Bio-strategies

Museum scientists are investigating the different strategies that microorganisms follow to dissolve minerals and extract metal nutrients.

The results will provide important new information about the adaptation of microorganisms to the mineral environment where they live, and explore the dependency of plants on minerals made available by microbes.

Aims and background

Some metals are necessary for life, acting as micronutrients for plants and other organisms. These metals become accessible to the organisms when microbes produce exudates - organic chemicals discharged by cells to attack mineral grains and release metals into the surrounding environment.

We aim to determine whether microorganisms can produce different types and amounts of exudates depending on the chemical composition and resistance to dissolution of the mineral that they are attacking.

Whether plants can access dissolved metals depends on the strategy used by microorganisms to dissolve minerals. This strategy therefore determines whether or not the action of the microorganisms is immediately beneficial for the large community of living organisms. We aim to determine the amount of dissolved metals available to plants, and the specific route by which the plants take up the metals.

Methods

We are culturing one microscopic fungus and one bacterium - both frequently found in soil habitats - on pieces of various silicate minerals. These minerals have variable resistance to weathering and metal nutrient content.

The resulting waters will be used to culture liverworts - tiny plants - to determine whether the plants can access the metals that were released by the fungus and bacterium.