School of Resources & Environment, Northeast Agricultural University, Harbin, 150030, China.
School of Resources & Environment, Northeast Agricultural University, Harbin, 150030, China.
Chemosphere. 2020 Jan;238:124594. doi: 10.1016/j.chemosphere.2019.124594. Epub 2019 Aug 14.
Enhancing the biodegradation efficiency of atrazine, a kind of commonly applied herbicide, has been attracted much more concern. Here, Zn which has long been considered essential in adjusting cell physiological status was selected to investigate its role on the biodegradation of atrazine by Arthrobacter sp. DNS10 as well as the transmembrane transport of atrazine during the biodegradation period. The results of gas chromatography showed that the atrazine removal percentages (initial concentration was 100 mg L) in 0.05 mM Zn and 1.0 mM Zn treatments were 94.42% and 86.02% respectively at 48 h, while there was also 66.43% of atrazine left in the treatment without exogenous Zn existence. The expression of atrazine chlorohydrolase gene trzN in the strain DNS10 cultured with 0.05 mM and 1.0 mM Zn was 7.30- and 4.67- times respectively compared with that of the non-zinc treatment. In addition, the flow cytometry test suggests that 0.05 mM of Zn could better adjust the membrane permeability of strain DNS10, meanwhile, the amount of atrazine accumulation in the strain DNS10 co-cultured with this level Zn was 2.21 times of that of the strain without Zn. This study may facilitate a better understanding of the mechanisms that exogenous Zn enhances the biodegradation of atrazine by Arthrobacter sp. DNS10.
提高莠去津（一种常用的除草剂）的生物降解效率引起了更多关注。在这里，选择锌（长期以来被认为是调节细胞生理状态所必需的元素）来研究其对节杆菌 DNS10 降解莠去津的作用以及莠去津在生物降解过程中的跨膜运输。气相色谱结果表明，在 48 h 时，0.05 mM Zn 和 1.0 mM Zn 处理中莠去津的去除率（初始浓度为 100 mg/L）分别为 94.42%和 86.02%，而在没有外源 Zn 存在的处理中，仍有 66.43%的莠去津残留。DNS10 菌株在 0.05 mM 和 1.0 mM Zn 培养条件下的莠去津氯水解酶基因 trzN 的表达分别比非锌处理高 7.30 倍和 4.67 倍。此外，流式细胞术测试表明，0.05 mM 的 Zn 可以更好地调节 DNS10 菌株的膜通透性，同时，该浓度 Zn 共培养的 DNS10 菌株中莠去津的积累量是无 Zn 菌株的 2.21 倍。本研究可能有助于更好地理解外源 Zn 增强节杆菌 DNS10 降解莠去津的机制。
