Abstract：
Chromium (Cr) is a heavy metal with a high toxicity and pathogenicity. Microbial reduction is an effective strategy to remove Cr(VI) at contaminated sites but suffers from the low populations and activities of Cr-reducing microorganisms in soils. This study proposed an in situ sonoporation-mediated gene transfer approach, which improved soil Cr(VI) reduction performance by delivering exogenous Cr-transporter chrA genes and Cr-reducing yieF genes into soil microorganisms with the aid of ultrasound. Besides the increasing populations of Cr-resistant bacteria and elevated copy numbers of chrA and yieF genes after sonoporation-mediated gene transfer, three new Cr-reducing strains were isolated, among which Comamonas aquatica was confirmed to obtain Cr-resistant capability. In addition, sonoporation-mediated gene transfer was the main driving force significantly shaping soil microbial communities owing to the predominance of Cr-resistant microbes. This study pioneered and evidenced that in situ soil sonoporation-mediated gene transfer could effectively deliver functional genes into soil indigenous microbes to facilitate microbial functions for enhanced bioremediation, e.g., Cr-reduction in this study, showing its feasibility as a chemically green and sustainable remediation strategy for heavy metal contaminated sites.
摘要：
铬(Cr)是一种具有高毒性和致病性的重金属。微生物还原是在污染场所去除Cr（VI）的有效策略，但土壤中Cr还原微生物的种群和活性较低。本研究提出了一种原位超声穿孔介导的基因转移方法，通过将外源Cr转运蛋白chrA基因和Cr还原yeF基因传递到土壤微生物中，从而提高了土壤Cr（VI）的还原性能。除了超声穿孔介导的基因转移后，耐Cr细菌的数量增加以及chrA和yieF基因的拷贝数升高，分离出三株新的Cr还原菌株，其中，海水中的Comamonas被证实具有抗Cr能力。此外,由于耐Cr微生物的优势，超声穿孔介导的基因转移是显着塑造土壤微生物群落的主要驱动力。这项研究开创并证明了原位土壤超声穿孔介导的基因转移可以有效地将功能基因传递到土壤土著微生物中，以促进微生物功能，从而增强生物修复。例如，在这项研究中减少Cr，显示了其作为重金属污染场地的化学绿色和可持续修复策略的可行性。
