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Front. Microbiol. | doi: 10.3389/fmicb.2018.02275

Proteome response of a meat starter Staphylococcus xylosus strain to anaerobiosis and nitrite exposure

  • 1Istituto di scienze delle produzioni alimentari (ISPA), Italy
  • 2Unità di Ricerca per l’Ingegneria Agraria Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria, c/o Area della Ricerca di Torino , Strada delle Cacce 73, 10135 Turin, Italy, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CREA), Italy
  • 3Istituto di studi sui sistemi intelligenti per l'automazione (ISSIA), Italy
  • 4Dipartimento di Scienze del suolo, delle pianta e degle alimenti, Università di Bari, Italy

The viability and competitiveness of Staphylococcus xylosus in meat mostly depend on the ability to adapt itself to rapid oxygen and nutrients depletion during meat fermentation. The utilization of nitrite instead of oxygen becomes a successful strategy for this strain to improve its performance in anaerobiosis; however, metabolic pathways of this strain underlying this adaptation, are partially known. The aim of this study was to provide an overview on proteomic changes of S. xylosus DSM20266Tcultured under anaerobiosis and nitrite exposure. Thus, two different cultures of this strain, supplemented or not with nitrite, were in vitro incubated in aerobiosis and anaerobiosis monitoring cell viability, pH, oxidation reduction potential and nitrite content. Protein extracts, obtained from cells collected as nitrite content was depleted, were analysed by 2DE/MALDI-TOF/TOF-MS. Results showed that DSM20266T growth was significantly sustained by nitrite in anaerobiosis, whereas no differences were found in aerobiosis. Accordingly, nitrite content was depleted after 13 hours only in anaerobiosis. At this time of sampling, a comparative proteomic analysis showed 45 differentially expressed proteins. Most differences were found between aerobic and anaerobic cultures without nitrite; the induction of glycolytic enzymes and glyoxylate cycle, the reduction of TCA enzymes, and acetate fermentation were found in anaerobiosis to produce ATP and maintain the cell redox balance. In anaerobic cultures the nitrite supplementation partially restored TCA cycle, and reduced the amount of glycolytic enzymes.These results were confirmed by phenotypic microarray that for the first time was carried out on cell previously adapted at the different growth conditions; overall, metabolic changes were similar between aerobiosis and anaerobiosis NO2-adapted cells, whilst cells grown under anaerobiosis showed different assimilation profiles by confirming proteomic data anaerobic; indeed, these latter extensively assimilated substrates addressed at both supplying glucose for glycolysis or fuelling alternative pathways to TCA cycle.
In conclusion, metabolic pathways underlying the ability of S. xylosus to adapt itself to oxygen starvation were revealed; the addition of nitrite allowed S. xylosus to take advantage of nitrite to this condition, restoring some metabolic pathway underlying aerobic behaviour of the strain.

Keywords: Meat starter, 2DE/MALDI-TOF/TOF-MS, phenotypic microarray, Food Preservatives, Metabolic pathways, Electrophoresis, Polyacrylamide Gel, Stress, Physiological

Received: 11 Jun 2018; Accepted: 06 Sep 2018.

Edited by:

Vittorio Capozzi, University of Foggia, Italy

Reviewed by:

Catherine Duport, University of Avignon, France
Régine TALON, INRA Centre Auvergne Rhône Alpes, France  

Copyright: © 2018 Quintieri, Giribaldi, Giuffrida, Creanza, Ancona, Cavallarin, De Angelis and Caputo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: PhD. Laura Quintieri, Istituto di scienze delle produzioni alimentari (ISPA), Bari, Italy, laura.quintieri@ispa.cnr.it