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The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis

Although great efforts have been made to elucidate the phenotypic responses of alga to varying levels of nutrients, osmotic environments, and photosynthetically active radiation intensities, the role of interactions among these variables is largely nebulous. Here, we describe a general method for es...

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Autores principales: Davis, Ryan W., Carvalho, Benjamin J., Jones, Howland D. T., Singh, Seema
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Netherlands 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4297879/
https://www.ncbi.nlm.nih.gov/pubmed/25620852
http://dx.doi.org/10.1007/s10811-014-0331-5
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author Davis, Ryan W.
Carvalho, Benjamin J.
Jones, Howland D. T.
Singh, Seema
author_facet Davis, Ryan W.
Carvalho, Benjamin J.
Jones, Howland D. T.
Singh, Seema
author_sort Davis, Ryan W.
collection PubMed
description Although great efforts have been made to elucidate the phenotypic responses of alga to varying levels of nutrients, osmotic environments, and photosynthetically active radiation intensities, the role of interactions among these variables is largely nebulous. Here, we describe a general method for establishing and maintaining semi-continuous cultures of the halophilic microalgal production strain, Dunaliella viridis, that is independent of variations in salinity and illumination intensity. Using this method, the cultures were evaluated to elucidate the overlapping roles of photosynthetic and osmotic adaptation on the accumulation and compositional variation of the biomass, photosynthetic productivity, and physiological biomarkers, as well as spectroscopic and morphological details at the single-cell level. Correlation matrices defining the relationships among the observables and based on variation of the illumination intensity and salinity were constructed for predicting bioproduct yields for varying culture conditions. Following maintenance of stable cultures for 6-week intervals, phenotypic responses to photo-osmotic drift were explored using a combination of single-cell hyperspectral fluorescence imaging and flow cytometry. In addition to morphological changes, release of lipid microparticles from the cells that is disproportionate to cell lysis was observed under hypotonic drift, indicating the existence of a reversible membrane permeation mechanism in Dunaliella. This phenomenon introduces the potential for low-cost strategies for recovering lipids and pigments from the microalgae by minimizing the requirement for energy intensive harvesting and dewatering of the biomass. The results should be applicable to outdoor culture, where seasonal changes resulting in variable solar flux and precipitation and evaporation rates are anticipated.
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spelling pubmed-42978792015-01-22 The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis Davis, Ryan W. Carvalho, Benjamin J. Jones, Howland D. T. Singh, Seema J Appl Phycol Article Although great efforts have been made to elucidate the phenotypic responses of alga to varying levels of nutrients, osmotic environments, and photosynthetically active radiation intensities, the role of interactions among these variables is largely nebulous. Here, we describe a general method for establishing and maintaining semi-continuous cultures of the halophilic microalgal production strain, Dunaliella viridis, that is independent of variations in salinity and illumination intensity. Using this method, the cultures were evaluated to elucidate the overlapping roles of photosynthetic and osmotic adaptation on the accumulation and compositional variation of the biomass, photosynthetic productivity, and physiological biomarkers, as well as spectroscopic and morphological details at the single-cell level. Correlation matrices defining the relationships among the observables and based on variation of the illumination intensity and salinity were constructed for predicting bioproduct yields for varying culture conditions. Following maintenance of stable cultures for 6-week intervals, phenotypic responses to photo-osmotic drift were explored using a combination of single-cell hyperspectral fluorescence imaging and flow cytometry. In addition to morphological changes, release of lipid microparticles from the cells that is disproportionate to cell lysis was observed under hypotonic drift, indicating the existence of a reversible membrane permeation mechanism in Dunaliella. This phenomenon introduces the potential for low-cost strategies for recovering lipids and pigments from the microalgae by minimizing the requirement for energy intensive harvesting and dewatering of the biomass. The results should be applicable to outdoor culture, where seasonal changes resulting in variable solar flux and precipitation and evaporation rates are anticipated. Springer Netherlands 2014-05-13 2015 /pmc/articles/PMC4297879/ /pubmed/25620852 http://dx.doi.org/10.1007/s10811-014-0331-5 Text en © The Author(s) 2014 https://creativecommons.org/licenses/by/4.0/ Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
spellingShingle Article
Davis, Ryan W.
Carvalho, Benjamin J.
Jones, Howland D. T.
Singh, Seema
The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis
title The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis
title_full The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis
title_fullStr The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis
title_full_unstemmed The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis
title_short The role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from Dunaliella viridis
title_sort role of photo-osmotic adaptation in semi-continuous culture and lipid particle release from dunaliella viridis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4297879/
https://www.ncbi.nlm.nih.gov/pubmed/25620852
http://dx.doi.org/10.1007/s10811-014-0331-5
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