CHOLINE REQUIREMENT OF THE MICROCRUSTACEANMOINA MACROCOPA:A PURIFIED DIET FOR CONTINUOUS CULTURE

Abstract
Under axenic culture conditions, choline is a required nutrient of the microcrustacean Moina macrocopa. Lecithin (phosphatidylcholine) as a component of an artificial biphasic diet serves as an efficient source of choline. Moina can synthesize choline efficiently via methylation of dietary ethanolamine. The animals assimilate dietary choline 10 times more efficiently from a particulate source than from a soluble one. Liver infusion, the only undefined component of the artificial medium, contains 1% choline and contributes substantially to choline's availability. The liver infusion can be adequately replaced by an increase in dietary particulate choline or soluble choline. As a result, the artificial medium for the growth and continuous reproduction of Moina is now completely defined. Moina macrocopa's requirement for choline in a particulate form is estimated to be 750-850mg/100 g diet at a culture temperature of 26°C.