J. Mater. Sci. Technol. ›› 2021, Vol. 79: 101-108.DOI: 10.1016/j.jmst.2020.11.042

• Research Article • Previous Articles     Next Articles

Electron transfer mediator PCN secreted by aerobic marine Pseudomonas aeruginosa accelerates microbiologically influenced corrosion of TC4 titanium alloy

Dan Liua,b,c, Hongying Yangc, Jianhui Lia, Jiaqi Lib, Yizhe Dongb, Chuntian Yangb, Yuting Jinb, Lekbach Yassirb, Zhong Lib, David Hernandezd, Dake Xub,*(), Fuhui Wangb, Jessica A. Smithd   

  1. aHebei Key Laboratory of Material Near-Net Forming Technology, Hebei University of Science and Technology, Shijiazhuang, 050018, China
    bShenyang National Laboratory for Materials Science, Northeastern University, Shenyang, 110819, China
    cSchool of Metallurgy, Northeastern University, Shenyang, 110819, China
    dDepartment of Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, 06050, USA
  • Received:2020-09-07 Revised:2020-11-04 Accepted:2020-11-17 Published:2020-12-09 Online:2020-12-09
  • Contact: Dake Xu
  • About author:* E-mail address: xudake@mail.neu.edu.cn (D. Xu).
    First author contact:

    1These authors contributed equally to this work.

Abstract:

Titanium alloys possess excellent corrosion resistance in marine environments, thus the possibility of their corrosion caused by marine microorganisms is neglected. In this work, microbiologically influenced corrosion (MIC) of TC4 titanium alloy caused by marine Pseudomonas aeruginosa was investigated through electrochemical and surface characterizations during a 14-day immersion test. Results revealed that the unstable surface caused by P. aeruginosa resulted in exposure of Ti2O3 and severe pitting corrosion with maximum pit depth of 5.7 μm after 14 days of incubation. Phenazine-1-carboxylate (PCN), secreted by P. aeruginosa, promoted extracellular electron transfer (EET) and accelerated corrosion. Deletion of the phzH gene, which codes for the enzyme that catalyzes PCN production, from the P. aeruginosa genome, resulted in significantly decreased rates of corrosion. These results demonstrate that TC4 titanium alloy is not immune to marine MIC, and EET contributes to the corrosion of TC4 titanium alloy caused by P. aeruginosa.

Key words: Titanium alloy, Microbiologically influenced corrosion, Pseudomonas aeruginosa, Extracellular electron transfer, Phenazine-1-carboxylate, Genetic modification