附石生物膜群落组成与脂质代谢对牧食压力的响应  

Response of community composition and lipid metabolism of epilithic biofilms to grazing pressure

作　　者：朱凤 汪兴中[2] 李银科 谭香[3,4] ZHU Feng;WANG Xingzhong;LI Yinke;TAN Xiang(Key Laboratory of Chemistry in Ethnic Medicinal Resources,Yunnan Minzu University,Kunming 650031,China;Zhejiang Provincial Key Laboratory of Aquatic Resources Conservation and Development,College of Life Sciences,Huzhou University,Huzhou 313000,Zhejiang,China;Key Laboratory of Aquatic Botany and Watershed Ecology,Wuhan Botanical Garden,Chinese Academy of Sciences,Wuhan 430074,China;Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station,the Chinese Academy of Sciences&Hubei Province,Wuhan 430074,China)

机构地区：[1]云南民族大学民族医药学院,昆明650031 [2]湖州师范学院水生生物资源养护与开发技术研究浙江省重点实验室,浙江湖州313000 [3]中国科学院武汉植物园水生植物与流域生态重点实验室,武汉430074 [4]中国科学院与湖北省丹江口湿地生态系统野外科学观测研究站,武汉430074

出　　处：《生态学杂志》2024年第12期3717-3725,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(32271665,32030069)资助。

摘　　要：附石生物膜富含多不饱和脂肪酸(PUFA),是河流食物网中的优质基础食物资源之一。附石生物膜不仅为消费者提供食物来源,同时也受到消费者反馈调节的影响,然而,目前对这种影响的认识仍不充分。为了揭示牧食压力对附石生物膜的影响,本研究通过为期35天的中宇宙实验,在两种不同培养条件下(有/无铜锈环棱螺(Bellamya aeruginosa)),利用脂肪酸测定和宏基因组测序技术比较了不同培养条件下附石生物膜的差异。结果表明,牧食压力下,附石生物膜中饱和脂肪酸(SAFA)和PUFA如花生四烯酸(ARA)的占比分别增加了7.72%和0.13%,单不饱和脂肪酸(MUFA)的占比则减少了10.14%。参与脂质代谢的微生物中,变形菌门(Proteobacteria)和蓝藻门(Cyanobacteria)的相对丰度减少,而疣微菌门(Verrucomicrobia)和放线菌门(Actinobacteria)的相对丰度增加;属级水平上,卟啉单胞菌属(Porphyromonas)与鞘脂单胞菌属(Sphingomonas)相对丰度减少,黄单胞菌属(Xanthomonas)相对丰度增加。此外,KEGG功能预测表明,附石生物膜中注释到脂肪酸降解通路的相对丰度显著减少,功能基因乙酰辅酶A酰基转移酶(acetyl⁃CoA acyltransferase)的相对丰度显著增加。综合结果表明,牧食压力下附石生物膜通过减少脂肪酸的降解来维持自身能量需求与稳定。Epilithic biofilm is a rich source of polyunsaturated fatty acids(PUFAs)and thus is a high⁃quality basal food resource in river food webs.Biofilms not only provide food for consumers but are also influenced by consumers.However,our understanding of such feedback is insufficient.To understand the impact of grazing pressure on biofilms,we conducted a 35⁃day mesocosm experiment under two different conditions,with and without Bellamya aeruginosa,and compared the differences in biofilm using fatty acid and metagenomic sequencing.Under grazing pressure,the proportion of saturated fatty acids(SAFAs)and PUFAs,such as arachidonic acid(ARA),increased by 7.72%and 0.13%,respectively,while the proportion of monounsaturated fatty acids(MUFAs)decreased by 10.14%.Among the microorganisms involved in lipid metabolism,the relative abundance of Pro⁃teobacteria and Cyanobacteria decreased,while that of Verrucomicrobia and Actinobacteria increased.At the genus level,the relative abundance of Porphyromonas and Sphingomonas decreased,while Xanthomonas increased.The relative abundance of the fatty acid degradation pathway in biofilm was significantly reduced,while that of the functional gene acetyl⁃CoA acyltransferase increased significantly in KEGG function prediction.Our findings suggest that biofilm can maintain energy demand and stability by reducing the degradation of fatty acids under grazing pressure.

关 键 词：牧食压力 附石生物膜 微生物群落 脂肪酸 宏基因组学 

分 类 号：Q178[生物学—水生生物学]