Ecological and Evolutionary Importance of Molecular Diversity in Dissolved Organic Matter

Project Information

sEEIngDOM

Grant agreement ID: 804673

DOI

10.3030/804673

Project closed

EC signature date 1 October 2018

Start date 1 February 2019

End date 31 May 2026

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 499 169,00

EU contribution

€ 1 499 169,00

Coordinated by

CARL VON OSSIETZKY UNIVERSITAET OLDENBURG
Germany

Periodic Reporting for period 5 - sEEIngDOM (Ecological and Evolutionary Importance of Molecular Diversity in Dissolved Organic Matter)

Reporting period: 2024-05-01 to 2025-12-31

Summary of the context and overall objectives of the project

Dissolved organic matter is central to the functioning of lakes and rivers that support life on Earth, such as by providing clean drinking water and sequestrating carbon dioxide from the atmosphere. Despite this importance, dissolved organic matter remains poorly understood because it has been measured with little resolution for nearly 200 years. Recent technological advances have shown that what we call dissolved organic matter is actually a mixture of thousands of unique chemical compounds of varying origin and composition, but the role of all these different molecules largely remains a mystery.

This project is discovering how the tremendous diversity of molecules found in dissolved organic matter matters for the function of lakes and human well-being. Our main objectives are to understand how dissolved organic matter is created by microbes and generate models to predict how it influences the benefits that freshwaters deliver to people. The outcomes of this work will deliver better predictions and tools to manage freshwaters and drinking water supplies.

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

This project has made two main achievements so far. The first has been to understand better how dissolved organic matter and microbes vary over large geographic areas. In 2019, we sampled 152 lakes from southern Italy and Croatia to northern Norway, spanning 30° of latitude. This is the largest lake survey every undertaken by a single research group, to our knowledge. We have discovered that the function of lakes varies with the diversity of molecules in dissolved organic matter and we are now analysing the role of microbes in generate this molecular diversity.

We also took advantage of our lake survey to sample microplastic pollution. We have discovered that pollution from microplastics and anthropogenic fibres can be entirely predicted from surrounding land use and in-lake water quality. Our efforts will help inform pollution control and remediation efforts.

The second main achievement has been to start an experiment where we will understand how microbes adapt and evolve to use different types of dissolved organic matter. The outcomes of this study has the long-term potential to improve drinking water treatment. We have cultured bacteria isolated from the natural environment and concentrated thousands of litres of lake water to purify dissolved organic matter. We are now growing the bacteria for thousands of generations on a novel media supplemented with the dissolved organic matter purified from lakes with different characteristics.

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)

Our work so far has advanced the state of the art in two major ways. First, there remains only one real test of how the diversity of chemical molecules in dissolved organic matter influences how lakes function. This past study involved an experiment within small containers submerged in two Canadian lakes. We have now detected an association between diversity and function across all of Europe and discovered that this association is stronger than the effect on ecosystem function typically ascribed to biodiversity. Second, we have explained how variation in the diversity of dissolved organic matter arises. These findings should change the way we think about the role of organic matter in nature and how it supports the benefits that ecosystems deliver to people.

The second half of this ERC project will delve into the mechanisms by which chemical diversity is created and how microorganisms adapt and evolve in response to it. We will use innovative lab and field experiments and expect to create fundamental knowledge that can ultimately benefit land management and drinking water treatment. We will also discover how chemical diversity in dissolved organic matter varies temporally. We have established a global network of 70 sites on every major continent where collaborators are collecting water monthly from Jan to Dec 2021 for our laboratory to analyse. This unprecedented analysis will track the ‘pulse’ of dissolved organic matter worldwide as it changes with the seasons.

Group with Dr Frank Yang