SCREENING AND ISOLATION OF ANTI-FUSARIUM MONILIFORME COMPOUNDS PRODUCING MICROORGANISMS FROM SOIL AND CORN

Fusarium moniliforme, a worldwide corn phytopathogen, is the agent res ponsible for production of the most recently discovered mycotoxin deno minated fumonisin. With intention to evaluate antifungal activity on F . moniliforme, 60 soil and 20 corn samples were screened for active mi croorganisms, using fumonisin producing F. moniliforme strain 113F. Cr ude extract was prepared with brain heart infusion-(BHI) culture of se lected microorganisms, and concentrated with addition of ethanol at 1: 1 ratio. The procedure screened 29 soil samples with positive inhibito ry activity on F. moniliforme, with isolation of 36 antagonistic micro organisms. Fifteen corn samples also showed positive screening results , with isolation of 15 antagonists. The 51 isolates were distributed i n 5 yeasts, 3 Gram-positive cocci, 3 Gram-negative cocci and 40 Gram-p ositive bacilli. All the 51 strains showed inhibitory activity on F. m oniliforme 113F, demonstrated by whole culture method, while only 34 s trains showed activity, when culture supernatant of same strains were assayed by antibiogram test. The sensitivity range of 5 selected antag onist strains was also compared using 10 toxigenic F. moniliforme. Con sidering the extracellular characteristic of these principles, the ana lysis of crude extract concentrate selected two Gram-positive cocci an d 3 sporulated Gram-positive bacilli, with perspectives of bioactive s ubstance production, for F. moniliforme control.