Kari Skjånes
Research Scientist
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Authors
Ralf Rautenberger Alexandre Detain Kari Skjånes Peter Simon Claus Schulze Viswanath Kiron Daniela Morales SanchezAbstract
Chlorella vulgaris is a freshwater microalga that synthesises large amounts of saturated lipids, which makes it suitable for production of bioenergy and biofuels. Since its cultivation usually requires freshwater, it competes with agriculture, economic development and ecological conservation for this limited natural resource. This study investigated the possibility of the partial replacement of freshwater by seawater (50 %) in the growth medium for a more sustainable biomass and lipid production. Chlorella vulgaris 211-11b was cultivated as shake-flask cultures in Bold's Basal Medium (BBM) formulated with 50 % freshwater and 50 % seawater under photoautotrophic, mixotrophic and heterotrophic conditions for eight days with glucose as organic carbon source in the latter two cases. The alga's best growth performance and highest lipid contents (49 % DW−1), dominated by palmitioleic and oleic acid, occurred under mixotrophic rather than photoautotrophic and heterotrophic conditions. This study demonstrates a more economic and ecologically sustainable biomass and lipid production of C. vulgaris by saving 50 % freshwater, which is available for other purposes.
Authors
Giorgia Carnovale Carmen Lama Sonia Torres Filipa Rosa Lalia Mantecon Svein Jarle Horn Kari Skjånes Carlos InfanteAbstract
Tetraselmis chui is known to accumulate starch when subjected to stress. This phenomenon is widely studied for the purpose of industrial production and process development. Yet, knowledge about the metabolic pathways involved is still immature. Hence, in this study, transcription of 27 starch-related genes was monitored under nitrogen deprivation and resupply in 25 L tubular photobioreactors. T. chui proved to be an efficient starch producer under nitrogen deprivation, accumulating starch up to 56% of relative biomass content. The prolonged absence of nitrogen led to an overall down-regulation of the tested genes, in most instances maintained even after nitrogen replenishment when starch was actively degraded. These gene expression patterns suggest post-transcriptional regulatory mechanisms play a key role in T. chui under nutrient stress. Finally, the high productivity combined with an efficient recovery after nitrogen restitution makes this species a suitable candidate for industrial production of high-starch biomass.
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Authors
Giorgia Carnovale Shaun Allan Leivers Filipa Rosa Hans Ragnar Norli Edvard Hortemo Trude Wicklund Svein Jarle Horn Kari SkjånesAbstract
Microalgal biomass is widely studied for its possible application in food and human nutrition due to its multiple potential health benefits, and to address raising sustainability concerns. An interesting field whereby to further explore the application of microalgae is that of beer brewing, due to the capacity of some species to accumulate large amounts of starch under specific growth conditions. The marine species Tetraselmis chui is a well-known starch producer, and was selected in this study for the production of biomass to be explored as an active ingredient in beer brewing. Cultivation was performed under nitrogen deprivation in 250 L tubular photobioreactors, producing a biomass containing 50% starch. The properties of high-starch microalgal biomass in a traditional mashing process were then assessed to identify critical steps and challenges, test the efficiency of fermentable sugar release, and develop a protocol for small-scale brewing trials. Finally, T. chui was successfully integrated at a small scale into the brewing process as an active ingredient, producing microalgae-enriched beer containing up to 20% algal biomass. The addition of microalgae had a noticeable effect on the beer properties, resulting in a product with distinct sensory properties. Regulation of pH proved to be a key parameter in the process.
Authors
Giorgia Carnovale Svein Jarle Horn Carlos Infante Volha Shapaval Edvard Hortemo Kari SkjånesAbstract
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Giorgia Carnovale Svein Jarle Horn Carlos Infante Volha Shapaval Edvard Hortemo Kari SkjånesAbstract
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In addition to the rapidly expanding field of using microalgae for food and feed, microalgae represent a tremendous potential for new bioactive compounds with health-promoting effects. One field where new therapeutics is needed is cancer therapy. As cancer therapy often cause severe side effects and loose effect due to development of drug resistance, new therapeutic agents are needed. Treating cancer by modulating the immune response using peptides has led to unprecedented responses in patients. In this review, we want to elucidate the potential for microalgae as a source of new peptides for possible use in cancer management. Among the limited studies on anti-cancer effects of peptides, positive results were found in a total of six different forms of cancer. The majority of studies have been performed with different strains of Chlorella, but effects have also been found using peptides from other species. This is also the case for peptides with immunomodulating effects and peptides with other health-promoting effects (e.g., role in cardiovascular diseases). However, the active peptide sequence has been determined in only half of the studies. In many cases, the microalga strain and the cultivation conditions used for producing the algae have not been reported. The low number of species that have been explored, as opposed to the large number of species available, is a clear indication that the potential for new discoveries is large. Additionally, the availability and cost-effectiveness of microalgae make them attractive in the search for bioactive peptides to prevent cancer.
Authors
Stig A. Borgvang Dorinde Mechtilde Meike Kleinegris Viswanath Kiron Katerina Kousoulaki Maria Barbosa Anabela Raymundo Carlos Unamunzaga Anne Kjersti Uhlen Sander Hazewinkel Hans Torstein Kleivdal Trude Wicklund Kai Kristoffer Lie Nils-Arne Ekerhovd Kristian Fuglseth Dag Hjelle Arne Edvard Rosland Hortemo Hans Petter Kleppen Jørund Hagen Helen Haaland Per Fredriksen Shuichi Satoh Rene Wijffels Kari SkjånesAbstract
The knowledge- and technology platform developed within the ALGAE TO FUTURE project aims to lay a foundation for an industrial microalgae production in Norway. In the project ALGAE TO FUTURE, funded by the Norwegian Research Council 2017-2021, with a consortium of 20 national and international research and industry partners, research and product development of microalgae biomass have been approached from multiple angles merging multiple research fields. The focus of the research has been bioprocess developments linked to lipids, carbohydrates and proteins, where species selection and cultivation conditions are used to obtain microalgae biomass with specific nutrient composition targeting specific products. We have chosen to target the development of three example products, namely 1) bread using algae biomass with high protein content, 2) beer using algae biomass with high content of starch and starch-degrading enzymes, and 3) fish feed using algae biomass with high PUFA content. These case studies have been chosen in order to demonstrate the use of algal biomass from various algae species with highly different nutrient composition suitable for different products. We have in this project studied the whole process line from small scale microalgae cultivation technology, upscaling cultivation, processing of algae biomass, shelf life, food/ feed product development, food safety and consumers attitudes. Some highlights from the four-year project period will be presented. Results from these activities may contribute towards the use of microalgae as part of the future Norwegian bioeconomy.
Authors
Waqas Muhammad Qazi Simon Ballance Katerina Kousoulaki Anne Kjersti Uhlen Dorinde Mechtilde Meike Kleinegris Kari Skjånes Anne RiederAbstract
Cell wall disrupted and dried Microchloropsis gaditana (Mg), Tetraselmis chui (Tc) and Chlorella vulgaris (Cv) microalgae biomasses, with or without ethanol pre‐treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread protein by 30%. Baking performance, protein quality and basic sensory properties were assessed. Compared to wheat, Mg, Tc and Cv contain higher amounts of essential amino acids and their incorporation markedly improved protein quality in the bread (DIAAS 57–66 vs 46%). The incorporation of microalgae reduced dough strength and bread volume and increased crumb firmness. This was most pronounced for Cv and Tc but could be improved by ethanol treatment. Mg gave adequate dough strength, bread volume and crumb structure without ethanol treatment. To obtain bread of acceptable smell, appearance, and colour, ethanol treatment was necessary also for Mg as it markedly reduced the unpleasant smell and intense colour of all algae breads. Ethanol treatment reduced the relative content of lysine, but no other essential amino acids. However, it also had a negative impact on in vitro protein digestibility. Our results show that Mg had the largest potential for protein fortification of bread, but further work is needed to optimize pre‐processing and assess consumer acceptance.
Authors
Giorgia Carnovale Filipa Rosa Volha Shapaval Simona Dzurendova Achim Kohler Trude Wicklund Svein Jarle Horn Maria J. Barbosa Kari SkjånesAbstract
The use of microalgal starch has been studied in biorefinery frameworks to produce bioethanol or bioplastics, however, these products are currently not economically viable. Using starch-rich biomass as an ingredient in food applications is a novel way to create more value while expanding the product portfolio of the microalgal industry. Optimization of starch production in the food-approved species Chlorella vulgaris was the main objective of this study. High-throughput screening of biomass composition in response to multiple stressors was performed with FTIR spectroscopy. Nitrogen starvation was identified as an important factor for starch accumulation. Moreover, further studies were performed to assess the role of light distribution, investigating the role of photon supply rates in flat panel photobioreactors. Starch-rich biomass with up to 30% starch was achieved in cultures with low inoculation density (0.1 g L−1) and high irradiation (1800 µmol m−2 s−1). A final large-scale experiment was performed in 25 L tubular reactors, achieving a maximum of 44% starch in the biomass after 12 h in nitrogen starved conditions.
Authors
Giorgia Carnovale Filipa Rosa Volha Shapaval Simona Dzurendova Achim Kohler Trude Wicklund Svein Jarle Horn Maria Barbosa Kari SkjånesAbstract
ABSTRACT The use of microalgal starch has been studied in biorefinery frameworks to produce bioethanol or bioplastics, however, these products are currently not economically viable. Using starch−rich biomass as an ingredient in food applications is a novel way to create more value while expanding the product portfolio of the microalgal industry. Optimization of starch production in the food−approved species Chlorella vulgaris was the main objective of this study. High−throughput screening of biomass composition in response to multiple stressors was performed with FTIR spectroscopy and nitrogen starvation was identified as an important factor for starch accumulation. Further studies were subsequently performed to assess the role of light distribution, investigating photon supply rates in flat panel photobioreactors. Biomass specific photon supply rate proved to have a strong effect on the accumulation of storage compounds and starch−rich biomass with up to 30% starch was achieved in cultures with low inoculation density (0.1 g L−1) and high irradiation (1800 μmol m−2 s−1). A final large scale experiment was performed in 25 L tubular reactors, achieving a maximum of 44% starch in the biomass after 12 hours in nitrogen starved conditions. Keywords: Chlorella vulgaris, starch, FTIR, photon supply rate, microalgae
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Authors
Mariosimone Zoccali Daniele Giuffrida Fabio Salafia Carmen Socaciu Kari Skjånes Paola Dugo Luigi MondelloAbstract
Both enzymatic or oxidative carotenoids cleavages can often occur in nature and produce a wide range of bioactive apocarotenoids. Considering that no detailed information is available in the literature regarding the occurrence of apocarotenoids in microalgae species, the aim of this study was to study the extraction and characterization of apocarotenoids in four different microalgae strains: Chlamydomonas sp. CCMP 2294, Tetraselmis chuii SAG 8-6, Nannochloropsis gaditana CCMP 526, and Chlorella sorokiniana NIVA-CHL 176. This was done for the first time using an online method coupling supercritical fluid extraction and supercritical fluid chromatography tandem mass spectrometry. A total of 29 different apocarotenoids, including various apocarotenoid fatty acid esters, were detected: apo-12’-zeaxanthinal, β-apo-12’-carotenal, apo-12-luteinal, and apo-12’-violaxanthal. These were detected in all the investigated strains together with the two apocarotenoid esters, apo-10’-zeaxanthinal-C4:0 and apo-8’-zeaxanthinal-C8:0. The overall extraction and detection time for the apocarotenoids was less than 10 min, including apocarotenoids esters, with an overall analysis time of less than 20 min. Moreover, preliminary quantitative data showed that the β-apo-8’-carotenal content was around 0.8% and 2.4% of the parent carotenoid, in the C. sorokiniana and T. chuii strains, respectively. This methodology could be applied as a selective and efficient method for the apocarotenoids detection.
Authors
Kari Skjånes Maria Barbosa Rene Wijffels Dorinde Kleinegris Katerina Kousoulaki Anne Kjersti Uhlen Viswanath Kiron Kai Kristoffer Lie Nils-Arne Ekerhovd Kristian Fuglseth Carlos Unamunzaga Stig A. BorgvangAbstract
With regard to the rapidly growing world population, microalgae can be regarded as one of the most promising resources for the sustainable supply of commodities for food and feed applications. Although the use of commercial microalgae for food has been mainly limited to dietary supplements, the recent development of more cost-effective production technology makes it feasible to explore various other food applications. In the project ALGAE TO FUTURE, funded by the Norwegian Research Council, we have developed a consortium of 20 research and industry partners to approach this topic from multiple angles merging multiple research fields. The Vision is to contribute towards a viable Norwegian microalgae industry within 10 years. The focus of the research is on bioprocess developments linked to lipids, carbohydrates and proteins, where cultivation conditions are used to obtain microalgae biomass with specific nutrient composition targeting specific products, without use of GMO. We have chosen to target the development of 3 example products, namely bread, beer and aquaculture feed, that will be produced in a commercial context towards the end of the project. These case studies have been chosen in order to demonstrate the use of algal biomass from various algae species with highly different nutrient composition suitable for different products. The project combines expertise on algae cultivation and optimisation at lab and pilot scales, fish feeding technology, biorefining, bioeconomy, baking technology, broadcast journalism and animation, food quality and safety with the experience of innovative farmer entrepreneurs, professional bakers, brewers and fish-feed producers in a cross-disciplinary manner.
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Kari SkjånesAbstract
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Poster – Microalgae: Active ingredients in brewing
Giorgia Carnovale, Kari Skjånes, Stig A. Borgvang
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Maria Hayes Leen Bastiaens Luisa Gouveia Spyros Gkelis Hanne Skomedal Kari Skjånes Patrick Murray Marco García-Vaquero Muge Isleten Hosoglu John Dodd Despoina Konstantinou Ivo Safarik Graziella Chini Zittelli Vytas Rimkus Victόria del Pino Koenraad Muylaert Christine Edwards Morten Laake Joana Gabriela Laranjeira da Silva Hugo Pereira Joana AbelhoAbstract
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Academic – Microalgal proteins for feed, food and health
M. Hayes, Hanne Skomedal, Kari Skjånes, ...
Authors
M. Hayes Hanne Skomedal Kari Skjånes H. Mazur-Marzec A. Torunska-Sitarz M. Catala M. Isleten Hosoglu M. García-VaqueroAbstract
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Several species of microalgae and phototrophic bacteria are able to produce hydrogen under certain conditions. A range of different photobioreactor systems have been used by different research groups for lab-scale hydrogen production experiments, and some few attempts have been made to upscale the hydrogen production process. Even though a photobioreactor system for hydrogen production does require special construction properties (e.g., hydrogen tight, mixing by other means than bubbling with air), only very few attempts have been made to design photobioreactors specifically for the purpose of hydrogen production. We have constructed a flat panel photobioreactor system that can be used in two modes: either for the cultivation of phototrophic microorganisms (upright and bubbling) or for the production of hydrogen or other anaerobic products (mixing by “rocking motion”). Special emphasis has been taken to avoid any hydrogen leakages, both by means of constructional and material choices. The flat plate photobioreactor system is controlled by a custom-built control system that can log and control temperature, pH, and optical density and additionally log the amount of produced gas and dissolved oxygen concentration. This paper summarizes the status in the field of photobioreactors for hydrogen production and describes in detail the design and construction of a purpose-built flat panel photobioreactor system, optimized for hydrogen production in terms of structural functionality, durability, performance, and selection of materials. The motivations for the choices made during the design process and advantages/disadvantages of previous designs are discussed.
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Kari Skjånes Stig A. Borgvang Thorsten Heidorn Celine Rebours Christian Guido Bruckner Margarita Novoa Garrido Åsbjørn KarlsenAbstract
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Chitralekha Nag Dasgupta J. Jose Gilbert Peter Lindblad Thorsten Heidorn Stig A. Borgvang Kari Skjånes Debabrata DasAbstract
Hydrogen production through biological routes is promising because they are environmentally friendly. Hydrogen production through biophotolysis or photofermentation is usually a two stage process. In the first stage CO2 is utilized for biomass production which is followed by hydrogen production in the second stage in anaerobic/sulfur deprived conditions in the next stage. The major challenges confronting the large scale production of biomass/hydrogen are limited not only on the performance of the photo bioreactors in which light penetration in dense cultures is a major bottleneck but also on the microbiology, biochemistry and molecular biology of the organisms. Other dependable factors include area/ volume (A/V) ratio, mode of agitation, temperature and gas exchange. Photobioreactors of different geometries are reported for biohydrogen production-Tubular, Flat plate, Fermentor type etc. Every reactor has its own advantages and disadvantages. No reactor is ideal for this purpose. Airlift, helical tubular and flat plate reactors are found most suitable with respect to biomass production. These bioreactors may be employed for hydrogen production with necessary modifications to overcome the existing bottlenecks like gas hold up, oxygen toxicity and improved agitation system. This review article attempts to focus on existing photobioreactors with respect to biomass generation and hydrogen production and the steps taken to improve its performance through engineering innovation that definitely help in the future construction of photobioreactors.
