Inactivation of <i>Aeromonas hydrophila</i> and <i>Vibrio parahaemolyticus</i> by Curcumin-Mediated Photosensitization and Nanobubble-Ultrasonication Approaches

• Main Authors: Shamil Rafeeq, Setareh Shiroodi, Michael H. Schwarz, Nitin Nitin, Reza Ovissipour
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Foods
• Subjects: curcumin; LED; UV-A; nanobubbles; aquatic pathogens; aquaponics
• Online Access: https://www.mdpi.com/2304-8158/9/9/1306

The antimicrobial efficacy of novel photodynamic inactivation and nanobubble technologies was evaluated against <i>Vibrio parahaemolyticus</i> and <i>Aeromonas hydrophila</i> as two important aquatic microbial pathogens. Photodynamic inactivation results showed that LED (470 nm) and UV-A (400 nm)-activated curcumin caused a complete reduction in <i>V. parahaemolyticus</i> at 4 and 22 °C, and a greater than 2 log cfu/mL reduction in <i>A. hydrophila</i>, which was curcumin concentration-dependent (<i>p</i> < 0.05). Furthermore, the photodynamic approach caused a greater than 6 log cfu/mL <i>V. parahaemolyticus</i> reduction and more than 4 log cfu/mL of <i>A. hydrophila</i> reduction in aquaponic water samples (<i>p</i> < 0.05). Our results with the nanobubble technology showed that the nanobubbles alone did not significantly reduce bacteria (<i>p</i> > 0.05). However, a greater than 6 log cfu/mL <i>A. hydrophila</i> reduction and a greater than 3 log cfu/mL of <i>V. parahaemolyticus</i> reduction were achieved when nanobubble technology was combined with ultrasound (<i>p</i> < 0.05). The findings described in this study illustrate the potential of applying photodynamic inactivation and nanobubble–ultrasound antimicrobial approaches as alternative novel methods for inactivating fish and shellfish pathogens.