6.9
Patents in the Emerging World of Bio-nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
6.10 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Abstract The resistance of common or resurgent pathogens to standard antibiotic
therapies is a significant health problem, so the need for new antimicrobial sources is
imperative. It is widely known that the most promising source of new drugs remains
natural products, mainly those of microbial origin. Such is the case of microbial
nanoparticles (NPs) which have unusual physical, chemical, and biological properties like as powerful antibacterial activities. While NPs synthesized by chemical
methods involve hazardous and expensive processes, nano-biosynthesis is a green
technology by which NPs are obtained through biological processes such as the
reduction of a metal salt by the action of biomolecules.
The aim of this chapter is to provide an overview of the continuing central role of
natural products like the NPs in the discovery and development of new pharmaceuticals. It is known that Actinobacteria are excellent producers of specialized biomolecules, such as NPs. Moreover, it was demonstrated that they have in their
genomes many more biosynthetic pathways, which constitute an untapped promising source of new antibacterial molecules and other therapeutic agents. Here, we
focus on those heavy metal-resistant strains, due to biogenic NPs are synthesized by
simple processes of metal reductions which can naturally occur as part of cellular
detoxification mechanisms. In this context, a brief description of the ways of the NPs
bioproduction is given. Although extracellular production of metal NPs has more
commercial applications in several areas, intracellular production is of the particular
dimension and with less polydispersity. This is remarkable due to the control over
particle size, and polydispersity is needed to be established for biotechnological
purposes. Also, a brief overview of some of the most important methods for
nanoparticle characterization is provided. The most applied techniques in NPs
characterization are ultraviolet-visible (UV-vis) spectrophotometer, transmission
electron microscopy (TEM), scanning electron microscopy (SEM), atomic force
microscopy (AFM), dynamic light scattering (DLS), X-ray powder diffraction
(XRD), Fourier transform infrared spectroscopy (FT-IR), Zeta potential measurement, particle size analysis (PSA), and energy dispersive X-ray spectroscopy (EDX).
By last, this chapter describes the mechanisms that explain the antimicrobial
properties of NPs, and it is believed that the more relevant traits of NPs are related
with their surface-reactive groups exposed, leading to the formation of reactive
oxygen species (ROS). This is indirectly related to their size, as the size of the
particle decreases and its surface area increases and determines the potential number
of reactive groups on the particle surface.
Keywords Antibiotic resistance · Microbial nanoparticles · Green technology ·
Actinobacteria · Antibacterial activity · Metal resistance · Nano-biosynthesis ·
Characterization techniques · Nanoparticle properties
196
D. Costa et al.
Patents in the Emerging World of Bio-nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
6.10 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Abstract The resistance of common or resurgent pathogens to standard antibiotic
therapies is a significant health problem, so the need for new antimicrobial sources is
imperative. It is widely known that the most promising source of new drugs remains
natural products, mainly those of microbial origin. Such is the case of microbial
nanoparticles (NPs) which have unusual physical, chemical, and biological properties like as powerful antibacterial activities. While NPs synthesized by chemical
methods involve hazardous and expensive processes, nano-biosynthesis is a green
technology by which NPs are obtained through biological processes such as the
reduction of a metal salt by the action of biomolecules.
The aim of this chapter is to provide an overview of the continuing central role of
natural products like the NPs in the discovery and development of new pharmaceuticals. It is known that Actinobacteria are excellent producers of specialized biomolecules, such as NPs. Moreover, it was demonstrated that they have in their
genomes many more biosynthetic pathways, which constitute an untapped promising source of new antibacterial molecules and other therapeutic agents. Here, we
focus on those heavy metal-resistant strains, due to biogenic NPs are synthesized by
simple processes of metal reductions which can naturally occur as part of cellular
detoxification mechanisms. In this context, a brief description of the ways of the NPs
bioproduction is given. Although extracellular production of metal NPs has more
commercial applications in several areas, intracellular production is of the particular
dimension and with less polydispersity. This is remarkable due to the control over
particle size, and polydispersity is needed to be established for biotechnological
purposes. Also, a brief overview of some of the most important methods for
nanoparticle characterization is provided. The most applied techniques in NPs
characterization are ultraviolet-visible (UV-vis) spectrophotometer, transmission
electron microscopy (TEM), scanning electron microscopy (SEM), atomic force
microscopy (AFM), dynamic light scattering (DLS), X-ray powder diffraction
(XRD), Fourier transform infrared spectroscopy (FT-IR), Zeta potential measurement, particle size analysis (PSA), and energy dispersive X-ray spectroscopy (EDX).
By last, this chapter describes the mechanisms that explain the antimicrobial
properties of NPs, and it is believed that the more relevant traits of NPs are related
with their surface-reactive groups exposed, leading to the formation of reactive
oxygen species (ROS). This is indirectly related to their size, as the size of the
particle decreases and its surface area increases and determines the potential number
of reactive groups on the particle surface.
Keywords Antibiotic resistance · Microbial nanoparticles · Green technology ·
Actinobacteria · Antibacterial activity · Metal resistance · Nano-biosynthesis ·
Characterization techniques · Nanoparticle properties
196
D. Costa et al.