Relation between cellulolytic bacteria and Azospirillum brasilense

ABSTRACT

The association of different strains of azospirilla and cellulose decomposing bacteria was studied in sterile soil. Azospirilla alone failed to use cellulose as a sole carbon source, while inoculation of a cellulose decomposer markedly increased azospirilla densities. Inoculation of active cellulose-solubilizing bacteria in combination with azospirilla in soil containing cellulose increased the acetylene reducing activity over that due to inoculation with azospirilla alone. Nitrogen gains and efficiency of fixation were markedly increased as a result of the association between Azospirillum and cellulose - solubilizing bacteria. Between 286-402 ug/g N were gained at the end of the incubation period which corresponded to 68.9-80.1 mg N fixed/g carbon oxidized