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热带海洋学报

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三角褐指藻藻际细菌定殖机制及益生功能基因的基因组学解析

彭赛君1, 2

  

  1. 1. 威海海洋职业学院, 山东 威海 264300;

    2. 山东省海洋经济藻类资源开发与利用工程技术协同创新中心, 山东 威海 264300


  • 收稿日期:2026-06-25 修回日期:2026-08-14 接受日期:2026-08-28
  • 通讯作者: 彭赛君
  • 基金资助:

    山东省自然科学基金(ZR2025QC1049); 山东省海洋经济藻类资源开发与利用工程技术协同创新中心科研开放专项资金项目(MADU20240001)

Genomic insights into colonization mechanisms and probiotic function genes of Phaeodactylum tricornutum phycosphere bacteria

PENG Saijun1, 2    

  1. 1. Weihai Ocean Vocational College, Weihai 264300, China;

    2. Marine Economic Algae Resources Development and Utilization Engineering Technology Collaborative Innovation Center of Shandong Province, Weihai 264300, China


  • Received:2026-06-25 Revised:2026-08-14 Accepted:2026-08-28
  • Supported by:

    Shandong Provincial Natural Science Foundation (ZR2025QC1049); Project of Marine Economic Algae Resources Development and Utilization Engineering Technology Collaborative Innovation Center of Shandong Province (MADU20240001)

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摘要： 藻际细菌在调控微藻生长、代谢及环境适应性方面发挥着关键作用, 是开发新型益生菌剂的重要微生物资源。本研究以模式硅藻三角褐指藻的藻际细菌为研究对象, 基于鸟枪法宏基因组测序技术, 通过组装与分箱获得宏基因组组装基因组(metagenome-assembled genomes, MAGs), 利用GTDB-TK解析藻际细菌物种, 系统检索与定殖粘附、细菌–宿主互作、抗氧化色素合成、B族维生素合成相关基因。分箱共获得11个中、高质量MAGs, 隶属于假单胞菌门(9个)和拟杆菌门(2个), 其中血红杆菌(Erythrobacter sanguineus, MAG11)相对丰度最高(35.14%)。基因功能注释分析揭示了四种潜在定殖机制, 包括LuxI/LuxR和QseB/QseC群体感应系统、细菌趋化、tad紧密粘附基因簇和IV型分泌系统, 提示多种机制可能协同参与细菌在藻际环境中的定殖。益生功能方面, 居海噬冷菌(Algoriphagus marincola, MAG9)具备合成虾青素、玉米黄素、β-胡萝卜素等7种天然抗氧化剂的潜力。10个MAGs均具备至少一种B族维生素的完整合成基因通路, 其中MAG4和MAG11分别可合成5种B族维生素, MAG8是唯一具备完整维生素B12从头合成潜力的MAG。本研究识别出的具有多抗氧化色素合成和多B族维生素合成潜力的MAGs, 为后续功能益生菌的筛选与开发提供了基因组学依据和候选资源。

关键词: 三角褐指藻, 藻际细菌, 宏基因组, 定殖机制, 益生功能基因

Abstract: Phycosphere bacteria play a crucial role in regulating the growth, metabolism, and environmental adaptability of microalgae, representing important microbial resources for the development of novel probiotics. In this study, we focused on the phycosphere bacteria of the model diatom Phaeodactylum tricornutum. Based on shotgun metagenomic sequencing, metagenome-assembled genomes (MAGs) were obtained through assembly and binning. Taxonomic annotation was performed using GTDB-TK, and systematic gene mining was conducted targeting genes involved in colonization and adhesion, bacteria–host interaction, antioxidant pigment biosynthesis, and B-vitamin biosynthesis. A total of 11 medium- and high-quality MAGs were recovered, affiliated with Pseudomonadota (9 MAGs) and Bacteroidetes (2 MAGs). Among them, Erythrobacter sanguineus (MAG11) exhibited the highest relative abundance (35.14%). Functional gene annotation revealed four potential colonization mechanisms, including LuxI/LuxR and QseB/QseC quorum sensing systems, bacterial chemotaxis, the tad tight adherence gene cluster, and the type IV secretion system, suggesting that multiple mechanisms may act synergistically to facilitate bacterial colonization in the phycosphere. Regarding probiotic functions, Algoriphagus marincola (MAG9) harbored the genetic potential to synthesize seven natural antioxidants, including astaxanthin, zeaxanthin, and β-carotene. Ten MAGs possessed complete biosynthetic gene pathways for at least one B-vitamin, among which MAG4 and MAG11 each encoded five complete B-vitamin pathways, while MAG8 was the sole MAG capable of de novo vitamin B12 biosynthesis. The MAGs identified in this study with the potential for multi-antioxidant pigment synthesis and multi-B-vitamin biosynthesis provide a genomic basis and candidate resources for the subsequent screening and development of functional probiotics.

Key words: Phaeodactylum tricornutum, phycosphere bacteria, metagenomics, colonization mechanism, probiotic function genes