Application of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for the Rapid Identification of Yeast Species From Polar Regions

Abstract

Protein profiling based on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) has proved to be a powerful tool for yeast identification. However, it is rarely used in the identification of yeast isolates from polar regions, which may be due to the limited data available for the differentiation of polar yeast species. The present study constructed a supplementary database of MALDI-TOF MS, including 33 yeast species from the Arctic and Antarctica. These yeast species were used to assess the accuracy and practicality of MALDI-TOF MS-based identification compared to the ribosomal DNA [internal transcribed spacer (ITS) and large subunit (LSU) gene regions] sequencing identification. Their dendrogram based on main spectra profiles (MSPs) in the supplementary database was somewhat consistent with their phylogenetic tree. The accuracy of MALDI-TOF MS identification was also compared by the ethanol-formic acid extraction method and the on-plate extraction method. In addition, peptide markers of some yeast species (e.g., Glaciozyma, Phenoliferia, Mrakia, and Vishniacozyma) were identified. It is concluded that the MALDI-TOF MS method can differentiate some closely related yeast species from polar regions, thus is suitable for the identification of polar yeasts.

Characterization of three Stenotrophomonas strains isolated from different ecosystems and proposal of Stenotrophomonas mori sp. nov. and Stenotrophomonas lacuserhaii sp. nov.

“…Each spectrum was generated using 240 laser shots (six series of 40 laser shots) and with linear positive mode over a mass range of m/z 2,000–20,000. The Autof ms1000 mass was calibrated prior to analysis using a calibrating agent (containing Escherichia coli DH5α, ribonuclease, and myoglobin; Autobio Diagnostics, China) as described by He et al (2022) . The spectral data yielded from the test strains were then compared to the database to obtain a score.…”

Identification of Pathogenic and Opportunistic Yeasts in Pigeon Excreta by MALDI-TOF Mass Spectrometry and Their Prevalence in Chon Buri Province, Thailand

“…Due to MALDI-TOF MS being able to detect a variety of pathogens rapidly, it has extensively been employed to identify microorganisms, such as bacteria, yeasts and molds, from clinical samples routinely [ 15 ]. Several studies have reported that this technique is rapid and exhibits high accuracy in fungal identification from clinical and environmental specimens [ 16 , 17 , 18 ]. It has also been implemented for biological, clinical, and biotechnological research.…”