Ilaria Stanzione

The use of multichannel LEDs is crucial in museum applications to design ad-hoc spectra able to combine fruition and protection needs, i.e., maximizing Colour Rendering Index and controlling energy content in risk wavelengths responsible for the photochemical degradation of the exposed objects. A similar approach could be applied also to prevent the biological risk, such as the fungi growth on artifacts, studying the microorganisms’ sensitivity to different wavelengths. The paper investigates the growth rate and the proteins and carbohydrates content of five different fungal strains cultivated inside experimental boxes equipped with four different monochromatic LEDs. It has been demonstrated that, even if fungi are heterotrophic organisms and do not need light to grow and develop, their growth rate, and their proteins and carbohydrates content change when exposed to different irradiance conditions. The acquired information is useful for a future design of ad-hoc SPDs to be implemented in museum applications.

Fungi produce surface-active proteins, among which hydrophobins are the most characterized and attractive also for their ability to form functional amyloids. Our most recent findings show that these abilities are shared with other classes of fungal proteins. Indeed, in this paper, we compared the characteristics of a class I hydrophobin (Vmh2 from Pleurotus ostreatus) and an unknown protein (named PAC3), extracted from the marine fungal strain Acremonium sclerotigenum, which does not belong to the same protein family based on its sequence features. They both proved to be good biosurfactants, stabilizing emulsions in several conditions (concentration, pH, and salinity) and decreasing surface tension to a comparable value to that of some synthetic surfactants. After that, we observed for both Vmh2 and PAC3 the formation of giant fibers without the need for harsh conditions or long incubation time, a remarkable ability herein reported for the first time.

We investigated the use of POXA1b laccase from Pleurotus ostreatus for the oxidation of anthracene into anthraquinone. We show that different pathways can occur depending on the nature of the redox mediator combined to laccase, leading to different structural isomers. The laccase combined with 2,2′-azine-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) leads to the formation of 1,4-anthraquinone and/or 1,2-anthraquinone. The unprecedented role of carbon nanotubes (CNTs) as redox mediators for oxidation of anthracene into 9,10-anthraquinone is shown and corroborated by density-functional theory (DFT) calculations. Owing to the efficient adsorption of anthraquinones at CNT electrodes, anthracene can be detected with low limit-of-detection using either laccase in solution, CNT-supported laccase or laccase immobilized at magnetic beads exploiting the adhesive property of a chimeric hydrophobin-laccase.

A chimeric enzyme based on the genetic fusion of a laccase with a hydrophobin domain was employed to functionalize few-layer graphene, previously exfoliated from graphite in the presence of the hydrophobin. The as-produced, biofunctionalized few-layer graphene was characterized by electrochemistry and Raman spectroscopy, and finally employed in the biosensing of phenols such as catechol and dopamine. This strategy paves the way for the functionalization of nanomaterials by hydrophobin domains of chimeric enzymes and their use in a variety of electrochemical applications.