光合细菌代谢灵活,环境适应性强,并且要求便宜,但是很多,能量补充剂,所有这些都使它们能够用于Cr(VI)修复。在这项研究中,对一株新鉴定的球形红细菌SC01菌株,研究了培养条件对总Cr去除率的影响。通过扫描电子显微镜和透射电子显微镜评估了四种不同细胞组分的亚细胞分布和Cr(VI)还原能力。实验表明,去除总Cr的最佳培养条件包括35°C的培养温度,pH值为7.20,NaCl浓度为5gL-1,光照强度为4000lx,和0.15的初始细胞浓度(OD680)。此外,还原后,大多数Cr以Cr(III)的形式存在于细胞膜中,与其他细胞成分相比,细胞膜的Cr(VI)还原率最高(99%)。此外,用FTIR对SC01细胞的理化性质进行了表征,XPS,和XRD分析,证实Cr成功地吸收在细菌细胞表面。CrPO4·6H2O和Cr5(P3O10)3沉淀物通过XRD分析特别鉴定。在用五种磷盐进行补充筛选后,通过添加Na4P2O7和(NaPO3)6盐,改善了生物沉淀引起的Cr(VI)还原,Cr(VI)还原率与Na4P2O7的添加量比对照高15%。因此,本研究提出了一种基于光合细菌和磷盐联合使用的新型Cr(VI)去除策略,这重要地增加了其在废水处理中的潜在应用。
Photosynthetic bacteria have flexible metabolisms and strong environmental adaptability, and require cheap, but plentiful, energy supplements, which all enable their use in Cr(VI)-remediation. In this study, the effects of culture conditions on the total Cr removal rate were investigated for a newly identified strain of Rhodobacter sphaeroides SC01. The subcellular distribution and Cr(VI) reduction ability of four different cellular fractions were evaluated by scanning electron microscopy and transmission electron microscopy. Experiments indicated that the optimal culture conditions for total Cr removal included a culture temperature of 35 °C, pH of 7.20, an NaCl concentration of 5 g L-1, a light intensity of 4000 lx, and an initial cell concentration (OD680) of 0.15. In addition, most Cr was found in the cell membrane in the form of Cr (III) after reduction, while cell membranes had the highest Cr(VI) reduction rate (99%) compared to other cellular components. In addition, the physical and chemical properties of SC01 cells were characterized by FTIR, XPS, and XRD analyses, confirming that Cr was successfully absorbed on bacterial cell surfaces. CrPO4‧6H2O and Cr5(P3O10)3 precipitates were particularly identified by XRD analysis. After screening supplementation with five phosphor salts, Cr(VI) reduction due to bioprecipitation was improved by the addition of Na4P2O7 and (NaPO3)6 salts, with the Cr(VI)-reduction rate combined with Na4P2O7 addition being 15% higher than that of the control. Thus, this study proposes a new Cr(VI)-removal strategy based on the combined use of photosynthetic bacteria and phosphor salts, which importantly increases its potential application in treating wastewater.