Open Access

Per- and polyfluoroalkyl substances – abbreviated as PFAS - are compounds that enter the environment through industrial material cycles. Their chemically stable carbon-fluorine bonds provide valuable technical properties for industrial applications, but also render them resistant and environmentally persistent. Consequently, PFAS accumulate in various biological systems and organisms, and can now be detected in numerous samples, including drinking water, human blood, and soil. This accumulation is concerning due to the documented harmful and/or carcinogenic properties of many PFAS compounds [1,2]. For this reason, it is important to understand the pathways of these compounds from industrial processes into the environment. Combustion processes, such as those in waste incineration, are of particular interest to ensure that no PFAS are released into the environment. In this project, various combustion processes at laboratory and pilot plant scales will be examined to determine the optimal parameters for the reduction of PFAS in different materials. Depending on the definition applied, the range of PFAS spans from ~4,700 to ~14,000 individual compounds, which can vary significantly in their chemical properties. This, combined with a variety of complex matrices, makes PFAS analysis particularly challenging [1,2]. Due to the complexity of PFAS, the analysis of fluorine sum parameters has become established in recent years. The application of High Resolution Continuum Source Graphite Furnace Molecular Absorption Spectroscopy (HR-CS-GFMAS) has seen increased usage [3]. However, such a methodology has not yet been established for gas analysis. Although OTM 45 was published in 2021, allowing the quantification of 50 individual PFAS, it is unclear whether this is representative of the entire class of substances [4]. Therefore, the aim of this project is to improve the analysis of PFAS in flue gas from laboratory and pilot plant facilities, thereby contributing to the understanding of their thermochemical degradation and the optimization of combustion parameters. In initial experiments, a suitable sampling apparatus consisting of impigners, a coil condenser, and gas washing bottles was tested and optimized. Cuttings, partially spiked with PFOA, and sewage sludge served as reference materials. For the measurement of sum parameters, an HR-CS-GFMAS method was developed and validated.

Infections with multi-resistant Gram negative pathogens are a major threat to our health system. In order to serve the needs in antibiotics development we selected untapped bioresources and implemented high throughput approaches suitable for the discovery of strains producing antibiotics with anti-Gram negative activity. Our approaches rely on the hypothesis that Termite associated bacteria are likely to produce potent antibiotics to defend their hosts against entomopathogenic microorganisms. Termite nests and guts harbor suitable, highly diverse microbiomes in which bacterial taxa are present known to potentially produce natural compounds. In a first step the diversity of Coptotermes species nest microbiomes was assessed carefully by using 16S rDNA amplicon sequencing on the Illumina MiSeq platform and nest material was selected to retrieve viable cells by using Nycodenz density gradient centrifugation. In order to analyze the diversity of the culturable termite nest microbiome, bacterial cells were either distributed in 384-well plates (approach 1) or encapsulated in small spheric agarose beads by an high throughput microfluidics technique (approach 2). Cultures obtained from approach 1 were scaled-up in 96-well Duetz-systems for characterization of diversity and for rapid supernatant screening using the bioluminescence-labeled E. coli pFU166. The generated droplets of approach 2 simultaneously received a small population of GFP-tagged Gram negative screening cells and were sorted for low fluorescence using FACS. After elimination of redundancy we performed a fast scale-up of active strains. Implementation of this pipeline allows us to prioritize antibiotics producing strains in a ultra-high throughput fashion and by cultivation of broad diversity in our approches.