Research

Theoretical framework: Coproporphyrin III is an important virulence factor associated with the skin disease acne vulgaris, which is caused by an infection with the monoderm actinobacterium Cutibacterium acnes. Monoderm bacteria utilize the so-called “coproporphyrin-dependent” heme biosynthesis pathway. In this pathway several enzymes catalyse the formation of the final product heme b, two of those (coproporphyrin ferrochelatase, CpfC; coproheme decarboxylase, ChdC) are uniquely found to be fused in one open reading frame in pathogenic C. acnes strains. Objectives: Employing high-end biochemical and biophysical methods to study different constructs of pathogenic C. acnes CpfC-ChdC fusion protein (full length; N-terminal CpfC domain only; C-terminal ChdC domain only), but also of CpfC and ChdC (not fused) of non-pathogenic C. acnes strains will provide in-depth knowledge of protein folding, interaction and enzymatic capabilities. Further, state-of-the art structural studies will be used to describe the enzyme in the most complete way, in order to understand steric constraints of the overall structure and active site architecture, which may lead to the secretion of coproporphyrin III. Methods: Biochemical and biophysical characterization of the selected CpfC-ChdC constructs and variants will be performed using multiple high-end spectroscopic methods, steady-state and pre-steady state kinetic characterizations. Further we will employ state-of the art structural biology methods (X-ray crystallography, Cryo-EM, SAXS) to gain profound knowledge of the enzyme’s structure to the very detail. Innovation: Combining our long-standing expertise on CpfCs and ChdCs is the perfect starting point to investigate the molecular mechanisms and enzymatic shortcomings that lead to the production and secretion of the very important virulence factor coproporphyrin III. Knowledge of this underlying biochemical features is a precondition for further studies, including future drug development.

The Josef Ressel Center “ReSTex – Recovery Strategies for Textiles”, addresses one of the central issues on the way to more sustainable societies and bioeconomies: the recycling of textiles. The focus is on utilization of cellulosic textiles and the separation of cellulosic blends, such as cotton / polyester, the so-called “polycotton”. The Ressel Center is located at the University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln and will tackle the scientific challenges of the topic together with its scientific partners, two institutes at the University of Natural Resources (BOKU) and one at TU Vienna, and four partner companies. Two general recycling routes will be explored: first, the selective dissolution of cellulosic blended textiles aims at separating the cotton and PET fractions in polymeric form without extensive degradation. Second, cellulose hydrolysis by biotechnological methods converts cellulose to fermentable carbohydrates while purifying out the PET fraction from polycotton blends. Initial work phases address screening and characterization of the starting textile blends, as well as evaluation of requirements for recycling. A database of spectral analysis data will be established and processed by AI. Several pre-treatment methods and special cellulose solvents for separation of cotton-rich articles will be tested. Follow-up work optimizes the solvents/solvent systems towards improved selectivity, suitable conditions for minimal impact on polymer integrity in case of high cotton fractions.

Through photosynthesis, marine algae convert gigatonnes of carbon dioxide into carbohydrates every year. In the form of algal polysaccharides, these structurally complex biomolecules determine to a large extent how much carbon is stored in the oceans. Specialised marine bacteria unlock this carbon energy by breaking down the polysaccharides through the action of carbohydrate-active enzymes (CAZymes) and releasing the carbon dioxide back into the atmosphere. However, some of the polysaccharides are not recycled quickly, but sink into the deep sea and sediments, where they can store carbon for millennia. To better understand these processes, great efforts are needed to further explore the marine carbon cycle. The same advances are also important to support emerging efforts to use algal biomass as a new sustainable resource for the bioeconomy. The enzymatic machinery responsible for the degradation of polysaccharides by marine bacteria has remained largely unexplored because of the size and heterogeneity of algal polysaccharides. Pure and defined oligosaccharides needed for systematic screenings of marine CAZymes are currently not available. Since conventional chemical synthesis is time-consuming and often not general enough, ASAP aims to obtain collections of oligosaccharides related to different classes of algal polysaccharides by using automated glycan assembly (AGA) technology. Oligosaccharides with many different sequences and sulfation patterns will be prepared from small sets of monosaccharide building blocks. Incubation of the synthetic oligosaccharides with samples containing carbohydrate-degrading activity and subsequent HPLC-MS analysis of the degradation products will provide information on: 1) the collective enzyme activities of a bacterial community in seawater and sediment samples; 2) the abilities of individual bacterial strains to degrade specific polysaccharides; 3) the substrate specificities of purified CAZymes.