Noncoding RNAs (ncRNAs) can finely control the expression of target genes at the posttranscriptional level in prokaryotes. Regulatory small RNAs (sRNAs) designed to control target gene expression for applications in metabolic engineering and synthetic biology have been successfully developed and used. However, the effect on the heterologous expression of species- or strain-specific ncRNAs in other bacterial strains remains poorly understood. In this work, aPseudomonas stutzerispecies-specific regulatory ncRNA, NfiS, which has been shown to play an important role in the response to oxidative stress as well as osmotic stress inP. stutzeriA1501, was cloned and transferred to theEscherichia colistrain Trans10. Recombinant NfiS-expressingE. coli, namely, Trans10-nfiS, exhibited significant enhancement of tolerance to oxidative stress. To map the possible gene regulatory networks mediated by NfiS inE. coliunder oxidative stress, a microarray assay was performed to delineate the transcriptomic differences between Trans10-nfiSand wild-typeE. coliunder H₂O₂shock treatment conditions. In all, 1184 genes were found to be significantly altered, and these genes were divided into mainly five functional categories: stress response, regulation, metabolism related, transport or membrane protein and unknown function. Our results suggest that theP. stutzerispecies-specific ncRNA NfiS acts as a regulator that integrates adaptation to H₂O₂with other cellular stress responses and helps protectE. colicells against oxidative damage.