English
norskBlar i forfatter "Hansen, Espen Holst"
Viser treff 1-14 av 14
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Adding zooplankton to the OSMAC toolkit: Effect of grazing stress on the metabolic profile and bioactivity of a diatom
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-03)“One strain many compounds” (OSMAC) based approaches have been widely used in the search for bioactive compounds. Introducing stress factors like nutrient limitation, UV-light or cocultivation with competing organisms has successfully been used in prokaryote cultivation. It is known that diatom physiology is affected by changed cultivation conditions such as temperature, nutrient concentration and ... -
Antimicrobial Activity of Securamines From the Bryozoan Securiflustra securifrons
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-21)Natural products and their derivatives have served as powerful therapeutics against pathogenic microorganisms and are the mainstay of our currently available treatment options to combat infections. As part of our ongoing search for antimicrobial natural products from marine organisms, one fraction prepared from the Arctic marine bryozoan <i>Securiflustra securifrons</i> was found to be active against ... -
Bioactivity of a Marine Diatom (Porosira glacialis [Grunow] Jorgensen 1905) Cultivated With and Without Factory Smoke CO2
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-16)Using industrial emissions as a strategy for CO<sub>2</sub> sequestration through carbon capture and utilization (CCU) in cultivation of microalgae can potentially change cultivation factors such as pH, nutrient availability and presence of trace metals, which could alter the growth and metabolism of the microalgae. It is therefore important to investigate whether such changes in culturing conditions ... -
Bioassay-Guided Fractionation Leads to the Detection of Cholic Acid Generated by the Rare Thalassomonas sp.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-20)Bacterial symbionts of marine invertebrates are rich sources of novel, pharmaceutically relevant natural products that could become leads in combatting multidrug-resistant pathogens and treating disease. In this study, the bioactive potential of the marine invertebrate symbiont Thalassomonas actiniarum was investigated. Bioactivity screening of the strain revealed Gram-positive specific antibacterial ... -
Bioassay-Guided Fractionation Leads to the Detection of Cholic Acid Generated by the Rare Thalassomonas sp.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-20)Bacterial symbionts of marine invertebrates are rich sources of novel, pharmaceutically relevant natural products that could become leads in combatting multidrug-resistant pathogens and treating disease. In this study, the bioactive potential of the marine invertebrate symbiont Thalassomonas actiniarum was investigated. Bioactivity screening of the strain revealed Gram-positive specific antibacterial ... -
Biomaterials and Bioactive Natural Products from Marine Invertebrates: From Basic Research to Innovative Applications
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-22)Aquatic invertebrates are a major source of biomaterials and bioactive natural products that can find applications as pharmaceutics, nutraceutics, cosmetics, antibiotics, antifouling products and biomaterials. Symbiotic microorganisms are often the real producers of many secondary metabolites initially isolated from marine invertebrates; however, a certain number of them are actually synthesized by ... -
Effects of supplemental LED light quality and reduced growth temperature on swede (Brassica napus L. ssp. rapifera Metzg.) root vegetable development and contents of glucosinolates and sugars
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-04)Background - Low growth temperatures and the special light qualities of midnight sun in northern Scandinavia, have both been shown to improve eating quality of swede root bulbs. To study the combined effect of these factors on root development and sensory-related compounds, plants were grown in phytotron under different 24 h supplemental light-emitting diode (LED) light colours, at constant 15 °C, ... -
Four new suomilides isolated from the cyanobacterium Nostoc sp. KVJ20 and proposal of their biosynthetic origin
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-20)The suomilide and the banyasides are highly modified and functionalized non-ribosomal peptides produced by cyanobacteria of the order Nostocales. These compound classes share several substructures, including a complex azabicyclononane core, which was previously assumed to be derived from the amino acid tyrosine. In our study we were able to isolate and determine the structures of four suomilides, ... -
Fra havets bunn til sykehuset
(Chronicle; Kronikk, 2023-08-19)I forskningsgruppa Marbio ved UiT Norges arktiske universitet jobber vi med å finne nye legemidler fra forbindelser som vi henter fra ulike planter, dyr og mikroorganismer. -
Inclusion of photoautotrophic cultivated diatom biomass in salmon feed can deter lice
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-29)The aim of this study was to evaluate the potential of diatom (microalgae) biomass as a lice-reducing ingredient in salmon feed. The original hypothesis was based on the fact that polyunsaturated aldehydes (PUAs), e.g. 2-trans, 4-trans decadenial (A3) produced by diatoms can function as grazing deterrents and harm copepod development. Salmon lice (Lepeophtheirus salmonis) is a copepod, and we intended ... -
Lysophosphatidylcholines and Chlorophyll-Derived Molecules from the Diatom Cylindrotheca closterium with Anti-Inflammatory Activity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-17)Microalgae have been shown to be excellent producers of lipids, pigments, carbohydrates, and a plethora of secondary metabolites with possible applications in the pharmacological, nutraceutical, and cosmeceutical sectors. Recently, various microalgal raw extracts have been found to have anti-inflammatory properties. In this study, we performed the fractionation of raw extracts of the diatom ... -
Mass Cultivation of Microalgae: I. Experiences with Vertical Column Airlift Photobioreactors, Diatoms and CO2 Sequestration
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-17)From 2015 to 2021, we optimized mass cultivation of diatoms in our own developed vertical column airlift photobioreactors using natural and artificial light (LEDs). The project took place at the ferrosilicon producer Finnfjord AS in North Norway as a joint venture with UiT—The Arctic University of Norway. Small (0.1–6–14 m<sup>3</sup>) reactors were used for initial experiments and to produce inoculum ... -
Mikroalger i fôr, ny løsning for å redusere lusepåslag på laks – Faglig sluttrapport
(Research report; Forskningsrapport, 2020-05)I dette prosjektet har vi testet ut en hypotese om at ved å erstatte vegetabilske oljer i fôr til oppdrettslaks med marine oljer, vil man kunne redusere lusepåslag hos laks. Vi har fôret laks med fire ulike fôr, der proteininnholdet er det samme, men oljen er variert. De ulike fôrene vi brukte var kontrollfôr som var standardfôr med vegetabilsk olje, og tre ulike testfôr der vegetabilsk olje ble ... -
Selective isolation of Arctic marine actinobacteria and a down-scaled fermentation and extraction strategy for identifying bioactive compounds
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-21)Actinobacteria are among the most prolific producers of bioactive secondary metabolites. In order to collect Arctic marine bacteria for the discovery of new bioactive metabolites, actinobacteria were selectively isolated during a research cruise in the Greenland Sea, Norwegian Sea and the Barents Sea. In the frame of the isolation campaign, it was investigated how different sample treatments, isolation ...
