Peptide ABMOK1 is composed of 12 amino acid and can interact with the membrane of Escherichia coli. We have carried out isolation, sequencing, prediction, and synthesis of ABMOK1, which is a peptide of membrane activity. LC-MS/MS mapped the ABMOK1 primary structure, CGYCGACVGVCK; SOPMA predicted secondary structure and random coil, while CAMP was used to predict the antimicrobial probability. LC-MS/MS, SOPMA, and CAMP from this study provide the foundation for comprehensive functional and structural characterization of the peptide ABMOK1. That is first time public peptide from Nitzschia sp. ABMOK1 was interacted with membrane of Escherichia coli with the features of an unstable membrane. The results may help point to new directions for future peptide research with benthic diatoms.