基于磷脂脂肪酸的热带西太平洋沉积物生源要素矿化过程探析  

Exploring biomineralization in the tropical western Pacific sediments based on phospholipid fatty acid analysis

作　　者：杨梓阳 任登龙 贺志鹏 李学刚[1,2,3,4] 宋金明 袁华茂[1,2,3,4] 段丽琴 李宁[1,2,3,4] 张倩 YANG Ziyang;REN Denglong;HE Zhipeng;LI Xuegang;SONG Jinming;YUAN Huamao;DUAN Liqin;LI Ning;ZHANG Qian(CAS Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Science,Qingdao 266071,China;University of Chinese Academy of Science,Beijing 100049,China;Marine Ecology and Environmental Science Laboratory,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,China;Center for Ocean Mega-Science,Chinese Academy of Science,Qingdao 266071,China;Offshore Oil Production Plant of Sinopec Shengli Oilfield Company,Dongying 257237,China;Shandong Freshwater Fisheries Research Institute,Jinan 250013,China)

机构地区：[1]中国科学院海洋研究所中国科学院海洋生态与环境科学重点实验室,山东青岛266071 [2]中国科学院大学,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,山东青岛266237 [4]中国科学院海洋大科学研究中心,山东青岛266071 [5]中国石油化工股份有限公司胜利油田分公司海洋采油厂,山东东营257237 [6]山东省淡水渔业研究院,山东济南250013

出　　处：《地学前缘》2022年第4期93-102,共10页Earth Science Frontiers

基　　金：国家自然科学基金项目(91958103,42176200);中国科学院战略性先导科技专项(XDA23050501);山东省自然科学基金资助项目(ZR2020YQ28)。

摘　　要：甄别生源要素参与的海洋沉积物矿化过程对探析生源要素的生物地球化学循环有重要的作用,矿化作用包括有氧呼吸、硝酸盐还原、铁锰异化还原及硫酸盐还原等多个过程,但如何区分这些过程一直是海洋沉积物矿化研究的难点。本研究采用气相色谱-质谱(GC-MS)联用对热带西太平洋沉积物中的磷脂脂肪酸(phospholipid fatty acid,PLFA)的组成进行了解析,并分析不同矿化过程中的主要PLFA种类及其影响因素,探究PLFA对沉积物矿化的指示作用。结果表明,PLFA总量在有氧呼吸过程中最高,而在硝酸盐还原过程中最低;且14:0、i14:0、i15:0和i19:0是有氧呼吸过程中微生物PLFA的主要组成,当其含量明显降低时可以指示沉积物矿化从有氧呼吸转变为硝酸盐还原;而10:0、17:0、20:0和22:0含量之和显著增加时则指示了硫酸盐还原过程的发生。在热带西太平洋沉积物中,总有机碳(TOC)和总有机氮(TON)含量以及间隙水NO_(3)-N含量是PLFA含量的重要影响因素,PLFA总量随着TOC和TON含量的减少而减少,并且TOC和TON的降解能够促进PLFA降解的发生,对PLFA组成有更直接的影响。Identification of marine sediment mineralization processes plays an important role in the study of biogeochemical cycling of biogenic elements,although such processes—including aerobic respiration,nitrate reduction,iron and manganese reduction,sulfate reduction,etc.—can be difficult to distinguish one from another.In this study,gas chromatography-mass spectrometry(GC-MS)was used to analyze the phospholipid fatty acid(PLFA)profiles and their influencing factors in different mineralization processes,and further explore the use of PLFAs as sediment mineralization indicator in the tropical western Pacific.The total PLFA content was found to be highest in aerobic respiration and lowest in nitrate reduction.The obvious decrease of the sum of 14:0,i14:0,i15:0 and i19:0—the main components of microbial PLFA in aerobic respiration—could have certain indication for the occurrence of nitrate reduction;whilst the decrease of the sum of 10:0,17:0,20:0 and 22:0 could indicate the occurrence of sulfate reduction.In the sediments of the tropical western Pacific,the total organic carbon(TOC),total organic nitrogen(TON)and NO_(3)-N content in porewater were important factors influencing PLFA.as the total PLFA content decreased with decreasing TOC and TON,whilst the degradation of TOC and TON promoted the degradation of PLFA,which had a more direct impact on the PLFA composition.

关 键 词：磷脂脂肪酸 矿化过程 指示作用 海洋沉积物 热带西太平洋 

分 类 号：P736.2[天文地球—海洋地质] P593[天文地球—海洋科学]