1. Nutritional quality and safety of the spirulina dietary supplements sold on the Slovenian marketJasmina Masten, Marta Jagodic Hudobivnik, Marijan Nečemer, Katarina Vogel-Mikuš, Iztok Arčon, Nives Ogrinc, 2022, original scientific article Abstract: The microalgae Spirulina may be a popular dietary supplement rich in essential nutrients
and vitamins, but oversight of the supplement industry, in general, remains limited, and increasing
incidents of adulteration, misbranding, and undeclared ingredients together with misleading claims
create potential risks. In response, this study characterized the elemental, amino acid and fatty acid
content of commercially available Spirulina supplements in Slovenia using EDXRF, ICP-MS and
GC-MS and compared the results with their nutritional declaration. The gathered data confirm that
Spirulina supplements are a good source of calcium (0.15 to 29.5% of RDA), phosphorous (3.36–26.7%
of RDA), potassium (0.5 to 7.69% of RDA) and selenium (0.01 to 38.6% of RDA) when consumed
within recommended amounts. However, although iron contents were relatively high (7.64 to 316%
of RDA), the actual bioavailability of iron was much lower since it was mainly present as the ferric
cation. This study also confirms that pure Spirulina supplements are a good source of essential
and non-essential amino acids, and !-6 but not !-3 polyunsaturated fatty acids. The presence of
additives resulted in significant variation in nutrient content and, in some instances, lower product
quality. Moreover, a high proportion (86.7%) of inappropriate declarations regarding the elemental
content was observed. Overall, the study conclusions underline the need for a stricter control system
for Spirulina-based supplements. Keywords: Spirulina, microalgae, cyanobacteria, elements, toxic elements, amino acids, fatty acids, authenticity, safety, quality Published in RUNG: 24.03.2022; Views: 2276; Downloads: 0 This document has many files! More... |
2. FUNCTIONALIZED NANOBODIES AS DIAGNOSTIC REAGENTS FOR THE DETECTION OF TOXIC MICROALGAESandra Oloketuyi, 2020, doctoral dissertation Abstract: Early detection and monitoring of toxic microalgae remains a challenge that will be necessary to overcome for understanding harmful algal bloom events and their consequent ecological and environmental impacts. Although there are diagnostic techniques based on microscopy, fluorescence in situ hybridization (FISH), DNA microarrays, real-time PCR, sandwich hybridization assays employed for the detection of harmful algal species, such techniques are not suitable for field monitoring and especially for the quantification of Alexandrium minutum due to abundance of cryptic species that cannot be differentiated based on morphology or genomic traits. These approaches are also time-consuming and laborious, hence there is need for alternative simple, rapid and cost-effective methods. In this study, our aim was to develop different nanobody-based capture strategies for the detection of A. minutum. Nanobodies were successfully displayed on the surface of Escherichia coli to facilitate detection of A. minutum. The method is simple and cost effective as no antibody purification step is necessary. As an alternative, A. minutum was quantified by exploiting the peroxidase activity of a G-quadruplex DNAzyme covalently bound to nanobodies and by means of a label free electrochemical immunosensor which exploit nanobodies bound via an irreversible SpyTag-SpyCatcher system as the specific immunocapture element. Such immunosensor was prepared by immobilizing the SpyTagged anti-A. minutum nanobody (SpyTagged C1) by means of a selfassembled monolayer (SAMs) of L- cysteine (L-Cys) displayed onto a gold nanoparticle-modified glassy carbon electrode. Electrochemical Impedance Spectroscopy (EIS) was performed to measure the electrical response of the circuit as the function of A. minutum immunocaptured cells. The results of EIS studies confirmed that the sensing chip detected A. minutum selectively, exhibited a wide dynamic range spanning from 103 to 109 cell L-1 and a limit of detection of 3.1× 103 cell L-1. The immunosensor data can be recorded and then analyzed with a portable potentiostat. Such device can be interfaced with a smart phone, a condition suitable for the rapid A. minutum quantification in situ. Keywords: Alexandrium minutum, nanobodies, bioreagents, immunosensor, toxic microalgae Published in RUNG: 17.06.2020; Views: 4813; Downloads: 240 Full text (2,95 MB) |
3. Electrochemical immunosensor functionalized with nanobodies for the detection of the toxic microalgae Alexandrium minutum using glassy carbon electrode modified with gold nanoparticlesSandra Oloketuyi, Elisa Mazzega, Janez Zavašnik, Kingkan Pungjunun, Kurt Kalcher, Ario De Marco, Eda Mehmeti, 2020, original scientific article Keywords: biosensors, toxic microalgae, nanobodies, impedance Published in RUNG: 07.02.2020; Views: 4048; Downloads: 0 This document has many files! More... |
4. Nanobody Engineering Provides Diagnostic Reagents For The Quantification Of The Toxic Microalgae Alexandrium minutumRobert Alvin Bernedo-Navarro, Sandra Oloketuyi, Giulio Bernardinelli, Eda Mehmeti, Kurt Kalcher, Ario De Marco, 2019, published scientific conference contribution abstract Keywords: Nanobodies, DNAzyme, electrochemical impedance spectroscopy, toxic microalgae Published in RUNG: 09.09.2019; Views: 4240; Downloads: 0 This document has many files! More... |
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