Elsevier

Water Research

Volume 88, 1 January 2016, Pages 467-474
Water Research

Autotrophic antimonate bio-reduction using hydrogen as the electron donor

https://doi.org/10.1016/j.watres.2015.10.042Get rights and content

Highlights

  • H2 was able to drive the autotrophic bioreduction of Sb(V) as electron donor.

  • H2 had higher electron utilization efficiency in reducing Sb(V) than lactate.

  • Lactate-fed culture was much more diverse than that for the H2-fed culture.

  • The H2-fed culture was dominated by a short rod-shaped phylotype of Rhizobium.

Abstract

Antimony (Sb), a toxic metalloid, is soluble as antimonate (Sb(V)). While bio-reduction of Sb(V) is an effective Sb-removal approach, its bio-reduction has been coupled to oxidation of only organic electron donors. In this study, we demonstrate, for the first time, the feasibility of autotrophic microbial Sb(V) reduction using hydrogen gas (H2) as the electron donor without extra organic carbon source. SEM and EDS analysis confirmed the production of the mineral precipitate Sb2O3. When H2 was utilized as the electron donor, the consortium was able to fully reduce 650 μM of Sb(V) to Sb(III) in 10 days, a rate comparable to the culture using lactate as the electron donor. The H2-fed culture directed a much larger fraction of it donor electrons to Sb(V) reduction than did the lactate-fed culture. While 98% of the electrons from H2 were used to reduce Sb(V) by the H2-fed culture, only 12% of the electrons from lactate was used to reduce Sb(V) by the lactate-fed culture. The rest of the electrons from lactate went to acetate and propionate through fermentation, to methane through methanogenesis, and to biomass synthesis. High-throughput sequencing confirmed that the microbial community for the lactate-fed culture was much more diverse than that for the H2-fed culture, which was dominated by a short rod-shaped phylotype of Rhizobium (α-Protobacteria) that may have been active in Sb(V) reduction.

Introduction

Metalloid Antimony (Sb), the ninth most mined metal (Scheinost et al., 2006), is widely used in manufacture of semiconductors, flame retardants, alloys for storage batteries and catalysts (Filella et al., 2002a). Antimony has serious negative effects on human health. For instance, prolonged exposure to antimony will induce pneumoconiosis, abdominal pain, diarrhea, dermatitis, spontaneous abortion and increased blood pressure (Sundar and Chakravarty, 2010). Antimony also has acute toxicity, which can damage the gastrointestinal system: e. g., oral exposure to antimony at relatively high concentrations can lead to burning stomach pains and colic (Sundar and Chakravarty, 2010). The U. S. EPA has established a maximum contaminant level (MCL) for Sb in drinking water at 6 μg/L (USEPA, 2009). China produces the most antimony in the world (88%), and Hunan province possesses the most abundant antimony reserves (Liu et al., 2010). Wastewaters from mines and smelting factories contain large amounts of antimony and frequently are discharged directly to receiving waters in China (Liu et al., 2010, He et al., 2012).

The common oxidation states of antimony are antimonate (Sb(V)), antimonite (Sb(III)), elemental antimony (Sb0), and antimonide (Sb(-III)). Sb(V) and Sb(III) are the states most frequently observed in natural water, usually in the form of Sb(OH)6- and Sb(OH)3, respectively (Filella et al., 2002b). Although trivalent antimony compounds are generally considered to be more toxic that the pentavalent state, biological reduction of Sb(V) to Sb(III) may have significance as a remediation technology for Sb contamination, because Sb(III) can readily precipitate with sulfide or be strongly adsorbed by Fe(III) hydroxides at neutral pH; thus, Sb(III) easily can be removed by centrifugation or filtration (Xiao et al., 2013).

Several physico-chemical treatment technologies are common for Sb(V) removal, such as adsorption on iron oxides or nano materials, coagulation, and electrochemical methods (Miao et al., 2014, Shan et al., 2014, Wu et al., 2010, Lan et al., 2014). Though biological Sb(V) reduction has gained interest in the past decade, the process remains poorly understood and was not demonstrated until very recently. Kulp et al. (2014) first reported the anaerobic microbial reduction of Sb(V) when they incubated Sb(V) with sediments collected from a stibnite mine. Abin and Hollibaugh (2014) isolated a Bacillales order strain (MLFW-2) able to reduce Sb(V) using lactate as the electron donor. Wang et al. (2013) employed sulfate-reducing bacteria (SRB) to convert Sb(V) to Sb (III) using lactate as electron donor. So far, all the Sb(V) microbial reduction studies reported were performed by the heterotrophic microorganisms using organic carbon as the carbon source and electron donor.

Chemolithotrophic microorganisms obtain energy from the oxidation of inorganic compounds, and many of them are autotrophs because they obtain their carbon from CO2 (Madigan et al., 2009). For example, hydrogenotrophic denitrification involves denitrifying bacteria (DB) that reduce nitrate (NO3-) or nitrite (NO2-) to nitrogen gas (N2) while oxidizing hydrogen (H2) as the electron donor (Mansell and Schroeder, 2002). Thus, the chemoautotrophic process does not need addition of organic carbon, which makes wastewater treatment safer, simpler, more reliable, and less costly (Lee and Rittmann, 2002, Nerenberg et al., 2002). Using H2 as the electron donor for respiration is a promising pathway for metals and metalloid reduction, because H2 is inexpensive and non-toxic, leaves no residual organic substrate, and has been applied for microbiological reductions of various oxidized contaminants, such as NO3, perchlorate (ClO4-), selenate (SeO42−), chromate (CrO42−) and arsenate (AsO43−) (Nerenberg et al., 2002, Chung et al., 2006a, Chung et al., 2006b, Lai et al., 2014, Marsh and Mclnerney, 2001, Santini et al., 2002, Zhao et al., 2011). The H2-based membrane biofilm reactor (MBfR), in which H2 is transferred through the hollow fiber membrane to biofilm attached on the fiber to drive the microbial respiration, is a promising technical approach for bioreduction of oxidized contaminants (Lee and Rittmann, 2002, Nerenberg et al., 2002, Chung et al., 2006a, Chung et al., 2006b, Lai et al., 2014, Marsh and Mclnerney, 2001, Zhao et al., 2011). So far, no study has reported microbial Sb(V) reduction coupled to the oxidation of H2 as the electron donor.

In this study, we enriched a microbial consortium able to reduce Sb(V) using H2 as the sole added electron donor, and we studied the stoichiometry of Sb(V) reduction using H2 or lactate as the electron donor. In particular, the reduction patterns and the metabolic products for the two donors were compared. Energy dispersive X-ray analysis (EDS) and scanning electron microscopy (SEM) were used to identify the reduction product. We also characterized the bacterial communities in both cultures using high-throughput sequencing. These insights document the novel microbial process of Sb(V) reduction and removal by H2-oxidizing autotrophs, providing information that gives a solid foundation for developing biological treatment of water containing Sb(V).

Section snippets

Sediment sample collection

We collected sediment samples from a flooded mine pit located at the Zitong mine (N 118.7E, 29.6N), an antimony mine in Hangzhou, China. Anoxic sediments were collected using a sediment sampler, and stored on ice in plastic bags prefilled with nitrogen gas (N2) before arriving at Zhejiang University.

Preincubation

The medium pH was adjusted to 7.0 ± 0.2 and contained the following ingredients (analytical grade) per L of deionized H2O: NaCl 0.2 g, MgCl2·6H2O 0.203 g, NaHCO3 0.2 g, NaH2PO4·2H2O 1.44 g, Na2HPO4

Antimonate reductions using hydrogen and lactate as electron donor

Fig. 1-A shows that the H2-fed cultures completely reduced 660 μM Sb(V) to Sb(III) in 10 days using H2 as the sole added electron donor. Sb(V) was not reduced in the positive and negative controls (Fig. S1 of Supplemental Information). The reduction occurred with the first addition (average Sb(V)-removal rate of 65.4 μM/day) and was accompanied by H2 consumption. Fig. 1-B shows that Sb(V) reduction using lactate as the sole electron donor had a similar pattern and rate (average Sb(V)-removal

Conclusions

We demonstrated autotrophic microbial Sb(V) reduction using H2 as the sole electron donor. The Sb(V)-reduction pattern of H2-fed cultures were similar to the trends of lactate-fed cultures. Electron distributions showed that almost all of electrons were associated with Sb(V) reduction for the H2-fed cultures, but a large part of electrons were diverted to methanogenesis and acetogenesis for lactate-fed cultures. SEM and EDS demonstrated the occurrence of precipitated Sb2O3 for all cultures, but

Acknowledgments

Authors greatly thank “National Natural Science Foundation of China (Grant No. 21377109, 21577123)”, the “Public Welfare Project of the Science and Technology Department of Zhejiang Province (2015C33016)”, and the “National High Technology Research and Development Program of China (2013AA06A205)” for their financial support.

References (60)

  • P. Parameswaran et al.

    Hydrogen consumption in microbial electrochemical systems (MXCs): the role of homo-acetogenic bacteria

    Bioresour. Technol.

    (2011)
  • A.C. Scheinost et al.

    Quantitative antimony speciation in shooting-range soils by EXAFS spectroscopy

    Geochim. Cosmochim. Acta

    (2006)
  • C. Shan et al.

    Efficient removal of trace antimony(III) through adsorption by hematite modified magnetic nanoparticles

    J. Hazard. Mater

    (2014)
  • A. Slobodkin et al.

    Bonch-Osmolovskaya, E.; Jeanthon, C. Evidence for the presence of thermophilic Fe(III)-reducing microorganisms in deep-sea hydrothermal vents at 130N (East Pacific Rise)

    FEMS Microbiol. Ecol.

    (2001)
  • H. Wang et al.

    Removal of antimony (Sb(V)) from Sb mine drainage: biological sulfate reduction and sulfide oxidation-precipitation

    Bioresour. Technol.

    (2013)
  • Z. Wu et al.

    Removal of antimony (III) and antimony (V) from drinking water by ferric chloride coagulation: competing ion effect and the mechanism analysis

    Sep. Purif. Technol.

    (2010)
  • J. Xu et al.

    Chlorate and nitrate reduction pathways are separately induced in the perchlorate-respiring bacterium Dechlorosoma sp. KJ and the chlorate-respiring bacterium Pseudomonas sp. PDA

    Water Res.

    (2004)
  • A.V. Zotov et al.

    Thermodynamic properties of the Sb(III) hydroxide complex Sb(OH)3(aq) at hydrothermal conditions

    Geochim. Cosmochim. Acta

    (2003)
  • C.A. Abin et al.

    Dissimilatory antimonate reduction and production of antimony trioxide microcrystals by a novel microorganism

    Environ. Sci. Technol.

    (2014)
  • F. Aulenta et al.

    Comparative study of methanol, butyrate, and hydrogen as electron donors for long-term dechlorination of tetrachloroethene in mixed anerobic cultures

    Biotechnol. Bioeng.

    (2005)
  • M. Basaglia et al.

    Selenite-reducing capacity of the copper-containing nitrite reductase of Rhizobium sullae

    FEMS Microbiol. Lett.

    (2007)
  • R.C. Blake et al.

    Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site

    Environ. Toxicol. Chem.

    (1993)
  • F. Caccavo et al.

    Geobacter sulfurreducens sp. nov., a hydrogen- and acetate-oxidizing dissimilatory metal-reducing microorganism

    Appl. Environ. Microbiol.

    (1994)
  • C.S. Carr et al.

    Enrichment of high-rate dechlorination and comparative study of lactate, methanol, and hydrogen as electron donors to sustain activity

    Environ. Sci. Technol.

    (1998)
  • J. Chung et al.

    Community structure and function in a H2-based membrane biofilm reactor capable of bioreduction of selenate and chromate

    Appl. Microbiol. Biotechnol.

    (2006)
  • R. Cord-Ruwisch et al.

    Growth of Geobacter sulfurreducens with acetate in syntrophic cooperation with hydrogen-oxidizing anaerobic partners

    Appl. Environ. Microbiol.

    (1998)
  • S.A. Dar et al.

    Competition and coexistence of sulfate-reducing bacteria, acetogens and methanogens in a lab-scale anaerobic bioreactor as affected by changing substrate to sulfate ratio

    Appl. Microbiol. Biotechnol.

    (2008)
  • L. Dijkhuizen et al.

    Regulation of autotrophic and heterotrophic metabolism in Pseudomonas oxalaticus OX1: growth on mixtures of acetate and formate in continuous culture

    Arch. Microbiol.

    (1979)
  • M. Duhamel et al.

    Growth and yields of dechlorinators, acetogens, and methanogens during reductive dechlorination of chlorinated ethenes and dihaloelimination of 1, 2-dichloroethane

    Environ. Sci. Technol.

    (2007)
  • R.C. Fehrmann et al.

    Scanning electron-microscopy of Rhizobium. spp adhering to fine silt particles

    Soil Sci. Soc. Am. J.

    (1978)
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