一株可降解膦酸酯东海原甲藻共生细菌的分离及其促藻效应  

Isolation of a phosphonate-degrading symbiotic bacterium from Prorocentrum donghaiense and its promoting effect on algal growth

作　　者：崔玉栋 刘鸿环 陈锦雪 Cui Yudong;Liu Honghuan;Chen Jinxue(Fujian Province Key Laboratory for the Development of Bioactive Material from Marine Algae,College of Oceanology and Food Sci-ences,Quanzhou Normal University,Quanzhou 362131,China)

机构地区：[1]泉州师范学院海洋与食品学院,福建省海洋藻类活性物质制备与功能开发重点实验室,福建泉州362000

出　　处：《海洋学报》2024年第9期38-51,共14页

基　　金：国家自然科学基金(42306167);福建省自然科学基金资助项目(2023J01896);泉州师范学院引进人才科研项目(H17012)。

摘　　要：海洋中的膦酸酯(C-P键有机磷)是可供浮游植物利用的一种潜在磷源。甲藻自身无法直接利用膦酸酯,但是其共生细菌可将膦酸酯降解为磷酸盐,从而促进藻细胞的生长。然而,目前尚未有针对特定菌株的相关研究。本研究在2-氨基乙基膦酸(2-AEP)作为唯一磷源条件下对东海原甲藻进行培养,对其中的共生细菌进行分离纯化,初步得到5种细菌。基因组测序结果表明,其中一株尹氏菌属细菌Yooniasp.PD-AEP-1中存在两种C-P裂解酶途径。通过藻菌共培养实验对菌株功能进行验证,结果显示,将藻细胞处理至磷饥饿状态之后,同时加入2-AEP与PD-AEP-1悬液,与只加2-AEP或只加细菌悬液的条件相比,藻细胞生长速率和体系内磷酸盐浓度显著升高,同时碱性磷酸酶活性及非光化学淬灭值则明显降低,表明PD-AEP-1具备将2-AEP降解为磷酸盐的能力,进而缓解了东海原甲藻细胞的磷限制状态,有效促进了藻细胞的生长。该研究表明,东海原甲藻共生细菌在降解膦酸酯从而为藻细胞提供磷源方面扮演着一定角色,这一过程很可能有助于东海原甲藻赤潮的暴发,凸显了海洋生态系统中藻-菌相互作用的重要性。Phosphonates in the ocean are a kind of potential phosphorus(P)source which could be utilized by phytoplankton.Although dinoflagellates cannot directly utilize phosphonates themselves,their symbiotic bacteria have the capability to degrade phosphonates into phosphate,thereby promoting the growth of algal cells.However,no studies focusing on a specific bacteria strain have been conducted thus far.In this study,Prorocentrum dong-haiense was cultured under conditions with 2-Aminoethylphosphonic acid(2-AEP)as the sole P source.Isolation and purification of the symbiotic bacteria from the culture was conducted and five kinds of bacteria were obtained.Genome sequencing results revealed the presence of two types of C-P lyase pathways in the bacterial strain desig-nated as Yoonia sp.PD-AEP-1.The function of the bacteira strain was verified through the co-culture of bacteria and algal cells.The results demonstrated that after the algal cells were treated to phosphorus-starved condition,when 2-AEP and the bacteria suspension were added together,as compared to conditions which only 2-AEP or the bacterial suspension of PD-AEP-1 was introduced,both the growth rate of algal cells and the phosphate concentra-tion in the cultures showed a significant increase.Meanwhile,alkaline phosphatase activity and non-photochemical quenching of the algal cells decreased significantly,indicating that PD-AEP-1 has the ability to degrade 2-AEP in-to phosphate,thereby alleviating phosphorus limitation for P.donghaiense cells and effectively promoting the growth of algal cells.The study suggests that symbiotic bacteria of P.donghaiense might play a part in providing P sources to the algal cells through the degradation of phosphonates.This process could probably contribute to the outbreak of P.donghaiense bloom,highlighting the importance of algae-bacteira interactions in marine ecosystems.

关 键 词：膦酸酯 东海原甲藻 共生细菌 促藻效应 赤潮 

分 类 号：P76[天文地球—海洋科学]