School of Resources ＆ Environment, Northeast Agricultural University, Harbin 150030, PR China.
School of Resources ＆ Environment, Northeast Agricultural University, Harbin 150030, PR China.
Ecotoxicol Environ Saf. 2019 May 15;172:159-166. doi: 10.1016/j.ecoenv.2019.01.070. Epub 2019 Jan 29.
The interaction between pure culture microorganisms has been evaluated allowing for the enhanced biodegradation of various kinds of pollutants. Arthrobacter sp. DNS10 previously enriched in an atrazine-containing soil was capable of utilizing atrazine as the sole nitrogen source for growth, and Enterobacter sp. P1 is a phosphorus-solubilizing bacterium that releases various kinds of organic acids but lacks the ability to degrade atrazine. Whether strain P1 could enhance atrazine biodegradation by the degrader strain DNS10 was investigated in this experiment. Gas chromatography and high-performance liquid chromatography results showed that co-culture of both strains degraded 99.18 ± 1.00% of the atrazine (initial concentration was 100 mg L), while the single strain DNS10 only degraded 38.57 ± 7.39% after a 48 h culture, and the resulting concentration of the atrazine final metabolite cyanuric acid were 63.91 ± 3.34 mg L and 26.60 ± 3.87 mg L, respectively. In addition, the expression of the atrazine degradation-related genes trzN, atzB and atzC in co-culture treatments was 6.61, 1.81 and 3.09 times that of the single strain DNS10 culture treatment. A substrates utilization test showed that the atrazine-degrading metabolites ethylamine and isopropylamine could serve as the nitrogen source to support strain P1 growth, although strain P1 cannot degrade atrazine or utilize atrazine for growth. Furthermore, the pH of the medium was significantly decreased when strain P1 utilized ethylamine and isopropylamine as the nitrogen source for growth. The results suggest that nondegrader strain P1 could promote the atrazine biodegradation when co-cultured with strain DNS10. This phenomenon is due to metabolite exchange between the two strains. Culturing these two strains together is a new biostimulation strategy to enhance the biodegradation of atrazine by culturing these two strains together.
已评估纯培养微生物之间的相互作用，以实现各种污染物的增强生物降解。先前在含莠去津的土壤中富集的节杆菌（Arthrobacter sp.）DNS10 能够将莠去津用作生长的唯一氮源，而肠杆菌（Enterobacter sp.）P1 是一种溶磷菌，可释放各种有机酸，但缺乏降解莠去津的能力。本实验研究了菌株 P1 是否可以通过降解菌 DNS10 来增强莠去津的生物降解。气相色谱和高效液相色谱结果表明，两菌株共培养降解了 99.18 ± 1.00%的莠去津（初始浓度为 100 mg/L），而单菌株 DNS10 在 48 h 培养后仅降解了 38.57 ± 7.39%，莠去津最终代谢物三聚氰胺的浓度分别为 63.91 ± 3.34 mg/L 和 26.60 ± 3.87 mg/L。此外，共培养处理中莠去津降解相关基因 trzN、atzB 和 atzC 的表达分别是单菌株 DNS10 培养处理的 6.61、1.81 和 3.09 倍。底物利用试验表明，莠去津降解代谢物乙胺和异丙胺可作为氮源支持菌株 P1 的生长，尽管菌株 P1 不能降解莠去津或利用莠去津进行生长。此外，当菌株 P1 将乙胺和异丙胺用作生长的氮源时，培养基的 pH 值显著降低。结果表明，当与菌株 DNS10 共培养时，非降解菌 P1 可以促进莠去津的生物降解。这种现象是由于两株菌之间的代谢物交换。将这两株菌一起培养是一种新的生物刺激策略，可通过共培养这两株菌来增强莠去津的生物降解。
