TY - JOUR
T1 - Axenic aerobic biofilms inhibit corrosion of SAE 1018 steel through oxygen depletion
AU - Jayaraman, A.
AU - Cheng, E. T.
AU - Earthman, J. C.
AU - Wood, T. K.
N1 - Funding Information:
Acknowledgments This work was supported by the Electric Power Research Institute (EPRI, award RP 8044-02). The authors also acknowledge the help of Peter Hallock and Jenny O’ Connor with the continuous reactor experiments.
PY - 1997
Y1 - 1997
N2 - Corrosion inhibition of SAE 1018 steel by pure-culture biofilms of Pseudomonas fragi and Escherichia coli DH5α has been evaluated in complex Luria-Bertani medium, seawater-mimicking medium, and modified Baar's medium at 30 °C. In batch cultures, both bacteria inhibited corrosion three to six fold compared to sterile controls, and the corrosion was comparable to that observed in anaerobic sterile media. To corroborate this result, a continuous reactor and electrochemical impedance spectroscopy were used to show that both P. fragi K and E. coli DH5α decreased the corrosion rate by 4- to 40- fold as compared to sterile controls; this matched the decrease in corrosion found with sterile medium in the absence of oxygen and with E. coli DH5α grown anaerobically. In addition, the requirement for live respiring cells was demonstrated by the increase in the corrosion rate that was observed upon killing the P. fragi K biofilm in continuous cultures, and it was shown that fermentation products do not cause an increase in corrosion. Hence, pure- culture biofilms inhibit corrosion of SAE 1018 steel by depleting oxygen at the metal surface.
AB - Corrosion inhibition of SAE 1018 steel by pure-culture biofilms of Pseudomonas fragi and Escherichia coli DH5α has been evaluated in complex Luria-Bertani medium, seawater-mimicking medium, and modified Baar's medium at 30 °C. In batch cultures, both bacteria inhibited corrosion three to six fold compared to sterile controls, and the corrosion was comparable to that observed in anaerobic sterile media. To corroborate this result, a continuous reactor and electrochemical impedance spectroscopy were used to show that both P. fragi K and E. coli DH5α decreased the corrosion rate by 4- to 40- fold as compared to sterile controls; this matched the decrease in corrosion found with sterile medium in the absence of oxygen and with E. coli DH5α grown anaerobically. In addition, the requirement for live respiring cells was demonstrated by the increase in the corrosion rate that was observed upon killing the P. fragi K biofilm in continuous cultures, and it was shown that fermentation products do not cause an increase in corrosion. Hence, pure- culture biofilms inhibit corrosion of SAE 1018 steel by depleting oxygen at the metal surface.
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U2 - 10.1007/s002530051007
DO - 10.1007/s002530051007
M3 - Article
C2 - 9274042
AN - SCOPUS:0030798109
VL - 48
SP - 11
EP - 17
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
SN - 0175-7598
IS - 1
ER -