Study of the production of hyaluronic acid by Streptococcus zooepidemicus cultivation in polyurethane foam

In this work we studied the production of hyaluronic acid by solid state cultivation of Streptococcus zooepidemicus in packed bed columns using polyurethane foam (PUF) as inert support. At first, preliminary experiment were conducted to better understanding of the system. It was verified that the system, initially employed did not have enough reliability of results for optimization and scheduling process. In view of these aspects were carried out modifications and developed a new system of packed bed, the CAS-SSC (Central Aeration System to Solid State Cultivation), to directly flow air into the bed, increasing the efficiency of oxygen distribution. A central composite rotational design (CCRD) was developed for the initial glucose concentration (IGC) and aeration (Aer) aiming the optimization for these two variables. However it was not possible to establish a statistical model that satisfactorily fits the experimental data, precluding the analysis of response surface for the variables in question. However, evaluating the IGC, among the conditions studied, the initial concentration of 15g.L-1 showed the highest AH yield per mass of substrate, 0.24 g of HA per g of glucose consumed. When we observe the system behavior over a sequence of 12 tests, reusing the support over the cultivations, the EPU kept constant the bed properties average pore size and surface area. The values obtained during the tests showed no significant difference at 5% level, giving an average production of 1.24 mg of HA per gram of EPU (AU)