Bettina Scholz

BioPol ehf. Skagaströnd · Phycology Marine Biotechnology

Report Summary Title Food-grade alginate from tissue cultivated brown seaweeds in a biorefinery approach Authors Scholz, B.; Örlygsson, G.; Moss, C.; Karsten, U. Doi Date 01.11.2023 Funding: Matvaelasjóður-Kelda 2022 Summary: Reproducible production yields and high-quality alginate from brown seaweeds can only be achieved by tissue cultivation, sin...

Seaweeds are a renewable natural source of a plethora of valuable compounds that have attracted the attention of scientists in recent years. Following the concepts of sustainability and zero-waste policy, the aim of the present study was to reduce pressures on the environment by the use of a sequential multiproduct biorefinery approach in combinati...

Zoosporic parasites (i.e. fungi and fungi-like aquatic microorganisms) constitute important drivers of natural populations, causing severe host mortality. Economic impacts of parasitic diseases are notable in the microalgae biotech industry, affecting production of food ingredients, biofuels, pharma- and nutraceuticals. While scientific research on...

Synthetic polymers are potent environmental toxic pollutants which are non-degradable and are accumulating in the environment. Therefore, the efforts of scientists have been focused on alternative natural biopolymers. Among the biodegradable polymers, polyhydroxyalkanoates (PHAs), including polyhydroxy-butyrate (PHB), have been recently recognized...

Report Summary ISBN: xxxx-xxxx Title Northern Icelandic marine microalgae as health promoting multi-functional feed protein and lipid source for Atlantic salmon (Salmo salar)-A whole algae concept Authors Scholz, B.; Karsten, U.; Örlygsson, G.; van West, P. Árnason, K. H. Summary: An increase in fish consumption, combined with a decrease in wild fi...

Seaweeds constitute one of the commercially important renewable marine living resources in coastal areas. To cope to extreme conditions, they have evolved unique compounds not found in higher plants. These compounds are group specific, and their concentrations vary depending on seasons and grade of exposure in wild seaweeds. Phlorotannins are a gro...

Overall, 12 northern Icelandic red algae from the BioPol indoor culture collection were tested for their potential to accumulate sulfated polysaccharides (sPS) under exposure to different stress conditions. Utilizing the one-factor-at-a-time principle, the test algae were exposed to a) 20°C, b) 45 PSU, c) 2000 μmol photons m −2 s −1 , d) very stron...

Obligate endoparasitic oomycetes are known to ubiquitously occur in marine and freshwater diatoms, but their diversity is still largely unexplored. Many of these parasitoids are members of the early-diverging oomycete lineages (Miracula, Diatomophthora), others are within the Leptomitales of the Saprolegniomycetes (Ectrogella, Lagenisma) and some h...

Microplastics have been found in most parts of the world including the cryosphere, the part of the Earth’s surface characterized by frozen water. Surprisingly, high concentration of microplastics has been observed in some cryosphere areas. Shrinking of the cryosphere could release considerable amount of microplastics entrapped in sea ice and glacie...

The genus Sirolpidium (Sirolpidiaceae) of the Oomycota includes several species of holocarpic obligate aquatic parasites. These organisms are widely occurring in marine and freshwater habitats, mostly infecting filamentous green algae. Presently, all species are only known from their morphology and descriptive life cycle traits. None of the seven s...

Investigations into simple holocarpic oomycetes are challenging, because of the obligate biotrophic nature of many lineages and the periodic presence in their hosts. Thus, despite recent efforts, still, the majority of species described remains to be investigated for their phylogenetic relationships. One of these species is Aphanomycopsis bacillari...

In principle, the enhancement of photoprotective compounds in response to UV stress was successful, although for example the MAA concentrations obtained initially were low and only in the range of natural occurring ones found in phytoplankton communities according to literature. Even in the final experiment under optimised conditions MAA concentrat...

Index Fungorum, Species Fungorum and MycoBank are the key fungal nomenclature and taxonomic databases that can be sourced to find taxonomic details concerning fungi, while DNA sequence data can be sourced from the NCBI, EBI and UNITE databases. Nomenclature and ecological data on freshwater fungi can be accessed on http://fungi.life.illinois.edu/,...

Chytridiomycota, often referred to as chytrids, can be virulent parasites with the potential to inflict mass mortalities on hosts, causing e.g. changes in phytoplankton size distributions and succession, and the delay or suppression of bloom events. Molecular environmental surveys have revealed an unexpectedly large diversity of chytrids across a w...

Key Ecological Roles for Zoosporic True Fungi in Aquatic Habitats, Page 1 of 2 Abstract The “Aquatic Phycomycetes” (sensu Sparrow) ( 1 ) constitutes an ecologically and economically important assemblage of eukaryotic microorganisms that share many morphological traits and ecological functions and interact with each other in the same aquatic ecosy...

Little is known about the role of chemotaxis in the location and attachment of chytrid zoospores to potential diatom hosts. Hypothesizing that environmental stress parameters affect parasite-host recognition, four chytrid-diatom tandem cultures (Chytridium sp./Navicula sp., Rhizophydium type I/ Nitzschia sp., Rhizophydium type IIa/Rhizosolenia sp.,...

The influence of environmental factors on the infection susceptibility of four different marine diatom host species to chytrid infection was tested under laboratory conditions, using host and parasite isolates obtained from diverse coastal areas in north-west Iceland in 2015. Specifically, a total of 120 monoclonal marine diatom host cultures of Na...

Seaweeds constitute one of the commercially important renewable marine living resources in Icelandic coastal areas. In the present study overall 16 seaweed species were brought into culture during a course of two years. In detail, two chlorophyceae (Ulva lactuca, Cladophora arcta), three phaeophyceae (Fucus spiralis, Fucus vesiculosus, Dictyosiphon...

The presence of eukaryotic parasites (i.e. chytridiomycetes and oomycetes) infecting benthic marine diatoms was revealed by a reconnaissance survey in the Solthörn tidal flat (southern North Sea, Germany) followed by 5 months of regular monitoring in order to assess the impact of these zoosporic fungal pathogens on microphytobenthic diatom communit...

Living organisms in aquatic ecosystems are almost constantly confronted by pathogens. Nevertheless, very little is known about diseases of marine diatoms, the main primary producers of the oceans. Only a few examples of marine diatoms infected by zoosporic parasites are published, yet these studies suggest that diseases may have significant impacts...

Marine microphytobenthic community composition in relation to habitat characteristics of sub-tidal flats in temperate and Arctic regions is well described. For sub-Arctic areas, especially for northern Icelandic intertidal flats, information is sparse or absent. To investigate sub-Arctic microphytobenthic community composition, surface sediments we...

Using sediment samples from the Solthörn tidal flat (southern North Sea, Germany), collected in bi-weekly intervals from June to July 2012, a range of qualitative and quantitative screening methods for oomycete and chytrid pathogens infecting benthic diatoms were evaluated. Pre-treatment of sediment samples using short ultrasound pulses and gradien...

Diatoms inhabiting intertidal flats are subject to strongly changing environmental conditions, which have a great influence on the oxygen, sulphide and pH gradients in the sediments. In previous studies, variations in pH in the range from 6.5 to 8.5 had only minor effects on the growth of benthic diatoms. In order to determine the physiological res...

Marine benthic diatoms growing in biofilms on sediment surfaces generally occur associated with heterotrophic bacteria, whereas modern molecular techniques and analyses of species-specific physiology create a demand for axenic cultures. Numerous benthic diatoms were isolated from surface sediments during a monitoring of the Solthörn tidal flat (sou...

Benthic diatoms inhabiting intertidal flats face highly variable environmental conditions, due to changing water levels and exposure during low tide. The present study is the second part of a more extensive study of the adaptive potential of these species in response to varying UV radiations in the Solthörn tidal flat (Lower Saxony, southern North...

The unconsolidated sediment of intertidal mudflats constitutes a highly unstable environment, due to continuously changing water levels and currents as well as temporary exposure to the air. Therefore, diatoms inhabiting marine intertidal areas are subjected to strongly changing surface light and UVintensities due to exposure at low tide. Five mari...

Alexandrium spp., Dinophysis spp. and Pseudo-nitzschia spp. are known to produce different classes of toxins, which are bio-accumulated in filter feeders such as the blue mussel Mytilus edulis during ingestion. If theses mussels are consumed by humans, these toxins can cause different illnesses and in some cases lead to death. Due their mode of act...

Microphytobenthic organisms inhabiting marine intertidal areas are subjected to strongly changing temperature and surface light regimes due to evaporation at low tide. In addition, seasonal fluctuations in temperatures significantly influence the taxonomic composition of benthic diatom communities in intertidal flats. In order to determine the phys...

Several monitoring events in different freshwater, brackish water and marine habitats were conducted in the years 2004–2011. In some cases, mass occurrences of potential toxic species were accompanied by other species. While the antibacterial toxicity tests (LUMIStox) of samples showed the highest values, the producing taxa were not identified, alt...

Diatoms inhabiting intertidal flats are subject to strongly changing salinities due to exposure to rain and desiccation at low tide. In order to determine the physiological responses of marine benthic diatoms to salinity changes, cultures of Navicula phyllepta, Achnanthes delicatula subsp. hauckiana and Nitzschia constricta, isolated from the Solth...

Marine intertidal flats are colonized by diatom-dominated biofilms, whereas coccoid and filamentous cyanobacteria usually occur only at some stages during the growth season. Increasingly, cyanobacteria were most abundant during warmer seasons, outcompeting other taxa and we assumed direct competition between diatoms and cyanobacteria. Therefore, th...

The microphytobenthos colonizing the intertidal flats forms an important component of the Wadden Sea. Ten sampling points along a 1-km transect were studied in a fringe area of the Solthörn tidal flat, southern North Sea, in order to determine seasonal differences in the microphytobenthos. An accompanying paper deals with the major component of the...

The benthic diatoms composition of the surface sediments were sampled at two-weekly intervals from May 2008 to May 2009 at ten stations along a transect across the intertidal zone of the Solthörn tidal flat (southern North Sea, Germany). Inorganic macronutrients (nitrate, nitrite, silicic acid and reactive dissolved phosphate) in the overlying wate...

Twenty-five intertidal diatom species were isolated from the Solthörn tidal flat (Lower Saxony, southern North Sea) and grown in semi-continuous cultures under standardised conditions, in order to observe differences in their biochemical gross compositions (e.g. protein, lipid, carbohydrate and ash contents). Composition, expressed as % dry weight,...

We tested two non-nodularin-producing strains of the cyanobacterium Nodularia spumigena, isolated from a marine (Kachelotplate) and a brackish water (Banter Sea, Wilhelmshaven) habitat in Lower Saxony, Germany, for allelochemical production (e.g. alkaloids, flavonoids) and allelopathic activities (e.g. algicidal, anti-microbial). The growth experim...

Bioassays employing the luminescent bacterium Vibrio fischeri (LUMIStox system), the brine shrimp (Artemia salina) as well as the acetylcholinesterase inhibition test were used to evaluate sediment toxicity of surface sediments from five East Sumatra rivers. In March and November of 2008 samples were collected from Rokan, Siak, Kampar, Indragiri an...

The unconsolidated sediment of intertidal mudflats constitutes a highly unstable environment, due to continuously changing water levels and currents, as well as temporary exposure to the air. As a consequence, diatoms inhabiting marine intertidal areas are subjected to wide variations in temperature, surface light intensity and salinity due to expo...

Culture media of 24 commonly occurring microalgal and cyanobacteria species were subjected to a screening for total alkaloids, saponins, and phenol compounds, especially flavonoids and tannins. Both Wagner's and Mayer's reagents were employed in the alkaloid screening. Ferric chloride solution was used to detect phenolic compounds. Tannins were ide...