Publikasjoner
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.
2021
Forfattere
Henrik Forsberg MathiesenSammendrag
Det er ikke registrert sammendrag
Forfattere
Giorgia Carnovale Filipa Rosa Volha Shapaval Simona Dzurendova Achim Kohler Trude Wicklund Svein Jarle Horn Maria J. Barbosa Kari SkjånesSammendrag
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.
Forfattere
Giorgia Carnovale Filipa Rosa Volha Shapaval Simona Dzurendova Achim Kohler Trude Wicklund Svein Jarle Horn Maria Barbosa Kari SkjånesSammendrag
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
Forfattere
Michal Sposob Radziah Wahid Svein Jarle HornSammendrag
Det er ikke registrert sammendrag
Forfattere
Michal Sposob Joo-Youn Nam Jun-Gyu Park Tae-Hoon Kim Yuhoon Hwang Sang Mun Jeong Yeo-Myeong YunSammendrag
This study attempted to enhance sulfidogenic activity via sulfate-reducing bacteria (SRB) enrichment and minimize organic carbon loss by methanogen inhibition in the sulfidogenic stage of a two-stage anaerobic digestion system (TSADS). To enrich SRB in the sulfidogenic stage, batch tests were performed with various granular sludge pretreatments. Starvation was the most effective pretreatment, increasing SO42− removal and minimizing chemical oxygen demand (COD) loss by inhibiting methanogen activity. Microbial community analysis showed that Desulfovibrio, Desulfotomaculum, and Syntrophobacter were the dominant SRB in the sulfidogenic stage (5.0%, 3.1%, and 2.4%, respectively). This enabled SO42− reduction (86%) and volatile fatty acid production (55% of fed COD) at a hydraulic retention time (HRT) of 4 h. Conversely, biogas with a reduced H2S content (110 ppmv) was produced in the methanogenic stage (HRT = 6 h). A granular sludge comparison revealed differences in their ecology, structure, and extracellular polymeric substance characteristics. Economic feasibility analysis demonstrated that TSADS can lead to a cost reduction of $80–90/1,000 m3 CH4 compared to single-stage anaerobic digestion.
Forfattere
Volkmar TimmermannSammendrag
Det er ikke registrert sammendrag
Sammendrag
Eradication of alien invasive species in the soil with steam as an alternative to chemical fumigation may allow contaminated soil to be reused. We have investigated steam disinfestation of soil to combat invasive plant species in three experiments including different temperatures and exposure durations using a prototype stationary soil-steaming device. The experiments included effects on seed germination of bigleaf lupine (Lupinus polyphyllus Lindl.), ornamental jewelweed (Impatiens glandulifera Royle), and wild oat (Avena fatua L.; one population from Poland and one from Norway), as well as effects on sprouting rhizome fragments of Canada goldenrod (Solidago canadensis L.) and Bohemian knotweed (Reynoutria x bohemica Chrtek & Chrtková). In Experiment 1, we tested four different soil temperatures of 64, 75, 79, and 98 C with an exposure duration of 90 s. In Experiments 2 and 3, we tested exposure durations of 30, 90, and 180 s and 90, 180, and 540 s, respectively, at 98 C. Seed pretreatment of 14 d cooling for L. polyphyllus and I. glandulifera, no seed pretreatment and 12-h moistening for A. fatua populations, and 5- and 10-cm cutting size for R. x bohemica were applied. Our results showed germination/sprouting was inhibited at 75 C for I. glandulifera (for 90 s) and 98 C for the other species; however, longer exposure duration was needed for L. polyphyllus. While 30 s at 98 C was enough to kill A. fatua seeds and S. canadensis and R. x bohemica rhizome fragments, 180-s exposure duration was needed to kill L. polyphyllus seeds. The results showed promising control levels of invasive plant propagules in contaminated soil by steaming, supporting the steam treatment method as a potential way of disinfecting soil to prevent dispersal of invasive species.
Forfattere
Thomas Solvin Kjersti Bakkebø Fjellstad Inger Sundheim Fløistad Gunnar Friis Proschowsky Torben Leisgaard Antti Lännenpää Tiina Ylioja Brynjar Skúlason Hallur S. Björgvinsson Nina Hårdnes Tremoen Ellinor Edvardsson Claes Uggla Espen StokkeSammendrag
Det er ikke registrert sammendrag
Forfattere
Geir-Harald StrandSammendrag
Det er ikke registrert sammendrag
Forfattere
Nina SvartedalSammendrag
Det er ikke registrert sammendrag