32737.1 94% OTU37 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 ALN40079.1 90% OTU38 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 AGR84883.1 90% OTU39 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 AWH64526.1 93% OTU40 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 RPI94506.1 97% OTU41 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 AFK32730.1 85%

Figure S1. Neighbor-joining tree showing the phylogenetic relationships of the deduced DsrB protein sequences translated from dsrB gene clone sequences obtained in this study to closely related sequences from the GenBank database. One representative clone type within each OTU is shown, and the number of clones within each OTU is shown in parentheses. The sequences from this study are shown in bold type, and they are coded as follows for the example of QZM-4: dsrB amino acid sequences of clone No. 4 from the Quzhuomu hot spring (QZM) sediment in Tibetan. The scale bar indicates the Jukes-Cantor distance. Bootstrap values of (1000 replicates) > 50% are shown.

Fig S1A

Desulfobacterales

Desulfovibrionales

Desulfobacterales Unclassified -Group I Deltaproteobacteria Desulfobacterales Unclassified -Group II Unclassified -Group III

Syntrophobacterales

Clostridia Nitrospirales

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Fig S1B

OTU3_QZM-6-20(7) OTU30_DG-16-26(2) OTU30_DG-14-6(8) OTU30_DG-5-1(10) OTU30_DG-4-1(21) OTU30_DG-1-4(44) OTU3_QZM-9-13(2) OTU3_QZM-7-17(6) OTU3_QZM-5-2(4) OTU41_DG-1-51(1) OTU6_QZM-6-10(1) Desulfosarcina cetonica(AAN31399.1) Desulfosarcina sp(AAK71938.1) OTU36_DG-14-18(2) OTU36_DG-16-4(9) Deltaproteobacteria Olavius ilvae(AAY97994.2)_Mediterranean Sea sediment Uncultured bacterium drsB(AFK32735.1)_Saline lakes of Qaidam OTU33_DG-14-1(13) OTU33_DG-16-9(3) Uncultured bacterium drsB(CBX19542.1)_Marine steel structures Desulfovibrionales Desulfobacterales Unclassified - Group I Desulfobacterales Unclassified - Group II Unclassified - Group III

Syntrophobacterales

Clostridia Nitrospirales

0.05

Fig S1C

Desulfobacterales Desulfonatronum lacustre(AAL57452.1) Desulfovermiculus halophilus(WP_027370031.1) Desulfonatronovibrio hydrogenovorans(WP_028575105.1) Desulfonatronovibrio hydrogenovorans(AAL57468.1) Desulfonatronovibrio magnus(WP_045212626.1) Desulfonatronospira thiodismutans(WP_008871012.1) Desulfonauticus submarinus(AAO27365.1)_Deep-sea hydrothermal vent Desulfonauticus sp.(KUJ96767.1)_Oil reservoir OTU10_QZM-6-9(3) OTU10_QZM-7-31(2) Desulfomicrobium orale(AAM03450.2) Deltaproteobacteria Desulfomicrobium escambiense(WP_028578006.1) Desulfomicrobium baculatum(WP_012805492.1) Desulfomicrobium norvegicum(BAB55558.1) Desulfomicrobium sp.(AAK71940.1)_Estuarine sediments Desulfomicrobium escambiense(BAB55556) Desulfobacterales Unclassified - Group I Desulfobacterales Unclassified - Group II Unclassified - Group III

Syntrophobacterales

Clostridia Nitrospirales

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Fig S1D

Desulfobacterales Desulfovibrionales OTU21_QZM-9-25(1) Desulfatiglans anilini(AAQ05940.2) sulfate-reducing bacterium mXyS1(AAQ05942.1) OTU17_QZM-9-1(1) OTU22_QZM-10-22(1) OTU22_QZM-14-22(2) Desulfobacterales OTU22_QZM-12-10(6) OTU20_QZM-9-11(9) OTU20_QZM-10-7(6) OTU20_QZM-11-16(1) Deltaproteobacteria OTU20_QZM-12-16(7) OTU39_DG-16-6(2) OTU15_QZM-9-8(1) OTU4_QZM-5-6(7) Unclassified - Group I OTU4_QZM-6-4(4) OTU4_QZM-7-4(8) OTU4_QZM-9-9(7) Desulfobacterales Unclassified - Group II Unclassified - Group III

Syntrophobacterales

Clostridia Nitrospirales

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Fig S1E

Desulfobacterales

Desulfovibrionales Desulfobacterales Unclassified-Group I Desulfobulbus propionicus(AAG28586.1) Desulfobulbus rhabdoformis(CAB95039.1) Desulfofustis glycolicus(AAL57456.1) Desulfobacterales Desulforhopalus singaporensis(AAL57466.1) OTU13_QZM-7-24(1) OTU32_DG-5-4(14) OTU34_DG-14-4(12) OTU34_DG-16-3(3) OTU2_QZM-4-7(13) Deltaproteobacteria Unclassified-Group II OTU2_QZM-5-9(12) OTU2_QZM-6-1(10) OTU2_QZM-7-2(10) OTU2_QZM-9-22(3) OTU2_QZM-12-23(1) OTU9_QZM-6-24(1) OTU9_QZM-7-23(1) OTU19_QZM-13-13(3) Unclassified-Group III OTU19_QZM-9-10(2) OTU19_QZM-12-30(1) OTU19_QZM-14-17(4)

Syntrophobacterales

Clostridia Nitrospirales

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Fig S1F

Desulfobacterales Desulfovibrionales Desulfobacterales Unclassified- Group I Desulfobacterales Unclassified- Group II Unclassified- Group III Desulfobacca acetoxidans (WP_013706581.1)_Three Gorges Reservoir Desulfobacca acetoxidans(AAQ05936.1) Uncultured bacterium drsB(ACQ73012.1)_Evander Mine Desulfotomaculum sp.(ABG91059.1)_Mafic sill OTU5_QZM-5-16(1) Uncultured bacterium drsB(AHZ11410.1)_Wetland soil of Florida Uncultured bacterium drsB(BAO00863.1)_Marine sediment Uncultured bacterium drsB(AID66180.1)_Marine sediment, Aarhus Bay station M1 OTU26_QZM-7-36(1) OTU11_QZM-7-16(3) OTU31_DG-1-41(1) Uncultured bacterium drsB(ABK90668.1)_Groundwater Uncultured bacterium drsB(AAO61099.2)_Schloeppnerbrunnen fen soil Uncultured bacterium drsB(AGI44391.1)_High arsenic shallow aquifers Uncultured bacterium drsB(ABB55406.1)_Groundwater OTU29_QZM-5-34(1) OTU25_QZM-5-26(1) OTU25_QZM-7-26(2) Deltaproteobacteria OTU1_QZM-4-1(12) OTU1_QZM-5-1(5) OTU1_QZM-6-12(4) OTU1_QZM-7-12(5) Syntrophobacterales OTU1_QZM-9-3(3) OTU1_QZM-10-25(1) OTU1_QZM-11-1(11) OTU1_QZM-12-2(8) OTU1_QZM-13-1(2) OTU1_QZM-14-20(4) OTU1_DG-1-12(12) OTU1_DG-4-2(2) OTU14_QZM-13-7(3) OTU14_QZM-14-10(4) OTU14_QZM-12-1(5) OTU14_QZM-11-9(6) OTU14_QZM-10-5(3) OTU14_QZM-9-5(14) OTU18_QZM-9-21(1) OTU16_QZM-10-1(13) OTU16_QZM-9-12(20) OTU16_QZM-11-7(7) OTU16_QZM-14-1(18) OTU23_QZM-12-14(1) OTU16_QZM-12-22(4) OTU16_QZM-13-4(11) Clostridia Nitrospirales

0.05 Fig S1G

Desulfobacterales Desulfovibrionales Desulfobacterales Unclassified- Group I Desulfobacterales Deltaproteobacteria Unclassified- Grounp II Unclassified- Group III

Deltaproteobacteria-Syntrophobacterales

OTU35_DG-14-9(1) OTU38_DG-16-2(1) OTU37_DG-14-7(1) OTU7_QZM-6-15(1) OTU7_QZM-7-14(2) OTU8_QZM-6-18(4) Clostridia OTU27_QZM-14-27(1) OTU24_QZM-14-9(1) Desulfotomaculum aeronauticum (AAK13054.1) Desulfotomaculum ruminis (WP_013843668.1) Uncultured bacterium drsB (CAY87207.1) OTU12_QZM-7-13(1) OTU40_DG-16-22(1) OTU28_QZM-9-45(1) Nitrospirales OTU28_QZM-14-37(1) Thermodesulfovibrio yellowstonii (AAC24112.1) Thermodesulfovibrio islandicus (AAK83214.1)

0.05