Potencial biotecnológico de bactérias endofíticas de Himatanthus sucuuba

Abstract

In the search for sustainable alternatives of disease management, biocontrol agents as well as their antagonistic relations, appear as important source for the applied biological control. In this context, the use of endophytic microorganisms for biological control purposes has been extensively studied. They mainly comprise fungi and bacteria that inhabit the interior of plants without apparently causing damage to their hosts. Their ability to biocontrol can come from several mechanisms, such as the production of deleterious substances to phytopathogens or competing for space and nutrients. Indirectly, inducing systemic resistance in the host or by the production of growth promoting substances. In this sense, this work aimed at the isolation, biochemical and molecular characterization and the search for endophytic bacteria that act to reduce diseases such as anthracnose or are associated with the promotion of plant growth, reducing production costs and the environmental impact caused by the inputs Chemicals. A total of 416 bacterial isolates were obtained from H. sucuuba, representing 73.08% of the leaf, 10.10% of the petiole and 16.82% of the peel. From the total of 308 bacteria analyzed, 48.78% fixed atmospheric nitrogen, 83.77% were able to produce AIA and 96.42% solubilized inorganic phosphate. As for the in vitro antagonistic assay, 219 bacteria were selected by mass selection for the paired culture and thermostability tests. In the direct comparison, 68.49% were able to substantially inhibit the growth of phytopathogens by antibiosis, with different levels of toxicity to the challenging pathogens , With respect to thermostability, 33.79% of the lineages were highlighted because they were able to inhibit the growth of the phytopathogens of the three tropical hosts, revealing a great range of action, and, showing that the metabolites produced proved to be thermostable, maintaining their activities even after Autoclaving.