Dominykas Salvaitis
PhD Candidate
(+47) 406 31 729
dominykas.salvaitis@nibio.no
Place
Bodø
Visiting address
Mørkvedbukta 30, 8020 Bodø
Authors
Niko Steiner Christian Bruckner Nikolai Buer Kiara Franke Anne Margrete Leiros Nilsen Ralf Rautenberger Leonard Rößler Dominykas Salvaitis Alexander O. Jueterbock Inka BartschAbstract
Seaweed cultivation represents an emerging industry in Europe, where most biomass is still derived from wild harvesting. A potential approach to establishing a sustainable seaweed production industry involves improving seaweed strains. Temperature priming, introducing moderate stress to enhance subsequent performance, offers a rapid approach for improving growth. We examined the effect of three weeks temperature priming (0, 10, 20 °C) of gametophytes of Saccharina latissima on the early life stages (gametophyte growth, sporophyte recruitment, juvenile sporophyte growth). Cold priming (0 °C) stimulated gametogenesis and produced significantly larger microscopic sporophytes. This size advantage of the juvenile sporophytes was carried through a temperature gradient experiment (0–21 °C) over two weeks, especially under optimum temperatures (5–15 °C). In a second experiment with a similar gametophyte priming approach, we cultivated sporophytes for six months in mariculture and investigated size, biomass and biochemical composition. Biomass of sporophytes from 0 °C primed gametophytes was twofold higher than of 10, and fourfold higher than of 20 °C-primed gametophytes. The difference in mineral composition in sporophyte blades between priming treatments was variable. Heavy metals (As, Cd) were lower under warm priming (20 °C) and few macro- and trace elements (K, P, S, Mn) significantly increased under cold priming. The results demonstrate a transgenerational carry-over effect from haploid gametophytes to diploid sporophytes and underscore the significance of gametophyte cold exposure for the growth of S. latissima sporophytes. It suggests that cold priming of gametophytes may serve as a form of winter mimicry to enhance growth and to modify biochemical composition in kelp cultivation.
Abstract
Brown seaweed A.nodosum has been widely used for feed and biostimulant purposes for many years. However, due to its high-water content (ranging >80% MC) it presents challenges like increasing costs of transportation and storage for downstream processing. Therefore, an effective dewatering step is essential to reduce the moisture content, concentrate the biomass and improve handling and processing efficiency. Mechanical dewatering is commonly applied as a pretreatment step in biorefining as it removes readily mobile water and reduces the moisture available for microbial deterioration during handling and storage. However, the efficiency of mechanical dewatering can be limited by the strong water-holding capacity of seaweed tissues and cell-wall components, resulting in substantial residual moisture in the pressed biomass. In this context, this study evaluates calcium chloride (CaCl2 ) and magnesium chloride (MgCl2 ) as pretreatment agents prior to hydraulic pressing of A. nodosum, assessing their effects on dewatering efficiency and the partitioning of protein-bound amino acids between the liquid and solid fractions.
Abstract
Mechanical dewatering using a twin-screw press not only reduces biomass moisture content but also facilitates the partitioning of valuable biochemical components between liquid and solid fractions. While mechanical dewatering is commonly applied as a low-energy pre-treatment step, its potential as a fractionation strategy for brown seaweed biorefinery remains largely unexplored. Pressure-driven separation generates a liquid fraction containing soluble compounds and a solid fraction enriched in structural biomass components. In this study, different pre-treatments were combined with twin-screw pressing to evaluate their influence on the distribution of protein-bound amino acids, fucose, and uronic acids in Alaria esculenta. The results demonstrated distinct partitioning patterns, with higher concentrations of all three component groups generally retained in the solid fraction, highlighting the potential of mechanical dewatering as an initial fractionation step in cascading seaweed biorefinery. This approach aims to establish mechanical dewatering as a scalable, low-energy entry point for downstream processing, supporting efficient valorization and zero-waste processing.