Transcriptome Analysis of S. piezotolerans

The S. piezotolerans WP3 strains were inoculated into 2216E media, after which the culture was collected and immersed in liquid nitrogen immediately when the cells reached exponential phase. Total RNA was isolated with TRI reagent-RNA isolation kit (Molecular research center, Cincinnati, USA). The RNA samples were treated with DNase I at 37 °C for 1 h to remove DNA contamination. The purified RNA were reverse transcribed to cDNA by RevertAid First Strand cDNA Synthesis Kit (Fermentas, Maryland, USA). The primer pairs used to amplify the selected genes for RT-qPCR were designed using Primer Express software (v3.0.1) (Applied Biosystems, CA, USA). PCR cycling was conducted using 7500 System SDS software (v2.0.6) (Applied Biosystems) in 20 μl reaction mixtures that included 1× SYBR Green I Universal PCR Master Mix (Applied Biosystems), 0.5 μM each primer, and 1 μl cDNA template^{91 (link),92 (link)}.