Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Record number 479185
Title Phototrophic pigment production with microalgae
Author(s) Mulders, K.J.M.
Source Wageningen University. Promotor(en): Rene Wijffels, co-promotor(en): Dirk Martens; Packo Lamers. - Wageningen : Wageningen University - ISBN 9789462571457 - 179
Department(s) Bioprocess Engineering
VLAG
Publication type Dissertation, internally prepared
Publication year 2014
Keyword(s) algen - fototropie - pigmenten - natuurlijke producten - metabolisme - carotenoïden - licht - gerichte mutagenese - algae - phototropism - pigments - natural products - metabolism - carotenoids - light - targeted mutagenesis
Categories Algae / Dyes and Paints
Abstract Abstract

Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary carotenoids.

Different microalgal groups each possess their own set of primary pigments. Besides, a selected group of green algae (Chlorophytes) accumulate secondary pigments (secondary carotenoids) when exposed to oversaturating light conditions.

In this thesis it was found for the first time that nutrient-depleted Isochrysis. aff. galbana T-ISO (Haptophytes) accumulates 3-hydroxyechinenone, a precursor of astaxanthin. Besides, it was found that nitrogen-depleted Chromochloris (Chlorella) zofingiensis (Chlorophyes) accumulates astaxanthin, presumably synthesised via echinenone, and ketolutein.

Inhibition of production of β-carotene derivatives (e.g. echinenone and astaxanthin) did not lead to increased production of primary carotenoids (e.g. lutein) or ketolutein in this species, suggesting that the regulatory mechanisms controlling the flux towards ketolutein and primary carotenoids are not affected by the decreased levels of β-carotene derivatives.

Besides, optimal yields of secondary carotenoids and triacylglycerol (TAG) on light were reached with C. zofingiensis for a range of biomass concentrations at the moment of nitrogen depletion.

This indicated that the biomass-specific photon absorption rate did not affect the amounts of energy used for secondary carotenoid and TAG production, for the range of biomass concentrations tested.

It was also found that nitrogen-depleted C. zofingiensis resupplied with nitrogen hardly degraded astaxanthin, whereas the other major secondary metabolites were degraded rapidly.

This indicated that the overall carotenoid yield on light as well as its content may possibly be improved by applying a repeated batch instead of a series of single batch cultivations, which are traditionally applied.

Finally, it was discussed that the highest increases in carotenoid yield on light can be reached by optimizing strain performance (using targeted genetic engineering and/or random mutagenesis), rather than by optimizing the cultivation conditions/operation mode or reactor design.

Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.