@article{fdi:010069969,
  title = {{L}ong-term sequestration of nickel in mackinawite formed by {D}esulfovibrio capillatus upon {F}e({III})-citrate reduction in the presence of thiosulfate},
  author = {{I}kogou, {M}. and {O}na-{N}guema, {G}. and {J}uillot, {F}arid and {L}e {P}ape, {P}. and {M}enguy, {N}. and {R}icheux, {N}. and {G}uigner, {J}. {M}. and {N}oel, {V}. and {B}rest, {J}. and {B}aptiste, {B}. and {M}orin, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n euxinic sediments, the reaction between iron and sulfides results in the formation of {F}e({II})-sulfides, which are known to play a key role in trace metal sequestration. {T}he present study investigates the sequestration of nickel during {F}e({II})-sulfide formation mediated by the (thio)sulfate-reducing bacterium {D}esulfovibrio capillatus in the presence of soluble {F}e({III})-citrate and thiosulfate as the terminal electron acceptor. {XRD}, {HRTEM} and {F}e {K}-edge {EXAFS} data indicate that biogenic mackinawite ({F}e{S}) was the sole mineral formed in our experiments. {T}hese data also show that the kinetics of mackinawite crystal growth was significantly accelerated when nickel was present in the starting solution. {I}n addition, the lack of detection of other {F}e({II})-sulfides indicates inhibition of the mackinawite ({F}e{S}) to greigite ({F}e3{S}4) and/or pyrite ({F}e{S}2) transformation that is likely related to (i) the efficiency of {D}esulfovibrio capillatus in reducing {S}(0) to {H}2{S} and (ii) the absence of {O}-2 during the experiments. {F}inally, chemical analyses show that 98% of the nickel is associated with biogenic mackinawite and no release of nickel from mackinawite was observed after up to 10 months of incubation under anoxic conditions. {T}his finding is consistent with {N}i {K}-edge {EXAFS} data which show that {N}i({II}) substitutes for {F}e({II}) in the structure of biogenic mackinawite. {T}his study shows that (thio)sulfate-reducing bacteria can efficiently promote the formation of mackinawite in euxinic sedimentary environments and that these {F}e({II})-sulfides can act as efficient and long-term trapping minerals for nickel in such settings. {C}onsidering the capacity of mackinawite at incorporating other trace metals such as {M}n, {C}o, {C}u and {Z}n, this iron sulfide could also serve as a host for these elements as well. {T}his study suggests that mackinawite likely plays a more important role in the biogeochemical cycles of {F}e, {S}, and associated trace metals than considered up to now.},
  keywords = {},
  booktitle = {},
  journal = {{A}pplied {G}eochemistry},
  volume = {80},
  numero = {},
  pages = {143--154},
  ISSN = {0883-2927},
  year = {2017},
  DOI = {10.1016/j.apgeochem.2017.02.019},
  URL = {https://www.documentation.ird.fr/hor/fdi:010069969},
}