1. Albrecht S L and Okon Y 1980 Cultures of Azospirillum. Methods Enzymol. 69, 740–749.
2. Bachhawat A K and Gosh S 1987 Iron transport in Azospirillum brasilense: Role of the siderophore spirilobactin. J. Gen. Microbiol. 133, 1759–1765.
3. Balandreau J 1986 Ecological factors and adaptive processes in N2-fixing bacterial populations of the plant environment. Plant and Soil 90, 73–92.
4. Baldani V L D, Alvarez MA de B, Baldani JI and Döbereiner J 1986 Establishment of inoculated Azospirillum spp. in the rhizosphere and in roots of field grown wheat and sorghum. Plant and Soil 90, 35–46.
5. Bani D C, Barberio M, Favili F, Gallori E and Polsinelli M 1980 Isolation and characterization of glutamate synthase mutants of Azospirillum brasilense. J. Gen. Microbiol. 119, 239–244.