Treat- Ment Yeast ext. Fodder** yeast Beef ext. Peptone Glycerol C N C/N PM 10 - 5 5 10 8.43 2.40 3.5/1 1 - 5.0 5 5 10 7.38 1.70 4.3/1 2 - 7.5 5 5 10 7.90 1.83 4.3/1 3 - 10 5 5 10 8.43 1.97 4.3/1 4 - 20 5 5 10 10.53 2.52 4.2/1 5* - 20 5 5 10 10.53 2.52 4.2/1 *plus of MgSO4 (0.3 g/l) **Fodder yeast contains 21% C and 5.5% N.

Table 4: Modification of the basic fermentation medium (g/l).