Novel peptides based on sea squirt as biocide enhancers to mitigate biocorrosion of EH36 steel

Microbiologically influenced corrosion (MIC) affects offshore production activities severely. Although adding biocides is a simple method, it can cause environmental damage over time. Using green biocide enhancers is a viable strategy to reduce the amount of biocides. In this study, four novel peptides, named Peptide T/Tc/Ts/Tcs, were designed by a natural peptide extracted from the Arctic sea squirt to enhance the efficacy of tetrakis hydroxymethyl phosphonium sulfate (THPS) in mitigating the biocorrosion of EH36 steel caused by Desulfovibrio ferrophilus . The combination of 40 ppm THPS and 100 nM Peptide T/Tc/Ts/Tcs reduced the corrosion rates of EH36 steel by 68 %, 71 %, 86 %, and 90 % after the 7-d incubation, respectively. Notably, 40 ppm THPS + 100 nM Peptide Ts/Tcs achieved similar antimicrobial and biocorrosion mitigation effects as 100 ppm THPS. It suggests that optimizing the cationic and hydrophobic properties of peptides could enhance the bactericidal properties of biocides.