Production of hyaluronic acid by Streptococcus zooepidemicus on protein substrates obtained from Scyliorhinus canicula discards

This work investigates the production of hyaluronic acid (H) by Streptococcus equi subsp. zooepidemicus in complex media formulated with peptones obtained from Scyliorhinus canicula viscera by-products. Initially, in batch cultures, the greatest productions were achieved using commercial media (3.03 g/L) followed by peptones from alcalase hydrolyzed viscera (2.32 g/L) and peptones from non-hydrolyzed viscera (2.26 g/L). An increase of between 12% and 15% was found in subsequent fed-batch cultures performed on waste peptones. Such organic nitrogen sources were shown to be an excellent low-cost substrate for microbial H, saving more than 50% of the nutrient costs. We appreciate the excellent technical support of Margarita Nogueira and Ana I. Duran (IIM-CSIC). We also thank to Ramiro Martinez (Novozymes A/S, Spain) for supplying us with alcalase. English used in this manuscript has been reviewed by Concorde Language School S.L. (Vigo, Spain). Isabel Rodriguez Amado was awarded with a postdoctoral contract from the Xunta de Galicia (Plan I2C, 2012). This research was funded by the projects MARMED 2011-1/164 (Atlantic Area Programme, EU), 0687_NOVOMAR_1_P (POCTEP Programme, EU) and iSEAS LIFE13 ENV/ES/000131 (LIFE+ Programme, EU).