School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
J Environ Sci (China). 2016 Apr;42:79-88. doi: 10.1016/j.jes.2015.08.011. Epub 2015 Oct 31.
Dissolved organic nitrogen (DON) extracted from Lake Shankou sediments using KCl was isolated into hydrophobic and hydrophilic fractions. The bioavailabilities of the hydrophobic and hydrophilic fractions to three types of bacterial communities collected from sediments, activated sludge and compost products were examined. The DON recoveries obtained by DAX-8 and cation exchange resins treatment were 96.17%±1.58% and 98.14%±0% for the samples obtained from N4 and N14 stations, respectively. After 25 days of incubation at 25°C, most DON (59% to 96%) was degraded. Hydrophilic DON exhibited a higher reduction rate than hydrophobic DON during the growth phase. Untreated wastewater from Changshuihe town was the main degradable DON source to station N4, and 93% of hydrophilic DON and 80% of hydrophobic DON were degraded. Station N14 received a large amount of refractory DON from forest soils and exhibited DON degradation rates of 82% and 71% for the hydrophilic and hydrophobic fractions, respectively. Amino acid contents and fluorescence intensities were also analyzed. Approximately 27% to 74% of amino acids were taken up by day 5, and their concentration gradually increased in the following days due to the decomposition of dissolved proteins. Parallel factor analysis resulted in identification of tryptophan-like proteins, tyrosine-like proteins and FA-like substances. During the growth phase, 40%-51% of the tryptophan-like proteins were taken up by bacteria, and the accumulation of tyrosine-like proteins was attributed to the release of biotic substances. The concentration of the FA-like substances decreased due to microbial decomposition.
从山口湖底泥中用 KCl 提取的溶解有机氮（DON）被分离为疏水性和亲水性两部分。考察了从沉积物、活性污泥和堆肥产物中收集的三种细菌群落对疏水性和亲水性部分的生物可利用性。分别用 DAX-8 和阳离子交换树脂处理从 N4 和 N14 站位获得的样品，DON 回收率为 96.17%±1.58%和 98.14%±0%。在 25°C 下培养 25 天后，大部分 DON（59%至 96%）被降解。亲水性 DON 在生长阶段比疏水性 DON 具有更高的还原率。来自长水河镇未经处理的废水是 N4 站位主要的可降解 DON 源，亲水性 DON 和疏水性 DON 分别有 93%和 80%被降解。N14 站位从森林土壤中接收了大量难降解的 DON，亲水性和疏水性部分的 DON 降解率分别为 82%和 71%。还分析了氨基酸含量和荧光强度。大约 27%至 74%的氨基酸在第 5 天被吸收，由于溶解蛋白的分解，其浓度在随后的几天逐渐增加。平行因子分析鉴定出色氨酸样蛋白、酪氨酸样蛋白和 FA 样物质。在生长阶段，细菌吸收了 40%-51%的色氨酸样蛋白，而酪氨酸样蛋白的积累归因于生物物质的释放。由于微生物分解，FA 样物质的浓度降低。
