Pure cultures isolated from the biofertilizers were tested for antagonistic activity against phytopathogenic fungi. All seven tested bacterial isolates suppressed by 50% or more the growth of Bipolaris sorokiniana and Sclerotium bataticola. B. amyloliquefaciens and Micrococcus luteus were the most effective isolates and suppressed all three fungi by more than 60% (Table 4).
Along with the antagonistic activity of the biofertilizers, their ability to synthesize physiologically active compounds was studied. In all three fertilizers, we found significant amounts of tryptophan ranging from 18 mg g1in Ecud to 388 mg g1 in Bamil (Table 5). Tryptophan is known as the major precursor of auxin IAA in plants and soil bacteria (Kravchenko et al., 1994; Barazani and Friedman, 1999; Bartel, 1997; Leyser, 2002).