Transformation of algal-dissolved organic matter via sunlight-induced photochemical and microbial processes: interactions between two processes
Transformation of algal-dissolved organic matter via sunlight-induced photochemical and microbial processes: interactions between two processes
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DOI：
10.1007/s11356-023-26024-2
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发表时间：
2023-02
影响因子：
5.8
通讯作者：
Xiulin Huang;ShiLin An;Shuo Chen;Jiaru Dai;J. Liu;Shuailong Wen;Tingzhen Li;Peng Xing;YingXun Du
中科院分区：
文献类型：
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作者：
Xiulin Huang;ShiLin An;Shuo Chen;Jiaru Dai;J. Liu;Shuailong Wen;Tingzhen Li;Peng Xing;YingXun Du
藻溶有机质（ADOM）是富营养化水体中溶解有机碳（DOC）的重要组成部分。虽然已知ADOM容易被微生物转化，但阳光诱导的光化学过程以及两者之间的相互作用在ADOM转化中的作用尚不清楚。本研究对ADOM进行了自然光下光化学处理（L处理）、微生物处理（M处理）和光化学+微生物同时处理（L&M） 3种处理，处理时间为18 d。结果表明，M处理在短波长处（a254和a280） DOC、显色性DOM （CDOM）的损失比L处理更有效，而L处理对a350和普遍存在的腐殖质样成分和色氨酸样成分的荧光成分的转化更有效。三种处理下DOC和CDOM的衰变动力学比较表明，光化学和生物同时作用对DOC的衰变速率有抑制作用，但对DOC不稳定组分的百分比没有抑制作用。L&M处理后蛋白样物质相对丰度较高，而M处理后腐殖质样物质和芳香性相对丰度增加，且L处理后产生低分子量化合物。我们的研究结果强调了光化学在ADOM处理过程中介导天然水化学多样性的重要性。
Algal-dissolved organic matter (ADOM) is an important fraction of dissolved organic carbon (DOC) in eutrophic water. Although ADOM is known to be readily transformed by microbes, the role of sunlight-induced photochemical process and the interactions between two processes on ADOM transformation remains unclear. In this study, three types of treatments for ADOM, including photochemical process under natural solar light (L treatment), microbial process (M treatment), and the simultaneous photochemical plus microbial process (L&M), were performed for 18 days. Our results showed that M treatment was more effective for the loss of DOC, chromophoric DOM (CDOM) at short wavelengths (a254anda280), than L treatment, while L treatment was more effective for the transformation ofa350and the fluorescent components of the ubiquitous humic-like component and the tryptophan-like component. Comparison in the decay kinetics of DOC and CDOM in the three treatments showed that the simultaneous photochemical and biological processes exhibited an inhibitory effect on DOC decay rate but not the percentage of labile DOC fraction. Higher relative abundance of protein-like substances was found after L&M treatment, while the relative abundance of humic-like substance and aromaticity increased after M treatment, and the low molecular-weight compounds were produced after L treatment. Our results emphasized the importance of photochemistry in processing ADOM to mediate the chemodiversity in natural water.