Microbial Nanotechnology: Challenges and Prospects for Green Biocatalytic Synthesis of Nanoscale Materials for Sensoristic and Biomedical Applications

Abstract

Nanomaterials are increasingly being used in new products and devices with a great impact on different fields from sensoristics to biomedicine. Biosynthesis of nanomaterials by microorganisms is recently attracting interest as a new, exciting approach towards the development of ‘greener’ nanomanufacturing compared to traditional chemical and physical approaches. This review provides an insight about microbial biosynthesis of nanomaterials by bacteria, yeast, molds, and microalgae for the manufacturing of sensoristic devices and therapeutic/diagnostic applications. The last ten-year literature was selected, focusing on scientific works where aspects like biosynthesis features, characterization, and applications have been described. The knowledge, challenges, and potentiality of microbial-mediated biosynthesis was also described. Bacteria and microalgae are the main microorganism used for nanobiosynthesis, principally for biomedical applications. Some bacteria and microalgae have showed the ability to synthetize unique nanostructures: bacterial nanocellulose, exopolysaccharides, bacterial nanowires, and biomineralized nanoscale materials (magnetosomes, frustules, and coccoliths). Yeasts and molds are characterized by extracellular synthesis, advantageous for possible reuse of cell cultures and reduced purification processes of nanomaterials. The intrinsic variability of the microbiological systems requires a greater protocols standardization to obtain nanomaterials with increasingly uniform and reproducible chemical-physical characteristics. A deeper knowledge about biosynthetic pathways and the opportunities from genetic engineering are stimulating the research towards a breakthrough development of microbial-based nanosynthesis for the future scaling-up and possible industrial exploitation of these promising ‘nanofactories’.

Magnetic Iron Oxide Nanoparticle (IONP) Synthesis to Applications: Present and Future

“…Several other methods have been reported for the synthesis of Fe 3 O 4 nanoparticles, such as chemical methods using plant extracts [ 81 , 82 ] and bacteria [ 83 , 84 ] as reducing agents, thermal decomposition/pyrolysis of organo-metallic precursors [ 85 , 86 ], ultrasound irradiation [ 87 ], gamma radiolysis [ 88 ], thesol–gel method [ 89 ] etc. Most of these methods yield polydisperse nanoparticles, surface capped nanoparticles and nanoparticles with impurities, in addition to poor reproducibility.…”

Antiproliferative effects on tumor cells of the synthesized gold nanoparticles against Hep2 liver cancer cell line

“…When going for large-scale productions, costs of culture media for microbial growth affects to a greater extent. For instance, currently, bacterial nanocellulose applications are much limited to a few biomedical devices, mainly due to the costs of culture medium [12].…”

Zinc Oxide Nanocomposites—Extracellular Synthesis, Physicochemical Characterization and Antibacterial Potential

“…Intracellular production involves bacteria biomass for the nanocomposite formation, while the extracellular approach, known also as the post-cultured method, excludes microbial cells and uses a supernatant rich in biologically active compounds (e.g., enzymes or metabolites) [ 6 ]. As has been highlighted by literature data [ 7 , 8 , 9 ], the post-cultured method (extracellular synthesis) has its advantages, such as lower cost, simpler downstream processing (e.g., nanomaterial separation and purification processes) and possibility to reuse the bacterial cultures. Moreover, the extracellular approach is also a more adequate choice to produce nanocomposites with organic deposits on their surfaces coming from microbial compounds of natural origin.…”