Bacterias del género bacillus como agentes de control biológico in vitro del hongo fitopatógeno Alternaria sp

Abstract

Alternaria sp is a phytopathogenic fungus that affects a large number of plant species, including broccoli, cauliflower, roses, cabbage, among others, so currently the greatest demand for the control of phytopathogens is based on the acquisition of chemical products and the continuous application of these, however, due to the environmental and health problems generated by them in the long term, a great interest in biological control has arisen, and alternatives that are friendly to the environment and the use of bacteria. One of the organisms of greatest interest in biological control are the bacteria of the Bacillus genus, due to the wide variety of secondary metabolites produced by them. From the bank of bacterial strains isolated from the Salesian Polytechnic University, in the laboratory phase it was subjected to thermotherapy in order to establish those with the capacity to produce endospores, after reducing the group to a total of 73 strains, a microscopic identification of Alternaria sp, by simple staining and of the bacteria by Gram staining and spore staining, it was identified that the strains are of the Bacillus type, the production of secondary metabolites was promoted by means of simple bioreactors, of the Aerated Batch type, where after the course of 48h it was obtained metabolites and the antibiogram test was applied, after the formation of inhibition halos it was reduced to a number of 15 strains of which dual confrontations were applied, obtaining diameters of the phytopathogenic fungus for the calculations related to the percentage of inhibition, where two stood out. strains H66 and F25 with antagonistic power demonstrating inhibition percentages greater than 40%, in addition that most of the strains 13 out of 15 respectively have inhibition percentages of more than 30%, which indicates that these Bacillus strains have a high potential for the biocontrol of Alternaria sp.