Environmental applications of mercury resistant bacteria

Baldi, Franco; Semplici, Franca; Filippelli, Marco

doi:10.1007/bf00342292

Cited by 14 publications

(6 citation statements)

References 23 publications

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“…However, the action of biotic factors (bacteria in the water column, in the sediment, and possibly in the digestive tract of the H. rigida nymphs) and/or abiotic factors (phototransformations, humic-acid-mediated reactions) may cause methylation and demethylation reactions to occur and thus modify metal transfers and the chemical forms accumulated in the organisms at the end of the experiment. Our current knowledge of these fundamental processes is still very much under controversy, especially in relation to the involved mechanisms, their localization within aquatic ecosystems (water column, sediment compartmentoxic or anoxic zone, organisms) and their sensitivity to various abiotic factors, especially acidification [5,6,17,40].…”

Section: Discussionmentioning

confidence: 99%

ACTIONS AND INTERACTIONS OF TEMPERATURE, pH AND PHOTOPERIOD ON MERCURY BIOACCUMULATION BY NYMPHS OF THE BURROWING MAYFLY HEXAGENIA RIGIDA, FROM THE SEDIMENT CONTAMINATION SOURCE

Odin¹,

Feurtet‐Mazel²,

Ribeyre³

et al. 1994

Environ Toxicol Chem

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Based on a three‐compartment system — water, natural sediment, Hexagenia rigida nymphs — an experimental study was set up, using a complete factorial design, to quantify the actions and interactions of three abiotic factors (temperature: 10, 18, and 26°C; photoperiod: 6, 12, and 18 h per day; pH: 5.0 and 7.5) on inorganic mercury (HgCl2) and methylmercury (CH3HgCl) bioaccumulation by Hexagema rigida (whole organism and gills). The two chemical forms of the metal were initially introduced into the sediment; the exposure duration was 15 d. Total Hg burdens measured at the whole‐organism level revealed a very high bioaccumulation capacity of this burrowing mayfly species and important differences between the two contamination conditions of the sediment source, a factor close to 20 observed in favor of methylmercury, for similar exposure conditions. Among the three abiotic factors taken into account, temperature and water‐column pH played an important role on Hg bioaccumulated by the nymphs, when considered in isolation and in interaction. An increase in temperature from 10 to 26°C gave rise to an increase in Hg bioaccumulation, with the higher differences close to a factor of 1.7. On the other hand, acidification of the water column from 7.5 to 5.0 led to a decrease in the amounts of the metal accumulated by Hexagenia rigida. These effects were similar for the two Hg compounds, but they were more pronounced when the experimental units were contaminated by methylmercury. This comparative analysis of the amounts of metal bioaccumulated by whole organism and by the gills, estimates of nymph activity within the sediment, and results from earlier lab studies have generated several hypotheses on the involved mechanisms. We propose that ingested sediment is the predominant route of exposure and that the gut acts as a selective barrier that favors organic Hg absorption.

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Section: Discussionmentioning

confidence: 99%

ACTIONS AND INTERACTIONS OF TEMPERATURE, pH AND PHOTOPERIOD ON MERCURY BIOACCUMULATION BY NYMPHS OF THE BURROWING MAYFLY HEXAGENIA RIGIDA, FROM THE SEDIMENT CONTAMINATION SOURCE

Odin¹,

Feurtet‐Mazel²,

Ribeyre³

et al. 1994

Environ Toxicol Chem

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“…Mercury tolerance or resistance has been reported in bacteria (Colwell et al 1976;Baldi et al 1991), protozoans (Berk et al 1978), crustaceans (Green et al 1976;Weis 1976), and fish (Weis 1984), but the mechanisms of action are not fully understood.…”

Section: A Aquatic Organismsmentioning

confidence: 96%

Mercury Hazards from Gold Mining to Humans, Plants, and Animals

Eisler

2004

Reviews of Environmental Contamination and Toxicology

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“…A number of studies of the effect of Hg-resistant bacteria on the stability of different Hg species have been carried out, but only a few have focused on HgS (Baldi & Olson, 1987;Baldi et al, 1989Baldi et al, , 1991Kalyaeva et al, 2001;Mindlin et al, 2001;Barkay et al, 2003). Baldi and Olson looked at the effect of adding cinnabar to pyrite in the presence of a Hg-resistant strain of Thiobacillus ferrooxidans; this study is one of the few that investigated the interaction of HgS with bacteria (Baldi & Olson, 1987).…”

Section: Introductionmentioning

confidence: 99%

Microbially enhanced dissolution of HgS in an acid mine drainage system in the California Coast Range

et al. 2013

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Mercury sulfides (cinnabar and metacinnabar) are the main ores of Hg and are relatively stable under oxic conditions (Ksp = 10⁻⁵⁴ and 10⁻⁵² , respectively). However, until now their stability in the presence of micro-organisms inhabiting acid mine drainage (AMD) systems was unknown. We tested the effects of the AMD microbial community from the inoperative Hg mine at New Idria, CA, present in sediments of an AMD settling pond adjacent to the main waste pile and in a microbial biofilm on the surface of this pond, on the solubility of crystalline HgS. A 16S rRNA gene clone library revealed that the AMD microbial community was dominated by Fe-oxidizing (orders Ferritrophicales and Gallionellas) and S-oxidizing bacteria (Thiomonas sp.), with smaller amounts (≤ 6%) being comprised of the orders Xanthomondales and Rhodospirillales. Though the order Ferritrophicales dominate the 16S rRNA clones (>60%), qPCR results of the microbial community indicate that the Thiomonas sp. represents ~55% of the total micro-organisms in the top 1 cm of the AMD microbial community. Although supersaturated with respect to cinnabar and metacinnabar, microcosms inoculated with the AMD microbial community were capable of releasing significantly more Hg into solution compared to inactivated or abiotic controls. Four different Hg-containing materials were tested for bacterially enhanced HgS dissolution: pure cinnabar, pure metacinnabar, mine tailings, and calcine material (processed ore). In the microcosm with metacinnabar, the presence of the AMD microbial community resulted in an increase of dissolved Hg concentrations up to 500 μg L ⁻¹during the first 30 days of incubation. In abiotic control microcosms, dissolved Hg concentrations did not increase above 100 ng L⁻¹ . When Hg concentrations were below 50 μg L⁻¹ , the Fe-oxidizing bacteria in the AMD microbial community were still capable of oxidizing Fe(II) to Fe(III) in the AMD solution, whereas concentrations above 50 μg L⁻¹ resulted in inhibition of microbial iron oxidation. Our experiments show that the AMD microbial community contributes to the dissolution of mercury sulfide minerals. These findings have major implications for risk assessment and future management of inoperative Hg mines worldwide.

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Environmental applications of mercury resistant bacteria

Cited by 14 publications

References 23 publications

ACTIONS AND INTERACTIONS OF TEMPERATURE, pH AND PHOTOPERIOD ON MERCURY BIOACCUMULATION BY NYMPHS OF THE BURROWING MAYFLY HEXAGENIA RIGIDA, FROM THE SEDIMENT CONTAMINATION SOURCE

ACTIONS AND INTERACTIONS OF TEMPERATURE, pH AND PHOTOPERIOD ON MERCURY BIOACCUMULATION BY NYMPHS OF THE BURROWING MAYFLY HEXAGENIA RIGIDA, FROM THE SEDIMENT CONTAMINATION SOURCE

Mercury Hazards from Gold Mining to Humans, Plants, and Animals

Microbially enhanced dissolution of HgS in an acid mine drainage system in the California Coast Range

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