In vivo evolutionary engineering of a boron-resistant bacterium: Bacillus boroniphilus
In vivo evolutionary engineering of a boron-resistant bacterium: Bacillus boroniphilus
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DOI：
10.1007/s10482-011-9557-2
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发表时间：
2011-05-01
影响因子：
2.6
通讯作者：
Cakar, Z. Petek
中科院分区：
文献类型：
--
作者：
Sen, Mustafa;Yilmaz, Ulku;Cakar, Z. Petek
硼是一种重要的工业和生物元素。然而，细菌和许多其他生命系统的耐硼机制及其运输仍然不清楚。在这项研究中，硼耐受性细菌，嗜硼芽孢杆菌DSM 17376，硼的抗性水平提高到300 mmol l（-1）硼，通过采用体内进化工程策略的基础上批量选择下连续暴露逐渐增加硼应力水平。在150 mmol l（-1）硼胁迫水平下，最终突变体群体的抗性是野生型抗性的1- 16倍。硼抗性突变体对铁和铜胁迫具有显著的交互抗性，对盐胁迫也具有交互抗性，表明这些胁迫类型之间存在共同的抗性机制。此外，高硼抗性突变体有高达2.8倍的硼含量比野生型，当暴露于高水平（150 mmol l（-1））的连续硼应力在整个培养。研究表明，进化工程是提高细菌硼抗性的有效途径，也是研究硼在微生物系统中耐受和转运的复杂机制的有效途径。
Boron is an industrially and biologically important element. However, the mechanisms of boron tolerance and its transport in bacteria and many other living systems are still not clearly understood. In this study, the boron resistance level of a boron-tolerant bacterium, Bacillus boroniphilus DSM 17376, was improved up to 300 mmol l(-1) boron, by employing an in vivo evolutionary engineering strategy based on batch selection under continuous exposure to gradually increasing boron stress levels. The resistance was heterogeneous within the final mutant population which ranged from about 1- to 16-fold of the wild type resistance at 150 mmol l(-1) boron stress level. Boron-resistant mutants had significant cross-resistance to iron and copper stresses, and were also cross-resistant to salt (NaCl) stress, suggesting a common resistance mechanism between these stress types. Additionally, highly boron-resistant mutants had up to 2.8-fold higher boron contents than the wild-type, when exposed to high levels of (150 mmol l(-1)) continuous boron stress throughout their cultivation. It was shown that evolutionary engineering is a successful approach to significantly increase bacterial boron resistance and investigate the complex mechanism of boron tolerance and transport in microbial systems.