Abstract：
Harnessing bacteria for superoxide production in bioremediation holds immense promise, yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide. This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain, a prevalent soil bacterial genus. Our research reveals that introducing a carbon source along with specific iron-binding ligands, including deferoxamine (DFO), diethylenetriamine pentaacetate (DTPA), citrate, and oxalate, robustly augments microbial superoxide generation. Moreover, our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(III)/Fe(II) and superoxide. Remarkably, among the tested ligands, only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(III). We identify an optimal Fe(III) to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture. This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals, significantly elevating bioremediation performance. Furthermore, our study reveals that DTPA augments superoxide production in cultures of diverse soils, with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation. This emphasizes the universal applicability of DTPA across multiple bacterial genera. In conclusion, our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals. These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation, offering innovative solutions for addressing environmental contamination challenges.
摘要：
在生物修复中利用细菌生产超氧化物具有巨大的前景，然而，其实际应用受到生产速度缓慢和超氧化物相对较弱的氧化还原电位的阻碍。这项研究探讨了一种具有成本效益的方法来使用节杆菌菌株扩增超氧化物生产，一种普遍存在的土壤细菌属。我们的研究表明，引入碳源以及特定的铁结合配体，包括去铁胺（DFO），二亚乙基三胺五乙酸酯（DTPA），柠檬酸盐和草酸盐,强有力地增加微生物超氧化物的产生。此外，我们的发现表明，这些铁结合配体通过调节Fe（III）/Fe（II）和超氧化物之间的电子转移速率，在将超氧化物转化为羟基自由基中起着关键作用。值得注意的是,在测试的配体中，当与Fe（III）复合时，只有DTPA成为该转化过程的有效促进剂。我们确定了约1：1的最佳Fe（III）与DTPA比例，以增强节杆菌培养物中的羟基自由基产生。这项研究强调了同时引入碳源和DTPA在促进超氧化物产生及其随后转化为羟基自由基方面的功效。显著提高生物修复性能。此外，我们的研究表明，DTPA增加了不同土壤中超氧化物的产生，除节杆菌以外的各种土壤微生物被确定为超氧化物产生的贡献者。这强调了DTPA在多个细菌属中的普遍适用性。总之,我们的研究介绍了一个有前途的方法，以提高微生物超氧化物的生产和其转化为羟基自由基。这些发现对生物修复中微生物活性氧的部署具有重要意义。为解决环境污染挑战提供创新的解决方案。
