Quorum 150t es

From ethanol materials of N. rugosus, the head was detached along with its antennae using scalpels under Olympus stereomicroscope (SZX7) and then shaken in 70% ethanol (1 min) using an ultrasound cleaner (Polsonic, Warsaw, Poland) to remove any dirt particles. Dehydration of the whole antennae was performed with a series of ethanol (70%, 80%, and 90%) for 15 min and bathed twice with 100% ethanol for about 10 min before drying at room temperature. The materials prepared for observation by SEM were kept on carbon tapes and subjected to a 20 nm layer of gold spray sputter coating in the sputter (Quorum 150T ES plus—Quorum Technologies, Laughton, East Sussex, UK) to improve the conductivity of the sample surface. Later, the gold-coated carbon-taped specimens were transferred into the closed chamber of SEM, and images were captured with Phenom XL scanning electron microscope (Phenom-World, Eindhoven, The Netherlands) and Hitachi UHR FE-SEM SU 8010 (High Technologies, Tokyo, Japan) at the Faculty of Natural Sciences, the University of Silesia in Katowice, scanning microscopy laboratory [18 (link),19 (link)].

The cultures used for enzymatic analyses (as described above) after incubation were examined using an AURIGA scanning electron microscope (Carl Zeiss Microscopy, GmbH). The cultures with MgO NPs, SiO₂ NPs, and C6Im were chosen for microscopic analysis. Additionally, the cultures without studied compounds were also investigated as control samples. Each sample was fixed with glutaraldehyde solution by adding 50 μL of glutaraldehyde (50%) to 1 mL of the sample. The fixation was carried out for 10 min. The samples were then centrifuged for 2 min at 8000 × g. Then the residues were gradually suspended in 1 mL of 50%, 70%, and 96% ethyl alcohol solutions. Before this procedure, higher concentrations of alcohol were used; samples were centrifuged for 2 min at 8000 × g, and 5 μL of bacterial suspension in 96% ethanol, from each sample, was applied to a microscope slide, covered with a 20 nm layer of carbon, and left to dry. The samples were then coated with a 20 nm layer of gold. Each layer of carbon was coated by a vacuum coater (Quorum 150T ES; Quorum Technologies, Lewes, UK). Furthermore, carbon tape bridges were made to avoid excessive charge accumulation. The secondary electron-mode photos were taken using a 60 μm aperture and a 20 keV acceleration voltage. The beam intensity was 1.5 nA, and the working distance was chosen at approximately 8 mm.