Lima D, Viana P, André S, Chelinho S, Costa C, Ribeiro R, Sousa J P, Fialho A M, Viegas C A
Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av Rovisco Pais, 1049-001 Lisboa, Portugal.
Chemosphere. 2009 Jan;74(2):187-92. doi: 10.1016/j.chemosphere.2008.09.083. Epub 2008 Nov 11.
A previously developed potential cleanup tool for atrazine contaminated soils was evaluated in larger open soil microcosms for optimization under more realistic conditions, using a natural crop soil spiked with an atrazine commercial formulation (Atrazerba FL). The doses used were 20x or 200x higher than the recommended dose (RD) for an agricultural application, mimicking over-use or spill situations. Pseudomonas sp. strain ADP was used for bioaugmentation (around 10(7) or 10(8) viable cells g(-1) of soil) and citrate for biostimulation (up to 4.8 mg g(-1) of soil). Bioremediation treatments providing fastest and higher atrazine biodegradation proved to differ according to the initial level of soil contamination. For 20x RD of Atrazerba FL, a unique inoculation with Pseudomonas sp. ADP (9 +/- 1 x 10(7) CFU g(-1)) resulted in rapid atrazine removal (99% of the initial 7.2 +/- 1.6 microg g(-1) after 8d), independent of citrate. For 200x RD, an inoculation with the atrazine-degrading bacteria (8.5 +/- 0.5 x 10(7) CFU g(-1)) supplemented with citrate amendment (2.4 mg g(-1)) resulted in improved biodegradation (87%) compared with bioaugmentation alone (79%), even though 7.8 +/- 2.1 microg of atrazine g(-1) still remained in the soil after 1 wk. However, the same amount of inoculum, distributed over three successive inoculations and combined with citrate, increased Pseudomonas sp. ADP survival and atrazine biodegradation (to 98%, in 1 wk). We suggest that this bioremediation tool may be valuable for efficient removal of atrazine from contaminated field soils thus minimizing atrazine and its chlorinated derivatives from reaching water compartments.
在更现实的条件下，使用添加了阿特拉津商业制剂（Atrazerba FL）的天然作物土壤，在更大的开放式土壤微宇宙中对先前开发的用于阿特拉津污染土壤的潜在清理工具进行了评估，以实现优化。所使用的剂量比农业应用推荐剂量（RD）高20倍或200倍，模拟过度使用或泄漏情况。假单胞菌属ADP菌株用于生物强化（约10⁷或10⁸个活细胞g⁻¹土壤），柠檬酸盐用于生物刺激（高达4.8 mg g⁻¹土壤）。事实证明，根据土壤污染的初始水平，能实现最快且更高阿特拉津生物降解的生物修复处理存在差异。对于Atrazerba FL的20倍RD，单独接种假单胞菌属ADP（9±1×10⁷ CFU g⁻¹）导致阿特拉津迅速去除（8天后初始的7.2±1.6 μg g⁻¹中有99%被去除），与柠檬酸盐无关。对于200倍RD，接种降解阿特拉津的细菌（8.5±0.5×10⁷ CFU g⁻¹）并添加柠檬酸盐改良剂（2.4 mg g⁻¹），与单独生物强化（79%）相比，生物降解得到改善（87%），尽管1周后土壤中仍残留7.8±2.1 μg g⁻¹的阿特拉津。然而，将相同数量的接种物分三次连续接种并与柠檬酸盐结合，可提高假单胞菌属ADP的存活率和阿特拉津的生物降解率（1周内达到98%）。我们认为，这种生物修复工具对于从污染的田间土壤中有效去除阿特拉津可能具有重要价值，从而将阿特拉津及其氯化衍生物进入水体的量降至最低。
