The aim of our research is to study energy production in microorganisms. The research covers several projects, of which the three main projects will briefly be presented below.
Anita Sellstedt (photo: Fredrik Larsson)
Hydrogen metabolism of Frankia
Nitrogen fixation occurs in Frankia both in free-living as well as in symbioses and may contribute as much as a quarter of the total yearly biologically fixed nitrogen globally in terrestrial ecosystem.
The most important recent achievement in the Frankia research field is the sequencing of three Frankia genomes. We were able to show that there are large differences in the genome sizes. Frankia EANpec1 was found to have the largest genome with 9.0 Mb, while Frankia ACN14a had an intermediate size of 7.5 Mb and Frankia HFPCcI3 was the smallest at 5.4 Mb. These numbers were correlated with geographical origin, host plant distribution and repeated sequences, such as IS. Our findings open up a new era in Frankia research, yielding possibilities to explore the molecular biology of Frankia.
An inevitable source of energy-inefficiency in the nitrogen-fixation process is the evolution of hydrogen; as much as 25% of the in vitro electron-flow through nitrogenase goes to hydrogen evolution. Some nitrogen-fixing systems have dealt with this problem of energy loss through evolving an extra enzyme, called uptake hydrogenase, which is very common in Frankia.
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Light micrograph of the bacterium Frankia showing vesicles. |
Light micrograph of our isolate of Chalara parvispora |
Cyanobacteria in association with boreal mosses
We were able to discover that cyanobacteria live in association with feather mosses in the boreal area. We also discovered that they are able of fixing nitrogen and thereby contributing to the N status of that ecosystem.
Heterotrophic production of lipids by algae
Algae are commonly autotrophic carbon dioxide fixing prokaryotes. They are also able of storing different compounds under a variety of conditions. This year a Thesis from my laboratory revealed that some microalgae are able to use glycerol as a carbon source under growing in heterotrophic conditions. Interestingly, a microalgae isolated in the lab and originating from Umeå area has this trait and also accumulated significant amounts of lipids under this condition.
Svensk sammanfattning
Key Publications
- Nzayisenga JC, Eriksson K, Sellstedt A (2018). Mixotrophic and heterotrophic production of lipids and carbohydrates by a locally isolated microalga using wastewater as growth medium. Bioresource Technology 257: 260-265.
- Leul M, Normand P, Sellstedt A (2009). The phylogeny of uptake hydrogenases. Int Microbiol. 12(1): 23-28.
- Normand et al., (2007). Genome structure reflects host biogeography in three plant symbionts Frankia sp. strains. Genome Research, 17, 7-15.
- Mohapatra A, Leul M, Mattsson U, Sellstedt A (2004). A hydrogen-evolving enzyme is present in Frankia R43. FEMS Microbiol. Lett.236: 235-240.
- DeLuca TH, O Zackrisson, M-C Nilsson, A Sellstedt (2002). Quantifying nitrogen fixation in feather moss carpets. Nature. 419: 917-920.
CV Dr. Anita Sellstedt
- 2002-ongoing: Professor at the Department of Plant physiology, Umeå University, Umeå
- 1991-2001: Senior lecturer, Umeå university
- 1990: Associate Professor/Docent, Umeå University
- 1989: Post Doc, Australia
- 1985: PhD, Department of Plant Physiology, Umeå University
Publication list
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More than protection: the function of TiO 2 interlayers in hematite functionalized Si photoanodes
Phys Chem Chem Phys. 2020, 22(48 ):28459-28467
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Bioethanol production from four abundant Indian agricultural wastes
Biofuels UK 2020, 11(5):607-613
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Screening Suitability of Northern Hemisphere Algal Strains for Heterotrophic Cultivation and Fatty Acid Methyl Ester Production
Molecules. 2020, 25(9):E2107
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Effects of light intensity on growth and lipid production in microalgae grown in wastewater
Biotechnol Biofuels. 2020, 13(4)
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A microstructured p-Si photocathode outcompetes Pt as a counter electrode to hematite in photoelectrochemical water splitting
Dalton Trans. 2019, 48(4):1166-1170
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Photo-electrochemical hydrogen production from neutral phosphate buffer and seawater using micro-structured p-Si photo-electrodes functionalized by solution-based methods
SUSTAINABLE ENERGY & FUELS 2018, 2(19):2215-2223
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Mixotrophic and heterotrophic production of lipids and carbohydrates by a locally isolated microalga using wastewater as a growth medium
Bioresour Technol. 2018; 257:260-265
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Adaptability of Trametes versicolor to the lignocellulosic inhibitors furfural, HMF, phenol and levulinic acid during ethanol fermentation
BIOMASS & BIOENERGY 2016, 90:95-100
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Genome Sequence of the Atypical Symbiotic Frankia R43 Strain, a Nitrogen-Fixing and Hydrogen-Producing Actinobacterium
Genome Announc. 2015, 3(6)
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Expression of fungal acetyl xylan esterase in Arabidopsis thaliana improves saccharification of stem lignocellulose
Plant Biotechnol J. 2015, 14 (1):387-397
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Biomass-Based Energy Production
in Introduction to Chemicals from Biomass, Second Edition (eds J. Clark and F. Deswarte) (2015), John Wiley & Sons, Ltd, Chichester, UK
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Structural and gene expression analyses of uptake hydrogenases and other proteins involved in nitrogenase protection in Frankia
Journal of Biosciences, 2013; 38(4):703-712
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Aspects of nitrogen fixing Actinobacteria, in particular free-living and symbiotic Frankia
FEMS Microbiol Lett. 2013 ;342 (2):179-186
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Kudahettige RL, Holmgren M, Imerzel P, Sellstedt A
Characterization of bioethanol production from hexoses and xylose by the white rot fungus Trametes versicolor
Bioenergy Research: Volume 5(2), (2012), 277-285
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Kosawang C, Kudahettige RL, Resman L, Sellstedt A
Hydrogen yield from a hydrogenase in Frankia R43 at different levels of the carbon source propionate
Journal of Environmental Management: 2011, Epub ahead of print
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Leul M, Normand P, Sellstedt A
The phylogeny of uptake hydrogenases in Frankia
International Microbiology: 2009 12:23-28
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Zackrisson O, DeLuca TH, Gentili F, Sellstedt A, Jäderlund A
Nitrogen fixation in mixed Hylocomium splendens moss communities
Oecologia: 2009 160:309-319
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Holmgren M, Sellstedt A
Identification of white-rot and soft-rot fungi increasing ethanol production from spent sulfite liquor in co-culture with Saccharomyces cerevisiae
Journal of Applied Microbiology: 2008 105:134-140
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Leul M, Normand P, Sellstedt A
The organization, regulation and phylogeny of uptake hydrogenase genes in Frankia
Physiologia Plantarum: 2007 130:464-470
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Santos CL, Vieira J, Sellstedt A, Normand P, Moradas-Ferreira P, Tavares F
Modulation of Frankia alni ACN14a oxidative stress response: activity, expression and phylogeny of catalases
Physiologia Plantarum: 2007 130:454-463
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Tavares F, Santos CL, Sellstedt A
Reactive oxygen species in legume and actinorhizal nitrogen-fixing symbioses: the microsymbiont's responses to an unfriendly reception
Physiologia Plantarum: 2007 130:344-356
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Sellstedt A, Normand P, Dawson J
Frankia - the friendly bacteria - infecting actinorhizal plants
Physiologia Plantarum: 2007 130:315-317
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DeLuca TH, Zackrisson O, Gentili F, Sellstedt A, Nilsson M-C
Ecosystem controls on nitrogen fixation in boreal feather moss communities
Oecologia: 2007 152:121-130
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Normand P, Lapierre P, Tisa LS, Gogarten JP, ..., Sellstedt A, Tavares F, et al
Genome characeristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography
Genome Research 2007 17:7-15
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Mohapatra A, Leul M, Sandstrom G, Sellstedt A
Occurrence and characterisation of the hydrogen-evolving enzyme in Frankia sp
International Journal Of Hydrogen Energy: 2006 31:1445-1451
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Nitrogen fixation and biomass production in symbiosis between Alnus incana and Frankia strains with differrent hydrogen metabolism
Physiol. Plant. 2006; 66(1):99-107
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Stahl L, Hogberg P, Sellstedt A, Buresh RJ
Measuring nitrogen fixation by Sesbania sesban planted fallows using N-15 tracer technique in Kenya
Agroforestry Systems: 2005 65:67-79
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Leul M, Mattsson U, Sellstedt A
Molecular characterization of uptake hydrogenase in Frankia
Biochem Soc Trans: 2005 33:64-66
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Leul M, Mohapatra A, Sellstedt A
Biodiversity of hydrogenases in Frankia
Curr Microbiol: 2005 50:17-23
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Gentili F, Nilsson MC, Zackrisson O, DeLuca TH, Sellstedt A
Physiological and molecular diversity of feather moss associative N-2-fixing cyanobacteria
Journal Of Experimental Botany: 2005 56:3121-3127
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Zackrisson O, DeLuca TH, Nilsson MC, Sellstedt A, Berglund LM
Nitrogen fixation increases with successional age in boreal forests
Ecology: 2004 85:3327-3334
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Mohapatra A, Leul M, Mattsson U, Sellstedt A
A hydrogen-evolving enzyme is present in Frankia sp. R43
FEMS Microbiol Lett: 2004 236:235-240
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Leitz G, Lundberg C, Fallman E, Axner O, Sellstedt A
Laser-based micromanipulation for separation and identification of individual Frankia vesicles
Fems Microbiology Letters: 2003 224:97-100
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Tavares F, Bernardo L, Sellstedt A
Identification and expression studies of a catalase and a bifunctional catalase-peroxidase in Frankia strain R43
Plant and Soil: 2003 254:75-81
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Mattsson U, Sellstedt A
Nickel affects activity more than expression of hydrogenase protein in Frankia
Curr Microbiol: 2002 44:88-93
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DeLuca TH, Zackrisson O, Nilsson M-C, Sellstedt A
Quantifying nitrogen-fixation in feather moss carpets of boreal forests
Nature: 2002 419:917-920
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Mattsson U, Johansson L, Sandstrom G, Sellstedt A
Frankia KB5 possesses a hydrogenase immunologically related to membrane-bound
Curr Microbiol: 2001 42:438-441
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Tavares F, Sellstedt A
DNase-resistant DNA in the extracellular and cell wall-associated fractions of Frankia strains R43 and CcI3
Curr Microbiol: 2001 42:168-172
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Mattsson U, Johansson L, Sandstrom G, Sellstedt A
Frankia KB5 possesses a hydrogenase immunologically related to membrane-bound [NiFe]-hydrogenases
Current Microbiology: 2001 42:438-441
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Mattsson U, Sellstedt A
Hydrogenase in Frankia KB5: expression of and relation to nitrogenase
Can J Microbiol: 2000 46:1091-1095
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Tavares F, Sellstedt A
A simple, rapid and non-destructive procedure to extract cell wall-associated proteins from Frankia
J Microbiol Methods: 2000 39:171-178
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Tavares F, Sellstedt A
DNase activities of the extracellular, cell wall-associated, and cytoplasmic protein fractions of Frankia strain R43
Applied and Environmental Microbiology: 1997 63:4597-4599
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Sellstedt A
Specificity and Effectivity in Nodulation by Frankia on Southern-Hemisphere Actinorhiza
Fems Microbiology Letters: 1995 125:231-236
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Sellstedt A, Rosbrook PA, Kang L, Reddell P
Effect of Carbon Source on Growth, Nitrogenase and Uptake Hydrogenase Activities of Frankia Isolates from Casuarina Sp
Plant and Soil: 1994 158:63-68
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Sellstedt A, Mattsson U
Hydrogen Metabolism in Casuarina-Frankia - Immunolocalization of Nitrogenase and Hydrogenase
Soil Biology & Biochemistry: 1994 26:583-592
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Sellstedt A, Stahl L, Mattsson U, Jonsson K, Hogberg P
Can the N-15 Dilution Technique Be Used to Study N-2 Fixation in Tropical Tree Symbioses as Affected by Water-Deficit
Journal of Experimental Botany: 1993 44:1749-1755
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Sellstedt A
Hydrogen Metabolism in Frankia - Is There a Plant Factor Affecting This Metabolism
Acta Oecologica-International Journal of Ecology: 1992 13:512-512
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Sellstedt A, Wullings B, Nystrom U, Gustafsson P
Identification of Casuarina-Frankia Strains by Use of Polymerase Chain-Reaction (Pcr) with Arbitrary Primers
Fems Microbiology Letters: 1992 93:1-5
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Sellstedt A, Atkins CA
Composition of Amino-Compounds Transported in Xylem of Casuarina Sp
Journal of Experimental Botany: 1991 42:1493-1497
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Sellstedt A, Reddell P, Rosbrook PA, Ziehr A
The Relations of Hemoglobin and Lignin-Like Compounds to Acetylene-Reduction in Symbiotic Casuarina
Journal of Experimental Botany: 1991 42:1331-1337
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Sellstedt A, Reddell P, Rosbrook P
The Occurrence of Hemoglobin and Hydrogenase in Nodules of 12 Casuarina-Frankia Symbiotic Associations
Physiologia Plantarum: 1991 82:458-464
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Sellstedt A, Smith GD
Nickel Is Essential for Active Hydrogenase in Free-Living Frankia Isolated from Casuarina
Fems Microbiology Letters: 1990 70:137-140
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Sellstedt A, Lindblad P
Activities, Occurrence, and Localization of Hydrogenase in Free-Living and Symbiotic Frankia
Plant Physiology: 1990 92:809-815
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Sellstedt A, Winship LJ
Acetylene, Not Ethylene, Inactivates the Uptake Hydrogenase of Actinorhizal Nodules During Acetylene-Reduction Assays
Plant Physiology: 1990 94:91-94
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Lindblad P, Sellstedt A
Occurrence and Localization of an Uptake Hydrogenase in the Filamentous Heterocystous Cyanobacterium Nostoc Pcc-73102
Protoplasma: 1990 159:9-15
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Lindblad P, Sellstedt A
Immunogold Localization of Hydrogenase in Free-Living Frankia Cpi1
Fems Microbiology Letters: 1989 60:311-315
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Sellstedt A, Hogberg P, Jonsson K
Diurnal-Variation in Acetylene-Reduction and Net Hydrogen Evolution in 5 Tropical and Sub-Tropical Nitrogen-Fixing Tree Symbioses
Journal of Experimental Botany: 1989 40:1163-1168
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Sellstedt A
Occurrence and Activity of Hydrogenase in Symbiotic Frankia from Field-Collected Alnus-Incana
Physiologia Plantarum: 1989 75:304-308
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Sellstedt A
Nitrogenase Activity, Hydrogen Evolution and Biomass Production in Different Casuarina Symbioses
Plant and Soil: 1988 105:33-40
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Hydrogen metabolism of Casuarina root nodules: A comparison of two inoculum sources
Physiologia Plantarum, 1987; 70(2): 367–372
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Sellstedt A, Winship LJ
Hydrogen Metabolism of Casuarina Root-Nodules - a Comparison of 2 Inoculum Sources
Physiologia Plantarum: 1987 70:367-372
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Winship LJ, Martin KJ, Sellstedt A
The Acetylene-Reduction Assay Inactivates Root Nodule Uptake Hydrogenase in Some Actinorhizal Plants
Physiologia Plantarum: 1987 70:361-366
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Sellstedt A
Nitrogen and Carbon Utilization in Alnus-Incana Fixing N-2 or Supplied with No3 at the Same Rate
Journal of Experimental Botany: 1986 37:786-797
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Sellstedt A, Hussdanell K, Ahlqvist AS
Nitrogen-Fixation and Biomass Production in Symbioses between Alnus-Incana and Frankia Strains with Different Hydrogen Metabolism
Physiologia Plantarum: 1986 66:99-107
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Sellstedt A
Acetylene reduction, H-2 Evolution and 15-N-2 Fixation in the Alnus incana-Frankia Symbiosis
Planta: 1986 167:382-386
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Sellstedt A, Hussdanell K
Biomass Production and Nitrogen-Utilization by Alnus-Incana When Grown on N-2 or Nh4+ Made Available at the Same Rate
Planta: 1986 167:387-394
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Huss-Danell K, Sellstedt A
Nitrogenase activity in response to darkening and defoliation in Alnus incana
Journal of Experimental Botany: 1985 36:1352-1358
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Sellstedt A, Huss-Danell K
Growth, nitrogen fixation and relative efficiency of nitrogenase in Alnus incana grown in different cultivation systems
Plant and Soil: 1984 78:147-158
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Nitrogenase activity in response to restricted shoot growth in Alnus incana
Can. J. Bot., 1983, 61(11): 2949-2955
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Ammonium effects on function and structure of nitrogen-fixing root nodules of Alnus incana (L.) Moench
Planta 1982; 156(4):332-40