title: A proteomic approach for rapid identification of Weissella species isolated from Korean fermented foods on MALDI-TOF MS supplemented with an in-house database.
abstract: Weissella are obligate heterofermentative lactic acid bacteria belonging to the Leuconostocaceae family. Some Weissella can be found in salted and fermented foods, such as kimchi and jeotgal, and plays an important role in the fermentation process. In the present study, for the first time, a rapid and accurate identification method for Weissella species from kimchi and jeotgal was developed based on MALDI-TOF MS, supplemented with an in-house database. Of the 135 Weissella spectra aligned with the MALDI bioTyper database, 56 isolates (41.5%) yielded no reliable identification results with low log scores (<1.7). After registering the spectra of six Weissella reference strains, all of the isolates were correctly identified, of which 113 (83.7%) and 22 (16.3%) were identified at the species and genus level, respectively. Moreover, a dendrogram generated by protein profiles of the different Weissella species clearly presented distinctive clusters, and PCA analysis separated the spectra of Weissella species into four clusters. In comparing food origins, different Weissella species were identified from two fermented foods. W. soli and W. cibaria were isolated from kimchi, while W. thailandensis and W. halotolerans were isolated from jeotgal. The results of our proteomic approach confirm that the MALDI bioTyper database, with our in-house Weissella database, is sufficient for Weissella identification. The MALDI-TOF MS method provides fast and reliable discrimination between different species in the genus Weissella and, therefore, will be useful for safety control in fish farms or in the production of fermented foods. This method can also be applied to the control of opportunistic pathogenic Weissella in human clinical infections.
authors.affiliation: Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.
authors.forename: Eiseul
authors.initials: E
authors.lastname: Kim
authors.affiliation: Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.
authors.forename: Youngjae
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.
authors.forename: Yoonju
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.
authors.forename: Sun-Kyung
authors.initials: SK
authors.lastname: Han
authors.affiliation: Department of Bioinformatics and Biosystems, Korea Polytechnics, Seongnam 13122, Republic of Korea.
authors.forename: Chang-Gyeom
authors.initials: CG
authors.lastname: Kim
authors.affiliation: Department of Bioinformatics and Biosystems, Korea Polytechnics, Seongnam 13122, Republic of Korea.
authors.forename: Dong-Won
authors.initials: DW
authors.lastname: Choo
authors.affiliation: Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.
authors.forename: Young-Rok
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea. Electronic address: hykim@khu.ac.kr.
authors.forename: Hae-Yeong
authors.initials: HY
authors.lastname: Kim
mesh_terms: D016208:Databases, Factual; D005285:Fermentation; D006801:Humans; D058889:Molecular Typing / Q000379:methods*; D040901:Proteomics / Q000379:methods; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D058836:Weissella / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Acetonitrile (PubChem CID: 6342); Ethanol (PubChem CID: 702); Fermented food; Formic acid (PubChem CID: 284); Jeotgal; Kimchi; MALDI-TOF MS; Trifluoroacetic acid (PubChem CID: 6422); Weissella; α-Cyano-4-hydroxycinnamic acid (PubChem CID: 5328791)