TY - JOUR
T1 - A novel Shewanella isolate enhances corrosion by using metallic iron as the electron donor with fumarate as the electron acceptor
AU - Philips, Jo
AU - Van den Driessche, Niels
AU - De Paepe, Kim
AU - Prévoteau, Antonin
AU - Gralnick, Jeffrey A.
AU - Arends, Jan B.A.
AU - Rabaey, Korneel
N1 - Publisher Copyright:
© 2018 American Society for Microbiology.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - The involvement of Shewanella spp. in biocorrosion is often attributed to their Fe(III)-reducing properties, but they could also affect corrosion by using metallic iron as an electron donor. Previously, we isolated Shewanella strain 4t3-1-2LB from an acetogenic community enriched with Fe(0) as the sole electron donor. Here, we investigated its use of Fe(0) as an electron donor with fumarate as an electron acceptor and explored its corrosion-enhancing mechanism. Without Fe(0), strain 4t3-1-2LB fermented fumarate to succinate and CO2, as was shown by the reaction stoichiometry and pH. With Fe(0), strain 4t3-1-2LB completely reduced fumarate to succinate and increased the Fe(0) corrosion rate (7.0 ± 0.6)-fold in comparison to that of abiotic controls (based on the succinate-versus-abiotic hydrogen formation rate). Fumarate reduction by strain 4t3- 1-2LB was, at least in part, supported by chemical hydrogen formation on Fe(0). Filtersterilized spent medium increased the hydrogen generation rate only 1.5-fold, and thus extracellular hydrogenase enzymes appear to be insufficient to explain the enhanced corrosion rate. Electrochemical measurements suggested that strain 4t3-1-2LB did not excrete dissolved redox mediators. Exchanging the medium and scanning electron microscopy (SEM) imaging indicated that cells were attached to Fe(0). It is possible that strain 4t3-1-2LB used a direct mechanism to withdraw electrons from Fe(0) or favored chemical hydrogen formation on Fe(0) through maintaining low hydrogen concentrations. In coculture with an Acetobacterium strain, strain 4t3-1-2LB did not enhance acetogenesis from Fe(0). This work describes a strong corrosion enhancement by a Shewanella strain through its use of Fe(0) as an electron donor and provides insights into its corrosion-enhancing mechanism.
AB - The involvement of Shewanella spp. in biocorrosion is often attributed to their Fe(III)-reducing properties, but they could also affect corrosion by using metallic iron as an electron donor. Previously, we isolated Shewanella strain 4t3-1-2LB from an acetogenic community enriched with Fe(0) as the sole electron donor. Here, we investigated its use of Fe(0) as an electron donor with fumarate as an electron acceptor and explored its corrosion-enhancing mechanism. Without Fe(0), strain 4t3-1-2LB fermented fumarate to succinate and CO2, as was shown by the reaction stoichiometry and pH. With Fe(0), strain 4t3-1-2LB completely reduced fumarate to succinate and increased the Fe(0) corrosion rate (7.0 ± 0.6)-fold in comparison to that of abiotic controls (based on the succinate-versus-abiotic hydrogen formation rate). Fumarate reduction by strain 4t3- 1-2LB was, at least in part, supported by chemical hydrogen formation on Fe(0). Filtersterilized spent medium increased the hydrogen generation rate only 1.5-fold, and thus extracellular hydrogenase enzymes appear to be insufficient to explain the enhanced corrosion rate. Electrochemical measurements suggested that strain 4t3-1-2LB did not excrete dissolved redox mediators. Exchanging the medium and scanning electron microscopy (SEM) imaging indicated that cells were attached to Fe(0). It is possible that strain 4t3-1-2LB used a direct mechanism to withdraw electrons from Fe(0) or favored chemical hydrogen formation on Fe(0) through maintaining low hydrogen concentrations. In coculture with an Acetobacterium strain, strain 4t3-1-2LB did not enhance acetogenesis from Fe(0). This work describes a strong corrosion enhancement by a Shewanella strain through its use of Fe(0) as an electron donor and provides insights into its corrosion-enhancing mechanism.
KW - Acetobacterium
KW - Biocorrosion
KW - Complexation
KW - Extracellular electron transfer mechanisms
KW - Fumarate fermentation
KW - Malate
KW - Microbially influenced corrosion
KW - Shewanella fodinae
KW - Solid electron donors
KW - Zero-valent iron
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U2 - 10.1128/AEM.01154-18
DO - 10.1128/AEM.01154-18
M3 - Article
C2 - 30054363
AN - SCOPUS:85054081815
SN - 0099-2240
VL - 84
JO - Applied and environmental microbiology
JF - Applied and environmental microbiology
IS - 20
M1 - e01154-18
ER -