Micheluz et al energy dispersive X-ray-spectroscopy data

# Micheluz et al energy dispersive X-ray-spectroscopy data

## paper: https://doi.org/10.3390/pathogens11121462

### Dataset:

Dataset1_Micheluz-et-al.csv

This is a CSV file with 206 lines and 12 columns.

Data are energy-dispersive X-ray spectroscopy data as weight%

Explanation of the heading: Site, the Italian city where the samples of Eurotium halophilicum were collected;

Structure, the features analysed (EPS, conidia, background); presence of crystal (TRUE/FALSE) indicates if in the areas/samples were detected biogenic crystals;

C, carbon; O, oxygen; Na, sodium; P, phosphorus; S, sulphur; Cl, chlorine, K, potassium; Ca, calcium; Au, gold; Total, the sum of all the elements.

Dataset1_Micheluz-et-al.csv

This is a CSV file with 24 lines and 8 columns.

Data are energy-dispersive X-ray spectroscopy data as atomic%

Explanation of the heading: ID, is the biogenic crystal analysed;  

C, carbon; O, oxygen; Na, sodium; S, sulphur; Cl, chlorine, Ca, calcium; Total, the sum of all the elements.

### Sampling

The mycelium samples analysed with Energy-dispersive X-ray spectroscopy were obtained by pressing a carbon-based, impurity-free adhesive tape (FungiTapeTM, Scientific Device Lab., Inc Glenview, IL, USA) onto the fungal colonies found on the spines of books in five Italian libraries in Turin, Venice, Genova and Rome (2 libraries in Rome).

### Methods

Energy-dispersive X-ray spectroscopy was performed with an INCA Oxford 250 system, maintaining the electron beam at 20 keV, with a mean working distance to the sample of 12.5 mm. The electron beam could be focused on very small areas, in the order of nm2, allowing a surface resolution that readily resolves objects that are a few tens of nm in dimension. This way, a database was obtained with repeated observations of the composition of conidia and other fungus structures carried out on samples from the covers of different books. Some samples were analysed with energy-dispersive X-ray spectroscopy also after metallisation in order to be able to focus on peculiar structures like the (apparently biogenic) crystals. When this was the case, the spectra obtained contained gold, also present in the background.

The calibration of the apparatus was based on the standards CaCO3, SiO2, albite, MgO, Al2O3, GaP, FeS2, wollastonite, feldspar MAD-10, Ti and Fe, supplied by Agar Scientific Ltd. (Stansted, UK) and the conventional ZAF correction (atomic number Z, absorption A, fluorescence F) from the Oxford INCA 250 software was applied to the measurements to convert apparent concentrations (raw peak intensity) into (semi-quantitative) concentrations corrected for inter-element matrix effects.

### Labels Used

Conidia = part of the fungal mycelium analysed

EPS = Extracellular polymeric material present in the mycelium

Background = the adhesive tape (made of carbon) used to collect the mycelium and prepare the samples for observation with scanning electron microscopy