Delaporte Elise, Karki Anand B, Fakhr Mohamed K
Department of Biological Science, The University of Tulsa, Tulsa, OK, United States.
Department of Biological Sciences, Sam Houston State University, Huntsville, TX, United States.
Front Microbiol. 2025 Jul 30;16:1621314. doi: 10.3389/fmicb.2025.1621314. eCollection 2025.
Aerotolerance is vital for the survival of in the food supply, but the genetic mechanisms underlying aerotolerance remain unclear. This study compares differential gene expression in one aerotolerant and one aerosensitive strain of (WP2202 and T1-21 respectively) in aerobic vs. microaerobic conditions using RNA-Seq technology. The results show that the aerotolerant strain differentially regulated a greater number of genes under aerobic vs. microaerobic conditions as compared to the aerosensitive strain, particularly during the first 6 h of exposure. Differential analysis between aerobic and microaerobic conditions showed that COG category S (genes with unknown functions) had the highest number of DEGs across all timepoints in both strains. When category S was excluded, COG category J (translation, ribosomal structure, and biogenesis) had the highest number of DEGs between aerobic vs. microaerobic conditions with downregulated genes occurring at most timepoints in the two strains. Several previously characterized oxidative stress genes were differentially regulated in both strains in response to aerobic conditions. Both strains upregulated multiple heat shock genes in response to oxygen exposure, supporting the hypothesis that these genes might play a role in the oxidative stress response. A few genes involved in iron acquisition or transport were significantly upregulated under aerobic conditions in the aerosensitive strain, potentially forming reactive oxygen radicals due to increased iron levels. A spike in gene expression after 12 h of oxygen exposure was noted for both strains in various genes across the genome. This study demonstrates differences in differential gene expression between an aerotolerant and an aerosensitive strain in response to exposure to atmospheric oxygen and sheds light into understanding aerotolerance. Numerous genes with potential roles in aerotolerance were identified which provides new avenues for future research. In particular, the benefits and drawbacks of iron to the oxidative stress response and the links between the oxidative stress response and the expression of heat shock genes require further investigation.
耐氧性对于食品供应中的[具体生物名称未提及]生存至关重要，但耐氧性背后的遗传机制仍不清楚。本研究使用RNA测序技术比较了一株耐氧菌株和一株对氧气敏感的菌株（分别为WP2202和T1 - 21）在需氧与微需氧条件下的差异基因表达。结果表明，与氧气敏感菌株相比，耐氧菌株在需氧与微需氧条件下差异调节的基因数量更多，尤其是在暴露的前6小时。需氧和微需氧条件之间的差异分析表明，COG分类S（功能未知的基因）在两个菌株的所有时间点中差异表达基因数量最多。当排除分类S时，COG分类J（翻译、核糖体结构和生物发生）在需氧与微需氧条件之间差异表达基因数量最多，且在两个菌株的大多数时间点下调基因出现。在两个菌株中，一些先前已表征的氧化应激基因在需氧条件下差异调节。两个菌株都因氧气暴露而上调了多个热休克基因，支持了这些基因可能在氧化应激反应中起作用的假设。在氧气敏感菌株中，一些参与铁获取或运输的基因在需氧条件下显著上调，可能由于铁水平升高而形成活性氧自由基。在氧气暴露12小时后，两个菌株在全基因组的各种基因中都出现了基因表达峰值。本研究证明了耐氧菌株和氧气敏感菌株在暴露于大气氧时差异基因表达的差异，并为理解[具体生物名称未提及]的耐氧性提供了线索。鉴定出了许多在[具体生物名称未提及]耐氧性中可能起作用的基因，为未来研究提供了新途径。特别是，铁对氧化应激反应的利弊以及氧化应激反应与热休克基因表达之间的联系需要进一步研究。
