Adaptation response of Pseudomonas fragi on refrigerated solid matrix to a moderate electric field

BMC Microbiology

Research Article

Dequan Zhang¹  Hong Zhang²  Chunjiang Zhang²  Feng Huang²  Wenbo Chen²  Honghai Hu² 

[1] Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, 100193, Beijing, People’s Republic of China;Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, 100193, Beijing, People’s Republic of China;College of Staple Food Technology, Chinese Academy of Agricultural Sciences, Institute of Food Science and Technology, 151900, Harbin, People’s Republic of China;

关键词: Adaptation response;    Moderate electric field;    Nutrient agar plates;    Psychrotrophic microorganisms;    Pseudomonas fragi;    Solid cellular foodstuffs;   

DOI  :  10.1186/s12866-017-0945-2

 received in 2016-09-02, accepted in 2017-02-03,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundModerate electric field (MEF) technology is a promising food preservation strategy since it relies on physical properties—rather than chemical additives—to preserve solid cellular foods during storage. However, the effectiveness of long-term MEF exposure on the psychrotrophic microorganisms responsible for the food spoilage at cool temperatures remains unclear.ResultsThe spoilage-associated psychrotroph Pseudomonas fragi MC16 was obtained from pork samples stored at 7 °C. Continuous MEF treatment attenuated growth and resulted in subsequent adaptation of M16 cultured on nutrient agar plates at 7 °C, compared to the control cultures, as determined by biomass analysis and plating procedures. Moreover, intracellular dehydrogenase activity and ATP levels also indicated an initial effect of MEF treatment followed by cellular recovery, and extracellular β-galactosidase activity assays indicated no obvious changes in cell membrane permeability. Furthermore, microscopic observations using scanning and transmission electron microscopy revealed that MEF induced sublethal cellular injury during early treatment stages, but no notable changes in morphology or cytology on subsequent days.ConclusionOur study provides direct evidence that psychrotrophic P. fragi MC16 cultured on nutrient agar plates at 7 °C are capable of adapting to MEF treatment.

【 授权许可】

CC BY   
© The Author(s). 2017