TY - JOUR

T1 - Isolation and characterization of a novel acidophilic zero-valent sulfur- and ferric iron-respiring Firmicute

AU - Holanda, Roseanne

AU - Johnson, D. Barrie

N1 - Copyright © 2020 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

PY - 2020/8/18

Y1 - 2020/8/18

N2 - A novel, obligately anaerobic, acidophilic bacterium (strain I2511), isolated from sediment in an abandoned copper mine, was shown to couple the oxidation of organic electron donors to the reduction of both zero-valent sulfur and ferric iron in acidic media. The isolate was an obligate heterotroph that used a variety of organic compounds as electron donors and required yeast extract for growth. Alternative electron acceptors (sulfate, tetrathionate, thiosulfate and nitrate) were not used by the novel isolate. The strain grew as motile, endospore-forming rods, and was mesophilic and moderately acidophilic, with a growth rate of 0.01 h-1 at optimum pH (3.7) and temperature (35°C). Analysis of its 16S rRNA gene sequence placed strain I2511 within the phylum Firmicutes, distantly related to validated species. Phylogenetic analysis and physiological traits indicate that the novel strain represents a species of a candidate novel genus. Strain I2511 was included in a microbial consortium in a low pH "hybrid" sulfidogenic bioreactor designed to remove chalcophilic metals from metal-contaminated liquors and was present in >50 % relative abundance when bioreactor was operated at pH ∼ 2.0. Results indicate that the novel isolate could be applied in biotechnologies to treat acidic and neutral pH, metal-rich effluents.

AB - A novel, obligately anaerobic, acidophilic bacterium (strain I2511), isolated from sediment in an abandoned copper mine, was shown to couple the oxidation of organic electron donors to the reduction of both zero-valent sulfur and ferric iron in acidic media. The isolate was an obligate heterotroph that used a variety of organic compounds as electron donors and required yeast extract for growth. Alternative electron acceptors (sulfate, tetrathionate, thiosulfate and nitrate) were not used by the novel isolate. The strain grew as motile, endospore-forming rods, and was mesophilic and moderately acidophilic, with a growth rate of 0.01 h-1 at optimum pH (3.7) and temperature (35°C). Analysis of its 16S rRNA gene sequence placed strain I2511 within the phylum Firmicutes, distantly related to validated species. Phylogenetic analysis and physiological traits indicate that the novel strain represents a species of a candidate novel genus. Strain I2511 was included in a microbial consortium in a low pH "hybrid" sulfidogenic bioreactor designed to remove chalcophilic metals from metal-contaminated liquors and was present in >50 % relative abundance when bioreactor was operated at pH ∼ 2.0. Results indicate that the novel isolate could be applied in biotechnologies to treat acidic and neutral pH, metal-rich effluents.

U2 - 10.1016/j.resmic.2020.07.003

DO - 10.1016/j.resmic.2020.07.003

M3 - Article

C2 - 32805394

VL - 171

SP - 215

EP - 221

JO - Research in Microbiology

JF - Research in Microbiology

SN - 0923-2508

IS - 7

ER -