Natural peptide as a kinetic promoter for methane hydrate formation: Insights from experiments and molecular simulations

The influence of biomolecules on the kinetics of gas hydrate formation has received some attention in the scientific community. However, the underlying physicochemical mechanisms are still not well understood. Recently, a peptide present in a protein produced by a marine methylotrophic bacterium was found to promote methane hydrate formation under natural conditions. In this study, we take an in-depth look at the effect of this natural peptide on the formation of methane hydrates. Our research employed a dual methodology. Methane hydrates were formed experimentally under high-pressure conditions to study the formation kinetics, while molecular dynamics simulations were carried out to reveal the mechanisms at the nanoscale. Our results confirm that the natural peptide acts as a kinetic promoter for hydrate formation at an environmentally relevant concentration of Image 1 . We argue that this effect is achieved by a stabilization of the nascent hydrate nuclei, via adsorption of the peptide at their surface. Our study highlights the role of each amino acid in the peptide sequence, and thus provides valuable insights into the design of efficient and sustainable promoters. More fundamentally, it lays a solid foundation for our understanding of the interactions between marine microbial communities and methane hydrate deposits.