Biology subjects

Cordero, O.

Publications and source records attributed to Cordero, O..

3 recordsLinked to original sources

bioRxiv2025

A division of labor controls the degradation of fucoidans in the ocean

Fucoidans--complex polysaccharides produced by brown algae and diatoms--contribute to long-term carbon sequestration due to their resistance to microbial degradation1,2. While individual microbes can break down portions of these polymers3-5, it remains unclear whether complete breakdown is possible in nature and, if so, by what mechanisms. Here we show that fucoidans are degraded through synergistic interactions between specialized bacteria with conserved metabolic functions. Using metabolomic analysis of a reconstructed marine consortium, we uncovered functional guilds of bacteria that target either the sulfated fucose backbone or the side-branches of rare monomers. This division of labor leads to an unexpectedly high number of positive interactions between different degraders that enhanced degradation efficiency up to 97.1%. Despite variation in fucoidan structure across different types of algae, the metabolic functions of degraders remained conserved, enabling quantitative prediction of degradation outcomes based on community composition. Our findings suggest that the environmental turnover of complex macromolecules depends not only on individual metabolic capabilities but also on ecological interactions shaped by substrate architecture. This work provides a mechanistic framework for understanding carbon cycling in the ocean and for engineering synthetic microbial consortia to degrade recalcitrant polysaccharides.

microbiology↗

bioRxiv2023

Interspecies interactions determine growth dynamics of biopolymer degrading populations in microbial communities.

Microbial communities perform essential ecosystem functions such as the remineralization of organic carbon that exists as biopolymers. The first step in mineralization is performed by biopolymer degraders, which harbor enzymes that can break down polymers into constituent oligo- or monomeric forms. The released nutrients not only allow degraders to grow, but also promote growth of cells that either consume the breakdown products, i.e., exploiters, or consume metabolites released by the degraders, i.e., scavengers. It is currently not clear how such remineralizing communities assemble at the microscale - how interactions between the different guilds influence their growth and spatial distribution, and hence the development and dynamics of the community. Here we address this knowledge gap by studying marine microbial communities that grow on the abundant marine biopolymer alginate. We used batch growth assays and microfluidics coupled to time-lapse microscopy to quantitatively investigate growth and spatial distribution of single cells. We found that the presence of exploiters or scavengers alters the spatial distribution of degrader cells. In general, exploiters and scavengers - which we collectively refer to as consumer cells - slowed down the growth of degrader cells. In addition, coexistence with consumers altered the production of the extracellular enzymes that breakdown polymers by degrader cells. Our findings reveal that ecological interactions by non-degrading community members have a profound impact on the functions of microbial communities that remineralize carbon biopolymers in nature. ImportanceBiopolymers are the most abundant source of carbon on the planet and their breakdown by microbial degraders releases metabolic products that allow cross-feeding cells to grow and fuel the assembly of microbial communities. While it is known that the growth of degraders can facilitate growth of downstream cross-feeders in microbial communities, it has remained generally unclear if and how cross-feeders influence growth of degraders. Bridging this knowledge gap is important because degraders primarily drive the remineralization of carbon, a central process in the carbon cycle. We found that the presence cross-feeders can influence the growth of degraders by altering their spatial distribution as well as extracellular breakdown enzyme activity. Our study sheds light on the role of microbial interactions in shaping the rate of carbon remineralization in nature.

microbiology↗

bioRxiv2021

Wrack enhancement of post-hurricane vegetation and geomorphological recovery in a coastal dune

Coastal ecosystems such as sand dunes, mangrove forests, and salt marshes provide natural storm protection for vulnerable shorelines. At the same time, storms erode and redistribute biological materials among coastal systems via wrack. Yet how such cross-ecosystem subsidies affect post-storm recovery is not well understood. Here, we report an experimental investigation into the effect of storm wrack on eco-geomorphological recovery of a coastal embryo dune in north-eastern Florida, USA, following hurricane Irma. We contrasted replicated 100-m2 wrack-removal and unmanipulated (control) plots, measuring vegetation and geomorphological responses over 21 months. Relative to controls, grass cover was reduced 4-fold where diverse storm wrack, including seagrass rhizomes, seaweed, and wood, was removed. Wrack removal was also associated with a reduction in mean elevation, which persisted until the end of the experiment when removal plots had a 14% lower mean elevation compared to control plots. These results suggest that subsides of wrack re-distributed from other ecosystem types (e.g. seagrasses, macroalgae, uplands): i) enhances the growth of certain dune-building grasses; and ii) boosts the geomorphological recovery of coastal dunes. Our study also indicates that the practice of post-storm beach cleaning to remove wrack - a practice widespread outside of protected areas - may undermine the resilience of coastal dunes and their services.

ecology↗