In the last decade, an increasing number of glycosaminoglycans (GAGs), chitin and chitosan applications have been reported. Their commercial demands have been extended to different markets, such as cosmetics, medicine, biotechnology, food and textiles. Marine wastes from fisheries and aquaculture are susceptible sources for polymers but optimized processes for their recovery and production must be developed to satisfy such necessities. In the present work, we have reviewed different alternatives reported in the literature to produce and purify chondroitin sulfate (CS), hyaluronic acid (HA) and chitin/chitosan (CH/CHs) with the aim of proposing environmentally friendly processes by combination of various microbial, chemical, enzymatic and membranes strategies and technologies.

The objective of this report was to investigate the isolation and recovery of different biocompounds and bioproducts from wastes (skins and heads) that were obtained from five species discarded by fishing fleets (megrim, hake, boarfish, grenadier, and Atlantic horse mackerel). Based on chemical treatments, enzymatic hydrolysis, and bacterial fermentation, we have isolated and produced gelatinous solutions, oils that are rich in omega-3, fish protein hydrolysates (FPHs) with antioxidant and antihypertensive activities, and peptones. FPHs showed degrees of hydrolysis higher than 13%, with soluble protein concentrations greater than 27 g/L and in vitro digestibilities superior to 90%. Additionally, amino acids compositions were always valuable and bioactivities were, in some cases, remarkable. Peptones that were obtained from FPHs of skin and the heads were demonstrated to be a viable alternative to expensive commercial ones indicated for the production of biomass, lactic acid, and pediocin SA-1 from Pediococcus acidilactici.