Mechanisms of recalcitrant fucoidan breakdown in marine Planctomycetota
Marine brown algae produce the highly recalcitrant polysaccharide fucoidan, contributing to long-term oceanic carbon storage and climate regulation. Fucoidan is degraded by specialized heterotrophic bacteria, which promote ecosystem function and global carbon turnover using largely uncharacterized mechanisms. Here, we isolate and study two Planctomycetota strains from the microbiome associated with the alga Fucus spiralis, which grow efficiently on chemically diverse fucoidans. One of the strains appears to internalize the polymer, while the other strain degrades it extracellularly. Multi-omic approaches show that fucoidan breakdown is mediated by the expression of divergent polysaccharide utilization loci, and endo-fucanases of family GH168 are strongly upregulated during fucoidan digestion. Enzymatic assays and structural biology studies reveal how GH168 endo-fucanases degrade various fucoidan cores from brown algae, assisted by auxiliary hydrolytic enzymes. Overall, our results provide insights into fucoidan processing mechanisms in macroalgal-associated bacteria.
Authors
- F.‐Xabier Contreras (ORCID: https://orcid.org/0000-0003-0875-634X)
- Oihana Terrones (ORCID: https://orcid.org/0000-0001-7421-6486)
- Carla Pérez-Cruz
- Alicia Moraleda-Montoya
- José Luis Chiara (ORCID: https://orcid.org/0000-0002-8153-1852)
- Jon Ander Nieto‐Garai (ORCID: https://orcid.org/0000-0002-8665-099X)
- Enrique Mann (ORCID: https://orcid.org/0000-0002-2050-4295)
- Beatriz Trastoy (ORCID: https://orcid.org/0000-0002-2178-732X)
- Marcelo E. Guerin (ORCID: https://orcid.org/0000-0001-9524-3184)
- June Olazar‐Intxausti (ORCID: https://orcid.org/0000-0003-0568-1119)
- Laura Alonso‐Sáez (ORCID: https://orcid.org/0000-0003-1757-4767)
- Isabel García‐Álvarez (ORCID: https://orcid.org/0000-0002-2273-5046)
- Maier Lorizate (ORCID: https://orcid.org/0000-0001-8173-2788)
- Mikel García-Alija (ORCID: https://orcid.org/0000-0002-8805-1325)
- Ana Martínez Gascueña (ORCID: https://orcid.org/0000-0002-6245-5823)
- Raquel Liébana (ORCID: https://orcid.org/0000-0002-2196-5632)
- Bárbara Rodríguez-Colinas
- Uxue Arrizabalaga
Institutions
- Ikerbasque (ES)
- Consejo Superior de Investigaciones Científicas (ES)
- University of the Basque Country (ES)
- Universidad Francisco de Vitoria (ES)
- BioCruces Health research Institute (ES)
- AZTI (ES)
- Instituto Biofisika (ES)
- Institute of Structural and Molecular Biology (GB)
- Instituto de Química Orgánica General (ES)
- Institut de Biologia Molecular de Barcelona (ES)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-12-30
- DOI
- https://doi.org/10.1038/s41467-024-55268-w
- Citations
- 21
- Primary Topic
- Seaweed-derived Bioactive Compounds
- Type
- article
- Field-Weighted Citation Impact
- 11.96
Funders
- “la Caixa” Foundation
- Diamond Light Source
- European Commission
- Eusko Jaurlaritza
- Ministerio de Economía y Competitividad
- Euskal Herriko Unibertsitatea
- Ministerio de Ciencia e Innovación
- European Regional Development Fund