umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Isolation and characterization of microalgal strains for biomass production and wastewater reclamation in Northern Sweden
Umeå University, Faculty of Science and Technology, Department of Chemistry.
Umeå University, Faculty of Science and Technology, Department of Chemistry.
2018 (English)In: Algal Research, ISSN 2211-9264, Vol. 32, p. 44-53Article in journal (Refereed) Published
Abstract [en]

Microalgal strains adapted to the harsh Nordic climate were isolated from Swedish fresh- and wastewater sources and tested for their ability to grow in municipal wastewater. The 62 strains able to grow in municipal wastewater belonged to 12 different genera, of those Desmodesmus, Scenedesmus and Chlorella were most representative. Eight axenic strains were further characterized, all of which could efficiently remove nitrogen (>90%) and phosphate (>99%) from the wastewater in less than two weeks. The microalga Coelastrella sp. had the highest performance in terms of both biomass concentration and total lipid content (1.46 g/L, 30.8%) after 13 days of cultivation. This is the first report of a Coelastrella strain isolated in Sweden. Even Chlorella vulgaris performed very well with a biomass concentration and total lipid content of 1.15 g/L and 34.2%, respectively. Finally, two Desmodesmus sp. strains showed desirable traits for biofuel-feedstock, due to their fast growth rates (1.18 and 1.08 d−1) together with high oil content (29.8% and 36.7% of DW).

Place, publisher, year, edition, pages
Elsevier, 2018. Vol. 32, p. 44-53
Keywords [en]
Microalgae, Northern Sweden, Municipal wastewater, Biomass production, Nitrogen, Phosphate
National Category
Other Chemistry Topics
Identifiers
URN: urn:nbn:se:umu:diva-145999DOI: 10.1016/j.algal.2018.03.006ISI: 000432649800005OAI: oai:DiVA.org:umu-145999DiVA, id: diva2:1193023
Projects
Bio4EnergyAvailable from: 2018-03-26 Created: 2018-03-26 Last updated: 2019-09-06Bibliographically approved
In thesis
1. Wastewater treatment and biomass generation by Nordic microalgae: growth in subarctic climate and microbial interactions
Open this publication in new window or tab >>Wastewater treatment and biomass generation by Nordic microalgae: growth in subarctic climate and microbial interactions
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nordic native microalgal strains were isolated, genetically classified and tested for their ability to grow in municipal wastewater. Eight of the isolated strains could efficiently remove nitrogen and phosphate in less than two weeks. Two of these strains, Coelastrella sp. and Chlorella vulgaris, were found to have high biomass concentration and total lipid content; also two Desmodesmus sp. strains showed desirable traits for biofuel-feedstock, due to their fast growth rates and high oil content.

The adaptation to subarctic climate was comparatively evaluated in three Nordic strains (C. vulgaris, Scenedesmus sp. and Desmodesmus sp.) and a collection strain (S. obliquus). Their growth performance, biomass composition and nutrients removal was investigated at standard (25°C) or low temperature (5°C), under continuous light at short photoperiod (3 h light, 25°C) or moderate winter conditions (6 h light, 15°C). Only the Nordic strains could grow and produce biomass at low temperature, and efficiently removed nitrogen and phosphate during both cold- and dark-stress. Phenotypic plasticity was observed in Scenedesmus and Desmodesmus under different growth conditions, adaptation to low temperature increased their carbohydrate content. Short photoperiod strongly reduced growth rates, biomass and storage compounds in all strains and induced flocculation in C. vulgaris, which, however, performed best under moderate winter conditions.

The symbiotic relationships between the Nordic microalga C. vulgaris and the naturally co-occurring bacterium Rhizobium sp. were investigated batchwise under photoautotrophic, heterotrophic and mixotrophic conditions, comparing the co-culture to the axenic cultures. The photoautotrophic algal growth in BG11 medium mainly supported Rhizobium activity in the co-culture, with no significant effects on C. vulgaris. In synthetic wastewater, a synergistic interaction only occurred under mixotrophic conditions, supported by CO2/O2 exchange and a lower pH in the culture, resulting in higher biomass and fatty acids content and more efficient wastewater treatment in the co-culture. Under heterotrophic conditions, the lower biomass production in the co-culture suggested a competition for nutrients, although nutrients removal remained efficient.

A pilot-scale high rate algal pond (HRAP) located in Northern Sweden was inoculated with the collection strain Scenedesmus dimorphus UTEX 417 and operated from spring to autumn. Using metabarcoding of 18S and 16S rRNA genes, the microbial diversity of eukaryotic and prokaryotic communities was revealed. S. dimorphus was initially stable in the culture, but other microalgal species later colonized the system, mainly due to parasitic infections and predation by zooplankton in summer. The main competitor algal species were Desmodesmus, Pseudocharaciopsis, Chlorella, Characium and Oocystis. Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria were the most abundant bacterial phyla in the HRAP. The structure of the microbial communities followed a seasonal variation and partially correlated to environmental factors such as light, temperature and nutrients concentrations.

Overall, these results contribute with new knowledge on the establishment and optimization of microalgal-based wastewater treatment systems coupled with biomass generation in Nordic areas. The use of native microalgal species is proposed as a potential strategy to overcome the limitations posed to algal cultivation in subarctic regions.

Place, publisher, year, edition, pages
Umeå: Umeå University, 2019. p. 75
Keywords
Microalgae, Wastewater, Nitrogen, Phosphate, Biomass, Lipids, Subarctic Climate, Light, Temperature, Bacteria, Photoautotrophy, Heterotrophy, Mixotrophy, HRAP, Metabarcoding, Microbial Communities, Alpha-diversity, Environmental Factors
National Category
Microbiology Other Biological Topics Biochemistry and Molecular Biology Chemical Sciences
Research subject
Biochemistry; Microbiology
Identifiers
urn:nbn:se:umu:diva-156470 (URN)978-91-7855-014-2 (ISBN)
Public defence
2019-03-15, Carl Kempe salen (KB.E3.03), KBC-huset, Umeå, 10:00 (English)
Opponent
Supervisors
Available from: 2019-02-22 Created: 2019-02-15 Last updated: 2019-02-21Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Ferro, LorenzaFunk, Christiane

Search in DiVA

By author/editor
Ferro, LorenzaFunk, Christiane
By organisation
Department of Chemistry
In the same journal
Algal Research
Other Chemistry Topics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 343 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf