ABC: use of Azolla for Biomining of heavy metals towards a Circular bioeconomy

Azolla is a small floating fern which grows vigorously due to its highly adaptable nature and symbiotic relationship with a nitrogen-fixing cyanobacteria. Azolla has an interesting root system, which can be discarded and regrown to suit a changing aquatic environment. This allows the plant to adapt to water contaminated with heavy metals, and provides a route towards exploiting this for repurposing Azolla into a biological biomining agent.
Each year, Europe produces an estimated 200,000 tonnes of spent consumer batteries. In addition to being a significant source of waste, these batteries also contain high levels percentage of hazardous heavy metals. To improve the sustainable use of batteries, conserve natural resources, and minimize environmental degradation, novel biotechnology routes towards heavy metal biomining are required.

The aim of this proposal is to discover the structure-function responsible for incorporating heavy metals into the cell walls of a plant. Polysaccharides are not assembled via a template-based system such as nucleic acids and proteins. Instead glycans are assembled using a suits of carbohydrate active enzymes which in combination to assemble polysaccharide structures. This project will build upon the research excellence into glycans within the centre for glycosciences at the Keele university.
This will be supported by a holistic study into the physiological, transcriptional, proteomic, and metabolic changes of Azolla grown in various heavy metals. This will reveal the molecular processes required for the selective integration of heavy metals into the cell wall. These enzymes will then be characterised in vitro for their functionality and specificity. Furthermore, they will be used to generate semi-synthetic biomaterials which can be test for functionality in places were using the living Azolla as a biomining agent would not be possible.
This project utilises pre-established techniques and protocols in the lab, which will allow a rapid progression of the project without additional input. We have established links with two UK-based industrial partners, who are keen to support this project. Technologies developed within this project have a clear route toward deployment via biologically aided bioremediation projects, and development of novel biomaterials. A clear demonstrator for the use of Azolla in managing heavy metals in aquatic environments would allow us to approach potential stakeholders for use in implementing the biotechnology developed in this project.