Department of Chemical Engineering

Bioprocessing Research Unit

 

Contact

Director: Dr Marianne Ellis
Emailm.j.ellis@bath.ac.uk
Tel: +44 (0) 1225 384484

 

Our research harnesses the power of biology to address global challenges in food, fuel and healthcare. We work closely with end users from clinicians, food and drinks companies to aeroplane manufacturers. We ensure our state-of-the-art technologies meet their needs whilst benefiting the environment by enabling the transition to a circular economy. Our core themes are:

The explosion of biological research and discovery is giving rise to a new generation of biologically based products and processes in biotechnology and medicine.

To make full use of this new biology, biochemical and biomedical engineers must translate the basic science into practical technology that can be widely used.

The Bioprocessing Research Unit carries out interdisciplinary research at the interface between biology, chemistry and chemical engineering.

In detail

Regenerating human cells to repair tissue

We are developing methods of growing human cells and tissues outside the body to repair or replace damaged tissues. After implantation, the new tissues should integrate into the human body and carry out their natural function.

Our research focuses on the regeneration of cartilage, bone and blood vessels, through cultivating the composite cells on both natural and synthetic polymers.

Complex three-dimensional tissue structures are reconstituted in purpose-designed bioreactor systems. The bioreactor allows careful control of the environmental conditions to optimise the growth of each cell type and its position in the overall structure. Controlling the growth and proliferation of the cells should lead to enhanced tissue properties that deliver the required performance when integrated into the surrounding tissue.

Creating smart biomaterials for medicine and sport

We are working on the development of "smart" biological membranes that can interact with their environment. Self-assembling biological structures and polymers that respond to their environment offer a wide range of interesting opportunities. One use is in coatings for therapeutic agents that can be inserted in the body to release a drug or other active agent in response to the patient's state. For example, by monitoring blood sugar levels and releasing a controlled flow of insulin in response.

A second use is as self-repairing biocompatible surfaces for coating replacement joints, other prosthetics and medical devices used in invasive treatments.

Smart polymer systems can also be used as fabrics for the production of clothing that responds to the state of the person wearing it. This has applications in sport, medicine and survival in extreme environments.

Developing clean technologies for industrial application

Our research explores the application of supercritical fluids to produce defined coatings on pharmaceutical products. The aim is to produce a "clean technology" process for pharmaceutical industries. It will replace existing processes that currently use solvents, both chlorinated and non-chlorinated, which are harmful to the environment.

We are exploring the recovery of the products of fermentation and biotransformation processes.

We are developing functionalised fluid polymers based on inorganic polymers. We are assessing their use as supported liquid membranes for selective separation and extraction. By exploiting affinity interactions, based on a ligand tentacle approach, we are developing an alternative to conventional chromatography resins.

Our work covers two aspects of design and development:

  • synthesis and characterisation of polymer supported ligands,
  • synthesis of tentacle resins.

We have extended this research into the separation of different cell types. These include:

  • Separation of malignant from healthy cells
  • Isolation of specific mutants during strain development
  • Selective removal of contaminants during extended fermentor operation.

Producing therapeutic quantities of substances such as human growth hormone and insulin can be time-consuming and expensive. This is because recombinant micro-organisms generally produce proteins which are inactive.

Activity can be regained through a series of steps known as protein refolding, but it is a slow and low-yielding process. We have recently explored the use of mathematical models to optimise refolding reactor operation, reversed micelles, use of the chaperones for in vitro refolding, and the use of hollow-fibre ultrafiltration membranes to minimise protein aggregation.

The use of gel filtration matrices to carry out refolding has proved particularly successful. This technique allows the protein to be refolded at high concentration, minimises aggregation and purifies the product in a single operation.

Using extremophile organisms in the treatment of industrial effluents

Organisms have evolved to live in almost every environment on Earth, even the most extreme, such as hot sulphur springs, volcanic vents and the salt-laden Dead Sea.

Most enzymes from mesophilic (or "conventional") organisms will denature and lose their biological activity above 45°C, at pH values outside the range 5 to 8, or in non-aqueous solvents. Extremophiles, which are generally micro-organisms, have adapted to live outside these confines. The cells and their constituents are extremely stable, and offer considerable biotechnological potential.These extremophiles open up new opportunities for the exploitation of living organisms and their components to create industrial products and processes, with the clear advantage of clean, efficient and safe technology.

Many effluents resulting from the synthesis of industrial chemicals are not treatable by conventional biological methods. They are currently treated using expensive and environmentally questionable technologies such as incineration.

We can use the ability of extremophile organisms to survive in "difficult" environments to develop new biological solutions for these problems.

We are working on techniques for the hybridisation of organisms to give them the ability to handle wastes containing mixtures of compounds that in combination pose particular challenges. We are also developing novel membrane bioreactors for accelerated culture evolution.