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- Cheregi, Otilia, et al.
(författare)
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Transcriptome analysis reveals insights into adaptive responses of two marine microalgae species to Nordic seasons
- 2023
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Ingår i: Algal Research. - 2211-9264. ; 74
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Tidskriftsartikel (refereegranskat)abstract
- There is an increasing interest in algae-based biomass produced outdoors in natural and industrial settings for biotechnological applications. To predict the yield and biochemical composition of the biomass, it is important to understand how the transcriptome of species and strains of interest is affected by seasonal changes. Here we studied the effects of Nordic winter and summer on the transcriptome of two phytoplankton species, namely the diatom Skeletonema marinoi (Sm) and the eustigmatophyte Nannochloropsis granulata (Ng), recently identified as potentially important for biomass production on the west coast of Sweden. Cultures were grown in photobioreactors in simulated Nordic summer and winter, and the gene expression in two phases was quantified by Illumina RNA-sequencing. Five paired comparisons were made among the four conditions. Sm was overall more responsive to seasons since 70 % of the total transcriptome (14,783 genes) showed differential expression in at least one comparison as compared to 1.6 % (1403 genes) for Ng. For both species, we observed larger differences between the seasons than between the phases of the same season. In summer phase 1, Sm cells focused on photosynthesis and polysaccharide biosynthesis. Nitrate assimilation and recycling of intracellular nitrogen for protein biosynthesis were more active in summer phase 2 and throughout winter. Lipid catabolism was upregulated in winter relative to summer to supply carbon for respiration. Ng favored lipid accumulation in summer, while in winter activated different lipid remodeling pathways as compared to Sm. To cope with winter, Ng upregulated breakdown and transport of carbohydrates for energy production. Taken together, our transcriptome data reveal insights into adaptive seasonal responses of Sm and Ng important for biotechnological applications on the west coast of Sweden, but more work is required to decipher the molecular mechanisms behind these responses.
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- Ekendahl, Susanne, 1965, et al.
(författare)
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Energieffektiv odling av marina mikroalger vid den svenska västkusten - potentiella applikationer : RISE Rapport 2020: 72
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- An energy-efficient cultivation method for microalgae has been further developed for the Nordic climate, specifically for the Swedish west coast. The principle for the cultivation process has earlier been developed by RISE for freshwater microalgae. In this project, we have used marine species, and thereby also seawater, in the cultivation. Utilization of natural seawater lowers the environmental impact since, during some circumstances, freshwater may become limiting even in Sweden. The aim of the study was to investigate if selected marine species could be rotated during the year to achieve a longer cultivation season and increased production of energy-rich algal biomass. Winter, spring and summer at the Swedish west coast were simulated in cultivation experiments in laboratory bioreactors with the species Skeletonema marinoi, usually thriving and blooming on the west coast in winter and spring, and Nannochloropsis granulata, which blooms in summer and produces high amounts of lipids. Nannochloropsis was shown to be more suitable for cultivation during spring and summer, when it comes to production of biomass and energy, while Skeletonema grew better during winter and displayed a higher uptake of phosphate than Nannochloropsis. The productivity of Nannochloropsis was in the same range as that of a previously studied freshwater microalgal species, Tetradesmus obliquus. We have shown the principle for a rotational cultivation strategy and that species adapted for a cold climate can give higher productivity during the cold season. Nevertheless, the selected species (Skeletonema) generally showed too low productivity when cultivated during winter to be energy efficient. More species need to be studied to identify those with a high productivity during winter conditions. Even if cold-adapted species are less productive than the summer-adapted ones, considering the available sunlight, they could still be used to prolong the growth season. The cultivation process of Nannochloropsis could also be optimized in an outdoor environment to prolong the season in different ways, since it was tolerant to cold conditions. In practice, the work-related consequences of a rotational cultivation should be weighed against its benefits for each application. Possible applications mainly include cleaning of air and seawater, production of energy, biomass and biomaterials for the industry.
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| 5. |
- Gilbert, F., et al.
(författare)
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2-D optical quantification of particle reworking activities in marine surface sediments
- 2003
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Ingår i: JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY. - 0022-0981. ; 285, s. 251-263
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Tidskriftsartikel (refereegranskat)abstract
- Particle and solute transport by faunal activities may significantly influence rates and pathways of organic matter mineralization during early diagenesis in surface sediments. One of the most frequently utilized techniques to quantify benthic biological reworking activities involves the calculation of a biodiffusion coefficient (D-b) estimated from model predictions of 1-D tracer distribution patterns. This technique is labor-intensive and time-demanding. Furthermore, it is normally used for measurements over several days and averages overall transport mechanisms from 3-D to 1-D on a cm scale. In the frame of this work, we developed a new technique based on the nondestructive screening of fluorescent particles (luminophores) using optical discrimination and CCD camera detection of fluorescence (2-D). At a site characterized by a dense population of the brittle star Amphiura filiformis and a high biodiffusion coefficient (obtained from 1-D distributions; D-b = 3 5.5 +/- 3.7 cm(-2) year(-1); n = 3), the optical reworking coefficient (ORC), estimated from the 2-D luminophore distribution patterns, was calculated (ORC = 27.4 +/- 9.1 DeltaQ cm(-2) h(-1); n=24). A nondestructive 2-D approach to quantify particle reworking may provide a powerful and complementary tool to further understand particle transport by the benthic fauna in surface sediments. The optical technique for 2-D detection of luminophores is relatively fast and easy to perform, with the ability to detect small scale (mm) particle movements on a time resolution of minutes or less. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 6. |
- Hakonen, Aron, 1970, et al.
(författare)
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Applications of imaging optodes
- 2007
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Ingår i: Pittsburg Conference on Analytical Chemistry (PITTCON).
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Konferensbidrag (refereegranskat)
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| 7. |
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| 8. |
- Hakonen, Aron, 1970, et al.
(författare)
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Plasmonic nanoparticle interactions for high-performance imaging fluorosensors
- 2011
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Ingår i: CHEMICAL COMMUNICATIONS. - 1359-7345. ; 47:12, s. 3433-3435
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a nanoparticle based ratiometric fluorosensor suitable for non-invasive high-resolution imaging of complex samples. Coextraction generates a movement of a solvatochromic dye, with a consequent shift from plasmophore coupled emission towards longer wavelength scattering enhanced emission. The nanoparticle doped sensors confirmed superior sensitivity, reversibility, durability and overall image quality.
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| 10. |
- Karlsson, Anna, 1967, et al.
(författare)
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Detection of glycoprotein receptors on blotting membranes by binding of live bacteria and amplification by growth.
- 1995
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Ingår i: Analytical biochemistry. - : Elsevier BV. - 0003-2697. ; 224:1, s. 390-4
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Tidskriftsartikel (refereegranskat)abstract
- Conditions have been adapted for detecting bacteria bound to glycoprotein receptors on blotting membranes using a self-enhancing detection method based on bacterial growth. Neutrophil plasma membrane proteins, mediating adherence of mannose-binding type-1-fimbriated Escherichia coli and concanavalin A (Con A) to intact human neutrophils, were separated by SDS-PAGE and transferred onto a polyvinylidene difluoride (PVDF) membrane. The PVDF membrane was immersed in a suspension of mannose-binding type-1-fimbriated E. coli, and after repeated washings, bound bacteria were allowed to multiply into bacterial colonies by placing the membrane on a solid nutrient substratum. About one major and eight minor glycoproteins, some of which also were detected by Con A, selectively induced colony formation in a mannose-inhibitable fashion. Binding of [35S]methionine metabolically labeled E. coli to PVDF membranes produced a virtually identical binding pattern, demonstrating further the accuracy of this self-enhancing detection method which is rapid, simple, and sensitive and avoids radioisotopes.
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