<p> Supplementary Information</p><p>As(V) resistance and reduction by bacteria and their performances in As removal from As-contaminated soils</p><p>Fig S1. The locations of 8 soil samples in the realgar mine areas in Shimen County of Huanan</p><p>Province of China. The red and blue triangles mean the realgar mine location and the slag heap site, respectively.</p><p>Table S1. The selected physicochemical properties of the experimental soils. Items Experimental soils Soil-1 Soil-2 Soil stype Alluvial soils Alluvial soils Total N g kg-1 1.85 1.53 Total P g kg-1 0.82 0.71 Total K g kg-1 12.3 18.1 Organic Matter g kg-1 22.1 19.3 Total As mg·kg-1 38.7 65.9 Available Fe mg·kg-1 21.5 33.2 Available Mn mg·kg-1 16.3 24.8 Available Al g·kg-1 0.96 1.33 pH 7.62 7.55 CEC cmol(+) kg-1 9.7 12.1 Fig S2. The growth situations of 28 bacterial isolates after being inoculated onto the solid LB culture media containing As(V) of 500, 1000, or 2000 mg L-1 for 48h. The labels in red indicated these isolates were selected out according to their growth situations in response to the corresponding As(V) levels. </p><p>500 mg L-1</p><p>3-2 8-3 8-4 1-2 1-3 3-1 5-3 6-1</p><p>2-1 3-3 6-2 8-2 8-5 1-1 2-6 5-2</p><p>2-2 5-1 4-1 6-3 2-5 8-1</p><p>2-4 2-3 4-3 4-2 7-2 7-1</p><p>1000 mg L-1</p><p>8-3 8-4 1-2 1-3 3-1 3-2 5-3 6-1</p><p>3-3 5-2 6-2 8-2 8-5 1-1 2-1 2-6</p><p>2-2 5-1 4-1 6-3 2-5 8-1</p><p>2-4 2-3 4-3 4-2 7-2 7-1</p><p>2000 mg L-1 6-1 1-2 1-3 3-1 3-2 5-3 8-3 8-4</p><p>2-1 8-5 1-1 2-6 3-3 5-2 6-2 8-2</p><p>2-2 4-1 6-3 2-5 5-1 8-1</p><p>2-4 2-3 4-3 4-2 7-2 7-1 Fig S3. The optical density of 9 bacterial isolates after exposed to different contents of As(V) in LB culture media.</p><p>4.0</p><p>3.5 2-2 4-3 4-2 4-1 7-2 7-1 8-5 8-4 8-3 3.0 m n 2.5 0 0 6</p><p> y t</p><p> i 2.0 s n e d</p><p>1.5 l a c i t</p><p> p 1.0 O</p><p>0.5</p><p>0.0 0 100 200 300 400 500 600 700 800 As content in culture medium mg L-1 Fig S4. The linear relationship between the decreased As calculated via the change of As fractionations before and after bio-extraction and the decreased As calculated via the change of total</p><p>As contents before and after bio- extraction. </p><p>12 s t n e t</p><p>1 y = 0.8913x + 2.2465 n - g o</p><p> c k R² = 0.4592</p><p>10 s g A</p><p> m l</p><p> a n t o o i t t</p><p> c</p><p> g 8 a n r i t r x a e p - o i m y = 0.5994x + 3.0702 b o</p><p> c 6 r</p><p> e R² = 0.4559 y t b f</p><p> a s</p><p>A d</p><p> n d a e 4 s e a r e o r f c e e b d</p><p> e 2 Soil-1 Soil-2 h T</p><p>0 0 5 10 15 The decreased As by comparing As fractionations before and after bio-extraction mg kg-1 Table S2. The morphological and biochemical characteristics of three bacterial isolates Characteristics Isolate 2-2 Isolate 4-3 Isolate 8-5 Cell morphology rod rod rod Gram stain - - - Oxidase + + + Catalase + + + Starch hydrolysis - - - Casein hydrolysis - - - nitrate reduction + + + Temperature (℃) 40 - - + Urease + + - V-P reaction - - + Citrate utilization + + + (Note：- negative；+ Positive) Table S3. Recently (2010-now) reported bacterial isolates capable of As(V) reduction. Bacterial isolates Initial concentration of As(V) Abilities of As(V) reduction Reference Pseudomonas taiwanensis SSMGP 2-2 10 mg L-1 (0.13 mM) After 6 h, all As(V) was completely reduced into As(III). This study Pseudomonas Monteilii SSMGP 4-3 Pseudomonas sp. SSMGP 8-5 10 mg L-1 (0.13 mM) After 24 h, almost 32% of initial As(V) was reduced into As(III). This study Shewanella sp. OM1 187.5 mg L-1 (2.5 mM) In 96 h, all As(V) was anaerobically reduced into As(III). Lukasz et al. 2014 Pseudomonas sp. OM2 187.5 mg L-1 (2.5 mM) In 72 h, all As(V) was anaerobically reduced into As(III). Lukasz et al. 2014 Serratia sp. OM17 Aeromonas sp. OM4 187.5 mg L-1 (2.5 mM) In 120 h, all As(V) was anaerobically reduced into As(III). Lukasz et al. 2014 Pseudomonas sp. PAHAs-1 112.5 mg L-1 (1.5 mM) In 48 h, all As(V) was reduced into As(III). Feng et al. 2014 Anaeromyxobacter sp. PSR-1 375 mg L-1 (5 mM) In 96 h, all As(V) was completely reduced into As(III). Kudo et al. 2013 Geobacter sp. OR-1 450 mg L-1 (6 mM) In 72 h, all As(V) was completely reduced into As(III). Ohtsuka et al. 2013 Citrobacter sp. NC-1 1500 mg L-1 (20 mM) In 24 h, all As(V) was reduced into As(III). Chang et al. 2012 Pantoea agglomerans sp. DSM 3493 75 mg L-1 (1 mM) In 60 h, 97% of initial As(V) was reduced into As(III). Wu et al. 2013 Bacillus thuringiensis sp.IAM 12077 75 mg L-1 (1 mM) In 22 h, 95% of initial As(V) was reduced into As(III). Wu et al. 2013 Bacillus cereus OSBH5 0.75 mg L-1 (0.01 mM) In about 140 h, all As(V) was reduced into As(III). Maity et al. 2011 Pseudomonas stutzeri OSBH2 0.75 mg L-1 (0.01 mM) In 160 h, all As(V) was reduced into As(III). Maity et al. 2011 Pseudomonas sp. AR-3 18.75 mg L-1 (0.25 mM) In 25 h, all As(V) was aerobically reduced into As(III). Liao et al. 2011 Citrobacter sp. AR-7 18.75 mg L-1 (0.25 mM) In 10 h, all As(V) was aerobically reduced into As(III). Liao et al. 2011 Geobacillus kaustophilus A1 1500 mg L-1 (20 mM) In 20 h, about 10% of initial As(V) was reduced into As(III). Cuebas et al. 2011 Pseudomonas sp. MP1400 150 mg L-1 (2.0 mM) In 24 h, all As(V) was completely reduced into As(III). Pepi et al. 2011 Pseudomonas sp. APSLA3 150 mg L-1 (2.0 mM) In about 100 h, all As(V) was completely reduced into As(III). Pepi et al. 2011 Pseudomonas sp. BPSLA3 150 mg L-1 (2.0 mM) In about 70 h, all As(V) was completely reduced into As(III). Pepi et al. 2011 Pseudomonas sp. MP1400d Pseudomonas sp. MP1400a References: Lukasz D, Liwia R, Aleksandra M, Aleksandra S (2014) Dissolution of arsenic minerals mediated by dissimilatory arsenate reducing bacteria: estimation of the physiological potential for arsenic mobilization. BioMed Res Int, 2014(1): 841892. Feng TC, Lin HP, Tang JZ, Feng YY (2014) Characterization of polycyclic aromatic hydrocarbons degradation and arsenate reduction by a versatile Pseudomonas isolate. Int Biodete Biodegr 90: 79-87. Kudo K, Yamaguchi N, Makino T, Ohtsuka T, Kimura K, Dong DT, Amachia S (2013) Release of arsenic from soil by a novel dissimilatory arsenate-reducing bacterium, Anaeromyxobacter sp. strain PSR-1. Appl Environ Microbiol 79: 4635-4642 Ohtsuka T, Yamaguchi N, Makino T, Sakurai K, Kimura K, Kudo K, Homma E, Dong DT, Amachi S (2013) Arsenic dissolution from Japanese paddy soil by a dissimilatory arsenate-reducing bacterium Geobacter sp. OR-1. Environ Sci Technol 47: 6263-6271 Chang YC, Nawata A, Jung K, Kikuchi S (2012) Isolation and characterization of an arsenate-reducing bacterium and its application for arsenic extraction from contaminated soil. J Ind Microbiol Biot 39: 37-44 Wu Q, Du J, Zhuang G, Jing C (2013) Bacillus sp SXB and Pantoea sp IMH, aerobic As(V)-reducing bacteria isolated from arsenic-contaminated soil. J Appl Microbiol 114: 713- 721 Maity JP, Kar S, Liu JH, Jean JS, Chen CY, Bundschuh J, Santra SC, Liu CC (2011) The potential for reductive mobilization of arsenic [As(V) to As(III)] by OSBH2 (Pseudomonas stutzeri) and OSBH5 (Bacillus cereus) in an oil-contaminated site. J Environ Sci Health A Tox/Hazard Subst Environ Eng 46: 1239-1246 Liao VHC, Chu YJ, Su YC, Hsiao SY, Wei CC, Liu CW, Liao CM, Shen WC, Chang FJ (2011) Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan. J Contam Hydrol 123: 20-29 Cuebas M, Villafane A, McBride M, Yee N, Bini E (2011) Arsenate reduction and expression of multiple chromosomal ars operons in Geobacillus kaustophilus A1. Microbiology 157: 2004-2011 Pepi M, Protano G, Ruta M, Nicolardi V, Bernardini E, Focardi SE, Gaggi C (2011) Arsenic-resistant Pseudomonas sp. and Bacillus sp. bacterial strains reducing As(V) to As(III), isolated from Alps soils, Italy. Folia Microbiol 56: 29-35</p>