| 1. |
- Sanli, Kemal, et al.
(författare)
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Metagenomic Sequencing of Marine Periphyton: Taxonomic and Functional Insights into Biofilm Communities
- 2015
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 6:1192
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Tidskriftsartikel (refereegranskat)abstract
- Periphyton communities are complex phototrophic, multispecies biofilms that develop on surfaces in aquatic environments. These communities harbor a large diversity of organisms comprising viruses, bacteria, algae, fungi, protozoans and metazoans. However, thus far the total biodiversity of periphyton has not been described. In this study, we use metagenomics to characterize periphyton communities from the marine environment of the Swedish west coast. Although we found approximately ten times more eukaryotic rRNA marker gene sequences compared to prokaryotic, the whole metagenome-based similarity searches showed that bacteria constitute the most abundant phyla in these biofilms. We show that marine periphyton encompass a range of heterotrophic and phototrophic organisms. Heterotrophic bacteria, including the majority of proteobacterial clades and Bacteroidetes, and eukaryotic macro-invertebrates were found to dominate periphyton. The phototrophic groups comprise Cyanobacteria and the alpha-proteobacterial genus Roseobacter, followed by different micro- and macro-algae. We also assess the metabolic pathways that predispose these communities to an attached lifestyle. Functional indicators of the biofilm form of life in periphyton involve genes coding for enzymes that catalyze the production and degradation of extracellular polymeric substances, mainly in the form of complex sugars such as starch and glycogen-like meshes together with chitin. Genes for 278 different transporter proteins were detected in the metagenome, constituting the most abundant protein complexes. Finally, genes encoding enzymes that participate in anaerobic pathways, such as denitrification and methanogenesis, were detected suggesting the presence of anaerobic or low-oxygen micro-zones within the biofilms.
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| 2. |
- Sandin, Per, et al.
(författare)
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Technology neutrality and regulation of agricultural biotechnology
- 2018
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Ingår i: Professionals in food chains: ethics, rules and responsibility. EurSafe 2018, Vienna, Austria 13 – 16 June 2018 / edited by: Svenja Springer, Herwig Grimm. - Wageningen, Netherlands : Wageningen Academic Publishers. - 9789086863211
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Konferensbidrag (refereegranskat)abstract
- Agricultural biotechnology, in particular genetically modified organisms (GMOs), is subject to regulation in many areas of the world, not least in the European Union (EU). A number of authors have argued that those regulatory processes are unfair, costly, and slow and that regulation therefore should move in the direction of increased ‘technology neutrality’. The issue is becoming more pressing, especially since new biotechnologies such as CRISPR increasingly blur the regulatory distinction between GMOs and non-GMOs. This paper offers a definition of technology neutrality, uses the EU GMO regulation as a starting point for exploring technology neutrality, and presents distinctions between variants of the call for technology neutral GMO regulation in the EU.
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| 3. |
- Sandhi, Arifin, 1986-, et al.
(författare)
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Phytofiltration of arsenic by aquatic moss (Warnstorfia fluitans)
- 2017
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424.
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Tidskriftsartikel (refereegranskat)abstract
- This work investigates whether aquatic moss (Warnstorfia fluitans) originating from an arsenic (As)-contaminated wetland close to a mine tailings impoundment may be used for phytofiltration of As. The aim was to elucidate the capacity of W. fluitans to remove As from arsenite and arsenate contaminated water, how nutrients affect the As uptake and the proportion of As adsorption and absorption by the moss plant, which consists of dead and living parts.Arsenic removal from 0, 1, or 10% Hoagland nutrient solution containing 0–100 μM arsenate was followed over 192 h, and the total As in aquatic moss after treatment was analysed. The uptake and speciation of As in moss cultivated in water containing 10 μM arsenate or arsenite were examined as As uptake in living (absorption + adsorption) and dead (adsorption) plant parts.Results indicated that W. fluitans removed up to 82% of As from the water within one hour when 1 μM arsenate was added in the absence of nutrients. The removal time increased with greater nutrient and As concentrations. Up to 100 μM As had no toxic effect on the plant biomass. Both arsenite and arsenate were removed from the solution to similar extents and, independent of the As species added, more arsenate than arsenite was found in the plant. Of the As taken up, over 90% was firmly bound to the tissue, a possible mechanism for resisting high As concentrations. Arsenic was both absorbed and adsorbed by the moss, and twice as much As was found in living parts as in dead moss tissue. This study revealed that W. fluitans has potential to serve as a phytofilter for removing As from As-contaminated water without displaying any toxic effects of the metalloid.
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| 4. |
- Björk, Mats, 1960-, et al.
(författare)
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Methane emissions from macrophyte beach wrack on Baltic seashores
- 2023
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Ingår i: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 52:1, s. 171-181
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Tidskriftsartikel (refereegranskat)abstract
- Beach wrack of marine macrophytes is a natural component of many beaches. To test if such wrack emits the potent greenhouse gas methane, field measurements were made at different seasons on beach wrack depositions of different ages, exposure, and distance from the water. Methane emissions varied greatly, from 0 to 176 mg CH4-C m−2 day−1, with a clear positive correlation between emission and temperature. Dry wrack had lower emissions than wet. Using temperature data from 2016 to 2020, seasonal changes in fluxes were calculated for a natural wrack accumulation area. Such calculated average emissions were close to zero during winter, but peaked in summer, with very high emissions when daily temperatures exceeded 20 °C. We conclude that waterlogged beach wrack significantly contributes to greenhouse gas emissions and that emissions might drastically increase with increasing global temperatures. When beach wrack is collected into heaps away from the water, the emissions are however close to zero.
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| 5. |
- Almered Olsson, Gunilla, 1951, et al.
(författare)
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Food systems sustainability - For whom and by whom? : An examination of different 'food system change' viewpoints
- 2018
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Ingår i: Development Research Conference 2018: “Rethinking development”, 22–23 August 2018, Gothenburg, Sweden.
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Konferensbidrag (refereegranskat)abstract
- The United Nations identifies the food crisis as one of the primary overarching challenges facing the international community. Different stakeholders in the food system have widely different perspectives and interests, and challenging structural issues, such as the power differentials among them, remain largely unexamined. These challenges make rational discourse among food system actors from different disciplines, sectors and levels difficult. These challenges can often prevent them from working together effectively to find innovative ways to respond to food security challenges. This means that finding solutions to intractable and stuck issues, such as the food crisis often stall, not at implementation, but at the point of problem identification. Food system sustainability means very different things to different food system actors. These differences in no way undermine or discount the work carried out by these players. However, making these differences explicit is an essential activity that would serve to deepen theoretical and normative project outcomes. Would the impact and reach of different food projects differ if these differences were made explicit? The purpose of this initial part of a wider food system research project is not to search for difference or divergence, with the aim of critique, but rather to argue that by making these differences explicit, the overall food system project engagement will be made more robust, more inclusive and more encompassing. This paper starts with some discussion on the different food system perspectives, across scales, regions and sectors but focuses primarily on the design of processes used to understand these divergent and at times contradictory views of what a sustainable food system may be. This paper draws on ongoing work within the Mistra Urban Futures project, using the food system projects in cities as diverse as Cape Town, Manchester, Gothenburg and Kisumu as sites for this enquiry.
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| 6. |
- Ahlman, Linnéa, 1987, et al.
(författare)
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Stress Detection Using Proximal Sensing of Chlorophyll Fluorescence on the Canopy Level
- 2021
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Ingår i: AgriEngineering. - : MDPI AG. - 2624-7402. ; 3:3, s. 648-668
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Tidskriftsartikel (refereegranskat)abstract
- Chlorophyll fluorescence is interesting for phenotyping applications as it is rich in biological information and can be measured remotely and non-destructively. There are several techniques for measuring and analysing this signal. However, the standard methods use rather extreme conditions, e.g., saturating light and dark adaption, which are difficult to accommodate in the field or in a greenhouse and, hence, limit their use for high-throughput phenotyping. In this article, we use a different approach, extracting plant health information from the dynamics of the chlorophyll fluorescence induced by a weak light excitation and no dark adaption, to classify plants as healthy or unhealthy. To evaluate the method, we scanned over a number of species (lettuce, lemon balm, tomato, basil, and strawberries) exposed to either abiotic stress (drought and salt) or biotic stress factors (root infection using Pythium ultimum and leaf infection using Powdery mildew Podosphaera aphanis ). Our conclusions are that, for abiotic stress, the proposed method was very successful, while, for powdery mildew, a method with spatial resolution would be desirable due to the nature of the infection, i.e., point-wise spread. Pythium infection on the roots is not visually detectable in the same way as powdery mildew; however, it affects the whole plant, making the method an interesting option for Pythium detection. However, further research is necessary to determine the limit of infection needed to detect the stress with the proposed method.
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| 7. |
- Guschanski, Katerina, et al.
(författare)
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The evolution of duplicate gene expression in mammalian organs
- 2017
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 27:9, s. 1461-1474
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Tidskriftsartikel (refereegranskat)abstract
- Gene duplications generate genomic raw material that allows the emergence of novel functions, likely facilitating adaptive evolutionary innovations. However, global assessments of the functional and evolutionary relevance of duplicate genes in mammals were until recently limited by the lack of appropriate comparative data. Here, we report a large-scale study of the expression evolution of DNA-based functional gene duplicates in three major mammalian lineages (placental mammals, marsupials, egg-laying monotremes) and birds, on the basis of RNA sequencing (RNA-seq) data from nine species and eight organs. We observe dynamic changes in tissue expression preference of paralogs with different duplication ages, suggesting differential contribution of paralogs to specific organ functions during vertebrate evolution. Specifically, we show that paralogs that emerged in the common ancestor of bony vertebrates are enriched for genes with brain-specific expression and provide evidence for differential forces underlying the preferential emergence of young testis-and liver-specific expressed genes. Further analyses uncovered that the overall spatial expression profiles of gene families tend to be conserved, with several exceptions of pronounced tissue specificity shifts among lineage-specific gene family expansions. Finally, we trace new lineage-specific genes that may have contributed to the specific biology of mammalian organs, including the little-studied placenta. Overall, our study provides novel and taxonomically broad evidence for the differential contribution of duplicate genes to tissue-specific transcriptomes and for their importance for the phenotypic evolution of vertebrates.
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| 8. |
- Stedt, Kristoffer, 1991, et al.
(författare)
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Post-harvest cultivation with seafood process waters improves protein levels of Ulva fenestrata while retaining important food sensory attributes
- 2022
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745.
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Tidskriftsartikel (refereegranskat)abstract
- Seaweed aquaculture can provide the growing human population with a sustainable source of proteins. Sea-based cultivation is an effective method for farming seaweeds on a large scale and can yield high biomass output. However, the quality and biochemical composition of the biomass is seasonally dependent, which limits the harvests to certain periods of the year. Here we show the possibility to extend the sea-based cultivation season of Ulva fenestrata when aiming for high protein levels, by post-harvest treatment in herring production process waters. We harvested U. fenestrata at an optimal period in terms of yield, but suboptimal in terms of protein content. We then cultivated the seaweed in onshore tank systems with the nutrient-rich process waters for 14 days. We monitored biomass yield, crude protein content, amino acid composition, and content of the health concerning metals arsenic, mercury, lead, and cadmium, as well as the sensory properties of the dried biomass. After cultivation in the process waters, biomass yields were 30 - 40% higher (210 – 230 g fresh weight) compared to in seawater (160 g fresh weight). Also, the crude protein and amino acid content increased three to five times in the process waters, reaching 12 - 17 and 15 – 21% dry weight, respectively. The protein enriched biomass followed food graded standards for heavy metal content, and consumption of the biomass does not exceed health based reference points. Additionally, no sensory attributes regarded as negative were found. This rapid, post-harvest treatment can help extend the cultivation season of sea-based seaweed farms, maximizing their output of sustainable proteins.
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| 9. |
- Steinhagen, Sophie, et al.
(författare)
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Harvest time can affect the optimal yield and quality of sea lettuce (Ulva fenestrata) in a sustainable sea-based cultivation : Seasonal Cultivation of Ulva fenestrata
- 2022
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Seaweed biomass is a renewable resource with multiple applications. Sea-based cultivation of seaweeds can provide high biomass yields, low construction, operation, and maintenance costs and could offer an environmentally and economically sustainable alternative to land-based cultivations. The biochemical profile of sea-grown biomass depends on seasonal variation in environmental factors, and the optimization of harvest time is important for the quality of the produced biomass. To identify optimal harvest times of Swedish sea-based cultivated sea lettuce (Ulva fenestrata), this study monitored biomass yield, morphology, chemical composition, fertility, and biofouling at five different harvesting times in April - June 2020. The highest biomass yields (approx. 1.2 kg fw [m rope]-1) were observed in late spring (May). The number and size of holes in the thalli and the amount of fertile and fouled tissue increased with prolonged growth season, which together led to a significant decline in both biomass yield and quality during summer (June). Early spring (April) conditions were optimal for obtaining high fatty acid, protein, biochar, phenolic, and pigment contents in the biomass, whereas carbohydrate and ash content, as well as essential and non-essential elements, increased later in the growth season. Our study results show that the optimal harvest time of sea-based cultivated U. fenestrata depends on the downstream application of the biomass and must be carefully selected to balance yield, quality, and desired biochemical contents to maximize the output of future sea-based algal cultivations in the European Northern Hemisphere.
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| 10. |
- Schrader, J., et al.
(författare)
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Cambial meristem dormancy in trees involves extensive remodelling of the transcriptome
- 2004
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Ingår i: The Plant Journal. - Malden : Wiley-Blackwell. - 0960-7412 .- 1365-313X. ; 40:2, s. 173-187
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Tidskriftsartikel (refereegranskat)abstract
- The establishment of the dormant state in meristems involves considerable physiological and metabolic alterations necessary for surviving unfavourable growth conditions. However, a global molecular analysis of dormancy in meristems has been hampered by the difficulty in isolating meristem cells. We used cryosectioning to isolate purified cambial meristem cells from the woody plant Populus tremula during active growth and dormancy. These samples were used to generate meristem-specific cDNA libraries and for cDNA microarray experiments to define the global transcriptional changes underlying cambial dormancy. The results indicate a significant reduction in the complexity of the cambial transcriptome in the dormant state. Although cell division is terminated in the dormant cambium, the cell cycle machinery appears to be maintained in a skeletal state as suggested by the continued presence of transcripts for several cell cycle regulators. The downregulation of PttPIN1 and PttPIN2 transcripts explains the reduced basipetal polar auxin transport during dormancy. The induction of a member of the SINA family of ubiquitin ligases implicated in auxin signalling indicates a potential mechanism for modulation of auxin sensitivity during cambial dormancy. The metabolic alterations during dormancy are mirrored in the induction of genes involved in starch breakdown and the glyoxysomal cycle. Interestingly, the induction of RGA1 like gene suggests modification of gibberellin signalling in cambial dormancy. The induction of genes such as poplar orthologues of FIE and HAP2 indicates a potential role for these global regulators of transcription in orchestrating extensive changes in gene expression during dormancy.
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