Nitrogen fixation by some locally isolated bacteria

ABSTRACT

Several bacterial isolates were tested for their potentiality to fix atmospheric nitrogen. Azomonas macrocytogenes was selected as the experimental organism because of the paucity of knowledge on the N[2] fixation by this organism. Total N[2]fixed was obtained with the modified Winogradsky N[2]free medium. Glucose was superior among the different carbon sources tested, supporting the highest value of total N[2]fixed. The essential amino [except cystine] were detected both within the cells as well as in the culture broth. Low levels of ammonia were found in the cell exudates, whereas relatively higher yields were detected intracellularly