Some observations on the nutritional requirements of Eikenella corrodens ATCC 23834T grown in continuous culture.

The type strain, ATCC 23834, of Eikenella corrodens was grown anaerobically in continuous culture in chemically defined media. Initial experiments showed that glucose was not utilized and it was subsequently omitted from all media. The initial chemically defined medium contained varying levels of 14 amino acids and 20 mM potassium nitrate, an essential nutrient for growth under these conditions. In this medium, the doubling time was 2.1 h, the optimum growth temperature 34 degrees C and 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 nitrate and varying levels of these amino acids, glutamate was found to be the major contributor to biomass increase. Its catabolism may be linked to a respiratory chain involving nitrate as the ultimate electron acceptor.