Understanding of the behavior and effects of plutonium (Pu) in the environment is an important aspect of developing responsible and effective strategies for remediation and environmental stewardship. This work studies the sorption and uptake of 239Pu by common environmental bacteria, Escherichia coli DH10β and Pseudomonas putida KT-2440. Plutonium was directly incorporated into growth media prior to inoculation (0.12 kBq mL-1), and samples from the liquid cultures of E. coli and P. putida were analyzed over a 15-d growth period through liquid scintillation counting (LSC) of plutonium in cell pellets and cell culture media following centrifugation. To improve its solubility in the liquid cultures, Pu was complexed with citrate prior to inoculation. P. putida cultures were also grown without citrate to examine potential impact of P. putida's ability to use citrate as a food source. The accumulation of Pu in P. putida cells was found to increase both with and without citrate complexation for the first 5 d and then plateau until the end of the study period (15 d). A higher activity concentration of Pu was found in P. putida cells grown with citrate complexation than without. The activity concentration of plutonium in E. coli cells was greater than that in P. putida cells, which may be the result of a stronger complexing agent made by E. coli for the purpose of iron uptake. There are a variety of factors that influence Pu behavior in bacterial systems, and results confirm that even in a simple system, multiple mechanisms are at play.

中文翻译：

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液体培养物中生长的大肠杆菌和恶臭假单胞菌中钚 239 的积累。

了解钚 (Pu) 在环境中的行为和影响是制定负责任且有效的修复和环境管理策略的一个重要方面。本工作研究了常见环境细菌、大肠杆菌 DH10β 和恶臭假单胞菌 KT-2440 对 239Pu 的吸附和摄取。在接种前将钚直接掺入生长培养基中 (0.12 kBq mL-1)，并通过钚液体闪烁计数 (LSC) 对 15 天生长期的大肠杆菌和恶臭假单胞菌液体培养物样品进行分析离心后的细胞沉淀和细胞培养基中。为了提高其在液体培养物中的溶解度，在接种前将 Pu 与柠檬酸盐复合。恶臭假单胞菌培养物也在不含柠檬酸盐的情况下生长，以检查恶臭假单胞菌使用柠檬酸盐作为食物来源的能力的潜在影响。发现恶臭假单胞菌细胞中 Pu 的积累在前 5 天内无论是否有柠檬酸盐络合都会增加，然后达到稳定状态，直到研究期结束（15 天）。在用柠檬酸盐络合生长的恶臭假单胞菌细胞中发现，与没有柠檬酸盐络合的情况相比，Pu 的活性浓度更高。大肠杆菌细胞中钚的活度浓度高于恶臭假单胞菌细胞中的钚活性浓度，这可能是大肠杆菌为了摄取铁而制造的更强的络合剂的结果。影响细菌系统中 Pu 行为的因素有多种，结果证实，即使在简单的系统中，也有多种机制在发挥作用。