Lu De-Chen, Yuan Ying, Tan Xin-Yun, Liu Le, Teng Jin-Hao, Cui Xue, Liu Tian-He, Zhang Jing, Du Zong-Jun, Wang Ming-Yi
Weihai Municipal Hospital, Weihai, China.
Marine College, Shandong University, Weihai, China.
Front Microbiol. 2025 Jul 18;16:1642517. doi: 10.3389/fmicb.2025.1642517. eCollection 2025.
Marine macroalgae-associated play crucial roles in global carbon cycling through polysaccharide degradation, yet their taxonomic and functional diversity remains understudied. Here, we describe six novel species (strains 3-376, 4-2040, 2-473A, 4-528, 4-911 and 463) within the families , , and isolated from macroalgal surfaces in the coastal area of Weihai, China. Metagenomic read recruitment and 16S rRNA abundance analyses demonstrated host-specific associations. Integrative taxonomic analyses, including phylogenomics (120 conserved proteins), 16S rRNA sequencing, and chemotaxonomy (e.g., MK-6 quinones, phosphatidylethanolamine lipids, and iso-C fatty acids), confirmed their novel status, with average amino acid identity (AAI), percentage of conserved proteins (POCP) distinguishing them from related taxa. Genomes (3.3-7.1 Mb; G + C 31.7-45.3%) revealed diverse polysaccharide utilization loci (PULs) targeting algal glycans like laminarin, alginate, and sulfated polymers (ulvan, chondroitin sulfate). 463 harbored the richest CAZyme/PUL repertoire (131 CAZymes, 15 PULs), while 4-911 lacked PULs, highlighting family-level specialization. This study expands the known diversity of core phycosphere , linking PUL evolution to habitat specialization. The novel species' distinct degradative capacities underscore their ecological roles in algal carbon processing and potential for biotechnological applications. Our integrated taxonomy-genomics approach advances understanding of microbial contributions to marine ecosystem dynamics.
与海洋大型藻类相关的微生物通过多糖降解在全球碳循环中发挥着关键作用，但其分类和功能多样性仍未得到充分研究。在这里，我们描述了从中国威海沿海地区大型藻类表面分离出的、、和科中的六个新物种（菌株3 - 376、4 - 2040、2 - 473A、4 - 528、4 - 911和463）。宏基因组读数招募和16S rRNA丰度分析表明了宿主特异性关联。综合分类分析，包括系统发育基因组学（120种保守蛋白）、16S rRNA测序和化学分类学（如MK - 6醌、磷脂酰乙醇胺脂质和异C脂肪酸），证实了它们的新物种地位，通过平均氨基酸同一性（AAI）、保守蛋白百分比（POCP）将它们与相关分类群区分开来。基因组（3.3 - 7.1 Mb；G + C 31.7 - 45.3%）显示出针对藻类聚糖（如海带多糖、藻酸盐和硫酸化聚合物（岩藻聚糖硫酸酯、硫酸软骨素））的多种多糖利用位点（PULs）。463拥有最丰富的碳水化合物活性酶/多糖利用位点库（131种碳水化合物活性酶，15个多糖利用位点），而4 - 911缺乏多糖利用位点，突出了科级别的特异性。这项研究扩展了核心藻际微生物群的已知多样性，将多糖利用位点的进化与栖息地特异性联系起来。这些新物种独特的降解能力突出了它们在藻类碳处理中的生态作用以及生物技术应用潜力。我们的综合分类 - 基因组学方法推进了对微生物对海洋生态系统动态贡献的理解。
