Research

Background

In many of the worlds oceans, currents carry debris and pollution originating from coastlines. This waste accumulates in regional gyres, where the worlds ocean currents meet, and can reach extremely high concentrations. Plastic is estimated to account for 60-80% of this debris, and is known to be gradually broken down by solar energy and the mechanic action of the sea. This means the majority of the plastic waste are several millimetres in size or less, which has made efforts to clean them from the ocean largely unsuccessful. These tiny plastic fragments, microplastics enter the digestive systems of resident organism, which are affected either by the physical size of the plastic or its toxicity from adsorbing organic pollutants.

Aim

Our team came up with three modules that aim to solve the micro-plastic pollution in the marine environment. We are engineering bacteria to be able to detect and aggregate micro-plastics into larger pieces to facilitate removal.
For the micro-plastics that cannot be aggregated we have an alternative approach which is to degrade the micro-plastics.
We are pursuing these as three separate modules which we will assemble once we have tested their competence.

Detection Module

Receptors based detection is a first step for both aggregation and degradation. The main receptor is human oestrogen receptor that binds to different types of micro-plastics.

Aggregation Module

In the case of aggregation, receptors on bacteria detect micro-plastics and induce the production of sticky extensions of cell membrane. First this allows bacteria stick to the plastics and once covered in bacteria allows micro-plastics to stick to one another.

Degredation Module

The degradation module, which is separate from aggregation module, also comes after receptor detection. This system metabolizes the micro-plastics and their derivatives that are otherwise toxic to the environment. As a result of degradation these materials are converted into non-toxic ones.