Light at 410 nm controls the growth of skin bacteria from Chelidonichthys lucerna (Osteichthyes: Triglidae)

Fish microbiota represents a community to be considered in fishery world for two main reasons: the occurrence of potential pathogens dangerous for human health and/or degraders of flesh. The most used techniques to control fish spoilage are icing and freezing. Furthermore, UV treatment and chemical disinfection are also considered. However, these treatments often compromise the quality of food, worsen the taste, smell, appearance in addition to loss of nutritional quality. In this scenario, the use of blue light in antimicrobial field opens new and interesting considerations.In this study, we focused the attention on the tub gurnard (Chelidonichthys lucerna L., 1758), a demersal teleost fish that was chosen as a model to irradiate with LED at 410 nm. The approach was efficient in greatly reducing the microbial community colonizing the skin of the fish. Furthermore, microorganisms isolated from C. lucerna, belonging to different Gram-negative (Aeromonas sp., Exiguobacterium undae, Acinetobacter sp., Acinetobacter baumannii) and Gram-positive species (Bacillus thuringiensis, Listeria sp.) showed a different sensitivity to blue light. However, the bacterial photoinactivation was light-dose dependent. Indeed, blue irradiation could slow down the spoilage of fish with food quality maintenance, help preserving human health and bring, in addition, economic advantage.