Abstracts: European Detergents Conference

10:00 – 10:30 | Wednesday, Main Auditorium
Microbial Synthesis of Mannosylerythriol- and Cellobioselipids
EN | Dr.-Ing. Susanne Zibek
(Fraunhofer Institute, Stuttgart, Germany)
Biosurfactants are microbial surface-active compounds that have interesting physical and chemical properties, such as low toxicity, biodegradability and foaming. They are naturally synthesized by several microorganisms and can be used as sustainable alternatives to synthetic surfactants. Cellobiose and mannosylerythritol lipids are promising glycolipid biosurfactants that can be produced by fungi e.g. of the genus Pseudozyma and Ustilago. Both types of biosurfactants showed a number of very interesting properties. Cellobiose lipids for example, have been proven to be efficient antimicrobial compounds. Mannosylerythritol lipids were described to have application potential in personal care, technical uses and pharmaceuticals.
Cellobiose and mannosylerythritol lipids were produced based on a variety of renewable resources and can be tailored in their surfactant performance. Different carbohydrates and plant oils were used as substrates for microbial biosurfactants synthesis.
Within our work the production of different cellobiose lipid variants were established using U. maydis strains. The cultivation methods, pH and the carbon source occurred to be crucial parameter for cellobiose lipid synthesis. With resting cells the product concentration as well as productivity was significantly increased.
In addition we produced mannosylerythritol lipids mixtures with varying composition by applying different Pseudozyma strains and optimized fermentation conditions. Furthermore the influence of different plant oil substrates on the composition of mannosylerythritol lipids was investigated. Product removal and carbon source were identified to have significant effects on productivity and composition of mannosylerythritol lipids. The surfactant properties of the obtained product mixtures were investigated with regard to product composition and purity.
After purification of the biosurfactants the properties can also be chemically or enzymatically modified to obtain further structural variants with better water solubility, enhanced emulsifier performance or different foaming behavior.
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10:30 – 11:00 | Wednesday, Main Auditorium
Enzyme Reactions in Microemulsions
EN | Prof. Thomas Hellweg
(University of Bielefeld, Germany)
Microemulsions are interesting reaction media for enzymes since most enzymes are soluble in water and a lot of important substrates are only soluble in oil [1]. Moreover, in microemulsions the oil and water phases are separated by a huge surfactant interface. The formed structures can be oil-, water- or bi-continuous. The dimension of these structures is in the nanometer range. Besides being interesting reaction media such systems are also interesting from a physical chemistry point of view since they exhibit interesting dynamics [1].
The present contribution will review some classical works on the use of microemulsions as reaction medium for enzyme catalyzed reactions and will present the use of sugar surfactant based microemulsions as reaction media for different enzymes like e.g. diisopropylfluorophosphatase and alcohol dehydrogenase.
Moreover, some recent results related to the extraction of hazardous compounds from surfaces using microemulsions will also be discussed [3].

References
[1] Wellert, S., B. Tiersch, J. Koetz, A. Richardt, A. Lapp, J. Gäb, O. Holderer, M. M. Blum, C. Schulreich, R. Stehle und T. Hellweg: European Biophys. J.; 40, 761 (2011)
[2] Wellert, S., A. Richardt, O. Holderer, und T. Hellweg, PCCP; 13, 3092 (2011)
[3] Vargas-Ruiz, S., C. Schulreich, A. Kostevic, B. Tiersch, J. Koetz, S. Kakorin, R. von Klitzing, M. Jung, T. Hellweg, S. Wellert, J. of Coll. Interf. Sci.; 471, 118 (2016)
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11:00 – 11:30 | Wednesday, Main Auditorium
Assessment of Biotechnological Processes towards Bio-based Surfactants
EN | Prof. Dr. Ulrich Schörken, Stephan Barbe
(TH Köln, Germany)
Fully bio-based surfactants and emulsifiers are produced from fatty acids or fatty alcohols as lipophilic tail and e.g. sugars, amino acids or peptides as hydrophilic head group. Commercialized products obtained from chemical condensation reactions are alkyl polyglycosides (APG), sorbitan esters, sucrose esters, N-acyl amino acids and N-acyl peptides. These compounds and structurally similar bio-based surfactants are accessible via biocatalysis and fermentation processes, though only a few products have been commercialized so far.
Direct enzymatic synthesis of sugars and amino acids with lipids is possible in reverse hydrolysis reactions. Utilizing glycosidases alkyl glycosides are accessible, while lipases enable the synthesis of sugar esters and amino acylases can catalyze the acylation of amino acids. Limitations of these reactions are too narrow substrate specificities of the commercially available biocatalysts and the need for complex reaction systems involving solvent handling and / or substrate modification. Some examples of lipase catalyzed sugar ester synthesis will be presented in more detail to explain the process conditions needed.
Lipopeptides and glycolipids are excreted by several microorganisms and a variety of different compounds are available. Among others, Bacillus strains produce lipopeptide surfactants like surfactin or lychenysin, which possess strong antibacterial properties. The strains have been significantly optimized and high yield production of surfactin is meanwhile done in production scale. Glycolipids are a structurally diverse group of biosurfactants comprising e.g. trehalose lipids, cellobiose lipids, mannosylerythritol lipids and the commercially available rhamno- and sophorolipids. Sophorolipids are low-foaming biosurfactants, which can be produced from Starmerella bombicola and related yeasts in large quantities. An assessment of different processing technologies will be given and data on sophorolipid fermentation, process modeling and biomass recycling will be presented.
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11:45 – 12:15 | Wednesday, Main Auditorium
Antimicrobial Textiles in Hospital and Care Sector – Effectiveness and Benefits in Use
EN | Prof. Dr. Dirk Höfer, Dr. Anja Gerhardts
(Hohenstein Institute, Germany)
According to a study by the European Centre for Disease Prevention and Control, approximately 3.2 million people are infected with nosocomial pathogens in Europe every year. How effective antibacterial textiles can break the chain of infection in nursing situations cannot be assessed from results of normative tests. The importance of antibacterial textiles in hospitals and care facilities is currently low, because the potential as additional hygienic measure is underestimated due to a lack of proof of benefit.
In a recent study, cotton and polyester substrates were finished with antimicrobial additives (silver, QAC, PHMB, etc.) and samples of antibacterial textiles from the market were purchased. The functionalized textiles were then tested using modified standard test methods, including contact times and organic loads with practical relevance. In addition, the transmission of germs between textile and skin was realistically simulated using a stamp model by means of an artificial skin substitute (HUMskin) and considering the interaction of pathogen, dose and application. By varying the test methods, textile finishes showed limited efficacies compared to the type testing, as it was expected. Nevertheless, the activity of selected textiles in the simulated application was still strong. In transfer scenarios, e.g. with Staphylococcus aureus, these textiles also showed significantly reduced values in the transmission of germs from textile to the skin.
The research results show the effectiveness of selected antibacterial finishes in practical scenarios. Therefore, it can be concluded that functionalized textiles can decisively contribute to the prevention of infection in targeted applications defined by an application matrix.
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12:15 – 12:45 | Wednesday, Main Auditorium
Application of Surfactants in Medical Industry
EN | Dr. Rumen Krastev
(University of Tübingen and Reutlingen University, Germany)
The medical industry is a fast growing branch of the economy. The knowledge of different scientific areas is jointed together to formulate the required products. This includes very good understanding of the processes which take part at different surfaces. The surfactants are used either during the production process or as a part of the final formulations. They are components of pharmaceutical formulations, active agent in the washing process in the hospitals or important part of the cleaning process for preparation of medical devices. The products treated with surfactants are in direct contact with the patients or even with the blood stream. This requires the surfactants to be characterized not only for their functionality but also for their biocompatibility and medical applicability.
The presentation discuss the requirements to the surfactants used in medical industry. The main legal regulation are summarized. The most important testing procedures are discussed. The presentation is based on examples for characterization of surfactants with various physical, chemical and biological techniques.
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12:45 – 13:00 | Wednesday, Main Auditorium
EN | Short Introduction of Scientific Posters by Authors
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14:30 – 15:00 | Wednesday, Main Auditorium
Gelled Complex Fluids – Combining Unique Structures with Mechanical Stability
EN | Prof. Dr. Cosima Stubenrauch
(University of Stuttgart, Germany)
Typical examples of complex fluids are micellar solutions, lyotropic liquid crystals, thermotropic liquid crystals, microemulsions, and emulsions. A gel, on the other hand, consists of a gelator and a solvent and can be defined as a dilute cross-linked system which exhibits no flow in the steady state. The unique selling point of gelled complex fluids is the fact that the two coexisting structures can take over two different functions. Gelled complex fluids are soft materials in which the microstructure of the complex fluid is combined with the mechanical stability of a gel! To obtain a gelled complex fluid one either adds a gelator to a complex fluid or replaces the solvent in a gel by a complex fluid. The most prominent example of a “natural” gelled complex fluid is the cell. There are various strategies via which one can form a gelled complex fluid one of which is orthogonal self-assembly, i.e. the independent but simultaneous formation of two coexisting self-assembled structures within one system. This contribution aims at describing the structure and potential applications of various gelled complex fluids and at clarifying whether the respective system is formed via orthogonal self-assembly. For this purpose, previous as well as current research activities will be presented and future perspectives will be addressed.
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15:00 – 15:30 | Wednesday, Main Auditorium
Presentation of GDCh Division Group Awards:
Young Academics Award with Oral Presentation of the Winner
EN | Moderation: Dr. Dieter Boeckh
(Chairman of the GDCh Division of Detergency and Formulations)
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15:30 – 16:00 | Wednesday, Main Auditorium
Analysis of Microbial Communities Relevant to Laundry & Home Care
EN | Prof. Dr. Markus Egert
(Furtwangen University, Germany)
“In-vironmental Microbiology” is an exciting sub-branch of Microbiology that deals with structure (composition) and function (physiology) of microbiomes (microbial communities) in the built environment of humans. Modern households are characterized by many niches that offer excellent conditions for microbial growth, because they are wet, warm and rich of nutrients. In particular kitchen sponges, sinks and surfaces that regularly get in contact with humans, their excretions and/or food remains of animal origin are counted among these microbiological “hot spots”. Over the last years, the use of high throughput next generation sequencing technologies has contributed much to our understanding of the structure of indoor microbiomes and their interactions with humans, although their concrete role in domestic infections, malodor-production and/or material damage is still largely obscure. Also domestic washing machines are densely colonized by a diverse microbiota. Microorganisms are most likely recruited from the tap water, but might also enter the machine via the dispenser drawer or the dirty laundry. In the washing machine, microorganisms lead to unaesthetic biofilms and malodor formation. Microbial colonization of washing machines might be favored by currently popular washing trends, such as low washing temperatures, reduced water consumption, and bleach-free liquid detergents. From a hygienic point of view, these trends are rather unfavorable. It is safe to assume that the washing machine microbiome also affects the post-washing laundry microbiome, thereby influencing unwanted phenomena such as staining and laundry malodor production. Admittedly, the functional interplay between the microbiomes of water, washing machine, and laundry during and after washing are far from being fully understood. Here, modern technologies such as metatranscriptomic approaches appear particularly helpful to better understand the functionality of interacting microbiomes in washing machines and on washed laundry and to develop specific hygiene strategies against microbiome-associated problems.
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16:15 – 16:45 | Wednesday, Main Auditorium
Colloidal Surfactants: Synthesis, Properties and Relevance for Technical Applications
EN | Dr. Andre Gröschel
(University of Duisburg-Essen, Germany)
Janus particles are “giant surfactants” that show increased affinity towards interfaces and enhanced interfacial stabilization capability. Over the years a considerable number of preparative strategies has been developed that allow the synthesis of these amphiphilic colloids in all conceivable shapes and sizes, and with a large variety of surface functionalities [1]. In this presentation, I will discuss recent concepts and trends that pursue the controlled preparation of synthetic (or biological) amphiphilic particles ranging in size from only few nanometers to several micrometers. Janus particles have been the subject of intense studies regarding their interfacial activity [2] and have thus progressed into various applications, such as dispersants [3], emulsifiers [4], compatibilizers [5] and foaming agents [6]. Due to this application potential, a critical view on scalability of current synthetic methods aims to identify candidates for the next step, relevance for technological innovation.

Literature
[1] Walther, A.; Müller, A. H. E. Chem. Rev.2013, 113, 5194–5261.
[2] Glaser, N.; Adams, D. J.; Böker, A.; Krausch, G. Langmuir2006, 22, 5227–5229.
[3] Gröschel, A. H.; et al. Angew. Chemie Int. Ed.2013, 52, 3602–3606.
[4] Walther, A.; Hoffmann, M.; Müller, A. H. E. Angew. Chemie Int. Ed.2008, 47, 711–714.
[5] Bahrami, R.; Löbling, T. I.; Gröschel, A. H.; Schmalz, H.; Müller, A. H. E.; Altstädt, V. ACS Nano2014, 8, 10048–10056.
[6] Szilvay, G. R.; et al. Biochemistry2007, 46, 2345–2354.
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16:45 – 17:05 | Wednesday, Main Auditorium
Impact of Charged Polysaccharides on Oppositely Charged Surfactants –
New Insights into a Structure-Property Relationship

EN | Philipp Buchold¹ ², Michael Gradzielski², Ralf Schweins¹
(¹ Institut Laue Langevin, Grenoble, France; ² Technical University Berlin, Germany)
Polysaccharides (PS) are the most abundant organic material in nature. Among them, charged PS are finely tuned, specialized macromolecules. For instance, hyaluronic acid (HA) or carboxy methyl cellulose (CMC) are known to modify strongly the viscosity of aqueos solutions already at concentrations below 1 wt%. Adding an oppositely charged surfactant can enhance or reverse this effect due to forming self-assambled complexes of surfactant and PS.
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17:05 – 17:25 | Wednesday, Main Auditorium
Shear Induced Transformation of Polymer-Rich Lamellar Phases
to Micron Sized Vesicles Investigated by Small Angle Scattering

EN | Sören Großkopf¹, Miriam Siebenbürger², Yvonne Hertle¹,
Oliver Wrede¹, Thomas Hellweg¹
(¹ Bielefeld University, Germany; ² Helmholtz Zentrum Berlin, Germany)
The aim of this work was to fabricate multi-lamellar-vesicles (MLV) out of a triblockcopolymer-rich lamellar phase applying stress and their identifaction via small angle scattering. Such large vesicles are of potential interest for the usage as thermosensitive drug delivery systems. The four-component System which has been used in this work consists of A) a polar component D2O, B) a apolar component o-xylene, C) an amphiphilic triblock-copolymer (EO21-PO47-EO21) as the surfactant and D) a cationic co-surfactant namely C8TAB (n‑octyl-trimethylammonium bromide). Small angle light, neutron and X-ray scattering was used to to identify either the lamellar phase and the resulting MLV. The rheo-small angle light scattering gives the option to identify the MLV while applying shear stress. Additionally different microscopy techniques – like polarized light, phase contrast and differential interference contrast - were used to to obtain a real image of the MLV.
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17:30 – 17:45 | Wednesday, Main Auditorium
DE | General Meeting of the GDCh Division of Detergency and Formulations
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17:45 – 18:00 | Wednesday, Main Auditorium
EN | Scientific Poster Session with Authors
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