Chapter 1 Green Synthesized Nanoparticles as a Promising Strategy for Controlling Microbial Biofilm Gabrielle Messias Souza, Karolinny Cristiny de Oliveira Vieira, Lauren Vila Naldi, Valéria Cataneli Pereira, and Lizziane Kretli Winkelstroter Abstract Microbial biofilms are communities of cells adhered to a surface embed- ded with a matrix of polymeric extracellular substances. The biofilm can present one or more species of microorganisms, depending on its duration and location. It may involve Gram-positive, Gram-negative bacteria and yeast such as Candida albicans, Coagulase negative Staphylococcus, Enterococcus spp., Klebsiela pneumoniae, Pseudomonas aeruginosa and Staphylococccus aureus. In addition to bacteria, other cellular elements may be aggregated in the biofilm, such as platelets, for example, when the biofilm is installed on a surface bathed in blood. In the health area, there are a variety of possible situations that allow biofilm formation in medical devices directly connected to the patient or indirectly by contamination of the machines or pipes of that environment. Biofilm formation has been linked to 60% of hospital infections. In this way, components and methods that can inhibit the biofilm formation or even dissolve it have been investigated. Nanobiotechnology is an area of nanotechnology related to the creation, use and improvement of nanostructures in biotechnological processes. Among the various research fields in this area is the synthesis, characterization and application of nanoparticles with different sizes, shapes and chemical compositions. The traditional methods used for the synthesis of these nanoparticles are generally chemical methods in which toxic solvents are used and the generation of dangerous by-products can occur and involve high energy consumption. Due to these factors, there is an increasing need to develop non-toxic and environmentally friendly procedures; but with a high yield and low cost. In this context, the routes of synthesis of nanoparticles by biological G. M. Souza · L. V. Naldi Health Sciences Faculty, University of Western Sao Paulo, Sao Paulo, Brazil K. C. de Oliveira Vieira Master in Health Science, University of Western Sao Paulo, Sao Paulo, Brazil V. C. Pereira · L. K. Winkelstroter (*) Health Sciences Faculty and Master in Health Science, University of Western Sao Paulo, Sao Paulo, Brazil © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021 N. R. Maddela et al. (eds.), Nanotechnology for Advances in Medical Microbiology, Environmental and Microbial Biotechnology, https://doi.org/10.1007/978-981-15-9916-3_1 1