Polyhydroxyalkanoates (PHAs) are intracellular storage polymers that enhance bacterial resistance in environments. While the role of PHAs regulation in thermophiles under high-temperature stimulation is understudied, this work investigates Aeribacillus pallidus BK1, a thermophile with heat resistance up to 155 °C. Our results showed that A. pallidus’s PHAs yield was 1.45 g/L. After 90 °C and 121 °C stimulations, the PHAs yield doubled to 3.33 g/L. The PHAs ratios increased from 35.63 % (60 °C) to 75.46 % (90 °C) and 77.15 % (121 °C). RNA-seq analysis revealed a common strategy of activating glucose transporters to enhance glucose uptake at both temperatures. At 90 °C, A. pallidus BK1 prioritized PHAs accumulation over the TCA cycle. At 121 °C, PHAs production was further enhanced by upregulating monomer polymerization and downregulating acetyl-CoA carboxylase expression. These findings offered valuable insights into the high-temperature defense mechanisms of thermophiles and suggested that A. pallidus BK1 holds promise as a bio-production platform for PHAs production under thermal stimulation.

中文翻译：

---

高温刺激增强嗜热菌 Aeribacillus pallidus BK1 中多羟基脂肪酸酯的积累


聚羟基脂肪酸酯 （PHA） 是细胞内储存聚合物，可增强环境中的细菌耐药性。虽然 PHAs 调节在高温刺激下嗜热菌中的作用研究不足，但这项工作研究了苍白芽孢杆菌 BK1，一种耐热性高达 155 °C 的嗜热菌。 结果表明，梅毒曲霉的 PHAs 产量为 1.45 g/L。在 90 °C 和 121 °C 刺激后，PHA 产量翻了一番，达到 3.33 g/L。PHAs 比率从 35.63 % （60 °C） 增加到 75.46 % （90 °C） 和 77.15 % （121 °C）。RNA-seq 分析揭示了激活葡萄糖转运蛋白以增强两种温度下葡萄糖摄取的常见策略。在 90 °C 时，A. pallidus BK1 优先于 TCA 循环的 PHAs 积累。在 121 °C 时，通过上调单体聚合和下调乙酰辅酶 A 羧化酶表达，进一步增强了 PHAs 的产生。这些发现为嗜热菌的高温防御机制提供了有价值的见解，并表明 A. pallidus BK1 有望作为热刺激下 PHAs 生产的生物生产平台。