SOME OBSERVATIONS ON THE NUTRITIONAL-REQUIREMENTS OF EIKENELLA-CORRODENS ATCC 23834(T) GROWN IN CONTINUOUS-CULTURE

The type strain, ATCC 23834, of Eikenella corrodens was grown anaerobi cally in continuous culture in chemically defined media. Initial exper iments showed that glucose was not utilized and it was subsequently om itted from all media. The initial chemically defined medium contained varying levels of 14 amino acids and 20 mM potassium nitrate, an essen tial nutrient for growth under these conditions. In this medium, the d oubling time was 2.1 h, the optimum growth temperature 34 degrees C an d the pH 7.2. The key growth-promoting amino acids were glutamate and serine, and the culture appeared to be nitrate limited. By growing the organism in a series of chemically defined media containing 40 mM nit rate and varying levels of these amino acids, glutamate was found to b e the major contributor to biomass increase. Its catabolism may be lin ked to a respiratory chain involving nitrate as the ultimate electron acceptor.