Microbial interactions driven by organic and inorganic metabolic exchange and their role in present and future biogeochemical cycles

Introduction

Many biogeochemical processes, such as carbon cycling in marine ecosystems, are driven by interactions between micro-algae and bacteria. Global warming changes our oceans, impacts algal-bacterial interactions, and affects the processes these interactions propel. If we are to find ways to ameliorate the effects of global warming, we need to understand the molecular mechanisms that mediate these key algal-bacterial interactions and integrate this knowledge into a biogeochemical context.

Challenges in Studying Interactions

A major challenge in studying these interactions, often mediated by secreted metabolites, is their complexity in nature. Therefore, we established ecologically relevant model systems with tunable complexities, including:

• Algal-bacterial co-cultures
• Genetically tractable synthetic communities
• Mini-cosms

These systems allow us to monitor and manipulate algae, bacteria, and their environment.

Research Objectives

We will combine microbiology and Earth sciences approaches to generate a blueprint of metabolic circuits that shape the algal-bacterial-environmental interaction landscape. Specifically, we will study:

1. The organic and inorganic secreted metabolome of algae and bacteria.
2. The physiological response of algae and bacteria to specific organic and inorganic metabolites, and the metabolic circuitry connecting algae, bacteria, and the marine environment.
3. The influence of climate change on algal-bacterial-environmental interactions, gaining insight into how key players in the ocean will likely respond to future climate.

Implications of the Research

Unveiling mechanisms of microbial interactions under various environmental conditions allows us to understand how future climate will impact these interactions and the processes they drive. Our interdisciplinary research offers a novel framework for studying the role of microbial interactions in biogeochemical cycling. It will contribute to improved climate change models and will provide valuable data for ocean stewardship policymakers.