School of Resources ＆; Environment, Northeast Agricultural University, Harbin, 150030, PR China.
School of Resources ＆; Environment, Northeast Agricultural University, Harbin, 150030, PR China; Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130132, PR China.
Chemosphere. 2022 Nov;307(Pt 2):135904. doi: 10.1016/j.chemosphere.2022.135904. Epub 2022 Aug 5.
The viable and degradation potential of the strains which adhered to soil minerals are essential for eliminating organic pollutants from soil. Herein, the interaction (growth, biofilm formation and survive) of Arthrobacter sp. DNS10, an atrazine degrading strain, with three kinds of typical soil minerals, such as montmorillonite, kaolinite and goethite, as well as the atrazine degradation gene (trzN) expression of the strain in the minerals system were studied. The results showed that montmorillonite had significant promotion effect on the growth of strain DNS10, followed by kaolinite, but goethite significantly inhibited the growth of strain DNS10. In contrast, goethite notably promoted the biofilm formation and there was less biofilm detected in montmorillonite containing system. The percentage of the survival bacteria in the biofilm that formed on montmorillonite, kaolinite and goethite was 53.8%, 40.8% and 28.2%. In addition, there were more reactive oxygen species (ROS) were detected in the cells that exposed to goethite than those of the cells exposed to kaolinite and montmorillonite. These results suggest that the electrostatic repulsion between kaolinite/montmorillonite and strain DNS10 prevents them from contacting each other and facilitates bacterial growth by allowing the strain to obtain more nutrients. Oppositely, the needle-like morphology of goethite might damage the strain DNS10 cell when they were combined by electrostatic attraction, and the goethite induced ROS also aggravate the cytotoxicity of goethite on strain DNS10. In addition, the relative transcription of trzN in the cells contacted with montmorillonite, kaolinite and goethite was 0.94-, 0.27- and 0.20- fold of the no mineral exposure treatment. Briefly, this research suggests that the minerals with different structure and/or physicochemical characteristics might cause various trend for the biofilm formation and degradation potential of the bacteria.
菌株对土壤矿物的生存能力和降解潜力对于消除土壤中的有机污染物至关重要。在此，研究了莠去津降解菌株 Arthrobacter sp. DNS10 与三种典型土壤矿物（蒙脱石、高岭土和针铁矿）的相互作用（生长、生物膜形成和存活），以及该菌株在矿物系统中的莠去津降解基因（trzN）表达。结果表明，蒙脱石对菌株 DNS10 的生长有显著的促进作用，其次是高岭土，但针铁矿显著抑制了菌株 DNS10 的生长。相比之下，针铁矿显著促进了生物膜的形成，而在蒙脱石体系中检测到的生物膜较少。在蒙脱石、高岭土和针铁矿上形成生物膜的存活菌比例分别为 53.8%、40.8%和 28.2%。此外，暴露于针铁矿的细胞中检测到的活性氧（ROS）比暴露于高岭土和蒙脱石的细胞中更多。这些结果表明，高岭土/蒙脱石与菌株 DNS10 之间的静电排斥阻止了它们相互接触，并通过使菌株获得更多的营养物质来促进细菌的生长。相反，针铁矿的针状形态可能在它们通过静电吸引结合时会破坏菌株 DNS10 细胞，而针铁矿诱导的 ROS 也会加重针铁矿对菌株 DNS10 的细胞毒性。此外，与蒙脱石、高岭土和针铁矿接触的细胞中 trzN 的相对转录水平分别为无矿物暴露处理的 0.94 倍、0.27 倍和 0.20 倍。简而言之，这项研究表明，具有不同结构和/或物理化学特性的矿物可能会导致细菌的生物膜形成和降解潜力呈现出不同的趋势。
