基于菌藻对比培养方法的洱海沉积物溶解性有机氮生物有效性评价

发布时间：2019-01-14 09:54

【摘要】：为了深入探究DON(溶解性有机氮)在湖泊水生生态系统中的重要营养作用和生态效应,寻找科学的DON生物有效性评价方法,选择洱海不同湖区表层沉积物样品,通过室内接种细菌和铜绿微囊藻进行对比培养,运用三维荧光-平行医疗法(3D EEM-PARAFAC)研究菌藻对比培养条件下湖泊沉积物DON生物有效性及各DON荧光组分生物有效性差异.结果表明:(1)藻类培养条件下洱海表层沉积物DON生物有效性(8.49%~42.5%)略低于细菌培养条件下的生物有效性(10.5%~45.3%).(2)藻培养条件下,DON生物利用率与藻细胞密度增长量呈显著正相关,即藻细胞密度的增长量可作为反映沉积物DON生物有效性的指标.(3)菌类培养过程中DON光谱学特征参数[如SUVA_(254)(254 nm处紫外吸收光谱系数)、S_R (275~295 nm处吸收光谱系数与350~400 nm处吸收光谱系数比值)等]与DON含量相关性总体较细菌培养好;培养液中SUVA_(254)有不同程度下降,S_R 指数均有上升,大分子DON和高芳香性DON可被微生物降解.相比于陆源荧光组分,内源荧光组分的生物有效性较差.(4)相比而言,藻类培养方法能更直观地反映沉积物DON对藻类生长的影响,可在一定程度上作为衡量湖泊沉积物DON生物有效性的指标,即藻类培养方法更适合评价洱海沉积物DON生物有效性.
[Abstract]:In order to explore the important nutrition and ecological effects of DON (dissolved organic nitrogen) in lake aquatic ecosystem, a scientific method for evaluating the bioavailability of DON was found, and samples of surface sediments from different lakes of Erhai Lake were selected. By inoculating bacteria and microcystis aeruginosa in laboratory, the bioavailability of DON in lake sediments and the bioavailability of DON fluorescence components were studied by using three-dimensional fluorescence parallel medical method (3D EEM-PARAFAC) under the condition of contrast culture of microcystis aeruginosa and microcystis aeruginosa. The results showed that: (1) the bioavailability of DON in the surface sediments of Erhai Lake (8.4942.5%) was slightly lower than that under bacteria culture (10.55.3%). (_ 2). The bioavailability of DON was positively correlated with the increase of algal cell density. That is to say, the increase of cell density of algae can be used as an index to reflect the bioavailability of DON in sediment. (3) the characteristic parameters of DON spectroscopy in the culture of bacteria [e.g. SUVA_ (254) (UV absorption coefficient at 254 nm), The ratio of absorption spectrum coefficient at 275 ~ 295 nm to absorption coefficient at 350 ~ 400 nm, etc., etc.) the correlation with DON content was generally better than that in bacterial culture. SUVA_ (254) in culture medium decreased to some extent, and SR index increased. Macromolecule DON and high aromatic DON could be degraded by microorganism. The bioavailability of endogenous fluorescent components is lower than that of terrestrial fluorescence components. (4) compared with terrestrial fluorescence components, algae culture method can more directly reflect the effect of sediment DON on algae growth. To some extent, the algae culture method is more suitable for evaluating the bioavailability of DON in lake sediments, that is to say, algae culture method is more suitable for evaluating the bioavailability of DON in lake sediments.
【作者单位】：北京化工大学;中国环境科学研究院环境基准与风险评估国家重点实验室;中国环境科学研究院国家环境保护湖泊污染控制重点实验室湖泊生态环境创新基地;
【基金】：国家自然科学基金项目(U1202235,41503113) 环境基准与风险评估国家重点实验室自由探索项目(2014-GOT-042-N-06)
【分类号】：X524

【相似文献】