*2.3. Culture Media and Culture Conditions for the Production of Polysaccharides*

Cultures were carried out in 0.5 L reactors (Infors HT Multifors, Bottmingen, Switzerland) containing 0.2 L of mineral culture medium, as previously described [13]. The high-cell density culture consisted of two phases: (1) an exponential-growth phase at 33 ◦C, which started with inoculation and lasted until exhaustion of the initially added glucose (17.5 g·L −1 ), and (2) a 72 h fed-batch phase at 28 ◦C, with 90 mL of 50% glycerol feeding solution, provided at a flow rate of 1.375 mL·h −1 . isopropyl β-D-1-thiogalactopyranoside (IPTG) (0.2 mM) was added to the culture 3 h after the beginning of the glycerol feed. Lactose acceptor (750 mg) and arabinose (0.5% and 2% *w*/*v* when added) were put in the glycerol feed and supplied continuously. The selecting ampicillin, chloramphenicol, and tetracycline antibiotics were used at 100, 25, and 15 µg·mL−<sup>1</sup> , respectively.
