lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Production stability and biomass quality in microalgal cultivation - contribution of community dynamics
Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. (MPEA)
Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. (MPEA)
Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. (MPEA)ORCID iD: 0000-0001-7155-3604
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The prospect of using constructed communities of microalgae in algal cultivation wasconfirmed in this study. Three constructed communities of diatoms (Diatom), greenalgae (Green) and cyanobacteria (Cyano), were each mixed with a natural communityof microalgae as baseline. The communities were cultivated in batch and semicontinuousmode and fed CO2 or cement flue gas (12-15 % CO2). Diatom had thehighest growth rate but Green had the highest yield. Dynamic changes in thecommunity composition occurred from start through batch to semi-steady state. Greenalgae were the most competitive group during the experiment. Euglenoids wererecruited from scarce species in the natural community and became a large part of thebiomass in semi-steady state in all communities. High temporal and yield stabilitywas demonstrated in all communities during semi-steady state. Biochemicalcomposition (lipids, proteins and carbohydrates) was similar for the threecommunities with lipids ranging 14-26 % of dry weight (DW), proteins (15-28 %DW) and carbohydrates (9-23 % DW). Filamentous cyanobacteria were outcompetedearly in the experiment. However, their minute presence in Cyano associated withhigher lipid and lower carbohydrates compared to Diatom and Green, suggesting theimportance of chemical interactions among microorganisms. Our results indicate thatculture functions (stability, biomass quality) were maintained while dynamic changesoccurred in community composition. We propose that a multi-species communityapproach can aid sustainability in microalgal cultivation, through complementary useof resources and higher culture stability. Local environmental conditions,complementary microalgal traits, and interactions among functional groups (algae,bacteria) should be considered in community design where natural succession andcrop rotation will likely provide stability for commercial-scale algal cultivation.

Keyword [en]
Microalgae, multi-species communities, production stability, algal cultivation, biomass composition, flue gas
National Category
Biological Sciences Ecology
Research subject
Ecology, Aquatic Ecology; Chemistry, Biotechnology; Environmental Science, Environmental technology
Identifiers
URN: urn:nbn:se:lnu:diva-46511OAI: oai:DiVA.org:lnu-46511DiVA: diva2:857082
Available from: 2015-09-28 Created: 2015-09-28 Last updated: 2016-12-07Bibliographically approved
In thesis
1. Microalgae - future bioresource of the sea?
Open this publication in new window or tab >>Microalgae - future bioresource of the sea?
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Unicellular microalgae are a renewable bioresource that can meet the challenge forfood and energy in a growing world population. Using sunlight, CO2, nutrients,and water, algal cells produce biomass in the form of sugars, proteins and oils, allof which carry commercial value as food, feed and bioenergy. Flue gas CO2 andwastewater nutrients are inexpensive sources of carbon and fertilizers. Microalgaecan mitigate CO2 emissions and reduce nutrients from waste streams whileproducing valuable biomass.My focus was on some of the challenging aspects of cultivating microalgae ascrop: the response of biomass production and quality to seasonality, nutrients andbiological interactions. Approach spans from laboratory experiments to large-scaleoutdoor cultivation, using single microalgal strains and natural communities insouthern (Portugal) and northern (Sweden) Europe.Half of the seasonal variation in algal oil content was due to changes in light andtemperature in outdoor large-scale cultures of a commercial strain (Nannochloropsisoculata). Seasonal changes also influence algal oil composition with more neutrallipids stored in cells during high light and temperature. Nitrogen (N) stress usuallyenhances lipid storage but suppresses biomass production. Our manipulationshowed that N stress produced more lipids while retaining biomass. Thus,projecting annual biomass and oil yields requires accounting for both seasonalchanges and N stress to optimize lipid production in commercial applications.Baltic Sea microalgae proved to be a potential biological solution to reduce CO2emissions from cement flue gas with valuable biomass production. A multi-speciescultivation approach rather than single-species revealed that natural or constructedcommunities of microalgae can produce equivalent biomass quality. Diversecommunities of microalgae can offer resilience and stability due to more efficientresource utilization with less risk of contamination, less work and cost for culturemaintenance.Stable algal biomass production (annual basis) was achieved in outdoor pilot-scale(1600 L) cultivation of Baltic Sea natural communities using cement flue gas as aCO2 source. Results indicate favorable algal oil content at northern Europeanlatitudes compared to southern European latitudes.My thesis establishes the potential of cultivating microalgae as a bioresource inScandinavia, and using a community approach may be one step towardssustainable algal technology.

Place, publisher, year, edition, pages
Växjö: Linnaeus University Press, 2015
Series
Linnaeus University Dissertations, 227/2015
Keyword
Microalgae, algal cultivation, bioresource, bioenergy, CO2 mitigation, multi-species community approach, seasonal variation
National Category
Biological Sciences Ecology Industrial Biotechnology
Research subject
Natural Science, Aquatic Ecology; Natural Science, Biotechnology; Environmental Science, Environmental technology
Identifiers
urn:nbn:se:lnu:diva-46512 (URN)978-91-87925-75-7 (ISBN)
Public defence
2015-10-16, Hörsalen Fullriggaren, Landgången 4, Kalmar, 09:30 (English)
Opponent
Supervisors
Available from: 2015-09-28 Created: 2015-09-28 Last updated: 2015-09-28Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Olofsson, MartinLindehoff, ElinLegrand, Catherine
By organisation
Department of Biology and Environmental Science
Biological SciencesEcology

Search outside of DiVA

GoogleGoogle Scholar

Total: 268 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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