Physiological and biochemical properties of the bacterial association of Klebsiella terrigena E6 and Bacillus firmus E3

Physiological and biochemical properties of the natural rhizospheric association of Klebsiella terrigena E6 and Bacillus firmus E3 were studied. It was demonstrated that this association fixed actively molecular nitrogen at a rate of 110 nmol ethylene per 1 mg protein per h. The dynamics of bacterial population in the association and in pure cultures were studied. The properties of this association depended on the ratio of its components; the maximal nitrogen fixation was recorded at a content of B. firmus E310 amounting to 15% of the total cell number. It was demonstrated that the stability basis of this association was the specific interactions via its components via metabolites--phenol and para-hydroxybenzoic acid--as well as via nitrogen fixation, respiration, and pH of the medium. A scheme of the interactions between the components of association is shown.[PUBLICATION ABSTRACT]