Activity Reports

Activity Report 2021                              Activity Report 2020

P-Campus activity report       P-Campus Activity Report 2020


Activity Report 2019                              Activity Report 2018

P-Campus Activity Report 2019      P-Campus Activity Report 2018                                          


Activity Report 2017                             Activity Report 2016              



Activity Report 2015                             Activity Report 2013/2014

     Activity Report 2013/2014


Projects funded by the ScienceCampus (summaries and contact persons):

Evaluation of different P-digestion methods for diverse environmental materials (EvaPhoN)

Various digestion procedures for total phosphorus were compared. Extracted materials were dry mass and ash from plants, animal tissues soil and sediments as well as seston. It was not primarily the aim to find a best way, but to identify the most important steps and to make the respective comparisons as a reference available to the ScienceCampus. In addition, the original sources of the methods, reviews and methods comparisons were compiled. We also provide some ashes as a reference material. The already thoroughly prepared work instructions will be regularly supplemented with the aim to create a methodological manual in the long run.

Contact person: PD Dr. Rhena Schumann (University of Rostock)

Genetic and nutritional effects on the efficiency of P use of monogastric animals

In order to identify measures to increase the efficiency of phosphorus (P) of monogastric animals, we investigated the physiological and transcriptional responses to modulated dietary P supply in growing pigs. The dietary P intake below and above current requirements was reflected in physiological serum parameters like inorganic phosphate, calcium, parathyroid hormone, vitamin D3 and cathepsin K, while the growth performance and feed intake were unaffected. The P supplementation above recommendations persistently affected animals as shown by microstructural bone parameters (increased Bone Mineral Density and Structure Model Index) and altered abundances of transcripts associated with bone morphology. Because of the multidisciplinary collaboration in this project, we were able to reveal the functional biodiversity of the animals regarding coping with a modulated dietary P supply. Genes found to be differentially expressed due to variable P supply are potential candidate genes for improved P efficiency.

Contact person: Prof. Dr. Klaus Wimmers (FBN)

Method Development for the Determination of particulate Glyphosate in Marine Environments; Bioavailability of Glyphosate

This study focused on glyphosate which is the active ingredient in commercial herbicide products such as Roundup®. This project was aiming for i. the method development for the extraction of glyphosate from particulate matter, ii. analysis of adsorption properties to soils from agricultural areas in Mecklenburg-West Pomerania and iii. analysis of the microbial degradation capacity and thus, the potential bioavailability of glyphosate for the Baltic Sea. Therefore, glyphosate was adsorbed to particulate matter such as sand, marine sediments with low and high organic carbon content and minerals. Glyphosate was extractable at different pH values depending on the type of particulate matter present. High extraction yields were obtained for glyphosate from minerals. However, extraction efficiency from sediments is insufficient, yet, and needs further improvements for glyphosate analysis from marine sediments. Adsorption isotherms for the soils from areas representative for the lowland landscape of Mecklenburg-West Pomerania indicate strong affinity of glyphosate to the selected soils. Cell culture experiments were conducted with Nodularia spumigena which is the predominant cyanobacterium for the Baltic Sea. The results of this project are currently under survey and will serve as the basis to develop further experimental strategies in order to identify factors which define glyphosate adsorption characteristics.  

Contact person: Dr. Marion Abraham (IOW)

Phenotypic and molecular characterization of P utilization and uptake efficiency of Solanum tuberosum

The aim of this project was to obtain knowledge about the genetic resources of potato with particular attention to the phosphorus efficiency (P-efficiency) and to submit a proposal for a follow up project. The data from the preliminary experiment show that different potato genotypes vary in their P-efficiency, which is in agreement with data from the literature. Based on these findings a project proposal with the topic “P-efficiency of potato” will be submitted to the German “Fachagentur für Nachwachsende Rohstoffe e.V. (FNR)”.

Contact person: Prof. Dr. Ralf Uptmoor (University of Rostock)

Recycling of phosphorus based organocatalysts through nanofiltration (RON)

In this project we demonstrated the application of organic solvent nanofiltration (OSN) as a sustainable alternative to distillation for the recycling of bifunctional phosphonium salts. We optimized the reaction and filtration process in respect to various process parameters (catalyst, solvent, membrane etc.) Under the optimized conditions the organocatalyst was retained up to 99% and could be recycled four times. The resulting paper was submitted to an internationally peer-reviewed journal.

Contact person: Dr. Thomas Werner (LIKAT)

Seed Projects Funding Period 2 (2019-2023)

EpiPTG - Dietary effects on DNA methylation in porcine parathyroid glands

M. Oster, (FBN) K. Wimmers (FBN), P. Wolf (UR), B. Vollmar (UMR)

It has been proposed that an adaptive response termed ‘Metabolic Programming’ offers the possibility
to induce different and stable phenotypes. To improve phosphorus (P) efficiency in pig husbandry, a
feeding experiment was conducted in 2018. Sows were supplied with variable amounts of dietary P
during pregnancy and lactation, which had an indirect impact on the offspring. Thus the
transgenerational design of this feeding study included nutritional challenges for the progeny of pigs
during foetal and postnatal development. Results of RNAseq data retrieved from the parathyroid
glands of the challenged offspring revealed transcriptional variations of a number of key genes
involved in mineral homeostasis, such as parathyroid hormone (PTH) and fibroblast growth factor
receptor 1 (FGF1R).
In this context, the relevance of possible epigenetic modifications must be clarified. To consider any
long-term effects with regard to a P homeostasis in finisher pigs, RNA-Seq data will be
complemented by the analysis of targeted DNA-methylation marks obtained via bisulfite sequencing.
In addition, directly affected parameters such as the serum level of PTH (released from the
parathyroid glands) and its effects on bone mineralization will be assessed. The comprehensive
molecular and phenotypic characterization forms the basis for the possible implementation of dietary
P conditioning in monogastric animals.

P-CAT - Development of enantioselective catalytic Wittig reactions based on chiral phosphorus compounds as catalysts

T. Werner (LIKAT), A. Börner (UR)

Project still running

P-ChemBind - Phosphorus-protein interactions in cross-linking

J. von Langermann (UR), T. Werner (LIKAT), U. Kragl (UR)

The aim of the seed project "P-ChemBind" was to develop an efficient short-cut method for binding P-based side chains to proteins. In sum, it was found that the more demanding reaction conditions required here result almost entirely in a direct denaturation or undesirable modification of the protein. The target compound could only be produced in low yields.
The conclusion to be drawn from this short project is that the proposed method is not experimentally promising. The lengthy alternative route, which is now necessary after all, is being worked on in project III.2 "Application of P-based organocatalysts and biocatalysts for the resolution of racemic carbonates".

PIAG - Plasma-induced degradation reactions in glyphosate-containing substrates

V. Brüser (INP), P. Leinweber (UR)

In this study, surface corona discharges were shown to be able to effectively degrade glyphosate (GLP) in water without the need for additional chemical or biological additives. It was also shown that GLP removal in water can be achieved within a short time and could thus be implemented in sewage treatment plants. The established analytical methods for detecting degradation proved to be suitable and easy to perform. To evaluate the postulated degradation pathway, an in-depth analysis of the intermediate and final products after GLP degradation needs to be carried out, which will also help to improve the system. Corona discharges are a promising technique to address the problems of GLP removal in water.

PQ4N - Phosphorus as a cue regulating microbial N2O production

N. Wrage-Mönnig (UR), M. Voss (IOW)

Phosphorus (P) has been shown to interact with nitrogen (N) transformations in soils, altering microbial sources of nitrous oxide (N2O) emissions. However, this P-regulated N response remains largely unclear. Interactions with water content as well as P-fertilisation history have rarely been investigated. Within this project, we carried out an incubation and a mesocosm experiment to increase understanding of the interactions.
Using a 15N-labelled NO3 tracer in a soil incubation experiment, we studied the influence of P addition on N conversions and N2O emission under soil water-holding capacities (WHC) of 45 and 60 %. We conclude from the results that P availability could increase N conversion via mineralization, decrease nitrification and increase denitrification, coupled with an increase in N2O production from denitrification, which was the main N2O source here despite moderate water contents.
In the mesocosm experiment, we studied effects of P-fertilisation history on reactions of N2O production processes to P addition. Therefore, soils from two treatments of a long-term P fertilisation experiment were incubated with or without P addition. Fluxes of NO, N2O and CO2 were measured continuously and event-based samples taken for isotopomeric measurement of N2O and molecular analysis of the microbial community. Largest cumulative N2O production was found on the low-P soil with P fertilisation. Preliminary isotopic signatures did not suggest differences in N2O sources among treatments, but over time of incubation. Molecular results are pending due to constraints caused by pandemic measures.
Overall, the seed project has shown that P has an effect on N conversions and N2O production. This effect depends on P fertilisation history and probably on the microbial community.

ProCycle - The role of protists in the phosphorus cycle of biological soil crusts

M. Albrecht, (UR), K. Glaser, (UR), M. Labrenz (IOW), P. Leinweber (UR)

The role of protists in biological soil crusts in general and in the metabolic cycle of P has received very little attention and study so far. In other habitats and communities, such as plankton and the rhizosphere, the prominent role of protists and thus the microbial loop is well known. Therefore, this seed project aims to investigate a simplified model system regarding the P cycle with 3 of the most important components of a biocrust: protists, bacteria and algae.
Various organisms were tested for suitability (size, growth, countability, etc.) and good candidates were identified, grown in various combinations in P-depleted medium. Samples for P analysis were taken at the beginning and end of the experiment and samples for cell determinations of all three organisms were also taken on two days.
The results for P showed that there was more molbydate-reactive phosphate in the presence of the protist than without. The cell counts prove that the protist has ingested and digested the bacteria offered. However, due to the fact that the P samples were only taken at two points in time, it is not clear whether the increase in P results from an active release or from the dieback of the protists.
The preliminary and main experiments of the seed project phase have shown that the setup works in principle. Various optimisation possibilities could be identified. The selection of organisms has already been optimised as part of the seed project, but requires further testing with more resistant protists.

Seed Projects Funding Period 1 (2015-2019)

AMPA - Synthesis of isotope-labeled AMPA for qualitative and quantitative analysis of glyphosate degradation in soil

M. Kanwischer (IOW), P. Leinweber (UR), A. Schulz (UR), T. Werner (LIKAT)

Wirth, M.A., Longwitz, L., Kanwischer, M., Gros, P., Leinweber, P., Werner, T. (2021) AMPA-15N – Synthesis and application as standard compound in traceable degradation studies of glyphosate. Ecotoxicology and Environmental Safety 225, DOI: 10.1016/j.ecoenv.2021.112768

Isotopically labelled substances are often used in tracer experiments to track them or their correspondingly labelled degradation products, e.g. by using sensitive instrumental analysis. In this particular case, however, the use of commercially available isotopically labelled glyphosate leads to the formation of a 15N-AMPA degradation product, which cannot be quantified and analytically verified using conventional analytical approaches.
In the AMPA project, synthesised 15N-AMPA was used to prove that the degradation of the 13C-15N glyphosate used in a lysimeter experiment took place via 15N-AMPA. Contents of 15N-AMPA could be quantified in the soil samples of the experiment after re-analysis.

Crysphos - Separation of organic phosphates by crystallization

J. von Langerman (UR), T. Werner (LIKAT)

The seed project "Crysphos" investigated the targeted crystallisation of organic phosphates using metallic ions from the lanthanide group, which should ultimately enable potential recycling. The experimental work clearly showed that an almost quantitative separation is possible for almost all organic phosphates investigated, whereby the solubility differences between lanthanum and yttrium salts can additionally be exploited.

Desalting - Desalting of marine water through electrodialysis

M. Kanwischer (IOW), U. Kragl (UR), D. Schulz-Bull (IOW)

Wirth, M.A., Sievers, M., Habedank, F., Kragl, U., Schulz-Bull, D.E., Kanwischer, M. (2019) Electrodialysis as a sample processing tool for bulk organic matter and target pollutant analysis of seawater. Marine Chemistry 217, DOI: 10.1016/j.marchem.2019.103719

Electrodialysis (ED) is an advancing seawater sample processing tool that enables the separation of analytes from the often interfering salt matrix. In this study, we present the evaluation of a laboratory scale ED system for both dissolved organic matter (DOM) and target pollutant analysis of seawater.
The developed sample processing protocol yields reproducible data and was found to be robust towards moderate changes in sample composition. At the final salinity of 0.1, the average recovery of DOM in the form of dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP) was 44, 53 and 89%, respectively. DOM loss occurred mainly in the late stage of the ED process.
When investigating specific ED processing parameters, it was discovered that the initial sample salinity does not influence DOM recovery. The final salinity, by contrast, is a dominant influence factor on DOM recovery. Furthermore, DOC and DOP recoveries could be improved by 8% by refining the electrical current in the ED cell. Surprisingly, adjustments of the sample pH did not lead to any improvements in DOM recovery.
The experiments with target analytes showed that the recovery of individual molecules is determined by their n-octanol water partition coefficients logKow. High recoveries > 80% were achieved for compounds with medium logKow of −1 to 3. Hydrophobic compounds with logKow > 3 were lost through surface adsorption to the system walls and tubing. Small, polar and charged compounds with logKow < −1 are prone to loss via ED membrane passage, which occurred predominantly in the late stage of the ED process. Consequently, sample processing with ED was deemed beneficial for the LC-MS or GC–MS analysis of polar target compounds, because they are often difficult to enrich from seawater. Furthermore, during LC-MS or GC–MS analyses, matrix-dependent ion suppression was reduced in ED isolates, giving rise to increased signal responses of 25 to 620%, which resulted in improved instrumental sensitivity.

DFG proposal - DFG proposal preparation "Influence of glyphosate and AMPA on biodiversity & biological activity in terrestrial and aquatic systems"; based on AMPA proposal

M. Kanwischer (IOW), P. Leinweber (UR)

The project will present the state of knowledge on interactions of glyphosate (GLP) with soil organisms and organism communities in terrestrial and aquatic ecosystems. Out of 629 scientific papers dealing with the above-mentioned interactions (search "Glyphosate + Organisms", Scopus, June 30, 2019), 127 were selected and evaluated during the two-month processing period. For the selection of publications to narrow down the topics, only bacteria, fungi and algae of soil and aquatic ecosystems were considered, as well as their effect on GLP degradation, nutrient cycling, and influences on plant nutrition and health. Higher organisms were not considered. After evaluation of the publications, such knowledge gaps were identified on the basis of contradictory findings or open problems, which can be investigated in the interdisciplinary network of the P-Campus and can provide important new insights into the behavior of GLP in the environment.

EvaPhon II & III - Evaluation of phosphorus digestion of natural materials

R. Schumann (UR)

see project P-Digest

Extremophile - Novel mechanisms of P-dependent energy transductions in an animal extremophile

I. Sokolova (UR), E. Sokolov (IOW), M. Zettler (IOW)

Hypoxia is a common stressor in the ocean oxygen minimum zones (OMZ) and is currently enhanced by the global climate change and anthropogenic input of nutrients into the ocean. Most marine metazoans cannot tolerate persistent hypoxia as reflected in mass mortalities and major decreases in biodiversity when the ambient oxygen concentration drops below 2 mg/L. However, a recent study of the OMZ off the Namibian coast led to a discovery of a unique bivalve species, Lembulus bicuspidatus, that thrives at extremely low oxygen concentrations (< 0.7 mg/L) where it forms abundant populations with high biomass. This ecological success of L. bicuspidatus at the OMZ margins implies existence of unique physiological and molecular mechanisms that regulate ATP production and P-dependent energy fluxes under extremely hypoxic conditions. We have sequenced the genome of L. bicuspidatus collected at the OMZ margin and obtained sequence information covering ~82 % of the Lembulus genome. Over 35,000 genes were identified and annotated, and based on these data, specific primers were designed to investigate the transcriptomic response of L. bicuspidatus to different oxygen conditions. The ongoing bioinformatics analysis is expected to generate the complete assembly of the mitochondrial genome and a partial (~82%) assembly of the nuclear genome of L. bicuspidatus, followed with annotation, phylogenetic and functional analysis. These data will be used as a basis of at least three peer-reviewed publications and a DFG proposal submitted in 2020-2021.

H-POP - Immobilization of P‐based organocatalysts by plasma techniques

V. Brüser (INP), T. Werner (LIKAT)

MitoP - The role of reversible phosphorylation in regulation of mitochondrial bioenergetics

I. Sokolova (UR), K. Wimmers (FBN)

Mitochondria are key intracellular targets of hypoxia-reoxygenation (H/R) stress due to their central role in ATP production and reactive oxygen species (ROS) generation. Intertidal bivalves such as oysters Crassostrea gigas are adapted to frequent H/R cycles and maintain aerobic function despite frequent oxygen fluctuations. To gain insight into the molecular mechanisms of H/R tolerance, we assessed the shifts in mitochondrial (phospho)proteome and functional changes in C. gigas mitochondria during hypoxia and recovery. Oyster mitochondria maintained OXPHOS capacity despite a decline in cytochrome c oxidase activity during H/R stress. Rearrangements of the mitochondrial proteome involved upregulation of mitochondrial electron transport system and ironbinding proteins and suppression of the metabolic pathways that channel electrons to ubiquinone, possibly as a mechanism to limit ROS production during H/R stress. H/R stress led to upregulation of a mitophagic activator PGAM5 and dephosphorylation of metalloendopeptidase OMA1, indicating stimulation of mitochondrial quality control mechanisms. Changes in abundance and phosphorylation levels of key proteins involved in the mitochondrial protein homeostasis indicate suppression of the protein synthesis during hypoxia, likely as an energy-saving mechanism. Thus, shifts in the mitochondrial (phospho- )proteome might play an important role in resistance to H/R stress of oysters ensuring mitochondrial integrity and function during oxygen fluctuations. This study provides insights into the potential role of proteomic shifts in adaptive response to H/R stress and serves as an important benchmark to understand the mechanisms underlying mitochondrial sensitivity to hypoxia (ischemia) and reoxygenation.

Sokolov, E.P., Sokolova, I.M. (2018) Compatible osmolytes modulate mitochondrial function in a marine osmoconformer Crassostrea gigas (Thunberg, 1793). Mitochondrion 45, 29-37, DOI: 10.1016/j.mito.2018.02.002

Sokolov, E.P., Markert, S., Hinzke, T., Hirschfeld, C., Becher, D., Ponsuksili, S., Sokolova, I.M. (2018) Effects of hypoxia-reoxygenation stress on mitochondrial proteome and bioenergetics of the hypoxia-tolerant marine bivalve Crassostrea gigas. J Proteomics 194, 99-111, DOI: 10.1016/j.jprot.2018.12.009

P-Aktiv - Evaluation of new P-based organocatalysts

A. Schulz (UR), T. Werner (LIKAT)

PAS - Plasma-based methods for digestion of biological substrates for P-analysis

V. Brüser (INP), P. Leinweber (UR), T. Leipe (IOW), R. Schumann (UR)

see project P-Digest

P-Digest - Compilation of long-term data and interlaboratory data on P digestion from different natural materials within the P-Campus for the Internet P-Handbook

V. Brüser (INP), P. Leinweber (UR), R. Schumann (UR), D. Zimmer (IOW)

Summary (from the projects EvaPhon II & III, PAS and P-Digest)
Within the framework of the cooperation between the partners of the P-Campus, it was found that different digestion and analysis methods are used for the analysis of total P in the individual working groups, the results of which are not always comparable one-to-one. In order to make it easier for young scientists in particular to familiarise themselves with the different working groups and to minimise the errors that may arise due to the different demands of the digestion and analysis methods, the existing methods were compiled in individual working groups and evaluated with their advantages and disadvantages or demands. The results of this work were compiled as part of the EvaPhoN seed projects as a "Handbook on the Selection of Methods for Digestion and Determination of Total Phosphorus in Environmental Samples" (e-Manual P Analytics). The resulting and still emerging chapters will be published online on the P-Campus website and will be freely available to P-Campus members as well as anyone else, after registration. The handbook is constantly being expanded. In 2020, work began on translating the chapters only available in German into English and putting them online.
As part of the work on the e-Manual P Analytics, the idea arose to test and evaluate novel digestion methods. Within the framework of the seed project PAS, different environmental samples (in dried and ashed state, e.g. water samples, plants, soil, sediment) were therefore investigated both with established digestion methods and with the plasma digestion method to be tested. The aim of the PAS project was to investigate whether physical plasma is suitable as an alternative digestion method of dried organic samples for the determination of phosphate content. A promising plasma source was a spark discharge in water for testing. For the experiments, the samples were suspended in distilled water and continuously exposed to the spark. Based on the results, it could be determined that the spark discharge in the existing system is only suitable to a limited extent for digesting the sample types used. It is therefore recommended to recheck the samples by another plasma source or to reconfigure the system used. Following the PAS project, it became apparent that the flood of data generated in the entire seed projects (EvaPhonN and PAS), as well as through several bachelor's and master's theses, dissertations, the BMBF joint project BACOSA, and through the testing of more and more materials by further doctoral students, also from outside the P-Campus, must be evaluated and compiled accordingly. This was done as part of the seed project P-Digest. Among other things, it was confirmed that the digestion method and the determination method must be well coordinated, since, for example, P cannot be determined by means of molybdenum blue in an aqua regia digestion due to the high HNO3 concentrations.

PIPAPo - Unraveling molecular signaling pathway involved in phosphorus acquisition of potato

K. Dehmer (IPK), R. Uptmoor (UR)

The phosphorus uptake of potato is low, but there are genotypic differences. The micro-RNAs miR399 and miR827 play an important role in P signaling. The seed project investigated whether potato genotypes with different P-acquisition efficiencies differ in the expression of the micro-RNAs and whether these micro-RNAs play a role in potato P-acquisition. For this purpose, two potato genotypes with different P-acquisition efficiency were grown with and without phosphate supply. The expression of the micro RNAs miR399 and miR827 in leaves and roots and the root-associated phosphatase activity were measured at different points in time. The phosphatase activity was significantly increased without phosphate supply at the first measurement time point after two weeks, the micro RNA expression in the roots after three weeks. No P-deficiency-induced increase in expression levels was detected in the leaves. A strong local signal for an increase in phosphatase activity (phosphorus deficiency at the roots) might have masked the systemic signal (increased micro-RNA expression) here. A direct correlation between micro-RNA expression and phosphatase activity could not be demonstrated. Differences between genotypes with different phosphorus acquisition efficiencies were not found.

In the PhD project "IV.2 Sustainability of potato production: Cloning and sequencing of candidate genes improving P acquisition efficiency to reduce fertilizer inputs" (start May 2020), the allelic variation of candidate genes for improving P uptake in potatoes on P-deficient soils will be evaluated for the first time.

P-NMR - 31P-NMR spectroscopy: further development of methods and application to P compounds and fluxes in the environment

P. Leinweber (UR), D. Michalik (LIKAT), D. Schulz-Bull (IOW)

Phosphorus (P) is an indispensable nutrient for living organisms in both terrestrial and aquatic ecosystems. However, an excess can trigger serious environmental problems, such as eutrophication of freshwater and marine ecosystems. The release of P from sediments into the water column depends on the P speciation, occurrence and lability of the different P forms. Therefore, the main objective of this project was to use the method of 31P nuclear magnetic resonance spectroscopy (31P-NMR) to achieve the most accurate characterisation of a sample set of sediments along a transect from northern German coastal waters to the central Baltic Sea. The results of the 31P-NMR spectroscopy show that the diversity of the different mono- and diester-P compounds decreases with increasing distance from the coast and that high proportions of more stable orthophosphate are present especially in greater water depths. There is a trend from many labile to fewer but more stable P compounds with decreasing terrestrial and increasing aquatic influence in accordance with the results of the complementary methods of sequential P fractionation and synchrotron-based X-ray absorption spectroscopy (XANES). This information can support the development of measures to reduce excess P inputs to aquatic environments and thus make a fundamental contribution to environmental protection.

Prüter, J., Leipe, T., Michalik, D., Klysubun, W., Leinweber, P. (2019) Phosphorus speciation in sediments from the Baltic Sea, evaluated by a multi-method approach. Journal of Soils and Sediments, DOI: 10.1007/s11368-019-02518-w

P-Recyclate - Process engineering concepts for the recovery of agriculturally usable P-recyclates from residues of animal production

C. C. Metges (UR), J. Tränckner (UR)

The aim of this project is to develop a technological concept for the utilisation of valuable substances such as phosphorus contained in liquid manure and sludge from fish farms. The concept development was laboratory-based in order to develop suitable and mutually compatible methods for the following technological questions:
▸ Phase separation
▸ Digestion of phosphorus from the solids contained in the liquid manure
▸ Precipitation of phosphorus mainly with calcium
▸ Drying or separation of the obtained P-containing recyclates

To investigate a possible increase in phosphorus digestion, the samples were subjected to anaerobic pre-treatment. The fermentation significantly increased the phosphorus content in the liquid phase and slightly increased the phosphate content. Acid digestion of the phosphorus contained in the samples was investigated using sulphuric acid, citric acid and hydrochloric acid in various volume proportions. The highest mobilisation was achieved with sulphuric acid, so that almost all the phosphorus could be mobilised at a ratio of 1:0.8. A maximum of 80% of the phosphorus was mobilised with citric acid and hydrochloric acid. Precipitation mainly as calcium phosphates took place from a pH value of 8. The digestibility of the obtained P-recyclates was highest at low drying temperatures with 55%, where no calcium hydroxide had to be added. In evaluation of the test results, the conception of a process for phosphorus recovery from liquid manure and similar sludges was created. This concept was presented to small and medium-sized enterprises and discussed, resulting in a research proposal for further process development. Within the framework of this project outline, which has already been positively evaluated, a prototype is being built for phosphorus and nitrogen separation from liquid manure and similar media.

Based on the results, an application was successfully submitted to the BMBF (KMU innovativ): Optimisation of material cycles in agriculture through targeted fractionation of liquid manure into phosphorus; nitrogen and organic carbon (abbreviation: PNC-Processing).

P-Redox - Cyclovoltammometric measurements on phosphorus ligands

R. Francke (UR), C. Hering-Junghans (LIKAT)

Within the framework of this project, an electrochemical measuring stand was to be set up and the methodology established in the Hering-Junghans working group. With the help of such a measuring stand, electrochemical analyses such as cyclic voltammetry and differential pulse polarography can be carried out, which allow information to be obtained about the redox chemistry of chemical compounds.
An electrochemical measuring stand consists of a potentiostat, a measuring cell with electrodes and a control computer. This equipment was procured with the help of a "material cost grant" from the FCI and should now be installed and prepared for routine measurements as part of this project. To ensure an efficient setup, the Hering-Junghans junior research group collaborated with Dr. Robert Francke's junior research group at the University of Rostock. The Francke Group deals solely with electrochemical issues and represented a perfect contact for the realisation of this project. The seed project was successfully completed and the Hering-Junghans working group is now able to routinely perform electrochemical measurements under inert gas. In a first application, it was possible to show that triphosphiranes are irreversibly reduced, which was an important contribution to a publication in Chemical Science. In addition, CV measurements were carried out for the working group of Prof. Dr. Axel Schulz, which will potentially also result in a publication.

SERAIP - Shifted excitation Raman difference spectroscopy testing for analysis of inorganic phosphorus, inositol phosphates (InsPx) and myo-inositol in environmental and animal samples

K. Sowoidnich (FBH), M. Oster (FBN), B. Sumpf (FBH), M. Maiwald (FBH), R. Schumann (UR), P. Leinweber (UR), G. Tränkle (FBH), K. Wimmers (FBN)

In the diets of poultry and pigs, most of the daily requirement of phosphorus (P) is obtained from plants in the form of inositol phosphates (InsPx), which, however, cannot be used efficiently due to a lack or absence of endogenous phytase activity. Analytical measurements to improve the use of InsPx are therefore essential to reduce the environmental impact of animal husbandry and to conserve valuable mineral P resources. In the seed project, selected P-containing compounds were detected in complex matrices such as feed, faeces and soil/sediments via Raman spectroscopy or SERDS (e.g. phytate, InsP5, InsP3, myo-inositol, Ca(H2PO4)2, CaHPO4, Ca3(PO4)2, Ca2O7P2, β-glycerophosphate, DL-α-glycerol-6-phosphate). These alternative physical techniques thus represent an alternative to the costly and time-consuming chemical analysis. The results achieved in the seed project help to trace the whereabouts of P along the agricultural cycle in feed, animals, farm manure, soil and water.

Sowoidnich, K., Oster, M., Wimmers, K., Maiwald, M., Sumpf, B. (2021) Shifted excitation Raman difference spectroscopy as enabling technique for the analysis of animal feedstuff. Journal of Raman Spectroscopy, DOI: 10.1002/jrs.6140

Seed Projects Incentive Fund (2013-2015)

EvaPhoN - Evaluation of phosphorus digestion in most diverse natural materials

Different digestion methods for total phosphorus were compared. Dry masses and ashes of plants, animal tissues, soil and sediments, and seston were materials digested. The primary goal was not to find a best method, but to identify the most important work steps and provide the respective comparisons to the ScienceCampus for reference. In addition, the original sources of methods, reviews and method comparisons have been compiled. We further provide some ashes as reference material. The already thoroughly prepared working instructions will continue to be supplemented regularly, so that in a few years a methods manual will be created.

Contact: PD Dr. Rhena Schumann (University of Rostock)

P-Eff-Mo - Genetic and nutritional influences on the efficiency of phosphorus use in the diets of monogastric animals

With the aim of deriving measures for improving phosphorus (P) efficiency in monogastric animals, the molecular and physiological responses to varying P supply in weaned piglets were investigated in a first experiment. The amount of P fed above and below currently applicable recommendations was reflected in the deflection of physiological serum parameters such as inorganic phosphate, calcium, vitamin D3, parathormone, and cathepsin K, while zootechnical parameters such as live weight and feed intake showed no differences. Increased P intake had an effect on bone tissue at the structural (increased Bone Mineral Density and Structure Model Index) and transcriptional levels (activation of signaling pathways associated with bone metabolism). Multidisciplinary collaboration on the project has made it possible to detect P-dependent changes in metabolism using physiological, molecular, and bone morphological parameters. Genes that were expressed in a diet-dependent manner are the basis for finding candidate genes for breeding P-efficient animals.

Contact: Prof. Dr. Klaus Wimmers (FBN)

Method development for the determination of particulate glyphosate in the marine environment; bioavailability of glyphosate

Glyphosate is the active ingredient in herbicidal formulations such as Roundup®. The aim of the project was firstly to develop methods for the extraction of marine particulate glyphosate, and secondly to analyze its adsorption properties on agricultural soils in Mecklenburg-Vorpommern. Furthermore, the microbial degradation and potential bioavailability of glyphosate for the Baltic Sea should be investigated. Adsorption experiments were carried out with Baltic Sea sediments with high and low organic carbon content, sand and minerals. Glyphosate could be extracted by varying the pH depending on the soil type. While high extraction yields were achieved for glyphosate from minerals, the extraction efficiency from sediments was not yet satisfactory and needs further development. The adsorption isotherms generated for the collected soil samples, which are representative for the landscape of Mecklenburg-Vorpommern, indicate a very high affinity for glyphosate to the soils. Cell culture experiments with the cyanobacterium Nodularia spumigena, which is typical for the Baltic Sea, were performed. The results of the project will be used to develop further strategies, especially to identify the factors that significantly determine the adsorption properties of glyphosate.

Contact: Dr. Marion Kanwischer (IOW)

Phenotypic and molecular characterization of P use and uptake efficiency in Solanum tuberosum

This project aimed to gain initial knowledge on potato genetic resources with a focus on phosphorus efficiency (P-efficiency) and then submit a project proposal for a follow-up project. Data from the preliminary experiment conducted showed that different potato genotypes differ in their P efficiency, which is also consistent with data from the literature. Based on these findings, a project application with the topic "P-Efficiency of Potatoes" will be submitted to the Fachagentur für Nachwachsende Rohstoffe e.V. (FNR).

Contact: Prof. Dr. Ralf Uptmoor (University of Rostock)

RON - Recycling of phosphorus-based organocatalysts by nanofiltration

In this project, commercially available and organic solvent nanofiltration membranes (OSN) were investigated as a sustainable alternative for the separation of bifunctional phosphonium salts by distillation. The reaction and filtration process were optimized with respect to various process parameters (catalyst, solvent, membrane, etc.). Under the optimized conditions, catalyst retention was up to 99%, and it could be reused four times. The results have been submitted as a publication in an international peer-reviewed journal.

Contact: Dr. Thomas Werner (LIKAT)