| 1. |
- Albers, Eva, 1966, et al.
(författare)
-
Influence of preservation methods on biochemical composition and downstream processing of cultivated Saccharina latissima biomass
- 2021
-
Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 55
-
Tidskriftsartikel (refereegranskat)abstract
- Saccharina latissima biomass cultivated along the Swedish west coast was subjected to four different scalable preservation methods after harvest; freezing, sun-drying, oven-drying and ensiling. Freeze-drying and freezing at -80 ?C were also included to provide dry and wet references. The effects of the different preservation methods on the composition of Saccharina biomass (on dry weight, DW, basis), and the recovery as well as properties of high-quality protein, alginate and biogas were evaluated. Sun-drying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods. Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass, while mannitol and laminarin were reduced compared to the other biomasses. Oven-drying and -20 ?C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasses which translated into the lowest total seaweed protein recovery using the pH-shift process. Highest protein yield was obtained with the freeze-dried reference. Ensiling lead to a significant decrease in the molecular weight of alginate, while sun-drying caused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield in the anaerobic digestion experiments while freezing at -80 ?C gave the highest yield, closely followed by freezing at -20 ?C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima, and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.
|
|
| 2. |
- Mayers, Joshua, 1988, et al.
(författare)
-
Identifying a marine microalgae with high carbohydrate productivities under stress and potential for efficient flocculation
- 2018
-
Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 31, s. 430-442
-
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.
|
|
| 3. |
|
|
| 4. |
- Olsson, Joakim, 1988, et al.
(författare)
-
Composition and processing of Ulva intestinalis from 8 different sites along the Swedish coast
- 2018
-
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.
|
|
| 5. |
- Olsson, Joakim, 1988, et al.
(författare)
-
Composition and processing of Ulva intestinalis from 8 different sites along the Swedish coast
- 2017
-
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. As a processing example to compare performance between the sites, all samples were run in hydrothermal liquefaction, which is a promising method for production of bio oil.
|
|
| 6. |
- Olsson, Joakim, 1988, et al.
(författare)
-
Effects of geographical location on potentially valuable components in Ulva intestinalis sampled along the Swedish coast
- 2020
-
Ingår i: Applied Phycology. - : Informa UK Limited. - 2638-8081. ; 1:1, s. 80-92
-
Tidskriftsartikel (refereegranskat)abstract
- Macroalgal biomass has the potential to become an important source of chemicals and commodities in a future biorefinery. Currently, production of macroalgal biomass is expensive and the content of high-value compounds is often low. Therefore, in this study the biochemical composition of Ulva intestinalis along the Swedish west coast and the east coast up to Stockholm was assessed with the aim of determining how the content of potentially valuable compounds, such as rhamnose, iduronic acid and PUFAs, could be maximized by utilizing natural variation in the choice of marine cultivation site. Along the investigated coastline, the salinity dropped from 19.4‰ at high latitudes along the west coast to 5.4‰ at Stockholm. Nitrogen and phosphorus availability varied, while temperature was similar at all locations. The two major components of biomass, carbohydrates and ash, varied inversely with the highest content of ash in the west and carbohydrates in the east. In addition, total fatty acids were significantly higher in west coast samples at 3.2 g 100 g–1 dw, with a higher proportion of mono- and polyunsaturated fatty acids. Some health-beneficial fatty acids were found, including EPA and DPA, at 10–50 mg 100 g–1 dw, respectively. The metal content and elemental composition varied widely, probably due to the influence of specific local conditions. The P content was correlated with the phosphorus concentration in waters at the locations. In PCA analysis, the monosaccharides constituting the cell wall polysaccharide ulvan were found to vary by geographical location, with higher levels possibly associated with lower salinities. However, only glucuronic acid differed significantly between sites. These results show the considerable geographical variability in the composition of Swedish U. intestinalis and suggest that different salinities could be used to create a lipid- or carbohydrate-rich biomass.
|
|
| 7. |
- Raikova, Sofia, et al.
(författare)
-
Effect of Geographical Location on the Variation in Products Formed from the Hydrothermal Liquefaction of Ulva intestinalis
- 2020
-
Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 34:1, s. 368-378
-
Tidskriftsartikel (refereegranskat)abstract
- Hydrothermal liquefaction (HTL) of macroalgae offers a promising route to advanced biofuel production, although the distinct biochemical compositions of different macroalgae species can lead to widely different product yields and compositions. On the basis of this, there is an implicit assumption that there exists a universal optimal feedstock species for a bioenergy-based biorefinery, which could be exploited across a wide region. However, no studies to date have examined the effect of this large geographical variation on a single macroalgae species for biofuel production. In this study, 24 samples of Ulva intestinalis were collected along 1200 km of Swedish coastline and assessed as a feedstock for HTL. Significant variation in composition was observed between samples from Baltic and Atlantic regions, but substantial variation also existed between sites within close proximity. This was reflected in the HTL biocrude oil yields, which varied between 9 and 20% (14-28% dry and ash-free basis) across the sample set. In a number of cases, greater variation was seen for adjacent sites than for sites at opposite ends of the sampling spectrum. Biocrude oil yields in this study also differed substantially from those previously obtained for U. intestinalis from the United Kingdom and Vietnam. Localized environmental conditions affected the HTL product composition significantly, in particular, the elemental distribution within the sample set. The variability observed in this study suggests that no single species will be dominant within a macroalgal biorefinery concept, but rather a species would need to be selected to match the needs of the exact local environment.
|
|
| 8. |
- Vaiciulyte, Sigita, 1988, et al.
(författare)
-
Sufficient CO2 concentration is crucial for high biomass formation of marine microalgae
- 2015
-
Ingår i: Proceedings of 4th Latin-American Society of Environmental and Algal Biotechnology Congress (SOLABIAA), November 8-13, Brazil.
-
Konferensbidrag (refereegranskat)abstract
- The effect of low and high CO2 concentration for the growth of marine green microalgae genera Chlorella and Picochlorum were investigated. Chlorella sp. A, Chlorella sp. B, Chlorella sp. C and Picochlorum sp. strains were grown in a batch culture under 20:4 hours of light:dark photoperiods and with either 0.035 % (ambient air) or 2.0 % of CO2 supply. Picochlorum sp. and Chlorella sp. C achieved the highest maximum growth rate (d-1) 1.06 and 1.05, respectively, when cultured with a high CO2 supply (2.0 %). Cultures supplied with low CO2 (0.035 %), did not enter into exponential growth phase, but formed biomass in a steady linear growth pattern, suggesting significant carbon limitation. Thus, it is clear that the supply of CO2 is critical for high rates of microalgal biomass production, and optimal CO2 ¬supply rate should be identified that also improves carbohydrate formation.
|
|
| 9. |
|
|
| 10. |
- Forghani Targhi, Bita, 1973, et al.
(författare)
-
Cultivation of microalgae- Chlorella sorokiniana and Auxenochlorella protothecoides- in shrimp boiling water residues
- 2022
-
Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 65
-
Tidskriftsartikel (refereegranskat)abstract
- Based on the ability of microalgae to purify industrial processing waters, the overall aim of this study was to evaluate whether currently wasted shrimp processing waters could be used as microalgal growth media to produce new protein-enriched food and feed ingredients. Low molecular weight (LMW) fractions of shrimp boiling water (SBW) which had been pre-flocculated using alginate (AL), carrageenan (CA), chitosan (CH) or Superfloc C-592 to recover shrimp protein via flotation, were used for cultivation of Chlorella sorokiniana and Auxenochlorella protothecoides to produce a protein-enriched microalgal biomass. CH-derived media induced the highest growth rates for both species with A. protothecoides out-performing C. sorokiniana. A. protothecoides best assimilated phosphate-phoshorous (P-PO4) and total phosphorous (TP) in all media; <63 mg/L and < 45 mg/L after 4 days, respectively. In upscaled aerated cultures of A. protothecoides in CH- and AL-derived media, P and TP uptake increased up to 85 and 127 mg/L, respectively. Further, 63% of the free amino acids (AA) were assimilated in both waters. Biomasses derived from SBW contained 37-43% protein and 15.0-17.4% fatty acids (FA) per DW; with 38-40% essential AA (EAA) and 21.3-22.5% polyunsaturated FA (PUFA), respectively Corresponding numbers for biomass cultivated in control media were 11 and 53%, protein and FA, respectively, and with 38% and 15.6% EAA and PUFA, respectively. Ability of A. protothecoides to assimilate TP and AA, and to generate a protein-rich biomass from LMW-fractions derived from SBW was thus revealed for the first time, and paves the way for a SBW-based biorefinery comprising chemical, physical and microbial processes to produce multiple products.
|
|
