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NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2024

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Regeneration of polyploidy from young thallus segments of Kappaphycus alvarezii was optimized for genetic improvement. Kappaphycus thallus segment cultured on sterile sea water supplemented with various combinations of Indole acetic acid, Kinetin and Acardian Marine Plant Extract Powder revealed differential response on callus proliferation and development of new thallus. Presence of Acardian Marine Plant Extract Powder (3 mg/l) in combination with Indole acetic acid and Kinetin (0.01 mg/l each) had induced the longest emerging thallus. Exposure of thallus to colchicine at 0.01% with above combination was optimal to induce high frequency regeneration of polyploidy mostly from the meristematic cells. Anatomical study of colchicine induced polyploidy revealed larger cortical cells with irregular thickening of epidermal layer. Phase contrast and Scanning Electron Microscopic study revealed increase in cell size in cortical region with significantly larger number of spherical shaped carrageenan globules in colchicine induced polyploidy than normal thallus. Single cells isolated using enzymatic treatments from colchicine induced polyploidy, shown chromosome number with a ploidy status of 4n ≈ 40. Whereas in normal thallus, only half the number of chromosomes (2n ≈ 20) were observed. Polyploidy were successfully acclimatized gradually using raft method for further evaluation. This is the first report reveals the induction and regeneration of polyploidy in Kappaphycus. The possible application of this finding in genetic improvement of Kappaphycus is discussed.

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Ochnaflavone is a naturally occurring biflavonoid mainly isolated from Ochna integerrima, manifests health benefits encompassing antidiabetic, anticancer, anti-cardiovascular, and anti-inflammatory activities. However, most bioactivity research has focused on in vitro experiments, rather than in vivo disease models, toxicological assessments, and human clinical trials. Moreover, a comprehensive review of the pharmacological aspects of ochnaflavone is conspicuously lacking. Thus, this review provides a concise and comprehensive summary of existing knowledge on the chemical structure, plant origin, physical properties, biotransformations, and multifaceted biological activities of ochnaflavone along with an in-depth exploration of the complex molecular mechanisms behind these activities, including signaling pathways and gene expression regulation, with the aim of promoting future theoretical needs for ochnaflavone in clinical trials and providing comprehensive insights into the research and application of this valuable natural compound.

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Horticultural food waste can be recovered to produce high-value products. Appropriate green solvents and a selection of cleaner production could unlock waste into useful resources for human health. This will significantly reduce greenhouse gas emissions, and CO2 production, and create economic opportunities to contribute to food security.

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During the cultivation of Ulva fenestrata in a land-based aquaculture system, the colonisation of the water tanks’ surfaces and eventually the macroalgal biomass by the biofouling diatom Fragilariopsis oceanica compromises the production process. Since germanium dioxide (GeO2) is an effective growth inhibitor of diatoms, this study aimed to understand how it affects the presence of F. oceanica and the photosynthesis and growth of U. fenestrata as a primary parameter contribution to the biomass production. A toxicological dose-response experiment showed that the diatom’s growth was inhibited at the low GeO2 concentration of 0.014 mg l−1. In contrast, the photosynthetic performances and growth rates of U. fenestrata remained unaffected under a wide GeO2 concentration range (0.022–2.235 mg l−1) in small- and large-scale experiments in 1-l glass beakers and 100-l Plexiglass water tanks, respectively. In the latter, the diatom density in the tanks was reduced by 40 %. The costs arising from the use of GeO2 can range between €2.35 and €8.35  kg−1 fresh weight of produced U. fenestrata biomass under growth conditions resulting in growth rates of 20 and 11.5 % d−1, respectively. GeO2 is an effective agent to control biofouling diatoms such as F. oceanica during the land-based biomass production of U. fenestrata.

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Eutrophication of coastal ecosystems often stimulates massive and uncontrolled growth of green macroalgae, causing serious ecological problems. These green tides are frequently exposed to light intensities that can reduce their growth via the production of reactive oxygen species (ROS). To understand the physiological and biochemical mechanisms leading to the formation and maintenance of green tides, the interaction between inorganic nitrogen (Ni) and light was studied. In a bi-factorial physiological experiment simulating eutrophication under different light levels, the bloom-forming green macroalga Ulva rigida was exposed to a combination of ecologically relevant nitrate concentrations (3.8–44.7 µM) and light intensities (50–1100 µmol photons m−2 s−1) over three days. Although artificial eutrophication (≥ 21.7 µM) stimulated nitrate reductase activity, which regulated both nitrate uptake and vacuolar storage by a feedback mechanism, nitrogen assimilation remained constant. Growth was solely controlled by the light intensity because U. rigida was Ni-replete under oligotrophic conditions (3.8 µM), which requires an effective photoprotective mechanism. Fast declining Fv/Fm and non-photochemical quenching (NPQ) under excess light indicate that the combined photoinhibitory and PSII-reaction centre quenching avoided ROS production effectively. Thus, these mechanisms seem to be key to maintaining high photosynthetic activities and growth rates without producing ROS. Nevertheless, these photoprotective mechanisms allowed U. rigida to thrive under the contrasting experimental conditions with high daily growth rates (12–20%). This study helps understand the physiological mechanisms facilitating the formation and persistence of ecologically problematic green tides in coastal areas.