| 1. |
- Mayers, Joshua, 1988, et al.
(författare)
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Identifying a marine microalgae with high carbohydrate productivities under stress and potential for efficient flocculation
- 2018
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Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 31, s. 430-442
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Tidskriftsartikel (refereegranskat)abstract
- Microalgal biomass represents a potential third generation feedstock that could be utilised as a source of carbohydrates for fermentative production of a range of platform biochemicals. Identifying microalgal strains with high biomass and carbohydrate productivities while also being amenable to downstream processes is key in improving the feasibility of these processes. Utilising marine microalgae capable of growing in seawater will decrease reliance on freshwater resources and improve the sustainability of production. This study screened several marine microalgae believed to accumulate carbohydrates to find new high performing strains. Four strains had high growth rates and accumulated carbohydrates > 35% DW under stress. The strain Chlorella salina demonstrated the highest biomass and carbohydrate productivity, and alkaline autoflocculation (4 mM NaOH) enabled biomass recoveries > 95% efficiency, resulting in an 8–10 × concentration of the culture. Under nutrient replete conditions, biomass productivity reached 0.6 g L −1 d −1 , significantly greater than that of nitrogen starved cultures. However, nitrogen starvation rapidly increased carbohydrate content to > 50% DW in 2 days, resulting in carbohydrate productivities > 0.20 g L −1 d −1 . Chlorella salina partitions the products of photosynthesis preferentially into carbohydrate synthesis under nitrogen starvation. A greater understanding of cellular physiology and carbon partitioning in response to nutrient stress will enable better control and optimisation of the bio-processes. This study has identified a potentially high performance marine microalga for carbohydrate production that is also amenable to low-cost harvesting.
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| 3. |
- Olsson, Joakim, 1988, et al.
(författare)
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Composition and processing of Ulva intestinalis from 8 different sites along the Swedish coast
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Seaweed has the potential to provide a large quantities of biomass as feedstocks for production of energy and chemicals. Compared to terrestrial biomasses, seaweed does not require arable land or fertilizer for cultivation, effectively not competing with food production. Significant efforts are now being made to improve both cultivation, extraction techniques and product development of seaweed to enable a seaweed industry in the future. An aspect that has thus far received little attention is on the optimisation of cultivation siting to maximise the content of valuable components in the biomass (and minimize waste), despite it being well known that variation in ambient conditions cause significant changes in biomass composition. In this study, we have investigated the opportunistic summer seaweed Ulva intestinalis, which is of commercial interest due to its high growth rate and broad distribution along the entire Swedish coast. To evaluate where cultivation could be most beneficial from a biomass composition perspective, samples were collected from 8 sites along the Swedish coastline between Tjärnö on the west coast to Stockholm on the east. At each site, 3 separate populations were sampled. For each sample the content and profile of metals, sugars, ash and lipids were measured. These measures are being evaluated to highlight trends relating to differences in location conditions. The largest impact could be seen on the sugar compostition, as monosaccharides present in the polysaccharide ulvan showed, roughly, a 2-fold increase on the east coast compared to the western coast.
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