570 Biowissenschaften, Biologie
Refine
Year of publication
Document Type
- Conference Proceeding (18)
- Article (12)
- Book (2)
- Doctoral Thesis (1)
- Other (1)
- Working Paper (1)
Keywords
- Alpha-glucan synthases (2)
- Aspergillus niger (2)
- Cell wall integrity (2)
- Crh transglycosylases (2)
- Fungal cell wall (2)
- Laser Rooting (2)
- Apfel (1)
- Aspergillus (1)
- Bio Lebensmittel (1)
- Blattdickenmessung (1)
Institute
- Fakultät AuL (34)
- Fakultät IuI (1)
The production of duckweed (Lemnaceae) as a novel protein source could make a valuable contribution to human nutrition. The greatly reduced habitus of duckweed enables simple cultivation with extremely low space requirements, making this free-floating freshwater plant ideal for substrate-free and vertical cultivation in controlled environment agriculture. Of particular importance in the design of a plant-producing Indoor Vertical Farming process is the determination of light intensity, as artificial lighting is generally the most energy-intensive feature of daylight-independent cultivation systems. In order to make the production process both cost-effective and low emission in the future, it is, therefore, crucial to understand and mathematically describe the primary metabolism, in particular the light utilization efficiency. To achieve this, a growth model was developed that mathematically describes the combined effects of plant density and light intensity on the growth rate of Lemna minor L. and physiologically explains the intraspecific competition of plants for light through mutual shading. Furthermore, the growth model can be utilized to derive environmental and process parameters, including optimum harvest quantities and efficiency-optimized light intensities to improve the production process.
Aspergillus niger is a filamentous fungus extensively utilized in industrial biotechnology for the production of enzymes, organic acids, and other metabolites. The increasing demand for enhanced protein production and efficient secretion pathways necessitates the development of novel screening methods. Although luciferase technology has been employed in mammalian cells and bacteria for an extended period, only recent advancements have expanded its applicability in fungal biology to investigate gene expression, signal transduction, and metabolic processes. The research landscape is shaped not only by optimization efforts and persistent challenges, but high-throughput methods are currently a primary focus, particularly for the screening of traits pertinent to industrial enzyme production.
In this study, we report successful heterologous expression and secretion of extracellular luciferases in A. niger. Using a luciferase-based high-throughput screening assay in 96-well plates, a sensitive method for evaluating the differences in secretion or production efficiency was introduced. This will be highly valuable for screening genetic modifications, for example, across mutant libraries of secretion signals, in future applications. Moreover, fusion of luciferases with homologous or heterologous proteins offers a straightforward approach for determining the secretion and production efficiencies of proteins, both without any enzymatic activity and with activity that is challenging to measure.
The findings of this study indicate that this novel assay addresses the limitations of conventional screening methodologies and may significantly enhance the application of luciferase technology in filamentous fungi. Moreover, the results demonstrate the potential for subsequent research to expand this approach, facilitating improved production systems for A. niger.
Multiple paralogs are found in the fungal genomes for several genes that encode proteins involved in cell wall biosynthesis. The genome of A. niger contains five genes encoding putative α-1,3-glucan synthases (AgsA-E) and seven genes encoding putative glucan-chitin crosslinking enzymes (CrhA-G). Here, we systematically studied the effects of the deletion of single (agsA or agsE), double (agsA and agsE), or all five ags genes (agsA-E) present in A. niger. Morphological and biochemical analysis of ags mutants emphasizes the important role of agsE in cell wall integrity, while deletion of other ags genes had minimal impact. Loss of agsE compromised cell wall integrity and altered pellet morphology in liquid cultures.
Previous studies have indicated that deletion of all crh genes in A. niger did not result in cell wall integrity-related phenotypes. To determine whether the ags and crh gene families have redundant functions, both gene families were deleted using iterative CRISPR/Cas9 mediated genome editing. The 12-fold deletion mutant was viable and did not exhibit growth defects under non-stressing growth conditions. A synergistic effect on cell wall integrity was observed in this 12-fold deletion mutant, particularly when exposed to cell wall-perturbing compounds. The cell wall composition, extractability of glucans by alkali, and scanning electron microscopy analysis showed no differences between the parental strain and mutants lacking ags genes, crh genes, or both. These observations underscore the ability of fungal cells to adapt and secure cell wall integrity, even when two entire cell wall protein-encoding gene families are missing.
Comparison of manual and automatic barcode detection in rough horticultural production systems
(2019)
Ein von 2016-2020 durchgeführtes Forschungsvorhaben hat die Praxis der Strategischen Umweltprüfung in Deutschland durch eine retrospektive Gesetzesfolgenabschätzung evaluiert, etwaige Defizite ermittelt und Gestaltungsoptionen für einen effizienten und effektiven Vollzug erarbeitet. Kernstück der Evaluation ist eine empirische Untersuchung anhand von Fallstudien in einem gestuften Vorgehen (Kaskadenmodell). Zum Einsatz kommt ein Methodenmix aus Dokumentenanalysen, Fragebögen und Interviews mit den jeweils beteiligten Akteuren sowie Workshops. Die Auswertung erfolgt sowohl quantitativ als auch qualitativ. Der Beitrag stellt Methodik und Erhebungskonzept des Projekts vor. Die gewonnenen Ergebnisse bleiben einem weiteren Aufsatz vorbehalten.
Durch Kartoffelviren kommt es zu erheblichen Ertragsverlusten in der Produktion sowie zu Qualitätseinbußen in der Züchtung und Vermehrung von Kartoffeln. Die frühzeitige Bereinigung von befallenen Vermehrungsbeständen hat sich als effektivste Maßnahme zur Vermeidung von Virusbefall bewährt. Die manuelle Selektion von Viren im Feldbestand ist mit hohem personellen Aufwand verbunden. Da erkrankte Pflanzen nicht immer eindeutige, selektierbare Symptome zeigen, lassen sich nicht alle virenbefallenen Pflanzen in Feldbeständen selektieren. Durch den Technologiefortschritt im Bereich der bildgebenden Sensortechnik zeigen sich neue Ansätze für die Detektion von viruskranken Pflanzen in Feldbeständen. Moderne Sensoren bieten die Möglichkeit, georeferenzierte und hochauflösende Informationen zum Virusbefall zu gewinnen. Die Sensoren können dabei boden- bzw. luftgestützt eingesetzt werden.