Enhanced steel corrosion inhibition through microbially induced carbonate precipitation with facultative anaerobic denitrifying bacterium

Denitrification processes are increasingly studied as a promising alternative to ureolytic microbially induced carbonate precipitation (MICP). This study investigates the capabilities of the newly isolated denitrifying bacterium, Stutzerimonas stutzeri CF3, in promoting calcium carbonate precipitation and enhancing steel corrosion resistance under both aerobic and anaerobic conditions. The facultative anaerobe was tested across a range of environmental parameters including pH levels (7.5–11.5), C/N ratios (5−15), NaCl salinity (0–5 %), and Ca²⁺ concentrations (0–30 mmol), to determine its adaptability and effectiveness in precipitating calcium carbonate. Our findings reveal that S. stutzeri CF3 not only survives but thrives under extreme conditions, demonstrating significant nitrate removal and robust calcium carbonate precipitation, particularly in high salinity and variable pH environments. Furthermore, the study examines the implications of S. stutzeri CF3 on steel corrosion, particularly Q235 steel, using Tafel polarization techniques, demonstrating enhanced corrosion resistance. These results underscore the dual utility of S. stutzeri CF3 in microbial self-healing concrete applications, pointing to its potential to improve the durability and integrity of construction materials by leveraging its versatile metabolic pathways.