| 1. |
- Abbott, D. Wade, et al.
(författare)
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Seaweed and Seaweed Bioactives for Mitigation of Enteric Methane : Challenges and Opportunities
- 2020
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Ingår i: Animals. - : MDPI AG. - 2076-2615. ; 10:12
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Forskningsöversikt (refereegranskat)abstract
- Simple Summary The need to become more efficient in agriculture and the food industry exists parallel to the challenge of climate change. Meat and dairy production is the target of much scrutiny due to methane (CH4) emissions and global warming. On the other hand, it should be noted that two-thirds of the world's agricultural land consists of pastures and permanent grasslands and is used for livestock grazing. This land is predominantly unsuitable for arable purposes but facilitates the production of high-quality human-edible protein in the form of ruminant animal-derived meat and milk. This makes a significant contribution to feeding the world's population. There is a need to reduce CH4 emissions, however, and several approaches are being researched currently. Seaweeds are diverse plants containing bioactives that differ from their terrestrial counterparts and they are increasingly under investigation as a feed supplement for the mitigation of enteric CH4. Seaweeds are rich in bioactives including proteins, carbohydrates and to a lesser extent lipids, saponins, alkaloids and peptides. These bioactives could also play a role as feed ingredients to reduce enteric CH4. This review collates information on seaweeds and seaweed bioactives and their potential to impact on enteric CH4 emissions. Seaweeds contain a myriad of nutrients and bioactives including proteins, carbohydrates and to a lesser extent lipids as well as small molecules including peptides, saponins, alkaloids and pigments. The bioactive bromoform found in the red seaweed Asparagopsis taxiformis has been identified as an agent that can reduce enteric CH4 production from livestock significantly. However, sustainable supply of this seaweed is a problem and there are some concerns over its sustainable production and potential negative environmental impacts on the ozone layer and the health impacts of bromoform. This review collates information on seaweeds and seaweed bioactives and the documented impact on CH4 emissions in vitro and in vivo as well as associated environmental, economic and health impacts.
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| 2. |
- Allahgholi, Leila, et al.
(författare)
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Composition analysis and minimal treatments to solubilize polysaccharides from the brown seaweed Laminaria digitata for microbial growth of thermophiles
- 2020
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Ingår i: Journal of Applied Phycology. - : Springer Science and Business Media LLC. - 0921-8971 .- 1573-5176. ; 32:3, s. 1933-1947
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Tidskriftsartikel (refereegranskat)abstract
- Brown macroalgae (Phaeophyta) hold high potential as feedstock for biorefineries due to high biomass productivity and carbohydrate content. They are, however, a challenging, unconventional feedstock for microbial refining and several processing problems need to be solved to make them a viable option. Pre-treatment is necessary to enhance accessibility and solubility of the biomass components but should be minimal and mild to assure sustainable and cost-effective processing. Here, two routes to pre-treatLaminaria digitata to release polysaccharides were investigated: hot water pre-treatment by autoclaving (121 °C, 20 min or 60 min) and a two-step extraction with mild acid (0.1 M HCl) followed by alkaline treatment. Hot water pre-treatment resulted in partial extraction of a mixture of polysaccharides consisting of alginate, fucoidan and laminarin. After mild acid pre-treatment, alginate was found in the remaining insoluble residues and was extracted in a second step via alkaline treatment using Na2CO3 (0.15 M) at 80 °C and CaCl2 (10%) for the precipitation. In addition to carbohydrates, a fraction of other components such as proteins, phenolic compounds, minerals and trace elements was detected in the extracts. Cultivation of the thermophilic bacterial strains Rhodothermus marinus DSM 16675 and Bacillus methanolicus MGA3 (ATCC 53907) in media supplemented with the respective extracts resulted in growth of both strains, indicating that they were able to utilize the available carbon source for growth. R. marinus displayed the highest cell density in the medium containing the extract from acid pre-treatment, whereas B. methanolicus growth was highest with the extract from hot water pre-treatment.
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| 3. |
- Hreggvidsson, Gudmundur O, et al.
(författare)
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Biocatalytic refining of polysaccharides from brown seaweeds
- 2020. - 1
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Ingår i: Sustainable Seaweed Technologies : Cultivation, Biorefinery and Applications - Cultivation, Biorefinery and Applications. - 9780128179437 - 9780128179444 ; , s. 447-504
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Bokkapitel (refereegranskat)abstract
- Brown macroalgae constitute 40% of the global production of seaweed, corresponding to approximately 10 million tonnes annually. Traditionally, seaweeds have been the source of hydrocolloids, food, and feed products. Due to possibilities for large-scale farming, brown macroalgae are a biomass with considerable potential for increased utilization. The main constituent polysaccharides, being alginate, cellulose, laminaran, and fucoidan, are the components of greatest importance for biorefinery usage. The polysaccharides can be extracted and applied for their physical or bioactive properties or used as a carbon source for microbial conversions to biofuels and commodity chemicals. The structural complexity and heterogeneous sugar composition of the polysaccharides make them a challenging biorefinery feedstock. These challenges can be overcome by the increasingly innovative biocatalytic tools, enzymes and microbes, that are being developed and that can be expected to open new opportunities and expand the product portfolio. However, there are still knowledge gaps, and further understanding is required on the molecular level of these interesting polymers, the tools, the refining possibilities, as well as transforming this knowledge to innovations—processes and products.
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