The role of protein modifications in senescence of freeze-dried Acetobacter senegalensis during storage

Microbial Cell Factories

Research

Frank Delvigne¹  Manoochehr Babanezhad²  Azeddine Bentaib³  Pierre Leprince³  Raziyeh Zarmehrkhorshid⁴  Philippe Thonart⁵  Rasoul Shafiei⁶ 

[1] Bio-industry Unit, Gembloux Agro-Bio Tech, Gembloux, University of Liège, Liège, Belgium;Department of Statistics, Faculty of Sciences, Golestan University, Gorgan, Iran;GIGA–Neuroscience, University of Liège, Liège, Belgium;Walloon Center of Industrial Biology, University of Liège, Liège, Belgium;Walloon Center of Industrial Biology, University of Liège, Liège, Belgium;Bio-industry Unit, Gembloux Agro-Bio Tech, Gembloux, University of Liège, Liège, Belgium;Walloon Center of Industrial Biology, University of Liège, Liège, Belgium;Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran;

关键词: Starter;    Acetic acid fermentation;    Oxidative stress;    Carbonylation;    AGEs;    Acetobacter;    2D-DiGE;    VBNC;    Protein;   

DOI  :  10.1186/1475-2859-13-26

 received in 2013-10-07, accepted in 2014-02-07,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundLoss of viability is one of the most important problems during starter culture production. Previous research has mostly focused on the production process of bacterial starters, but there are few studies about cellular protein deterioration causing cell defectiveness during storage. In the present study, we investigated the influence of storage temperature (−21, 4, 35°C) on the cellular protein modifications which may contribute to the senescence of freeze-dried Acetobacter senegalensis.ResultsHeterogeneous populations composed of culturable cells, viable but non-culturable cells (VBNC) and dead cells were generated when freeze-dried cells were kept at −21 and 4°C for 12 months whereas higher storage temperature (35°C) mainly caused death of the cells. The analysis of stored cell proteome by 2D-DiGE demonstrated a modified pattern of protein profile for cell kept at 4 and 35°C due to the formation of protein spot trains and shift of Isoelectric point (pI). Quantification of carbonylated protein by ELISA showed that the cells stored at 4 and 35°C had higher carbonylated protein contents than fresh cells. 2D-DiGE followed by Western blotting also confirmed the carbonylation of cellular proteins involved in translation process and energy generation. The auto-fluorescent feature of cells kept at 35°C increased significantly which may be an indication of protein glycation during storage. In addition, the percentage of cellular unsaturated fatty acid and the solubility of cellular proteins decreased upon storage of cells at higher temperature suggesting that peroxidation of fatty acids and possibly protein lipidation and oxidation occurred.ConclusionsHigh storage temperature induces some deteriorative reactions such as protein oxidation, lipidation and glycation which may cause further protein modifications like pI-shift, and protein insolubility. These modifications can partly account for the changes in cell viability. It can also be deduced that even moderate carbonylation of some critical cellular proteins (like ribosomal proteins) may lead to VBNC formation or death of freeze-dried bacteria. Moreover, it seems that other mechanisms of biomolecule deterioration preceding protein carbonylation lead to VBNC formation under very low storage temperature.

【 授权许可】

CC BY   
© Shafiei et al.; licensee BioMed Central Ltd. 2014