Final Report Summary - MINEPEP (Establishing of a novel technology platform for bio-based mineral processing: Development of peptides as agents for the separation of rare earth minerals via bio-flotation) The MinePep project addresses the development of an innovative, clean process for the recovery of raw materials from primary and secondary sources. The overarching long-term project objective was the establishment of a technological platform allowing the target-orientated development of peptides for the specific separation of compounds from metallic resources such as ores or secondary sources. Another secondary long-term goal is the establishment of a biological tool kit for the selection and modification of biomolecules useful for bio-flotation processes. These bio-related objectives were achieved providing the basis for further development of separation processes.The outgoing phase (03/2015-02/2016) started in Vancouver, Canada at the University of British Columbia (UBC). The researcher was trained by highly experienced phage specialists in all kinds of techniques regarding phage surface display (PSD), inorganic material treatment and analyzing techniques. Specific objectives in the first phase of the project were the training on the PSD technique and the selection of special lamp phosphor specific binding peptides as a test case. Identified peptides were characterized with respect to their target specificity and affinity and their interaction with the target under varying conditions.The return phase (03/2016-02/2017) started in Dresden, Germany at the Helmholtz-Institute Freiberg for Resource Technology (HIF). Specific objectives in the second phase of the project were the smart peptide design and site-directed modifications for flotation applications. Second goal was the implementation of the PSD technique at the return host Helmholtz-Institute Freiberg for Resource Technology (HIF) and the dissemination of techniques and results. These objectives were achieved except the smart peptide design and site-directed modifications were started.a) Work carried out to achieve the project’s objectivesThe UBC laboratory was perfectly prepared for the scientist’s start and experiments began immediately. The researcher was trained in a wide range of material pretreatment techniques to avoid microbial contamination and nonspecific phage binding. The pretreatment of the inorganic target material was customized for use in PSD applications. The main goal in the first project period was to learn the PSD technique for the separation of inorganic compounds. The training included the use of two completely different phage clone libraries. The researcher is now prepared for the screening of different kinds of peptide libraries, working with different microbes and different infection techniques. Identified phage clones were amplified, sequenced, and analyzed in bio-panning experiments. Their binding affinity was compared to the binding of the wild type phage. The phage clones that showed the strongest binding to the target material were analyzed in additional experiments in order to further characterize their binding affinity and specificity. Phage clones with high selectivity were bound to the target and visualized by antibody labeling and fluorescence microscopy.During the second period of the project the researcher started the implementation of the PSD techniques in her team at HIF. The studies of six students, researchers and PhD students were influenced by the new techniques. The phage production with a stable peptide expression in the E. coli host strain was analyzed to develop reproducible binding tests. Peptides were genetically modified and expressed in E. coli to characterize their binding behavior to the target material. Results were published in peer-reviewed journals1,2, presented in oral presentations at conferences and to the general public and used as basic concept for the preparation of three individual project proposals. The project ideas have drawn attention of several industry partners. A new peptide library was used to identify CeMgA11O19:Tb (CAT) binding phage clones. Hereby, phage with extraordinary binding characteristics were identified. Using several spectroscopic (e.g. Attenuated Total Reflectance Infrared Spectroscopy (ATR-IR), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), Raman) and microscopic methods (e.g. He ion microscopy, Atomic Force Microscopy (AFM)) the researcher identified ATR-IR as suitable fast techniques for the identification of binding forces between peptide and inorganic material surface. These results are a preliminary investigation for future bio-flotation experiments. b) Main results, conclusions and their potential impact and use The researcher successfully applied 8 different phage peptide libraries and was able to implement the PSD technology in her team at HIF. Based on the acquired knowledge the researcher is able to identify the appropriate library for different targets. Together with students the researcher optimized PSD protocols and the phage peptide amplification. The identification of highly specific peptides for any target material is now possible and provides a basis for the new technology platform at HIF. During phage library screening the researcher identified two very good LaPO4:Ce,Tb (LAP) binders: FL 464 (100 times better LAP binding compared to the wild type phage) and FL 606 and four very good CAT binders. Alanine scanning experiments with FL 464 identified the most important amino acids for the target binding and improved the phage peptide binding via arginine and cysteine exchange by alanine (Figure 1). With these findings the researcher is able to optimize and regulate the peptide binding to individual materials in material mixtures. These result enable the application of phage peptides in bio-flotation processes to realize a stepwise separation and recycling of individual rare-earth containing fluorescent phosphors. The researcher published the results in 3 articles1,2,3 and presented the results in 2 external talks (ProcessNet, day of the open lab), and in discussions at the European Resources Forum and Biohydrometallurgy symposium. Subsequent to the project, results will be be presented at two conferences in talks in 2017 (Green and Sustainable Chemistry, International Biohydrometallurgy Symposium). Based on the generated MinePep results the researcher was motivated to develop new project ideas. The researcher applied for three different grants to develop an independent young investigators group and acquired the attention of five industry partners and many experienced scientists. The researcher applied for a patent based on the new project idea.c) Socio-economic impact of the projectThe PSD technique was successful in the identification of LAP and CAT binding peptides. In future projects these biomolecules will be applied in bio-flotation systems where they should reduce the contamination of the environment by toxic chemicals and increase the recycling of rare earth minerals and other important components of electronic scrap. With this novel biotechnological approach the recycling of rare earth components from electronic scrap should become economically worthwhile and the reduction in use of toxic chemicals for these tasks should give an equivalent reduction of toxic damage to the environment. The development of a technology platform for new recycling processes based on biomolecules is of high socio-economic impact and can be used for a high diversity of applications. The demand of metallic resources is growing regularly in Europe due to the fast development of high-tech products. To cover the need of raw materials, new and eco-friendly recycling technologies are important. The MinePep project and following projects will help to develop new recycling processes that are ecofriendly and guarantee the sustainable availability of resources. The new processes will increase recycling rates, reduce critical waste, will increase the efficiency of separation processes and avoids toxic chemicals. All these factors will lead to the development of a sustainable recycling economy. The MinePep project supported the researcher as a women in science and facilitated the beneficiary’s reintegration after her maternity leave. During the MinePep project the researcher was supervising four women and supported directly their scientific career. The researcher started the generation of a network of scientist and industry partners in Germany, Europe, Canada and South Africa. This network brings together people interested in the development of new recycling strategies and helps the researcher to generate an independent scientific career. 1 S. Curtis, F. L. Lederer, et al, Biotechnol. Bioeng., 2017. 2 F.L. Lederer, S.B. Curtis, et al, Biotechnol. Bioeng., 2017.3 F.L. Lederer, S.B. Curtis, et al, Chemie Ingenieur Technik., 2016. Documentos relacionados final1-minepep-finale-report-summary-17082017.docx
