Antagonist actinomycetes metabolites against plant pathogens fungi of agricultural importance

The study was conducted over the years 2012-2013 in order to evaluate the antagonistic effects of the metabolites of actinomycetes against phytopathogenic fungi of agricultural importance. To demonstrate the antagonist activity of antibiosis, bioassays were performed in vitro using the method of wells with cell-free filtrates and the double layer method with chloroform in order to kill living cells of actinomycetes and evaluate only the metabolites present in both methodologies. Three actinomycetes isolate previously selected by their antifungal activity APA2, AAH53 and APC70 were confronted with the fungus Alternaria solani, Colletotrichum coccodes y Fusarium oxysporum. All submitted actinomycetes antagonistic activity is in both methodologies, however greater antagonist activity was observed in trials with double-layer methodology, reaching up to 86% inhibition for C. coccodes and 72% for A. solani. Both have phytopathogenic fungi with actinomycete APC70. The analysis of three isolates of actinomycetes by comparing the sequences of 16S rRNA genes revealed that the isolates belong to the genus Streptomyces. Phylogenetic analysis revealed that strain is closely related APA2 Streptomyces longisporoflavus, isolation AAH53 with Streptomyces mutabilis and APC70 with Streptomyces griseus.