Springer Online Journal Archives 1860-2000
Process Engineering, Biotechnology, Nutrition Technology
Summary In the productions of biomass and vitamin B12 using methanol as the sole carbon source, it is necessary to use a medium in which methanol is the growth limiting substrate. Other inorganic salts should be in slight excess so that the yield of cells and the intracellular content of vitamin B12 do not vary. From basic principles of chemostat culture, a medium was optimized for Pseudomonas AM-1 a methanol utilizing bacterium, for the concentrations of various inorganic salts. This was done in a series of chemostat cultures at a dilution rate of 0.1 h−1. Optimum amounts of NH4 +, PO4 3- and Mg2+ were estimated from the minimum concentration of the salt at which methanol became growth limiting. The optimum concentrations of Ca2+, Fe2+, Mn2+, and Zn2+ as a group were determined in the same way. Cu2+, Mo6+, Co2+ and B3+ are required at concentrations of μg/l and they were not studied as these very low level can be introduced as contaminants from other salts. The optimum medium composition (in g/l) was as follows: (NH4)2SO4, 1.0; H3PO4, 75×10−3; MgSO4 · 7H2O, 30×10−3; CaCl2 · 2H2O, 3.3×10−3; FeSO4 · 7H2O, 1.3×10−3, MnSO4 · 4H2O, 0.13×10−3; ZnSO4 · 7H2O, 0.13×10−3; CuSO4 · 5H2O, 40×10−6; Na2MoO4, 40×10−6; CoCl2 · 6H2O, 40×10−6; H3BO3, 30×10−6 and methanol 4.
Type of Medium: