Microarray analysis of the wildtype and recombinant E. coli strain containing an ncRNA nfiS to H2O2 shock

The aim of this study was to investigate the expressional changes profiles of the wildtype and recombinant Escherichia coli strain which contains an non-coding RNA nfiS from the nitrogen-fixing Pseudomonas stutzeri A1501 after hydrogen peroxide shock, so as to lay a theoretical foundation for further clarifying the mechanism of this ncRNA to enhance the resistance ability of E.coli to oxidative stress. In our early research, an ncRNA named NfiS from the nitrogen fixing bacteria Pseudomonas stutzeri A1501 was identified to play an important role in the response to oxidative as well as osmotic stress. In this work, the nifS gene was transferred to E. coli Trans10. Heterologous expression of the nfiS in Trans10 enhanced its tolerance to salt stress and oxidative stress. To further study the effect of nfiS on gene expression in E. coli, microarray assay was performed to delineate the transcriptome difference between nfiS-expressing strain and wild type under H2O2 shock treatment. E. coli Trans10 and the derivatives strain Trans10-nfiS were cultured in LB broth at 30 °C overnight and then transferred into fresh LB broth the next day till the OD600 was raised to 0.6. Subsequently, 20 mM H2O2 was added into the medium and incubated at 30 °C, 220 rpm for 10 min. Cells were collected by centrifugation and stored in - 80 °C refrigerator for subsequent research.