title: Metaproteomics and ultrastructure characterization of Komagataeibacter spp. involved in high-acid spirit vinegar production.
abstract: Acetic acid bacteria (AAB) are widespread microorganisms in nature, extensively used in food industry to transform alcohols and sugar alcohols into their corresponding organic acids. Specialized strains are used in the production of vinegar through the oxidative transformation of ethanol into acetic acid. The main AAB involved in the production of high-acid vinegars using the submerged fermentation method belong to the genus Komagataeibacter, characterized by their higher ADH stability and activity, and higher acetic acid resistance (15-20%), compared to other AAB. In this work, the bacteria involved in the production of high-acid spirit vinegar through a spontaneous acetic acid fermentation process was studied. The analysis using a culture-independent approach revealed a homogeneous bacterial population involved in the process, identified as Komagataeibacter spp. Differentially expressed proteins during acetic acid fermentation were investigated by using 2D-DIGE and mass spectrometry. Most of these proteins were functionally related to stress response, the TCA cycle and different metabolic processes. In addition, scanning and transmission electron microscopy and specific staining of polysaccharide SDS-PAGE gels confirmed that Komagataeibacter spp. lacked the characteristic polysaccharide layer surrounding the outer membrane that has been previously reported to have an important role in acetic acid resistance in the genus Acetobacter.
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland.
authors.forename: Cristina
authors.initials: C
authors.lastname: Andrés-Barrao
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland.
authors.forename: Maged M
authors.initials: MM
authors.lastname: Saad
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Cabello Ferrete
authors.affiliation: Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bravo
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland.
authors.forename: Marie-Luise
authors.initials: ML
authors.lastname: Chappuis
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland.
authors.forename: Ruben
authors.initials: R
authors.lastname: Ortega Pérez
authors.affiliation: Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
authors.forename: Pilar
authors.initials: P
authors.lastname: Junier
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland.
authors.forename: Xavier
authors.initials: X
authors.lastname: Perret
authors.affiliation: Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Sciences III, Geneva, Switzerland. Electronic address: Francois.Barja@unige.ch.
authors.forename: François
authors.initials: F
authors.lastname: Barja
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D000434:Alcoholic Beverages / Q000382:microbiology*; D020561:Alphaproteobacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005285:Fermentation; D008969:Molecular Sequence Data; D010802:Phylogeny; D040901:Proteomics
chemical_list: D001426:Bacterial Proteins; D019342:Acetic Acid
keywords: 2D-DIGE; BCAA; Electron microscopy; Komagataeibacter; Membrane polysaccharides; TCA cycle