Experts. Valuable new Perspectives.

We highly value interactions with experts from different scientific areas in order to recieve valuable feedback on our project and to reflect on our own work as a student team. When focusing on one specific project for months one might lose sight of the big picture and gets lost in details. Input from experts from inside and outside of our own research was very inspiring and opened up fascinating new perspectives on our project. We discussed our project with multiple experts in order to obtain as much feedback concerning various aspects of our work as possible. We wish to express our gratitude towards Prof. Dr. Rainer Zawatzky for scientific input and safety concerns, TBM Edelmetal Recycling, a company in gold recycling for technical and economical input and Dr. Rackwitz from Peptide Specialties Laboratories GmbH for insight in chemical peptide synthesis and finally the Federal German Armed Forces for safety concerns.

Already in a very early phase of the project, we talked to Prof. Dr. Rainer Zawatzky, group leader and safety representative at the German Cancer Research Center (DKFZ) as well as deputy chairman of the regional office of the BUND (a German NGO for preservation of the environment). Our discussion focused on three topics: The impact of synthetic biology in general and our project in particular on the environment, synthetic biology as a risk-technology and finally sustainability, since we intend to provide an energy-efficient alternative to conventional gold-recycling.

We received valuable input concerning communicating our project and software to the general public. Prof. Zawatzky pointed out that possible concerns of society regarding our project should be negligible for the planning of our project. In his long experience as researcher, he often experienced anxiety of non-scientists towards his research as well as doubts regarding the effectiveness of advances in Human Practice. He emphasized that interactions with critical people may not lead to the anticipated outcome. However, we believe that it is in fact possible to address and to banish fears by engaging society in your work and by encouraging communication between science and the society.

We visited Peptide Specialties Laboratories GmbH, a leader in customized peptide synthesis established in Heidelberg. Managing director Dr. Hans-Richard Rackwitz gave us fascinating insight in chemical peptide synthesis in his company (a German video tour is availible on youtube), which is based on the merryfield synthesis using Fmoc chemistry.

One of Peptide Specialties Laboratories GmbH's “specialties” is the incorporation of many non-proteinogenic amino acids including D-conformations, phosphorylated monomers, DTPA- and DOTA-coupled amino acids as well as e.g. chloride and amid substitutions. Equipped with a range of synthesizers, they are able to produce 5 to 100 mg of peptides with a length of up to 75 amino acids within 2 to 3 weeks. In order to guarantee substantially 100 % purity of the final product, Peptide Specialty Laboratories performs extensive HPLC purification and MALDI-TOF analysis to provide the customer with sufficient informations about the product.

Dr. Rackwitz pointed out that most of the produced peptides are used for immunological studies; therefore, a minimal length of 8 amino acids should be achieved by NRPS synthesis to be commercially relevant. Furthermore, he told us that upscaling of chemical peptide synthesis up to tons as needed for clinical research is comparably easy. The challenge herein lies in fulfilling good manufacturing practices requirements, which also involve separate production lines to avoid cross-contamination. Since our NRPS peptides are currently expressed in vivo, this implies complex purification strategies. Alternatively, one could think of in vitro production using immobilized NRPS assembly lines, especially for the production of peptides with complex monomers that would be more expensive if synthesized chemically.

We wish to thank Dr. Rackwitz for an inspiring and insightful morning!

Since one aim of our project is improve the efficiency of gold-recycling, we concluded that we should gain a deeper understanding of the current methods to recover gold and discuss the potential of our approach to recycle gold with experts in this field. Hence, a delegation of our team visited a professional gold-recycling company TBM Edelmetall Recycling. We engaged in an interesting discussion with TBM's manager Dr. h.c. Thomas Müller and Ulrich Kohlmetz from the Berolina GmbH, who introduced us to the state-of-the-art process of gold recovery and its limitations.

In general, Dr. Müller explained to us, recycling is a stable business. In order to estimate feasibility of our project idea, we have to consider aspects like the cost structure of our company, the individual starting material, the capacity of our plants and finally the gold price at the international stock exchange. Dr. Müller and Mr. Kohlmetz also pointed out that the feasibility of new technologies is limited by the high investment, which is necessary to realize them compared to established methods, although these might be less cost- and energy-efficient.

Following dissolving of gold-containing waste in aqua regia, the two methods currently used for gold recovery are precipitation and electrolysis. Since electrolysis is a very time-consuming process, fractionated precipitation is preferred method.

Like many other furnace processes, metal recovery may cause severe environmental pollution when performed unwary. Additionally, the recovery of the dissolved gold from aqua regia is incomplete and the remaining solutions still contain low gold concentrations. Something Dr. Müller and Mr. Kohlmetz called our attention to is passivation: When dissolving alloys in aqua regia, the individual metals are dissolved with varying efficiency. This often leads to pieces of metal covered in silver-chloride, which can’t be dissolved and need to be crushed manually. Another issue we should consider is, that very large volumes of solutions e.g. for fluid flow, cleaning need to be handled and disposed of correctly. Concentration and composition of remaining metals in these solutions will affect applying regulations.

The advantage of gold recovery by Delftibactin is the efficiency also at low gold concentrations. Therefore, instead of offering an alternative strategy for gold recycling, we could apply our idea as extension of the existing methods, thereby increasing the overall efficiency. Both Dr. Müller and Mr. Kohlmetz were very interested in our project. They agreed to supply us with stripper solution, aqua regia containing electronic waste as well as galvanic rinsing solution to further evaluate the power of gold recovery by Delftibactin. We would like to express our gratitude for the exciting insight we received!

As we were also very interested in the feasibility of using in vivo NRPS expressing systems at an industrial scale for a variety of applications, we met with Dr. Raoul Haschke of the Heidelberg Technology Park UniTT Start-Up Centre. This initiative assists young researches as well as other university members in developing their start-up ideas and helps them make the transition to the free market.

Based on the example of a Delftibactin producing E. coli strain (see the Delftibactin project), which could be used for inexpensive gold recycling from electronic trash, we had a long and fruitful discussion. Dr. Haschke gave us a lot of of very helpful advice on financial aspects we should consider, which we then also used in our modelling. He also advised us to consider everything in a broader context: For example, assuming we have developed a process for recycling gold from industrial waste, we should think about what happens with the rest of the trash we cannot recycle using Delftibactin. Some of it, e.g. platinum or even the plastic would also be valuable, thus in an ideal case an industrial plant would be able to process all of these valuable resources. Finally, Dr. Haschke also explained to us which steps we should take for the creation of a start-up utilizing our ideas. We highly appreciate his input, which opened up new economical perspectives on our project!

Seeing safety concerns as one of the major issues in a Human Practice Advance, we wanted to gain a deeper knowledge of professional biosafety, in this case, defense against biological weapons. We arranged to take part in an open day at the ABC-defense regiment (i.e. atomic, biological and chemical weapon defense) organized by the Federal German Armed Forces. Especially the part about biological weapons was of interest for us, as many people we talked to pointed out safety concerns as one of their major fears regarding synthetic biology. Hence, we wanted to know, how experts in biosafety approach these issues. Read about our experiences here!

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