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Zeitschriftenbeiträge (peer-reviewed)


Weckesser, F.; Leßke, F.; Luthardt, M.; Hülsbergen, K. (2021): Conceptual Design of a Comprehensive Farm Nitrogen Management System. Agronomy 11, 2501 (12). DOI: 10.3390/agronomy11122501
 Volltext   Open Access

Data that are required for nutrient management are becoming increasingly available in digital format, leading to a high innovation potential for digital nitrogen (N) management applications. However, it is currently difficult for farmers to analyze, assess, and optimize N flows in their farms using the existing software. To improve digital N management, this study identified, evaluated, and systematized the requirements of stakeholders. Furthermore, digital farm N management tools with varying objectives in terms of system boundaries, data requirements, used methods and algorithms, performance, and practicality were appraised and categorized. According to the identified needs, the concept of a farm N management system (FNMS) software is presented which includes the following modules: (1) management of site and farm data, (2) determination of fertilizer requirements, (3) N balancing and cycles, (4) N turnover and losses, and (5) decision support. The aim of FNMS is to support farmers in their farming practices for increasing N efficiency and reducing environmentally harmful N surpluses. In this study, the conceptual requirements from the agricultural and computer science perspectives were determined as a basis for developing a consistent, scientifically sound, and user-friendly FNMS, especially applicable in European countries. This FNMS enables farmers and their advisors to make knowledge-based decisions based on comprehensive and integrated data.

Wahmann, R.; Moser, S.; Bieber, S.; Cruzeiro, C.; Schröder, P.; Gilg, A.; Leßke, F.; Letzel, T. (2021): Untargeted Analysis of Lemna minor Metabolites: Workflow and Prioritization Strategy Comparing Highly Confident Features between Different Mass Spectrometers. Metabolites 11, 832 (12). DOI: 10.3390/metabo11120832
 Volltext   Open Access

Metabolomics approaches provide a vast array of analytical datasets, which require a comprehensive analytical, statistical, and biochemical workflow to reveal changes in metabolic profiles. The biological interpretation of mass spectrometric metabolomics results is still obstructed by the reliable identification of the metabolites as well as annotation and/or classification. In this work, the whole Lemna minor (common duckweed) was extracted using various solvents and analyzed utilizing polarity-extended liquid chromatography (reversed-phase liquid chromatography (RPLC)-hydrophilic interaction liquid chromatography (HILIC)) connected to two time-of-flight (TOF) mass spectrometer types, individually. This study (introduces and) discusses three relevant topics for the untargeted workflow: (1) A comparison study of metabolome samples was performed with an untargeted data handling workflow in two different labs with two different mass spectrometers using the same plant material type. (2) A statistical procedure was observed prioritizing significant detected features (dependent and independent of the mass spectrometer using the predictive methodology Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA). (3) Relevant features were transferred to a prioritization tool (the FOR-IDENT platform (FI)) and were compared with the implemented compound database PLANT-IDENT (PI). This compound database is filled with relevant compounds of the Lemnaceae, Poaceae, Brassicaceae, and Nymphaceae families according to analytical criteria such as retention time (polarity and LogD (pH 7)) and accurate mass (empirical formula). Thus, an untargeted analysis was performed using the new tool as a prioritization and identification source for a hidden-target screening strategy. Consequently, forty-two compounds (amino acids, vitamins, flavonoids) could be recognized and subsequently validated in Lemna metabolic profile using reference standards. The class of flavonoids includes free aglycons and their glycosides. Further, according to our knowledge, the validated flavonoids robinetin and norwogonin were for the first time identified in the Lemna minor extracts.


Krappmann, M.; Leßke, F.; Letzel, T.; Luthardt, M. (2015): The Software-Landscape in (Prote)Omic Research. Journal of Proteomics & Bioinformatics 8 (7), S. 164-175. DOI: 10.4172/jpb.1000365
 Volltext   Open Access

(Bio)Informatics plays a major role in (prote)omic research experiments and applications. Analysis of an entire proteome including protein identification, protein quantification, detecting biological pathways, metabolite identification and others is not possible without software solutions for analyzing the resulting huge data sets. In the last decade plenty of software-tools, -platforms and databases have been developed by vendors of analytical hardware, as well as by freeware developers and the open source software community. Some of these software packages are very much specialized for one (omic) topic, as for example genomics, proteomics, interactomics or metabolomics. Other software tools and platforms can be applied in a more general manner, e.g. for generating workflows, or performing data conversion and data management, or statistics. Nowadays the main problem is not to find out a way, how to analyze the experimental data, but to identify the most suitable software for this purpose in the vast software-landscape. This review focuses on the following issue: How complex is the link between biology, analysis and (bio) informatics, and how complex is the variety of software tools to be used for scientific investigations, starting from microorganisms up to the detection of a proteome. Thereby the main emphasis is on the variety in software for (LC) MS(/MS) proteomics. In the World Wide Web sites like ExPASy show extensive lists of proteomics software, leaving it to the user to identify which software actually serves their purposes. First we consider the huge variability of software in the field of proteomics research. Then we take a closer look on the variability of MS data and the incompatibilities of software tools with respect to that. We give an overview over commonly used software technologies and finally end up with the question, whether open source software would not add more value to this field.

Wissenschaftliche Poster


Donauer, J.; Luthardt, M.; Leßke, F.; Hülsbergen, K. (2021): Development of a web-based farm-nutrient-management system: requirements and model structure, AGROSYM 2021: XII International Agriculture Symposium, Bosnien-Herzegovina.

Weckesser, F.; Hülsbergen, K.; Leßke, F. (2021): Integration of diverse data into a Farm-Nitrogen-Mangement System (FNMs). Mitteilungen der Gesellschaft für Pflanzenbauwissenschaften, 63- Jahrestagung der Gesellschaft für Pflanzenbauwissenschaften e.V., Closing the Cycle: Pflanze und Tier im Agrarsystem Band 32, S. 138.

Weckesser, F.; Hülsbergen, K.; Luthardt, M.; Leßke, F. (2021): Wissensbasierte Entscheidungsunterstützung zum Umbruch von Leguminosen-Gras Beständen. Tagung: Nährstoffmanagement im ökologischen Landbau, 26. und 27. August 2021, TUM School of Life Sciences - Weihenstephan.


Krappmann, M.; Leßke, F.; Letzel, T. (2013): Achroma - a software strategy for analysing (a-)typical mass spectrometric data. Anakon-Tagung, 4. bis 7. März 2013, Essen - Deutschland.


Luthardt, M.; Krappmann, M.; Leßke, F.; Letzel, T. (2012): openMASP – high performance software technology for analytical chemistry. Umweltsymposium, Leipzig - Deutschland.


Krappmann, M.; Luthardt, M.; Wenig, P.; Leßke, F.; Letzel, T. (2011): Cloudy Analytics – High Performance Software Technology for Analytical Chemistry. 8. Langenauer Wasserforum, 07.-08.11.2011, Langenau - Deutschland.

Prof. Dr. Frank Leßke

Hochschule Weihenstephan-Triesdorf

Fakultät Bioingenieurwissenschaften
Am Hofgarten 10
85354 Freising

T +49 8161 71-5780