Boronic Acid Moieties Stabilize Adhesion of Microalgal Biofilms on Glassy Substrates: A Chemical Tool for Environmental Applications

Abstract

Photosynthetic organisms such as diatoms microalgae provide innovative routes to eco-friendly technologies for environmental pollution bioremediation. Living diatoms are capable to incorporate in vivo a wide variety of chemical species dispersed in seawater, thus being promising candidates for eco-friendly removal of toxic contaminants. However, their exploitation requires immobilization methods that allow to confine microalgae during water treatment. Here we demonstrate that a biofilm of Phaeodactylum tricornutum diatom cells grown on the surface of a glassy substrate bearing boronic acid protruding moieties is stably anchored to the substrate resisting mechanical stress and it is suitable for removal of up to 80 % metal ions (As, Cr, Cu, Zn, Sn, Pb, Sb) in a model polluted water sample. Control experiments also suggest that stabilization of the biofilm adhesion occurs by interaction of boronic acid surface groups of the substrate with the hydroxyl groups of diatoms extracellular polysaccharides.

Living Diatom Microalgae for Desiccation-Resistant Electrodes in Biophotovoltaic Devices

“…Cells were recovered at 360g for 12 min at room temperature (RT). For the preparation of each bioanode, the microalgae pellet was suspended in 20 slide coating an area of 0.8 cm 2 (0.8 × 1.0 cm 2 ) prior to air-dry (Figure 1a). This methodology allows us to obtain artificial films of diatoms onto an ITO slide containing a known number of cells (10 6 cells per slide, unless stated otherwise).…”

“…Being mainly autotrophic, they easily grow even in low-nutrient environments . The broad availability of diatoms in all marine ecosystems also enables them to be cultured at a large scale, thus envisaging their application as bio factories of high added-value products such as pigments, oils, biofuel, and nanostructured biosilica-based materials for medicine, photonics, optoelectronics, and environmental bioremediation . Diatoms also bear profitable features for application in BPEC solar energy conversion technologies because benthonic microalgae can generate biofilms adhering to a variety of materials, such as electrodes’ surfaces, thus allowing their spontaneous colonization.…”

Drug Delivery through Epidermal Tissue Cells by Functionalized Biosilica from Diatom Microalgae

“…Frustules have a hierarchical organization of silica layers, with intricated micro and nano-porous patterns, thus providing high mechanical resistance and surface area [ 1 ]. Moreover, diatom biosilica can be easily functionalized with a wide variety of tailored molecules depending on its specific application [ 13 , 14 , 15 , 16 , 17 ] and it represents an eco-friendly alternative to synthetic silica nanoparticles, whose preparation requires expensive and organic solvent-consuming experimental protocols [ 18 ]. Besides integer biosilica shells of living diatoms, a huge amount of fossil sediments, i.e., the diatomaceous earth (DE) or diatomite [ 8 ], is available at extremely low costs.…”