[Optimization of the medium for the yeast synthesis of biotin].

In order to increase the yield of biotin produced by the culture Sporobolomyces pararoseus, the medium containing sucrose, asparagine, MgSO4 (NH4)2SO4, KH2PO4, vitamin complex and trace elements was optimized. With the aid of a fractional factor experiment (2(5-1)) and a complete factor experiment (2(4)), the proportion of constituents was chosen in such a way as to double biotin yield, i.e. to increase it to 55.25 micrograms/l. An enrichment of the medium with yeast autolysate, casein hydrolysate and peptone in the presence of adenine increased biotin yield to 105.7 micrograms/l and cell productivity from 6.1 to 8.0 micrograms/l dry biomass.