Refine
Document Type
- Article (4)
- Conference Proceeding (1)
- Other (1)
Is part of the Bibliography
- yes (6)
Keywords
- Lemnaceae (3)
- Standardized production (2)
- Water lentils (2)
- Yield (2)
- Amino acid (1)
- Amino acids (1)
- Animal nutrition (1)
- Animal performance (1)
- Biomass production (1)
- Controlled environment (1)
Institute
- Fakultät AuL (6) (remove)
Duckweeds are fast-growing and nutritious plants, which are gaining increased attention in different fields of application. Especially for animal nutrition, alternative protein sources are needed to substitute soybean meal. The current bottleneck is the standardized production of biomass, which yields stable quantities of a defined product quality. To solve this problem, an indoor vertical farm (IVF) for duckweed biomass production was developed. It consists of nine vertically stacked basins with a total production area of 25.5 m2. The nutrient solution, a modified N-medium, re-circulated within the IVF with a maximum flow rate of 10 L min−1. Nutrients were automatically added based on electrical conductivity. In contrast, ammonium was continuously supplied. A water temperature of 23 °C and a light intensity of 105 μmol m−2 s−1 with a photoperiod of 12:12 h were applied. During a 40-day production phase, a total of 35.6 kg of fresh duckweed biomass (equals 2.1 kg of dried product) was harvested from the IVF. On average, 0.9 kg day−1 of fresh biomass was produced. The dried product contained 32% crude protein (CP) and high levels of proteinogenic amino acids (e.g. lysine: 5.42 g, threonine: 3.85 g and leucine: 7.59 g/100 g CP). Biomass of this quality could be used as a protein feed alternative to soybean meal. The described IVF represents a modular model system for duckweed biomass production in a controlled environment and further innovations and upscaling processes.
Duckweed is gaining attention in animal nutrition and is considered as a potential alternative protein source for broiler chickens. In order to evaluate the nutritional value of duckweed, three individual batches were investigated. They consisted of a mixture of Lemna minuta and Lemna minor (A, 17.5% crude protein), Spirodela polyrhiza (B, 24.6% crude protein) and Lemna obscura (C, 37.0% crude protein). Treatment diets contained 50% batch A, 50% batch B, and 25, 50 and 75% of batch C. All diets were fed to broiler chickens (Ross 308) from an age of 21 to 27 days. Diets with a share of 50 and 75% of batch C led to decreased feed intake (109.3 and 74.9 g/day, respectively) compared to the control. Standardized ileal digestibility of crude protein and amino acids differed significantly between duckweed batches, at values for methionine between 49.9 and 90.4%. For all amino acids, batch A consistently had the lowest and batch C the highest digestibility. Batches had different tannin contents of 2943, 2890 and 303 mg/kg for batches A, B and C, respectively. The apparent ileal digestibility of phosphorus differed significantly between all batches (50.8–78.9%). Duckweed can be used as a protein feed for broiler chickens. However, a defined and stable biomass composition optimized for the requirements of broiler chickens is needed.
Obst und Gemüse sind reich an gesundheitsfördernden Inhaltsstoffen und stellen einen wichtigen Bestandteil einer gesunden Ernährung dar. Sind roh verzehrbare frische Produkte mit humanpathogenen Erregern kontaminiert, können sie jedoch Infektionen und Lebensmittelvergiftungen auslösen. Diese Literaturstudie gibt auf Basis aktueller Publikationen einen Überblick über Quellen und Eintragswege humanpathogener Bakterien und Viren sowie über Präventions- und Dekontaminationsmaßnahmen entlang der Produktions- und Verarbeitungskette von Obst und Gemüse. Auf pflanzlichen Oberflächen sind humanpathogene Erreger vergleichsweise unwirtlichen Umweltbedingungen ausgesetzt, wie z.B. wechselnden Klimabedingungen, Nährstoffmangel, der Konkurrenz mit dem natürlichen Mikrobiom und pflanzlichen Immunreaktionen. Die Überlebensfähigkeit bakterieller Erreger auf frischen Produkten ist daher von ihrer Anpassungs- und Konkurrenzfähigkeit abhängig. Diese beruht auf spezifischen Eigenschaften, wie der Fähigkeit zur Anpassung des Stoffwechsels, zur Adhäsion an die pflanzliche Oberfläche und zum Schutz vor biotischen und abiotischen Umwelteinflüssen. Zur Anpassung humanpathogener Bakterien an Habitate außerhalb des menschlichen bzw. tierischen Wirtes können mobile genetische Elemente beitragen, die durch horizontalen Gentransfer übertragen werden. Ein verbessertes Verständnis dieser ökologischen Wechselwirkungen wird die Identifikation neuer Ansatzpunkte zur Verbesserung der mikrobiellen Lebensmittelsicherheit vorantreiben. Das gewachsene wissenschaftliche Interesse hat auch zu einer Weiterentwicklung der mikrobiologischen Methoden und der quantitativen Risikobewertung geführt. Basierend auf diesem breiten Literaturüberblick werden abschließend kritische Verständnislücken und entscheidende wissenschaftliche Fragestellungen im Bereich der mikrobiellen Sicherheit verzehrfertiger pflanzlicher Lebensmittel aufgezeigt. Als Leser haben Sie die Möglichkeit, diese Literaturstudie auch ausgehend von den resultierenden wissenschaftlichen Fragestellungen in Kapitel 10 zu lesen, die Sie zu den entsprechenden Kapiteln führen.
In order to produce protein-rich duckweed for human and animal consumption, a stable cultivation process, including an optimal nutrient supply for each species, must be implemented. Modified nutrient media, based on the N-medium for duckweed cultivation, were tested on the relative growth rate (RGR) and crude protein content (CPC) of Lemna minor and Wolffiella hyalina, as well as the decrease of nitrate-N and ammonium-N in the media. Five different nitrate-N to ammonium-N molar ratios were diluted to 10% and 50% of the original N-medium concentration. The media mainly consisted of agricultural fertilizers. A ratio of 75% nitrate-N and 25% ammonium-N, with a dilution of 50%, yielded the best results for both species. Based on the dry weight (DW), L. minor achieved a RGR of 0.23 ± 0.009 d−1 and a CPC of 37.8 ± 0.42%, while W. hyalina’s maximum RGR was 0.22 ± 0.017 d−1, with a CPC of 43.9 ± 0.34%. The relative protein yield per week and m2 was highest at this ratio and dilution, as well as the ammonium-N decrease in the corresponding medium. These results could be implemented in duckweed research and applications if a high protein content or protein yield is the aim.
Duckweeds can be potentially used in human and animal nutrition, biotechnology or wastewater treatment. To cultivate large quantities of a defined product quality, a standardized production process is needed. A small-scale, re-circulating indoor vertical farm (IVF) with artificial lighting and a nutrient control and dosing system was used for this purpose. The influence of different light intensities (50, 100 and 150 µmol m−2 s−1) and spectral distributions (red/blue ratios: 70/30, 50/50 and 30/70%) on relative growth rate (RGR), crude protein content (CPC), relative protein yield (RPY) and chlorophyll a of the duckweed species Lemna minor and Wolffiella hyalina were investigated. Increasing light intensity increased RGR (by 67% and 76%) and RPY (by 50% and 89%) and decreased chlorophyll a (by 27% and 32%) for L. minor and W. hyalina, respectively. The spectral distributions had no significant impact on any investigated parameter. Wolffiella hyalina achieved higher values in all investigated parameters compared to L. minor. This investigation proved the successful cultivation of duckweed in a small-scale, re-circulating IVF with artificial lighting.