Growth patterns of bacterial cultures depending on the nitrogen availability

Abstract

Morphological and ultrastructural growth patterns of bacterial cultures in response to the nitrogen availability were demonstrated using cultivation and scanning electron microscopy (SEM). It was found that strains of Pseudomonas sp. 1CB and Streptomyces sp. 21A are able to grow only in the medium with available nitrogen. Rhizobium sp. 2A formed biofilm on glass in medium with nitrate and in medium without available nitrogen. In a non-nitrogenous medium, an increase in the diameter of bacterial cells was observed due to the intensive secretion of polysaccharide mucus, which can be considered a mechanism of protection of the nitrogenase complex from the damaging effect of oxygen.