长江口邻近海域表层沉积物中的细菌藿多醇及对低氧区的响应判别  

Response of Bacteriohopanepolyols to Hypoxic Conditions in the Surface Sediments of the Yangtze Estuary and Its Adjacent Areas

作　　者：尹美玲 段丽琴[1,2,3,4] 宋金明 张乃星[5] YIN Mei-ling;DUAN Li-qin;SONG Jin-ming;ZHANG Nai-xing(Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;School of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Laboratory for Marine Ecology and Environmental Sciences,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,China;Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China;North China Sea Marine Forecasting Center of State Oceanic Administration,Qingdao 266033,China)

机构地区：[1]中国科学院海洋研究所海洋生态与环境科学重点实验室,青岛266071 [2]中国科学院大学地球与行星科学学院,北京100049 [3]青岛海洋科学与技术国家实验室海洋生态与环境科学功能实验室,青岛266237 [4]中国科学院海洋大科学研究中心,青岛266071 [5]国家海洋局北海预报中心,青岛266033

出　　处：《环境科学》2021年第3期1343-1353,共11页Environmental Science

基　　金：国家自然科学基金项目(41976037,41676068);中国科学院青年促进会项目(2016191);中国科学院海洋研究所青年汇泉学者项目;烟台“双百计划”项目。

摘　　要：作为新型细菌生物标志物的细菌藿多醇(bacteriohopanepolyols,BHPs)在有机质来源追踪和环境变化响应等方面有明确的指示作用.本文应用高效液相色谱串联大气压化学电离源质谱法(HPLC-APCI-MS)分析,在解析长江口邻近海域表层沉积物中BHPs的组成、分布和来源特征基础上,探讨了BHPs对长江口邻近海域季节性低氧的指示作用.结果表明,长江口邻近海域表层沉积物中共检测出12种BHPs,其含量范围(以TOC计)为3.79~269μg·g^(-1).BHPs以细菌藿四醇(bacteriohopanetetrol,BHT)、2-甲基BHT、氨基BHPs和腺苷藿烷及同系物为主要组分,分别占总量的40%、22%、12%和4%.各组分含量及相应指标呈现出明显的空间变化趋势,其中,主要来源于海洋自生来源的BHT呈现明显的"离岸增加"趋势;主要为陆源贡献的腺苷藿烷等土壤标志物BHPs呈现明显的"离岸降低"特征.Rsoil指数呈现出与腺苷藿烷等土壤标志物BHPs相似的空间分布格局,其陆源有机质贡献从近岸的61.5%下降至外海的1.66%,表明长江口邻近海域近岸有机质主要为陆源输入,而外海主要为海源贡献.细菌藿四醇同分异构体BHT-Ⅱ来源于厌氧氨氧化细菌,其相对含量的高值区与长江口低氧区分布相一致,且与底层水溶解氧(DO)含量呈显著负相关,表明低氧环境有利于BHT-Ⅱ的生成,BHT-Ⅱ可用于指示海洋低氧区环境特征.Bacteriohopanepolyols(BHPs),as a novel bacterial biomarker,show clear potential for tracking organic matter sources and environmental change.To evaluate BHPs as indicators of seasonal hypoxia in the Yangtze Estuary and its adjacent areas,the composition,distribution,and source of BHPs in surface sediments were analyzed using high-performance liquid chromatographyatmospheric pressure chemical ionization-mass spectrometry(HPLC-APCI-MS).A total of 12 BHPs were detected with a normalized TOC concentration of 3.79-269 μg·g^(-1).The BHPs present in the surface sediments were dominated by bacteriohopanetetrol(BHT),2-methyl-BHT,amino-BHPs,and adenosylhopane and its homologues,accounting for 40%,22%,12%,and 4% of the total BHPs,respectively.Each of these components and their corresponding indices show clear spatial trends.Specifically,BHT showed an"offshore increase " trend, which was mainly attributed to marine autochthonous inputs;and soil marker BHPs including adenosylhopane,which were dominated by terrestrial sources,showed an"offshore decrease"trend.The Rsoilindex indicated a similar spatial pattern to the soil marker BHPs,with the relative contribution of terrestrial organic matter decreasing from 61.5% in coastal waters to 1.66% in the open ocean.This suggests that the organic matter in the coastal waters was mainly derived from terrestrial sources while marine sources were dominant in the open ocean.BHT-Ⅱ,the BHT stereoisomer,was derived from anaerobic ammonium oxidizing bacteria.High BHT-Ⅱ ratios were consistent with seasonal hypoxic zones in the Yangtze Estuary and,furthermore,these ratios were significantly negatively correlated with dissolved oxygen(DO) concentrations in the bottom waters.These observations indicate that hypoxic environments are beneficial to BHT-Ⅱ production,implying that BHT-Ⅱ can be used as an indicator of marine hypoxia.

关 键 词：细菌藿多醇(BHPs) 生物地球化学行为 来源判别 低氧 长江口邻近海域 

分 类 号：X55[环境科学与工程—环境工程]