The increasing demand for seafood recorded over the years led to an increase in the by-products produced by the seafood processing sector. These by-products, which can represent up to 70% of the processed product, are rich in nutrients and bioactive compounds, so if recovered, by means of eco-friendly methods, they can be used in lot of sectors, such as food, packaging, cosmetics and pharmaceutics. In the present work, two lactic acid bacteria (Lactobacillus lactis and L. brevis) and the yeast Yarrowia lipolytica, able to produce organic acids and proteases during the fermentation process, were used to extract chitin from deep-water shrimp (Aristeus antennatus) by-products. The results showed that L. lactis was the most effective microorganism in removing both the mineral and protein fractions, being chosen for the optimization of the extraction technique of chitin, eventually converted in chitosan. The chitosan showed a deacetylation degree (DD) of 82%, which led to good film-forming capacity. The developed biological technique allowed valorizing shrimp by-products by recovering chitin and chitosan, which was able to produce biofilm to be employed to prolong seafood shelf life, in a circular economy point of view, contributing even more to increase the sustainability of the production sector.

The increasing demand for seafood over the years has led to an increase in by-products produced by the seafood processing sector. These by-products, which can represent up to 70% of processed products, are rich in nutrients and bioactive compounds, allowing them to be used in several sectors, such as food, packaging, cosmetics and pharmaceutics, provided that recovery occurs in an eco-friendly manner. In the present work, two lactic acid bacteria (Lactobacillus lactis and L. brevis) and the yeast Yarrowia lipolytica, which are organisms capable of producing organic acids and proteases during the fermentation process, were used separately to extract chitin from deep-water shrimp (Aristeus antennatus) by-products. The results showed that L. lactis was the most effective microorganism in removing both the mineral and protein fractions; therefore, it was chosen to optimize the chitin extraction technique, after which chitin was eventually converted into chitosan. The obtained chitosan showed a deacetylation degree (DDA%) of 82%, indicating good film-forming capacity. The developed biological technique allowed the valorization of shrimp by-products by recovering chitin and eventually chitosan, allowing us to produce biofilms that could help prolong seafood shelf life and, from a circular economy point of view, contributing further to promoting the sustainability of the production sector.