Siderophores production and in vitro antifungal activity of two Plant Growth Promoting Bacteria: Gluconacetobacter diazotrophicus and Burkholderia tropica

ORMAZABAL, CELESTE; BERNABEU, PAMELA; CAVELLO, IVANA; LUNA, MARÍA FLAVIA

Rosario, Sante Fe

Congreso; IX Congreso Argentino de Microbiología General SAMIGE; 2013

Sociedad Argentina de Microbiología General

In the last decades there has been an increased interest in the use of Plant Growth Promoting Bacteria (PGPB) for biological control as an alternative of reducing the population of phytopathogenic organisms and decreasing the use of chemicals in agriculture. It has been demonstrated that PGPB can exert this function by diverse forms such as production of siderophores and other biological products, induction systemic resistance, among others. Two N2-‑xing endophytic bacteria, Gluconacetobacter diazotrophicus Pal 5 and Burkholderia tropica MTo293, were described as potential PGPB, but their biocontrol capabilities have been poorly characterized. In this way, batch cultures with these bacteria growing independently under dierent nutritional condition were carried out to evaluate siderophores production and, on the other hand, plate assays using dierent phytopathogenic fungi were made for determining their abilities of inhibit fungal growth. Both microorganism produced siderophores under iron depletion, independently of others nutritional conditions. Six dierent fungi strains were tested and both microorganisms showed growth inhibition against Fusarium graminiae (Fusarium head blight) and Alternaria alternata (tomato and others).