C6-HSL信号及群体淬灭对海洋聚球藻(Synechococcus)菌藻共栖体系的调控作用  

Regulatory effects of the C6-HSL signal molecule and quorum quenching on marine Synechococcus in the bacteria-algal system

作　　者：乔真 李佳霖[1] 秦松[1] QIAO Zhen;LI Jialin;QIN Song(Key Laboratory of Coastal Biology and Bioresource Utilization,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China;University of Chinese Academy of Science,Beijing 100049,China)

机构地区：[1]中国科学院烟台海岸带研究所海岸带生物学与生物资源利用重点实验室,山东烟台264003 [2]中国科学院大学,北京100049

出　　处：《海洋科学》2024年第9期52-62,共11页Marine Sciences

基　　金：国家自然科学基金(42176131)。

摘　　要：为探究细菌群体感应己酰-L-高丝氨酸内酯(N-hexanoyl-L-Homoserine lactone,C6-HSL)信号和群体淬灭作用对海洋聚球藻(Synechococcus)生长及藻菌互作关系的调控作用,以采集自南黄海中部表层海水的聚球藻富集样品进行培养实验,使用流式细胞术、高通量测序检测培养体系的细胞丰度、群落组成;构建共现性网络,明确C6-HSL对培养体系中微生物的相互作用程度的影响。结果显示C6-HSL信号可以促进聚球藻生长,7 d培养周期结束时实验组中聚球藻丰度约为对照组的1.83倍,而对细菌生长无明显促进作用;C6-HSL信号改变了培养体系中的细菌群落组成,其中α-变形菌中Rhodobacteraceae和Thalassospira属的占比升高,而γ-变形菌中Marinobacter属的占比下降,构建的共现性网络显示体系中微生物互作程度和网络紧密度均降低。分离聚球藻共栖细菌,筛选获得具有C6-HSL群体淬灭活性的6株菌,分别属于变形菌门(Proteobacteria,5株)和厚壁菌门(Firmicutes,1株),可以通过胞内途径实现群体淬灭;群体淬灭活性菌能够促进聚球藻生长,且群体淬灭活性强的菌株促生作用更强。本研究论证了群体感应C6-HSL信号和细菌的群体淬灭能力对聚球藻和共栖细菌的互作关系有调控作用,为后续深入探索基于群体感应信号分子作用的藻菌互作关系的研究提供了新的科学依据。This study aimed to explore the regulatory effects of N-hexanoyl-L-homoserine lactone(C6-HSL)signal and quorum quenching on the growth and algal–bacterial interactions of marine Synechococcus.Enriched culture samples of Synechococcus were collected from surface waters of the central South Yellow Sea.Flow cytometry and high-throughput sequencing were used to analyze cell abundance and microbial community composition.Further-more,microbial co-occurrence networks were constructed to assess the influence of C6-HSL on the extent of mi-crobial interactions in the culture system.The results revealed that the growth of Synechococcus was significantly enhanced by C6-HSL,with its abundance in the experimental group being approximately 1.83 times higher than that in the control group after a 7-day cultivation period.However,no significant effect was observed on heterotrophic bacterial growth.C6-HSL signals altered the composition of bacterial communities within the culture system,thereby increasing the proportion of Rhodobacteraceae and Thalassospira in alpha-proteobacteria and decreasing the proportion of Marinobacter in gamma-proteobacteria.The addition of C6-HSL reduced microbial interactions and network tightness.Six strains exhibiting C6-HSL quenching activity were isolated from Synechococcus culture samples,of which five were identified as Proteobacteria and one as Firmicutes.These strains achieved quor-um-quenching activity through the intracellular pathway.The bacteria displaying quorum-quenching activity pro-moted Synechococcus growth,with stronger effects observed for those with higher quorum-quenching activity.This study elucidated the regulatory effects of quorum-sensing C6-HSL signal and bacterial quorum-quenching ability on the interaction between Synechococcus and symbiotic bacteria,providing a scientific basis for further investigation into algal–bacterial interactions.

关 键 词：海洋聚球藻 群体感应抑制活性 藻菌相互作用 C6-HSL CV026 

分 类 号：P735[天文地球—海洋生物学]