College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo 315211, China.
Sci Total Environ. 2024 Nov 10;950:175201. doi: 10.1016/j.scitotenv.2024.175201. Epub 2024 Aug 3.
The disparities in harmful algal blooms dynamics are largely attributed to variations in cyanobacteria populations within aquatic ecosystems. However, cyanobacteria-cyanophage interactions and their role in shaping cyanobacterial populations has been previously underappreciated. To address this knowledge gap, we isolated and sequenced 42 cyanophages from diverse water sources in China, with the majority (n = 35) originating from freshwater sources. We designated these sequences as the "Novel Cyanophage Genome sequence Collection" (NCGC). NCGC displayed notable genetic variations, with 95 % (40/42) of the sequences representing previously unidentified taxonomic ranks. By integrating NCGC with public data of cyanophages and cyanobacteria, we found evidence for more frequent historical cyanobacteria-cyanophage interactions in freshwater ecosystems. This was evidenced by a higher prevalence of prophage integrase-related genes in freshwater cyanophages (37.97 %) than marine cyanophages (7.42 %). In addition, freshwater cyanophages could infect a broader range of cyanobacteria orders (n = 4) than marine ones (n = 0). Correspondingly, freshwater cyanobacteria harbored more defense systems per million base pairs in their genomes, indicating more frequent phage infections. Evolutionary and cyanophage epidemiological studies suggest that interactions between cyanobacteria and cyanophages in freshwater and marine ecosystems are interconnected, and that brackish water can act as a transitional zone for freshwater and marine cyanophages. In conclusion, our research significantly expands the genetic information database of cyanophage, offering a wider selection of cyanophages to control harmful cyanobacterial blooms. Additionally, we represent a pioneering large-scale and comprehensive analysis of cyanobacteria and cyanophage sequencing data, and it provides theoretical guidance for the application of cyanophages in different environments.
水华蓝藻动态的差异在很大程度上归因于水生生态系统中蓝藻种群的变化。然而，蓝藻-噬藻体相互作用及其在塑造蓝藻种群中的作用以前被低估了。为了弥补这一知识空白，我们从中国不同水源中分离并测序了 42 株噬藻体，其中大部分（n=35）来自淡水来源。我们将这些序列指定为“新型噬藻体基因组序列集”（NCGC）。NCGC 显示出显著的遗传变异，其中 95%（40/42）的序列代表以前未识别的分类等级。通过将 NCGC 与公共的噬藻体和蓝藻数据整合，我们发现了淡水生态系统中历史上蓝藻-噬藻体相互作用更为频繁的证据。这表现在淡水噬藻体（37.97%）中前噬菌体整合酶相关基因的出现频率高于海洋噬藻体（7.42%）。此外，淡水噬藻体可以感染更广泛的蓝藻目（n=4），而海洋噬藻体则不能（n=0）。相应地，淡水蓝藻在其基因组中每百万碱基对拥有更多的防御系统，表明其受到的噬菌体感染更为频繁。进化和噬藻体流行病学研究表明，淡水和海洋生态系统中蓝藻和噬藻体之间的相互作用是相互关联的，半咸水可以作为淡水和海洋噬藻体的过渡区。总之，我们的研究极大地扩展了噬藻体的遗传信息数据库，为控制有害蓝藻水华提供了更多的噬藻体选择。此外，我们代表了对蓝藻和噬藻体测序数据的大规模和全面分析的先驱，为噬藻体在不同环境中的应用提供了理论指导。
