Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, School of Resources and Environment, Anhui Agricultural University, Hefei, 230036, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
World J Microbiol Biotechnol. 2019 Mar 28;35(4):64. doi: 10.1007/s11274-019-2634-9.
Chromate is one of the hazardous toxic pollutants. Reduction of Cr(VI) to Cr(III) has shown to reduce the toxicity of chromate. This work examined the reduction of Cr(VI) using an anaerobic batch cultures of Shewanella oneidensis MR-1 containing Fe(III). To do so, 10 mg/L Cr(VI) was reduced to Cr(III) within 3 days along with the oxidization of Fe(II) to Fe(III). The removal rate of Cr(VI) increased with increasing the concentration of Fe(III). In the absence of Cr(VI), the Fe(II) concentration of the batch culture increased with the growth of S. oneidensis MR-1. These data showed that S. oneidensis MR-1 could reduce Fe(III) into Fe(II), resulting in reduction of Cr(VI) to Cr(III). During this process, the anthraquinone-2,6-disulfonate (AQDS) acted as an electron shuttle. Microscopic analysis showed that Cr(VI) had toxic effects on S. oneidensis MR-1 due to the appearance of Cr species on the bacterial surface. CrO or Cr(OH) precipitates formed during Cr(VI) reduction was identified using X-ray photoelectron spectroscopy. The AQDS as an electron shuttle enhanced the Cr(VI) reduction by S. oneidensis MR-1. Microbial reduction of Cr(VI) can be a useful technique for Cr detoxification.
铬酸盐是一种有害的有毒污染物。将六价铬还原为三价铬已被证明可以降低铬酸盐的毒性。这项工作研究了利用含有 Fe(III) 的 Shewanella oneidensis MR-1 的厌氧批量培养物还原六价铬。为此，在 3 天内将 10mg/L 的六价铬还原为三价铬，同时将 Fe(II)氧化为 Fe(III)。随着 Fe(III)浓度的增加，Cr(VI)的去除率增加。在没有 Cr(VI)的情况下，随着 S. oneidensis MR-1 的生长，批量培养物中的 Fe(II)浓度增加。这些数据表明，S. oneidensis MR-1 可以将 Fe(III)还原为 Fe(II)，从而将 Cr(VI)还原为 Cr(III)。在此过程中，蒽醌-2,6-二磺酸钠 (AQDS) 充当电子穿梭体。显微镜分析表明，由于细菌表面出现铬物种，Cr(VI)对 S. oneidensis MR-1 具有毒性作用。使用 X 射线光电子能谱鉴定了在 Cr(VI)还原过程中形成的 CrO 或 Cr(OH)沉淀。AQDS 作为电子穿梭体增强了 S. oneidensis MR-1 对 Cr(VI)的还原。微生物还原六价铬可以是一种有用的铬解毒技术。
