FLUORESCENT-ANTIBODY TECHNIQUE TO IDENTIFY AZOSPIRILLUM-BRASILENSE ASSOCIATED WITH ROOTS OF GRASSES

Bacteria associated with roots of grasses from Florida, Ecuador and Venezuela were isolated and their N2-fixing ability was demonstrated by C2H2 reduction assay. The bacterial isolates have been classified as Azospirillum brasilense (formerly Spirillum lipoferum). These N2-fixing isolates have been compared with several Brazilian strains. Fluorescent antibody (FA) techniques were used to assist identifying isolates of N2-fixing bacteria from grass roots. Tests with antisera prepared against four strains of Azospirillum were used to define serological groups. Antigen-antibody specificity was demonstrated using both Azotobacter and Azospirillum antisera against known species of other soil microorganisms and numerous unidentified soil bacteria. Several applications of the FA technique are suggested to identify N2-fixing bacteria associated with grass roots. © 1979.