Microbial formation of lanthanide-substituted magnetites by Thermoanaerobacter sp. TOR-39.
The potentially toxic effects of soluble lanthanide (L) ions, although microbially induced mineralization can facilitate the formation of tractable materials, has been one factor preventing the more widespread use of L-ions in biotechnology. Here, we propose a new mixed-L precursor method as compared to the traditional direct addition technique. L (Nd, Gd, Tb, Ho and Er)-substituted magnetites, L( y )Fe(3 - y )O(4) were microbially produced using L-mixed precursors, L( x )Fe(1 - x )OOH, where x = 0.01-0.2. By combining lanthanides into the akaganeite precursor phase, we were able to mitigate some of the toxicity, enabling the microbial formation of L-substituted magnetites using a metal reducing bacterium, Thermoanaerobacter sp. TOR-39. The employment of L-mixed precursors enabled the microbial formation of L-substituted magnetite, nominal composition up to L(0.06)Fe(2.94)O(4), with at least tenfold higher L-concentration than could be obtained when the lanthanides were added as soluble salts. This mixed-precursor method can be used to extend the application of microbially produced L-substituted magnetite, while also mitigating their toxicity.
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Ji-Won
JW
Moon
Yul
Y
Roh
Lucas W
LW
Yeary
Robert J
RJ
Lauf
Claudia J
CJ
Rawn
Lonnie J
LJ
Love
Tommy J
TJ
Phelps
D001431:Bacteriological Techniques; D002254:Carbonates / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005240:Feasibility Studies; D005290:Ferric Compounds / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D005682:Gadolinium / Q000378:metabolism; D006695:Holmium / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D028581:Lanthanoid Series Elements / Q000378:metabolism* / Q000633:toxicity; D013696:Temperature; D013725:Terbium / Q000378:metabolism; D046968:Thermoanaerobacter / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013997:Time Factors
D002254:Carbonates; D005290:Ferric Compounds; D028581:Lanthanoid Series Elements; C473845:akaganeite; D013725:Terbium; D005682:Gadolinium; C486982:siderite; D006695:Holmium; D052203:Ferrosoferric Oxide