| 1. |
- Bergman, Birgitta, et al.
(författare)
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The cyanobacterium–Azolla symbiosis: Interactions and cell differentiation
- 2007
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Ingår i: Abstracts of the Annual Main Meeting of the Society for Experimental Biology, Glasgow, Scotland, 31st March - 4th April, 2007. - : Elsevier BV.
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Konferensbidrag (populärvet., debatt m.m.)abstract
- Selected cyanobacteria form stable nitrogen-fixing symbioses with diverse eukaryotes. The water-fern Azolla carries a nitrogen-fixing cyanobacterium (cyanobiont) in its leaves and shows a pronounced intimacy between its partners. It is the only perpetual N2-fixing symbiosis, i.e. the cyanobiont is vertically transmitted in sporocarps between plant generations. The cyanobiont also seems incapable of independent growth which may suggest gene loss and that the symbiosis is on its way to evolve into a N2-fixing plant. Proteomic analyses of the cyanobiont (2-D coupled to MS) resulted in an identification of about 79% of proteins analysed. Processes upregulated were related to energy production, nitrogen and carbon metabolism and stress, while photosynthesis and metabolic turnover rates were downregulated, stressing a slow heterotrophic mode of growth, high heterocyst frequencies and nitrogen-fixing capacities. Peptide mass spectra of NifH demonstrated the presence of a 300–400 Da protein modification localized to a 13 amino acid sequence. Additionally, a short phylogenetic distance between the cyanobiont and some sequenced cyanobacteria (Section IV) and the database hits of the proteins identified by proteomics, together suggest that the Azolla cyanobiont may represent a novel cyanobacterial genus. The genome of the cyanobiont will be sequenced in 2007 (DOE/JGI, USA).
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| 2. |
- Zhao, Meng, et al.
(författare)
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Three-dimensional cross-linked sugarcane bagasse carbon material: A substitute for graphene with excellent performance in capacitive deionization and highly efficient Cu2+removal
- 2024
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Ingår i: Colloids and Surfaces A. - : ELSEVIER. - 0927-7757 .- 1873-4359. ; 684
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Tidskriftsartikel (refereegranskat)abstract
- Capacitive deionization (CDI) is a high-performance, low-energy consumption, and environmentally friendly water treatment technology with a broad application prospect in heavy metal removal. Selecting electrode materials with high capacitance and low resistance is essential for improving CDI's desalting efficiency. This article discusses the utilization of sugarcane bagasse (C-N-X) and the production procedures of CDI materials. The unique 3D cross-linked structure of C-N-X provides excellent mass transfer properties and significant advantages in capacitance and conductivity. The results of X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectrometer (FTIR) show that bagasse biochar with graphene-like structure and abundant functional groups provides active sites for Cu2+ removal. In this paper, C-N-X is first used as CDI electrode material to remove Cu2+. Electrochemical tests show that the specific capacitance of C-N-X is still stable at about 47 F g ? 1, and the removal capacity of Cu2+ (25 mg L-1) reaches 66.79 mg g-1 within 4 h after 700 cycles. The experimental results and DFT calculations confirm the adsorption selectivity of C -N-700 for Cu2+.
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| 3. |
- Zheng, Weiwen, et al.
(författare)
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Structural Characteristics of the Cyanobacterium–Azolla Symbioses
- 2009
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Ingår i: Prokaryotic Symbionts in Plants. - Dordrecht Heidelberg London New York : Springer Berlin/Heidelberg. - 9783540754596 - 9783540754602 ; , s. 235-263
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Structure is a fundamental base for all life forms, whether plants or microbes. The development of special structures results in unique functions. Though structures of the mutualistic Azolla–cyanobacterial symbiosis are still largely un-explored, they have attracted attention of researchers in the past two decades. The occurrence of the leaf cavity and trichomes within the water-fern Azolla are hallmarks for the two cyanobacterial–plant symbiotic systems. The trichomes and the multicellular filaments are suggested to be involved in metabolic exchange between the cyanobionts and host plants due to their cell wall ingrowths, i.e., transfer cell characteristics. At the apical region of the Azolla plant, the primary branched trichomes touch each other, thereby forming linked bridge-like structures that lead to partitioning of the cyanobacteria into the young leaf cavities, thus promoting horizontal transfer of the cyanobiont during vegetative growth and asexual reproduction via sporophyte fragmentation. The trichomes developing during the sexual reproduction stages of Azolla facilitate the partitioning of the motile cyanobiont into the sporocarps, thus promoting a vertical transfer of cyanobacteria between Azolla generations, a capacity unique among cyanobacterial–plant symbioses. The cyanobionts in Azolla, Blasia and Anthoceros undergo pronounced morphological, physiological and molecular modifications to keep a synchronized development with the plant partner and to meet needs for maintaining a mutualistic symbiosis.
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