Successful theses
The Bachelor's or Master's thesis is the final step in which you, as a student, show that you can successfully implement the study content - practically as well as theoretically. This provides the basis for the next steps of your professional career in science or business.
The final theses at Faculty of Chemistry and Biotechnology are usually closely related to larger-scale research projects or are carried out together with other research institutions or companies from industry. This means that the final thesis is also part of current innovative research and development. As a university of applied sciences, we are particularly interested in application-oriented topics.
This results in a broad spectrum of research and development focuses. This enables you to tie in with your own interests and specialise in them - without losing the overall view. Contribute your potential in the best possible way!
We as a faculty are proud of our graduates and are pleased to be able to give you a small insight here into the variety of final theses in the fields of biotechnology, chemistry, nuclear chemistry and polymer sciences at the FH Aachen University of Applied Sciences.
Some examples of final theses
Spectroscopic characterization of Aloe Vera extracts
Bachelor thesis (Applied Chemistry) by Franziska Block
Franziska Block completed her bachelor thesis with us on the topic of "Spectroscopic characterization of Aloe Vera extracts". The aim of her work was the simultaneous cost-effective quantification (multicomponent analysis) of organic acids and sugars from freeze-dried aloe vera samples. For this purpose, she applied two different spectroscopy methods - UV-VIS and NMR spectroscopy. For the latter method, the aim was to perform and adapt a method established on high-field (500 MHz) spectrometers on a less expensive 80 MHz benchtop. Overall, the work has shown that multicomponent analyses on benchtop spectrometers are quite successful for many sample substances. This method is a handy (compared to a 500 MHz high-field spectrometer), cost-effective alternative suitable for smaller laboratories. For certain constituents of aloe vera, the reference measurements of the established method could be reproduced. Other components, however, cannot be easily quantified on the 80 MHz spectrometer. However, this provides interesting aspects for subsequent work: An evaluation of the spectra by means of multivariate analysis could enable a quantitative determination of all important components. The same applies to the UV-VIS investigations.
The FH Aachen would like to thank Ms Block for her commitment and wishes her all the best for the future.
Supervisor of the thesis: Prof. Dr. Yulia Monakhova
Determination of sugars and organic acids in aloe vera extracts by HPLC
Bachelor thesis (Applied Chemistry) by Alexander May
The bachelor thesis of Alexander May entitled "Determination of sugars and organic acids in aloe vera extracts by means of HPLC" was carried out at FB 3 in the laboratory "Instrumental Analytics". Ingredients - sugars and organic acids - were to be determined by means of HPLC with UV detection. By varying different analysis parameters, a method was to be developed that was tested for reproducibility and robustness. An important result of this work was the comparison between two HPLC columns on which the different substances were selectively separated from each other and detected. A suitable column was found on which the sugars and acids contained in the plant could be detected simultaneously by UV. The methodology can help in the quality control of aloe vera products as well as various plant extracts, e.g. in food analysis. In the future, in addition to further refining the measurement parameters, the sample preparation will also be optimised - this will help to improve the difficult determination of sugars. In addition, the investigation of other components, such as minerals, is to be taken into account in this analysis in the future.
The FH Aachen thanks Mr May for his cooperation and wishes him continued success and all the best for the future!
Supervisor of the thesis: Prof. Dr. Yulia Monakhova
Creation and optimisation of a buffer system for PEG-based nucleic acid purification using chemagen products
Master's thesis (biotechnology) by Julian Breuer
Genetic engineering work has become an integral part of various industrial processes. Whether in waste management, agriculture or medicine, work with and on DNA is diverse and ecologically as well as economically promising. In order to be able to work genetically, DNA is of course needed. And to isolate it, there are different methods and procedures, depending on the organism from which it is to be isolated.
Mr Julian Breuer from FH Aachen also wrote his Master's thesis on this topic. In cooperation with PerkinElmer chemagen Technologie GmbH, he examined the established buffer system for the extraction of DNA from blood and optimised it according to various parameters, such as yield, purity, DNA fragment length or runtime of the isolation.
For this purpose, the buffer components were modelled with the help of a statistical data processing programme, the optimal components were determined and used according to the resulting model. Thus, various buffer systems were created and further experimentally investigated and optimised with regard to the yield and purity of the extracted DNA.
Julian Breuer
Mr Breuer was able to show that a PEG-based buffer system (polyethylene glycol) in combination with the chemagic™ 360 extraction unit is able to exceed the yields of other extraction systems without negatively affecting the purity or fragment lengths of the DNA obtained. PEG is a liquid or solid, water-soluble and non-toxic polymer that is used, for example, as a binder in pharmaceuticals and cosmetics, but also plays a role in archaeological conservation.
Mr Breuer's work has made a significant contribution towards a new, competitive DNA extraction system. Until then, however, further investigations are necessary, e.g. to determine the influence of the sample material.
The FH Aachen would like to thank PerkinElmer chemagen Technologie GmbH and especially Mr. Breuers for their cooperation and wishes them a successful future and all the best.
Supervisor of the thesis: Prof. Dr. Johannes Bongaerts
Development of a data basis for the taxonomic differentiation of the three subspecies of Streptococcus equi
Bachelor thesis (biotechnology) by Ina Li
The identification of bacteria is of great importance, especially in medicine. Depending on which pathogenic, i.e. "disease-causing", bacteria trigger an infection, different therapies have to be applied. Accordingly, scientists all over the world are looking for ways to clearly identify bacteria.
However, the small size, huge diversity and sometimes minute differences of bacteria make it almost impossible to accurately identify individual species and subspecies by morphological criteria. Therefore, bacteria are mainly distinguished and assigned to a species on the basis of genetic characteristics and their metabolic pathways. A skilful selection of tests, through the combination of the different results, then enables an exact identification of the bacterium.
In cooperation with the National Reference Centre for Streptococci at the University Hospital Aachen, Ms. Ina Li from the FH Aachen University of Applied Sciences worked in her bachelor thesis on a way to distinguish between the three subspecies equi, zooepidemicus and ruminatorum of the bacterium Streptococcus equi.
Streptococcus equi subsp. equi is, as the name suggests, primarily found in horses and other ruminants and causes so-called druse in them. This is an extremely contagious respiratory tract infection which, if left untreated, can pose a danger to the animals, but also to weakened humans. A clear identification of the pathogen is therefore indispensable for the selection of the right therapy.
First of all, Ms Li investigated the relationships between the subspecies on the basis of certain genes. However, it turned out that this investigation was not sufficient to distinguish the subspecies. Ms Li therefore developed a combination of genetic, microbiological and metabolic tests that can reliably identify at least the equi subspecies. The differentiation of the other two subspecies, however, remains a challenge.
The FH Aachen thanks all those involved, especially Ms Li, for their cooperation and wishes all the best for the future and much success.
Supervisor of the thesis: Prof. Dr. Johannes Bongaerts
Construction and expression of a minimal phosphonate biosynthetic gene cluster and investigation of phosphonate biosynthesis in Kitasatospora TÜ4103
Master's thesis (biotechnology) by Mattis Irle
What do we do when bacteria appear against which our common antibiotics no longer have any effect?
Mattis Irle will probably have asked himself this question and, in his Master's thesis in cooperation with the TU Braunschweig and the Deutsche Sammlung für Mikroorganismen und Zellkulturen GmbH, investigated a largely unexplored antibiotic from the class of phosphonate antibiotics.
To do this, he cultivated the actinomycete Kitasatospora sp., which was only recently discovered to produce an antibiotically active phosphonate. Mr Irle then constructed a so-called "minimal phosphonate biosynthesis gene cluster" (mBGC), i.e. a gene sequence that carries the information for certain key enzymes of phosphonate precursor production. He then introduced this into Kitasatospora sp. and stimulated an increased reading of these genes, a so-called overexpression.
Subsequently, it could be proven that the overexpression of the mBGC leads, as hoped, to an increase in phosphonate production. In addition, Mr Irle's work provides the basis for a scaled production of the phosphonate antibiotic using Kitasatospora sp. in the bioreactor, making the analysis of the substance more accessible to subsequent researchers.
It was also surprising that Kitasatospora sp. apparently produces another antibiotically active substance, which, however, has yet to be identified.
The FH Aachen thanks Mr Irle for his cooperation and wishes him continued success and all the best for the future!
Supervisor:s of the thesis:Prof. Dr. Bongaerts
Analysis of the integration sites for high and stable expression in CAP® cells
Bachelor thesis (biotechnology) by Timon Rausch
FH Aachen | Victor Messerschmidt
II Integrating viral factors (green) at a suitable location in the genome can increase virus production.
In recent years, viruses have played an unusually large role. The pandemic emphatically showed that research into viral infections and viruses is and remains a central challenge for medicine.
On the other hand, viruses can also be very useful. For example, they serve as so-called gene ferries in gene therapy. Here, the natural behaviour of viruses is used to smuggle their DNA first into the cell and then into its genome. The cells are thus given the opportunity to repair a genetic defect, for example.
For such gene therapies, however, larger quantities of viruses are needed, which must first be produced in insect or mammalian cells. And this is where Timon Rausch started his research. He set himself the goal of looking for places in the human genome where an introduced viral DNA can be particularly effective and form as many viral copies as possible.
What sounds slightly like the plan of a Bond villain is of great importance for virology. Thus, based on Mr. Rausch's results, virus production in human cells can be increased and made more efficient, thus simplifying research with (human pathogenic) viruses worldwide.
The FH Aachen would like to thank Mr Rausch for his commitment and wishes him all the best for the future.
Supervisor:s of the thesis:Prof. Dr. Jost Seibler
The all-or-nothing response of mast cells at the single cell level after activation by FcεRI
Bachelor thesis (biotechnology) by Julia Dickmeis
RWTH Aachen | EME
Right: Microscopic image of a degranulating mast cell. The opening granules, which release their contents into the environment, can be seen.
In the course of her bachelor's thesis at the Institute of Biochemistry and Molecular Immunology at RWTH Aachen University, Julia Dickmeis researched the reaction of mast cells when they were stimulated via a special receptor (FcεRI), as is the case, for example, in an allergic reaction. This involved the behaviour of mast cells, that some of them secrete inflammatory mediators, in technical jargon "degranulate", whereas other mast cells do not.
In this context, she compared two different methods in order to expand the experimental repertoire of the research group and to establish a new method that allows extended insights into mast cells.
The method used by Ms Dickmeis in her work was able to show a behaviour of the cells that previous methods could not detect. Thus, it could be confirmed that when the Fcε receptors are stimulated, the degranulation of the mast cells actually takes place differently, i.e. not all cells show the same response to the stimulus.
With the knowledge she has gained, Ms Dickmeis contributes to a better understanding of the mechanisms of allergic reactions, for example, or to refining therapies for autoimmune reactions. However, the more detailed backgrounds of this "all-or-nothing" reaction of the mast cells need to be further investigated in order to be better understood.
The University of Applied Sciences thanks Ms Dickmeis for her commitment and wishes her every success for the future.
Supervisor:s of the thesis:Prof. Dr. rer. nat. Peter Öhlschläger
Experimental assessment and modelling of inhibition to maximise the yield of hydrogen formation with Thermotoga neapolitana
Bachelor thesis (biotechnology) by Jessica Graalmann
A multi-parameter optimisation of hydrogen productivity and yield was carried out using combined experimental and modelling methods. Anaerobic fermentations at 77 °C for 46 to 72 hours were used. The pH inhibition, influence of buffer type, ionic strength and media additives were investigated. It was found that the organism is strongly pH inhibited and increases its productivity with buffers of low molarity. Furthermore, salt additives could be determined that increase the hydrogen yield. In the course of the optimisations, the theoretically possible hydrogen yield of 4.0 mol H2 per mol glucose with Yhydrogen= 3.9 ± 0.2 molH2-molGlucose-1, could almost be achieved. Furthermore, acetate and lactate were produced as valuable by-products. Yacetate=1.76 ± 0.14 molacetate-molglucose-1, Ylactate=0.20 ± 0.02 mollactate-molglucose-1.
This provides a process by which hydrogen can be obtained from renewable plant raw materials without the use of electrical energy.
This is work in an ongoing research project. The research is being continued within the framework of several final theses. A demonstration plant for the production of hydrogen from biowaste is currently being developed. In another project, an electro-biotechnological approach is being pursued with which electrons can be transferred into the microorganisms in order to increase the yield beyond the theoretical metabolic maximum.
The University of Applied Sciences thanks Ms Graalmann for her commitment and wishes her every success for the future.
Supervisor:s of the thesis:
- Prof. Dr.-Ing. Nils Tippkötter, Bioprocess Engineering and Downstream Processing
- M. Sc. Berit Rothkranz, Biochemical Engineering and Downstream Processing
Extraction and chromatographic separation of lipophilic biomolecules from algae cultures with supercritical CO2
Master's thesis (Biotechnology) by Lena Braun
In developing the method for chromatographic separation, the optimal parameter settings were determined using statistical design of experiments (DoE). The separation of the three unsaturated fatty acids oleic acid, linoleic acid and linolenic acid was successful, but the individual products could not be isolated in complete pure form.
The supercritical extraction was first carried out with a fatty acid standard to determine the best settings for the parameters. After optimising the parameters, the fatty acids were extracted from the algae Acutodemus obliquus and Chlorella sorokiniana. From C. sor okiniana three times the amount of free fatty acids of A. obliquus could be extracted. The extraction of the fatty acids is almost complete in a single step; a preceding cell disruption using a high-pressure homogeniser is not necessary.
With the results, a laboratory procedure could be established with which bio-certifiable fatty acids can be extracted from algae. The algae are used to purify paper mill effluent, so that there is a closed-loop process with high added value. The fatty acids have a large market in the cosmetics sector and as food additives.
It could be shown that the integrated extraction, separation and purification of the fatty acids is feasible. A technical publication is to be submitted from the results. Furthermore, a follow-up project is planned to further optimise the separation and scale up the process to the 50 L scale.
The University of Applied Sciences thanks Ms Braun for her commitment and wishes her every success for the future.
Supervisor:s of the thesis:
- Prof. Dr.-Ing. Nils Tippkötter, Bioprocess Engineering and Downstream Processing
- Dr. Simone Krafft, Biochemical Engineering and Downstream Processing