Fishing bacteria with a nanonet

New strategies and tools are thus necessary to fill the gap between intensive and conservation agriculture. Nanomaterials have recently been proposed in a multitude of contexts as groundbreaking materials to deal with a broad range of problems and surpass the limits posed by traditional approaches. In agriculture, novel and groundbreaking tools have been developed employing nanomaterials to deliver agrochemicals to plants for both improving nutrition (nanofertilisers) and protecting plants (nanopesticides), but reducing the impact of these compounds on the environment and human health by reducing the global amount provided and improving the efficiency of their actions. Similar results can be obtained, however, following a more 'green' and sustainable approach based on microorganisms. Microbes preferentially live in complex structures, adhering to surfaces, that are termed biofilms. Such a particular lifestyle is extremely advantageous for these organisms to resist to harsh environmental conditions, toxic substances (pollutants), biocidal agents (antimicrobials, immune systems) and predators. We have proposed employing microbial biofilms grown onto nanomaterials. Recently we developed an electrospun nanofibrous scaffold as the support for microbial cell growth. Specifically, we grew a bacterial species with the ability to colonise the rhizosphere of several crop plants (e.g. maize, wheat, rice, oat, coffee) on electrospun 3D polycaprolactone nanofibres. Since electrospinning conditions (polymer solution, potential, rate of deposition, collecting tool, rotation speed and distance from the spinneret) strongly affect the morphology of the materials deposited [13], several trials were performed aimed at generating an artificial 3D scaffold mimicking the micromorphology of the soil structure, i.e. resembling the features of surface distribution in soils. Microbial inoculum composition and environmental conditions for microbial growth were set according to those suitable for biofilm formation and development in conventional microbial media. The electrospun nanoscaffold was capable of providing a suitable surface for bacterial attachment, colonisation of the framework and development of a proper biofilm, and finally, of preserving its viability and vitality for months.