Origin lab v 8.5 pro

FTIR spectra were collected on a Nicolet 6700 FTIR spectrometer (Thermo Scientific, Madison, WI, USA). The Smart iTR ATR sampling accessory was used. The spectra of the lyophilized AGP extracts were collected over the range of 4000–650 cm⁻¹. Three samples of each material were examined in the same conditions. For each sample, 200 scans were averaged with a spectral resolution of 4 cm⁻¹. Then, a final average spectrum was calculated for a given material. These spectra were baseline corrected and normalized to 1.0 at 1019 cm⁻¹. To highlight the differences between the samples, the principal component analysis (PCA) of the spectra was performed in the mid-infrared region of 4000–400 cm⁻¹ using Unscrambler 10.1 (Camo Software AS., Norway). The maximum number of components taken for the analysis was five, and the NIPALS algorithm was used (Szymanska-Chargot et al., 2015 (link); Chylińska et al., 2016 (link)). The visualisation of FTIR spectra and PCA analysis were performed using the OriginPro program (Origin Lab v. 8.5 Pro, Northampton, USA).

Infrared absorption spectra were recorded with a Nicolet 6700 FT-IR spectrometer (Thermo Fisher Scientific, Waltham, MA, United States) with the Smart iTR ATR sampling accessory. Approximately 2 mg of bacterial lyophilizates were deposited on ATR crystal. Absorption spectra were collected in the region between 4000 and 650 cm^–1. For each bacterial lyophilizate, three samples were examined in the same conditions. For each sample, 200 scans were averaged with a spectral resolution of 4 cm^–1. Then, a final average spectrum was calculated for each sample. Baseline corrections if needed and normalization were obtained using Omnic Software (v. 8.2, Thermo Fisher Scientific Inc., United States). Further analysis of spectra was performed using Origin Software (OriginLab v8.5 Pro, Northampton, United States).