Antimicrobial Effect of Squid Ink on Common Microbial Causing Biofilm Attaching to Silicone

Abstract

Present study consisted a possible novel natural antimicrobial agent replacing chemicals for preventing the microbial growth and microbial biofilm accumulated on silicone. Since squid ink has long proved to play various primary roles in wide ranges of alternative therapeutic medicine and food applications. This research was designed to report the potential antimicrobial effects of squid ink especially after heat treatment against the microorganisms causing biofilms. Various temperature conditions comprising room temperature (RT), 40, 60, 80, and 100°C were applied to the crude squid ink. Two fresh ink samples isolated from splendid squid (Loligo duvauceli) and soft cuttlefish (Sepioteuthis lessoniana) were determined for their antimicrobial activities after heat treatment on most reported microbes causing biofilms on these plastic substrates. The results showed that after pretreatment at RT-50°C for 15 min, fresh crude ink ofL.duvauceliconsistently presented higher bioactive activity (> 15 mm diameter) thanS.lessoniana(5-10 mm diameter), based on a zone of inhibition of disc diffusion method. From this study, both squid inks could definitely be future applied as active antimicrobial ingredients into silicone.