Unlocking the hidden role of Algae in the plant rhizoSphere

Project Information

AlgaeSphere

Grant agreement ID: 101206630

DOI

10.3030/101206630

Project terminated on 26 October 2025

EC signature date 3 March 2025

Start date 1 April 2025

End date 31 March 2027

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 209 914,56

Coordinated by

UNIVERSIDAD DE CORDOBA
Spain

Periodic Reporting for period 1 - AlgaeSphere (Unlocking the hidden role of Algae in the plant rhizoSphere)

Reporting period: 2025-04-01 to 2027-03-31

Summary of the context and overall objectives of the project

Modern agriculture must increase productivity while reducing environmental impacts such as soil degradation and nutrient runoff. A major opportunity lies in improving plant health through the rhizosphere microbiome, the community of microorganisms living around plant roots. While research has mainly focused on bacteria and fungi, recent evidence indicates that microalgae are also common members of plant-associated microbiomes and may enhance plant growth and resilience. However, the ecological roles of algae in root microbial communities remain poorly understood.

The AlgaeSphere project aimed to uncover how algae interact with bacteria in the plant rhizosphere and how these interactions could be harnessed to support sustainable agriculture. The project pathway to impact was based on (i) identifying and isolating algae associated with crop roots, (ii) evaluating their influence on plant growth and microbial community structure, and (iii) using this knowledge to enable the design of stable algal-bacterial communities with potential biotechnological applications. Ultimately, AlgaeSphere contributes to the long-term development of microbial solutions that may reduce fertiliser dependence and support environmentally friendly crop production.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the implemented period (7 months), AlgaeSphere successfully carried out key foundational activities. A major field sampling campaign was organized in collaboration with local stakeholders, resulting in the collection of rice plants and associated rhizosphere material. These samples enabled the establishment of a controlled laboratory microcosm system to test the effect of algal inoculation on rice seedlings under reproducible conditions.

The project generated two valuable biological resources: (1) a collection of approximately 50 axenic algal isolates representing diverse morphotypes, and (2) a large rhizosphere bacterial isolate library built using high-throughput community-based culturing approaches. In parallel, experimental workflows were optimized for algal isolation, DNA extraction, sample preservation, and plant phenotyping. Microcosm endpoint samples were stored for future sequencing-based analysis of microbial community composition.

Although the fellowship ended early due to the researcher’s recruitment into a permanent academic position at the host institution, the work performed established the experimental and biological foundation needed to complete the remaining analyses and develop synthetic algal–bacterial communities in follow-up research.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

AlgaeSphere advances the state of the art by treating microalgae as active and relevant members of plant microbiomes rather than as external inputs or fertilizer additives. The creation of curated algal and bacterial isolate libraries from rice rhizosphere environments provides a valuable platform for future research on microbial interactions, synthetic community design, and sustainable biofertilization strategies.

While sequencing-based community analyses and downstream validation were not completed within the shortened funded period, the project outputs already enable further progress toward applied innovations. Key needs for uptake include completing metabarcoding datasets, identifying algal isolates at species level, experimentally testing strain compatibility and stability in co-culture, and validating plant-growth effects at larger scale. These steps can support the future development of microbial consortia that contribute to reduced agricultural inputs, improved soil health, and novel biotechnological applications.