Bactericidal activity of elastin-like polypeptide biopolymer with polyhistidine domain and silver

•Elastin biopolymer with polyhistidine domain (ELPH12) has been produced and purified.•ELPH12 has been investigated as silver binding agent for bactericidal activity.•ELPH12-Ag act as a bactericidal agent for Escherichia coli.•ELPH12-Ag act as a bactericidal agent for Vibrio harveyi.•Potential for artificial protein based antibacterial in health care and coastal aquaculture. In the present study, elastin-like biopolymer (ELP) composed of a polyhistidine domain has been investigated as a silver binding agent for antibacterial activity against Escherichia coli, a model test strain for Gram-negative bacteria for antibacterial assays of nanoparticles, and Vibrio harveyi, an opportunistic pathogen which cause mass mortality in shrimp Penaeus monodon reared in coastal aquaculture. The concentration dependent antimicrobial activity of ELPH-Ag on E. coli and V. harveyi was examined by agar well diffusion method and further confirmed through growth curves using spectrophotometer assisted absorption observations. The increased concentrations of ELP-Ag effectively checked the bacterial growth and increased the diameter of inhibition zone. The results showed a minimum inhibitory concentration of 37μg/ml. This study has an application in formulating artificial protein based antibacterial in diverse fields of healthcare and management of disease in coastal aquaculture.