Fig. 2
Impact of the nutrient environment on pamamycin production in S. albus J1074/R2. The strain was grown on a mineral mannitol-based medium containing 10 g L−1 (55 mM) of the sugar alcohol as sole carbon source (J1074/R2 Control), supplemented with different amino acid mixtures, containing three to five amino acids (designated by the one letter code) at a concentration of 3 mM each (a, b). The strain was grown on a mineral mannitol-based medium containing 10 g L−1 (55 mM) of the sugar alcohol as sole carbon source (J1074/R2 Control), supplemented individually with branched-chain amino acids (I, L, and V) at a concentration of 3 mM each (c, d). The data comprise the total pamamycin titer after 96 h (a, c), and the final pamamycin spectrum (b, d). Statistical significance was assessed by a t-test (p < 0.05, *; p < 0.01, **). n = 3