Investigation of Antibiotic, Siderophore, volatile metabolites production by Bacillus and Pseudomonas Bacteria

Different species of Bacillus and Pseudomonads are among the most important bacterial antagonists that are capable of controlling phytopathogenic fungi and bacteria. In the green house experiments, 5 bacterial isolates belonged to Bacillus (Sch-5،Sch-3، Ssh-4, Ssh-3) and Pseudomonads Ckk-1 which showed higest effectiveness in controling of Rhizoctonia solani (isolates RsK and RsA) were selected. In experiment for investigation of Antibiotic production percent inhibiton of mycelial growth of R solani by bacterial isolates was determined. This experiment carried out for RsK isolate in 3 treatments (2 bacterial isolates and control) with 3 replications and for RsA in 5 treatments (include 4 bacterial isolates and control) with 3 replications. Growth of RsA on NAG was determined 5 days later. The results showed that Sch-3،Ssh-3، Ckk-1،Ssh-4 inhibitory effect against RsA were 58/8%. 62/2%. 74/4%. 83/3% respectively. Isolates Sch-3 and Sch-5 inhibitory effect were 68/8% and 60% against RsA respectively. In another experiment, to study volatile metabolites produtions in 3 treatments (2 bacterial isolates and control) with 3 replications for RsK and in 5 treatments (4 bacterial isolates and control) with 3 replications for RsA. The results indicated that fungal isolate RsK growth was about 8mm against bacterial isolates Sch-5, Sch-3 and fugal isolate RsK against Ckk-1, Ssh-4, Sch-3, Ssh-3 was 8, 8, 10, 12mm respectively. there were significant differences among control and other treatments. The over all results indicated that all bacterial isolates could produce volatile and non-volatile metabolites and Ckk-1 isolate of Pseudomonas was capable of siderophore and hydrogen cyanide production which are their most important mode of action against plant pathogenic microorganisms.