Figure 3.

Medium optimization of YL-1 polysaccharide production. (a) nitrogen source; (b) carbon source; (c) initial glucose concentration; (d) NaCl concentration. Peptone, yeast extract, (NH4)₂SO₄ and corn steep powder were selected as nitrogen sources and dosed at a concentration of 10 g/L. Sucrose, starch, glucose and maltodextrin were selected as carbon sources and dosed at a concentration of 50 g/L. Initial carbon source concentration was adjusted in six gradients of 20, 50, 100, 150, 200, 300 g/L. NaCl concentration in culture was set in gradients of 0, 0.2, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 g/L. All tests were performed in triplicate and repeated at least once, and the results were expressed by their means ± SD (standard deviation). Statistical significance of the treatment effects was determined by Duncan’s multiple range t-test.