Team Ashesi are aiming to harness synbio to increase the precision, and therefore sustainability, of gold mining.

Our collaboration was initiated on July 20th 2022, with a meeting to discuss the overview of our respective projects and identify potential areas for cooperation. With team members possessing a wealth of experience with 3D CAD modelling, Team Ashesi offered to troubleshoot any potential issues surrounding the 3D printing of our bionic hand, designed to illustrate the utility of our silk-rGO composite material in tendon reconstruction and reinforcement. In turn, Team Exeter offered to provide assistance with modelling of the genetic circuitry designed by Team Ashesi. Over the course of August, both teams worked on troubleshooting the other’s project.

Figure 1 - The initial meeting between Team Exeter and Team Ashesi Ghana on 20/7/2022

Team Ashesi are using E. coli to detect both the presence of Au²⁺ ions directly in the soil, or the presence of iron and arsenic ions, commonly found co-located in the soil with gold ions, trapped in sulphur-containing complexes. Therefore, the team devised genetic circuits, designed to produce visible amounts of a coloured reporter protein in the presence of these marker ions. The team was interested in modelling the necessary input ion concentration to generate a visible change in the concentration of the reporter protein, to determine the viability of the system as an in-field detection kit.

Team Ashesi provided Matthew with preliminary SimBiology files for 2 genetic circuits designed to report the presence of gold and iron ions respectively, as well as schematics for the mode of action of these circuits. In turn, Matthew derived the sets of differential equations underpinning the planned metal ion detection, modelling transcription, translation and mRNA and protein degradation using elementary kinetics. The Hill equation was used to model the proportion of the inducible promoter region which the coloured reporter protein of each circuit is under the control of. The details of the genetic circuit and differential equations are outlined in the figure below. Matthew then translated these sets of equations into SimBiology models and met with Team Ashesi to discuss his work on August 19th 2022.

Figure 2 - Schematic showing the genetic circuit devised by Team Ashesi Ghana to detect gold ions, and the differential equations derived by Matthew to model it

In this meeting, Matthew explained the equations underpinning the gold-sensing module and illustrated the behaviour of the model in SimBiology using the model analyser function. He used a preliminary set of input values for rate constants (modelling transcription and translation rate constants as a function of construct length, and degradation rate constant of mRNA as an order of magnitude greater than that for protein). In order to better explain how to formulate such equations, Matthew then derived the corresponding set of equations for the iron-sensing module in the meeting. Using the knowledge gained in this meeting, Team Ashesi then devised an equivalent model for the arsenic-sensing module, which was verified by Matthew.

During the development of genetic circuitry models for Team Ashesi, Matthew gained invaluable knowledge on how to model control of protein expression using inducible promoters, as well as how to model degradation processes, allowing a modelled system to reach a long-term steady state. Matthew then applied this experience of modelling degradation to refine Team Exeter’s model of MaSp synthesis with differential gene expression of CycA and alanine tRNA (overexpression). Moreover, during this time period, Matthew met with Professor Ozgur Akman (Associate Professor of Mathematics for Biology and Medicine and member of the Living Systems Mathematics group) and discussed the validity of the models thus far developed. Matthew gained valuable insights into the importance of modelling degradation to bound protein production over time. Professor Akman also emphasised the importance of reducing a system to its simplest possible form for modelling and seeking the least complicated mathematical formulation which can accurately capture the behaviour of the biological system modelled.

Team Ashesi was incredibly helpful in terms of compensating for our lack of engineers in our team. We sent them a CAD model of the prototype of our bionic hand. We are grateful to the engineering team for their troubleshooting, which included animation and motion studies and ensured that our prototype would work as expected.

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Over the course of our podcast's production, we collaborated with four other iGEM teams during this 6 episode series. Throughout the creation of each episode we mentored all involved teams in the technical aspects of recording. Predominantly, this entailed talking teams through the required software and microphone set ups to ensure optimum sound quality. In turn, our guests prepared relevant material ahead of recording sessions, specific to the discussion topic we had selected. The knowledge afforded by their research enabled our podcasts to be interesting and deeply informative. Additionally, the manner in which these teams presented their projects was really helpful for us in determining how to strike the balance between being concise as well as detailed and engaging. From all teams we took communication inspiration, and this will be invaluable for shaping the manner in which we present our own project going forward.

KU Leuven

Inspired by KU Leuven’s project addressing the various barriers that exist to scientists internationally, we invited them to share some of the stories they had collected. In this episode, devoted to all things inclusivity, we discussed the difficulties of African Americans, women, and persons with disabilities in STEM and how we can look to alleviate these issues in the future. This international collaboration was invaluable in helping us to understand just how barriers to STEM vary across the world.

Sheffield

The University of Sheffield team were extremely enthusiastic participants and their insights and humour helped to create a fun and engaging episode. This included a description of ‘a day in the life’ as a scientist as well as an insight into their project surrounding directional evolution.

Vienna

The University of Vienna team collaborated with us on an episode where they gave an in-depth and fascinating insight into their biobrick project and its potential applications in the reduction of global carbon emissions.

Bath

The University of Bath’s team joined us to discuss their project in phosphorus bioremediation of wastewater and sustainable fertiliser production. They gave a fantastic insight into what it’s like for a new iGEM team and educated wonderfully on the direct environmental impact synthetic biology can provide in an eloquent way.

More details into the specific content of each episode can be found on our education page.