Alternative sources of marine bioactive compounds from the Black Sea: Isolation and characterization of fish skin collagen from Neogobius melanostomus (Pallas 1814) (Perciformes: Gobiidae)

Round goby-Neogobius melanostomus is the common discard catch species from the shelf zone in the Black Sea, and the abundance rate increases yearly. The aim of this work was the isolation and characterization of collagen from the skin of round goby-N. melanostomus in the Black Sea. The results revealed that the skin of N. melanostomus presented high protein concentration (80%), rich in glycine (34%), alanine (11%), proline (9%) and hydroxyproline (7%), which are characteristic of typical molecules of collagen protein. Thus, the yield of collagen is estimated at 10%. The zero surface net charge of the sample was estimated between pH 5–6, indicating its proximity to the collagen isoelectric point. In addition, FTIR results confirmed its highly organized helical structure, which was preserved in Round Goby species. The biological assays showed that there is a significant increase in cell viability according to control samples in 48 h. Cytotoxicity behavior​ demonstrated that the marine collagen obtained by round goby fish skin is noncytotoxic. In conclusion, these results indicate that this goby species is a potential marine source of collagen.