Silver Nanoparticles Synthesized by the Heavy Metal Resistant Strain Amycolatopsis Tucumanensis. Application in Green Biotechnology to Control Red Strip Disease in Sugarcane

The production of bioetanol and sugar from sugarcane is an important economic activity in several countries. Sugarcane is susceptible to different phytopathogens. Over the last years, the red strip disease caused by the bacterium Acidovorax avenae subsp. avenae produced significant losses in sugarcane crops. Bio-nanotechnology emerged as an eco-friendly alternative to the biosynthesis of antimicrobial molecules. The aims of this study were to (a) produce extracellular silver nanoparticles using the heavy metal resistant strain Amycolatopsis tucumanensis, (b) evaluate their antibacterial and antifungal in vitro effect and (c) determine the potential of silver nanoparticles to protect sugarcane against red stripe disease. Amycolatopsis tucumanensis synthesized silver nanoparticles with excellent physicochemical properties that were able to control the growth of A. avenae subsp. avenae and Fusarium sp. in in vitro assays. In addition, in vivo assays in sugarcane were successful, showing a control upon the red strip disease when the silver nanoparticles were applied as preventive treatment. To our knowledge, this is the first report of silver nanoparticles extracellularly synthesized by an Amycolatopsis strain that were able to inhibited the growth of phytopathogens and control the red strip disease in sugarcane