Hyaluronic acid (HA) is a linear and high molecular mass polymer formed by repeating disaccharide units of N-acetyl-D-glucosamine and D-glucuronic linked by β(1-3) and β(1-4) glycosidic bonds. Because its physicochemical and biological properties, such as lubricity, viscoelasticity, water holding capacity and biocompatibility, HA has numerous and increasing applications in food, cosmetic and clinical areas such as plastic surgery, treatment of arthritis, major burns and intra-ocular surgery [1, 2]. This glycosaminoglycan has traditionally been extracted from animal tissues such as synovial fluid, rooster combs, cartilage, vitreous humour and umbilical cords [3, 4]; however, fermentative HA production by Streptococcus generates yields with higher concentrations of HA at lower costs and with more efficient downstream processes [5–7]. Among the strains of this bacteria, S. zooepidemicus is one of the most commonly used [6, 7]. The strains of this bacteria are facultative anaerobes, but they are also aerotolerant, catalase-negative and have fastidious nutrient requirements with respect to organic nitrogen [5, 8].
Although several strategies have been reported for increasing microbial HA, including pH-gradient stress , continuous culture , lysozyme or hyaluronidase addition [10, 11], agitation and aeration conditions [12–14], medium optimisation , the type of bioreactor , effect of aminoacids and mineral salts [17, 18] and fed-batch operation , there is almost no studies of new sources of sugars and proteins from organic waste materials in order to reduce both production costs and pollution problems. More than 80% of these costs are due to these nutrients (sugars and proteins) and commercial formulations are not an economical resource for industrial production of HA.
Peptones obtained from fish viscera residues have been found to be an excellent substrate for different microbial processes [20–25]. Recently, we studied the appropriateness of two marine peptones for the production of lactic and hylauronic acids . Furthermore, mussel processing wastewaters (MPW), a residual material rich in glycogen obtained from canning companies, has been used in several bioproductions, including the production of gibberellins , amylase , bacteriocins [29–31], glucose oxidase  and citric acid . From an environmental point of view, both residues generate serious pollution problems on Galician coasts (NW, Spain) as they are produced in large volumes and have a high organic load, which makes their depuration extremely difficult. The European Union guidelines about this problem are based on the development and implementation of an efficient and integral waste management and valorisation processing in order to obtain zero-wastes, zero-discharges and zero-pollution.
The main aim of this work was to investigate the fermentative capacity of culture media formulated with MPW and marine peptones, obtained from two different, highly polluting marine by-products, in order to replace the expensive commercial sources of carbohydrates and proteins usually used in hyaluronic acid production by S. zooepidemicus. The kinetic parameters obtained from a modified logistic equation were successfully used to compare accurately the corresponding metabolite productions.