24年12月9日文献情报（4篇）

24年12月9日文献情报

1. 题目: Response and roles of algal organic matter under copper stress: Spectral and mass spectrometry analysis

文章编号: N24120904
期刊: Science of the Total Environment
作者: Shuqi Wu, Yunkun Qian, Yanan Chen, Jun Guo, Yijun Shi, Dong An
更新时间: 2024-12-09
摘要: Eutrophication leads to various environmental issues, including pollution caused by the production of algal organic matter (AOM). Algae typically respond to environmental changes (e.g., light, temperature, copper [Cu(II)] concentration and pH) by regulating the production and release of different substances, thereby causing unpredictable effects on water quality. We explored the characteristics of AOM and the response mechanisms of algae under Cu(II) stress in the study, using fluorescence spectrum and high-resolution mass spectrometry (HRMS) analysis. The growth of Microcystis aeruginosa was inhibited under Cu(II) stress which was irreversible at Cu(II) concentration ≥ 2 μmol/L. Tryptophan- and humic-like fluorophores were important constituents of extracellular organic matter (EOM), and their contents increased with the addition of Cu(II), indicating that Cu(II) stimulates the production of tryptophan- and humic-like compounds. In addition, fulvic acid-like compounds in EOM were the main components binding to Cu(II) and were overproduced by algae under Cu(II) stress. It was found by HRMS at the molecular level that the formula numbers of EOM generally increased over inhibition time. Under 1 μmol/L Cu(II) stress, nitrogenous compounds (CHON formulae) were the primary AOM, accounting for 37.3–52.0 %. In addition, algae release a large amount of condensed aromatic structures to balance Cu(II) stress. This study provides a molecular-level analysis to explain the variation trends and response mechanisms of algae under various Cu(II) concentrations. The research methods are helpful for utilizing multiple advanced analysis methods to study algae growth and AOM release.
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2. 题目: A systematic review of the variability of freshly-emitted and aged black carbon based on various measurement techniques

文章编号: N24120903
期刊: Science of the Total Environment
作者: Bobo Wu, Zichun Wu, Jiahang Dou, Zhiliang Yao, Xianbao Shen, Ao Wang, Long Li, Xuewei Hao
更新时间: 2024-12-09
摘要: Black carbon (BC) poses acute negative health and environmental impacts. Accurate BC quantification is important for assessing its impacts and developing effective control strategies. However, the unclear optical properties and numerous methods of BC restrict its accurate quantification. Elemental carbon (EC), refractory black carbon (rBC), and equivalent black carbon (eBC) are terminology used for BC quantification by various techniques, with an essential parameter of mass absorption cross-section (MAC) characterizing its optical properties. This review summarizes the measurement principles, along with the advantages, limitations, and uncertainties of mainstream instruments used for BC quantification, based on findings from numerous studies. Then, we categorically compared the MAC of BC for different emission sources and regions, and those are not consistent. The MAC values of freshly-emitted and aged BC are both influenced by the combustion sources, while the transport process present significant impact on aged BC. Average MAC values of BC for urban, rural, and other areas are 10.1 ± 3.7 m²/g, 13.4 ± 5.7 m²/g, and 13.7 ± 8.2 m²/g at 550 nm, respectively. Furthermore, we systematically explored the relationship between eBC, EC, and rBC of freshly-emitted and aged BC to establish unambiguous links between these terms. Averaged mass ratios of eBC/EC, eBC/rBC and EC/rBC are 0.81, 0.94, and 1.32 for freshly-emitted BC, 1.17, 2.14, and 1.60 for aged BC, respectively. Overall, it is urgent to establish standard methods for accurate BC quantification in the future to reduce the uncertainty of quantitative results by different techniques.
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3. 题目: Deciphering the link between particulate organic matter molecular composition and lake eutrophication by FT-ICR MS analysis

文章编号: N24120902
期刊: Water Research
作者: Minli Guo, Mingxing Yu, Xu Wang, Naidong Xiao, Arnaud Huguet, Yunlin Zhang, Guanglong Liu
更新时间: 2024-12-09
摘要: Eutrophication has emerged as a significant environmental problem for global lakes. As an essential carrier of nutrients, particulate organic matter (POM) plays a vital role in the eutrophication process of these aquatic systems. In this study, POM from seven lakes with different trophic states in the middle and lower reaches of the Yangtze River (China) was characterized using carbon and nitrogen stable isotopes and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The aim was to elucidate the relationship between the source and molecular composition of POM during the eutrophication process of lakes. The results indicated that POM was mainly composed of autochthonous (62.7%) and allochthonous (37.3%) sources, with the contribution from autochthonous sources being more pronounced across the different sources. The POM formulas mainly consisted of the subclasses CHO, CHON, CHOP, CHOS, and CHONS. Notably, CHOP formulas had the highest proportion of labile formula compounds, according for 51.56%. The unsaturation, aromaticity, and oxidation of unique POM formulas gradually decreased with increasing trophic states. A significant positive correlation was observed between CHOP and the percentage of labile compounds (MLB_L%) in unique POM formulas. The relative abundance of lipid and protein compounds of unique POM formulas showed a positive correlation with lake trophic states, which indicated that with the increase of lake trophic states, the content of autochthonous POM gradually increased. Herein, we inferred that with the intensification of lake eutrophication, the autochthonous POM increased, which was accompanied by a further increase of labile P-containing compounds in POM, thus leading to the increasing eutrophication process of lakes in the form of positive feedback. Overall, this investigation of POM at the molecular level illustrates the deep-rooted mechanism of frequent lake eutrophication. This is of great significance in understanding the fate of POM and effectively controlling lake eutrophication.
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4. 题目: Marine anoxia impede the transformation of dissolved organic carbon released by kelp into refractory dissolved organic carbon

文章编号: N24120901
期刊: Marine Pollution Bulletin
作者: Lingyun Zhao, Hongyan Xing, Rongyu Xin, Jichen Liu, Huawei Qin, Yuanqing Ma, Zefeng Tian, Mengjie Wang, Yaoyang Ma, Mingliang Zhang
更新时间: 2024-12-09
摘要: The transformation of dissolved organic carbon (DOC) released by macroalgae into refractory dissolved organic carbon (RDOC) through microbial carbon pump (MCP) represents a crucial carbon sequestration process. This process mainly takes place in coastal areas, where it is likely affected by marine anoxia. The interactions between the components of DOC released by kelp and the community structure of heterotrophic bacteria both under normoxic and anoxic conditions were studied by three-dimensional fluorescence parallel factor analysis (PARAFAC), Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometry (FT-ICR-MS) and 16S rRNA high-throughput sequencing. Following 240 days of decomposition, we found that the proportion of labile dissolved organic carbon (LDOC) was 4.61 % greater under anoxic conditions compared to normoxic conditions. Conversely, the proportion of RDOC was 8.06 % lower under anoxic conditions than under normoxic conditions. These findings suggest that anoxia hinders the conversion of LDOC to RDOC in the DOC released by kelp. Although normoxic conditions favor RDOC production, anoxic conditions could be more advantageous for the transport of DOC to the deep ocean, potentially enhancing carbon sequestration. The cultivation of macroalgae in anoxic zones may further boost their carbon sequestration potential.
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