大型海藻龙须菜(Gracilaria lemaneiformis)藻段凋落分解对环境的影响及细菌群落演替特征  

Effects of litter decomposition of Gracilaria lemaneiformis segments on environment and its succession characteristics of bacterial community

作　　者：胡晓娟[1] 赵秀 杨宇峰[2,3] 曹煜成 Hu Xiaojuan;Zhao Xiu;Yang Yufeng;Cao Yucheng(Key Laboratory of South China Sea Fishery Resources Exploitation&Utilization,Ministry of Agriculture and Rural Affairs/Guangdong Provincial Key Laboratory of Fishery Ecology and Environment,South China Sea Fisheries Research Institute,Chinese Academy of Fish-ery Sciences,Guangzhou 510300,China;Institute of Hydrobiology,Jinan University,Guangzhou 510632,China;Southern Marine Sci-ence and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China)

机构地区：[1]中国水产科学研究院南海水产研究所农业农村部南海渔业资源开发利用重点实验室/广东省渔业生态环境重点实验室,广东广州510300 [2]暨南大学水生生物研究所,广东广州510632 [3]南方海洋科学与工程广东省实验室(珠海),广东珠海519082

出　　处：《海洋学报》2023年第8期130-142,共13页

基　　金：国家自然科学基金面上项目(41977268);南方海洋科学与工程广东省实验室(珠海)创新团队建设项目(31102211);中国水产科学研究院基本科研业务费(2020TD54);中国水产科学研究院南海水产研究所中央级公益性科研院所基本科研业务费(2021SD08);国家现代农业产业技术体系项目(CARS-48)。

摘　　要：为解析大型海藻龙须菜(Gracilaria lemaneiformis)阴干藻段凋落分解对环境的影响及细菌群落演替规律,本文通过室内模拟凋落实验,分析了龙须菜凋落物分解过程中营养盐含量变化及藻体、水体、沉积物细菌群落结构特征。结果发现,龙须菜阴干藻段在较短时间内迅速凋落分解,50d时,藻体分解率达到83.5%。凋落过程中,水体总有机碳、总氮、总磷的含量分别较初始时升高了241.2%、229.8%和101.3%。水体溶解氧含量从初始的1.87mg/L降至第50天的0.32mg/L,降幅达82.9%。凋落过程中,龙须菜藻体附着细菌数量维持在107copy/g。凋落物藻体附着细菌丰富度与多样性在凋落分解过程中持续升高。优势菌群落结构变化受水体总有机碳、总氮、总磷和溶解氧含量影响显著,其中浮霉菌门、螺旋体门、厚壁菌门、δ-变形菌相对丰度不断上升,拟杆菌门、α-变形菌、γ-变形菌相对丰度不断下降。凋落过程中,凋落物藻体附着细菌中与代谢相关的功能基因丰度持续下降。结果表明,龙须菜藻体凋落会导致水体营养盐浓度升高,浮霉菌门、螺旋体门、厚壁菌门、δ-变形菌等细菌对龙须菜的凋落分解具有重要作用。In order to clarify the effects of litter decomposition of Gracilaria lemaneiformis segments on environ-ment and the succession of bacterial community,the characteristics of nutrient content in seaweed,water and sedi-ment,and succession characteristics of bacterial community attached to the seaweed,water and sediment were car-ried out by the simulation experiment.The results showed that its decomposition rate reached 83.5%after 50 d.The content of total organic carbon(TOC),total nitrogen(TN)and total phosphorus(TP)in water increased by 241.2%,229.8%and 101.3%,respectively,compared with the initial period.The content of dissolved oxygen(DO)in water decreased by 82.9%,which from 1.87 mg/L to 0.32 mg/L.In addition,the number of bacteria attached to G.lemanei-formis remained at 107 copy/g,while the richness and diversity of bacteria continued to increase during the decom-position processes.The bacteria community structure was significantly affected by total organic carbon,total nitro-gen,total phosphorus and DO in water.The relative abundances of Planctomycetes,Spirochaetae,Firmicutes andδ-Proteobacteria increased,while that of Bacteroidetes,α-Proteobacteria andγ-Proteobacteria decreased.During the process of decomposition,the functional gene abundance of metabolism attached to G.lemaneiformis continued to decline.Briefly,the results indicated that decomposition of G.lemaneiformis segments would lead to the increas-ing of nutrient concentration in water.And Planctomycetes,Spirochaetae,Firmicutes andδ-Proteobacteria played important roles in the process of decomposing of G.lemaneiformis.

关 键 词：龙须菜 凋落 环境因子 细菌群落 

分 类 号：P735[天文地球—海洋生物学] Q949.29[天文地球—海洋科学]