A DIBASAL (MINIMUM SALT, MAXIMUM YIELD) SOLUTION FOR ASPERGILLUS NIGER; ACIDITY AND MAGNESIUM OPTIMUM

Abstract

A. niger was grown at 35[degree]C for 4 days. Absorption of Mg, but not of other macronutrients, was altered by variations in acidity. Values in acidity-yield curves depended on variations in Mg and micronutrient content of the soln. The dibasal soln. (minimum salt soln. for max. yield) was found to contain all the nutrient elements in minimal quantity, as detd. in quantity-yield tests with the individual elements. Max. yields, therefore, can be obtained when all essential elements are present in minimal quantity. The fungus requires not more than 106 mg. of macronutrient salts per gram of substance formed. Possible methods for computing the approx. composition of the dibasal nutrient soln. for other organisms are indicated.