Abstract: | A synthetic medium for Opercularia coarctata was developed that contains 20 amino acids, 10 vitamins, an 8-component balanced salt solution, Fe2(SO4)3·(NH4)2SO4·24H2O, Tween 80, stigmasterol, a 7-component nucleic acid mixture, phenol red as an indicator, and 2,500 U.S.P. units/ml penicillin to maintain sterility. This medium supported axenic survival for 96 hr. Multiple supplements of thioctic acid, niacin, niacinamide, inositol, PABA, oleic acid, and Fe(NO3)2·9H2O instead of Fe2(SO4)3·(NH4)2SO4·24H2O coverted the survival medium into a growth medium, which permitted 36–45 days continuous cultivation of populations in excess of 4 × 103 cells/3.0 ml final volume. Five generations were produced during the 48 hr logarithmic growth period. Serial transfers at 72 hr and during periods of greatest cell density produced a maximum of 8 generations 96 hr after initiation but the medium failed to sustain growth through more than 6 serial transfers. Extension of this investigation to formulating a minimal axenic medium is discussed. |